Abeta-degrading enzymes in Alzheimer's disease.

PubMed

Miners, James Scott; Baig, Shabnam; Palmer, Jennifer; Palmer, Laura E; Kehoe, Patrick G; Love, Seth

2008-04-01

In Alzheimer's disease (AD) Abeta accumulates because of imbalance between the production of Abeta and its removal from the brain. There is increasing evidence that in most sporadic forms of AD, the accumulation of Abeta is partly, if not in some cases solely, because of defects in its removal--mediated through a combination of diffusion along perivascular extracellular matrix, transport across vessel walls into the blood stream and enzymatic degradation. Multiple enzymes within the central nervous system (CNS) are capable of degrading Abeta. Most are produced by neurons or glia, but some are expressed in the cerebral vasculature, where reduced Abeta-degrading activity may contribute to the development of cerebral amyloid angiopathy (CAA). Neprilysin and insulin-degrading enzyme (IDE), which have been most extensively studied, are expressed both neuronally and within the vasculature. The levels of both of these enzymes are reduced in AD although the correlation with enzyme activity is still not entirely clear. Other enzymes shown capable of degrading Abetain vitro or in animal studies include plasmin; endothelin-converting enzymes ECE-1 and -2; matrix metalloproteinases MMP-2, -3 and -9; and angiotensin-converting enzyme (ACE). The levels of plasmin and plasminogen activators (uPA and tPA) and ECE-2 are reported to be reduced in AD. Reductions in neprilysin, IDE and plasmin in AD have been associated with possession of APOEepsilon4. We found no change in the level or activity of MMP-2, -3 or -9 in AD. The level and activity of ACE are increased, the level being directly related to Abeta plaque load. Up-regulation of some Abeta-degrading enzymes may initially compensate for declining activity of others, but as age, genetic factors and diseases such as hypertension and diabetes diminish the effectiveness of other Abeta-clearance pathways, reductions in the activity of particular Abeta-degrading enzymes may become critical, leading to the development of AD and CAA.

Angiotensin-converting enzyme inhibition and novel cardiovascular risk biomarkers: results from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study.

PubMed

Cesari, Matteo; Kritchevsky, Stephen B; Atkinson, Hal H; Penninx, Brenda W; Di Bari, Mauro; Tracy, Russell P; Pahor, Marco

2009-02-01

Beneficial effects of angiotensin-converting enzyme (ACE) inhibitors seem to be mediated by mechanisms that are partly independent of blood pressure lowering. The present study evaluates effects of an ACE inhibitor (ie, fosinopril) intervention on novel cardiovascular risk factors. Data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study, a double-blind, crossover, randomized, placebo-controlled trial enrolling subjects > or =55 years old with high cardiovascular disease risk profile. Biomarkers of hemostasis (ie, plasminogen activator inhibitor 1, D-dimer), inflammation (ie, C-reactive protein, interleukin-6), and endothelial function (ie, endothelin 1, vascular cell adhesion molecule 1) were measured at the baseline, at the midterm, and at end of follow-up (after 1 year) clinic visits. Paired t test analyses (after Sidak's adjustment, P < .009) were performed to compare biomarkers modifications after fosinopril/placebo interventions. Mean age of the sample (n = 290, women 43.4%) was 66.0 years old. No significant differences were reported for C-reactive protein, interleukin 6, plasminogen activator inhibitor 1, vascular cell adhesion molecule 1, and endothelin 1 levels in the comparisons between fosinopril and placebo interventions. D-dimer was the only biomarker showing a significant difference between fosinopril intervention (median 0.32 microg/mL, interquartile range 0.22-0.52 microg/mL) and placebo (median 0.29 microg/mL, interquartile range 0.20-0.47 microg/mL, P = .007) when analyses were restricted to participants with higher compliance to treatment and receiving the maximum ACE inhibitor dosage. Angiotensin-converting enzyme inhibition does not significantly modify major biomarkers of inflammation, hemostasis, and endothelial function. Further studies should confirm the possible effect of ACE inhibitors on the fibrinolysis pathway.

Addition of vitamin D reverses the decline in GFR following treatment with ACE inhibitors/angiotensin receptor blockers in patients with chronic kidney disease.

PubMed

Soares, Abel Esteves; Maes, Michael; Godeny, Paula; Matsumoto, Andressa Keiko; Barbosa, Décio Sabbatini; da Silva, Taysa Antonia F; Souza, Flávio Henrique M O; Delfino, Vinicius Daher Alvares

2017-12-15

Vitamin D has anti-inflammatory, anti-fibrotic effect, and may block the intrarenal renin-angiotensin system. Adequate vitamin D levels in conjunction with the use of Angiotensin-converting Enzyme Inhibitors/Angiotensin Receptor Blockers may help to slow down chronic kidney disease progression. To study a possible beneficial effect of vitamin D supplementation in chronic kidney disease patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers on chronic kidney disease progression we performed a clinical study involving vitamin D supplementation in patients with deficiency of this vitamin. This study was conducted in two chronic kidney disease clinics in the city of Londrina, Brazil, from October 2010 to December 2012. It was involved stage 3 and 4 chronic kidney disease (estimated glomerular filtration rate between 60 and 15mL/min/1.73m 2 ) patients with and without vitamin D deficiency. The patients ingested six-month cholecalciferol 50,000IU oral supplementation to chronic kidney disease patients with vitamin D deficiency. We hypothesize changes in estimated glomerular filtration rate over study period. Our data demonstrate reservation of estimated glomerular filtration with cholecalciferol supplementation to chronic kidney disease patients taking angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. The combination treatment of angiotensin converting enzyme inhibitors/angiotensin receptor blockers with cholecalciferol prevents the decline in estimated glomerular filtration in patients with chronic kidney disease following treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and may represent a valid approach to reduce renal disease progression in chronic kidney disease patients with vitamin D deficiency. This result needs confirmation in prospective controlled clinical trials. Copyright © 2017. Published by Elsevier Inc.

A biological/chemical process for reduced waste and energy consumption: caprolactam production. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-05-01

A biological/chemical process for converting cyclohexane into caprolactam was investigated: microorganisms in a bioreactor would be used to convert cyclohexane into caprolactone followed by chemical synthesis of caprolactam using ammonia. Four microorganisms were isolated from natural soil and water, that can utilize cyclohexane as a sole source of C and energy for growth. They were shown to have the correct metabolic intermediates and enzymes to convert cyclohexane into cyclohexanol, cyclohexanone, and caprolactone. Genetic techniques to create and select for caprolactone hydrolase negative-mutants were developed; those are used to convert cyclohexane into caprolactone but, because of the block, are unable tomore » metabolize the caprolactone further. Because of a new nylon carpet reycle process and the long time frame for a totally new bioprocess, a limited study was done to evaluate whether a simplified bioprocess to convert cyclohexanol into cyclohexanone or caprolactone was feasible; growth rates and key enzyme levels were measured in a collection of microorganisms that metabolize cyclohexanol to determine if the bioactivity is high enough to support an economical cyclohexanol bioprocess. Although these microorganisms had sufficient bioactivity, they could tolerate only low levels (<1%) of cyclohexanol and thus are not suitable for developing a cost effective bioprocess because of the high cost of dilute product recovery.« less

Withholding versus Continuing Angiotensin-converting Enzyme Inhibitors or Angiotensin II Receptor Blockers before Noncardiac Surgery: An Analysis of the Vascular events In noncardiac Surgery patIents cOhort evaluatioN Prospective Cohort.

PubMed

Roshanov, Pavel S; Rochwerg, Bram; Patel, Ameen; Salehian, Omid; Duceppe, Emmanuelle; Belley-Côté, Emilie P; Guyatt, Gordon H; Sessler, Daniel I; Le Manach, Yannick; Borges, Flavia K; Tandon, Vikas; Worster, Andrew; Thompson, Alexandra; Koshy, Mithin; Devereaux, Breagh; Spencer, Frederick A; Sanders, Robert D; Sloan, Erin N; Morley, Erin E; Paul, James; Raymer, Karen E; Punthakee, Zubin; Devereaux, P J

2017-01-01

The effect on cardiovascular outcomes of withholding angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers in chronic users before noncardiac surgery is unknown. In this international prospective cohort study, the authors analyzed data from 14,687 patients (including 4,802 angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users) at least 45 yr old who had in-patient noncardiac surgery from 2007 to 2011. Using multivariable regression models, the authors studied the relationship between withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers and a primary composite outcome of all-cause death, stroke, or myocardial injury after noncardiac surgery at 30 days, with intraoperative and postoperative clinically important hypotension as secondary outcomes. Compared to patients who continued their angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, the 1,245 (26%) angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users who withheld their angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers in the 24 h before surgery were less likely to suffer the primary composite outcome of all-cause death, stroke, or myocardial injury (150/1,245 [12.0%] vs. 459/3,557 [12.9%]; adjusted relative risk, 0.82; 95% CI, 0.70 to 0.96; P = 0.01) and intraoperative hypotension (adjusted relative risk, 0.80; 95% CI, 0.72 to 0.93; P < 0.001). The risk of postoperative hypotension was similar between the two groups (adjusted relative risk, 0.92; 95% CI, 0.77 to 1.10; P = 0.36). Results were consistent across the range of preoperative blood pressures. The practice of withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was only modestly correlated with patient characteristics and the type and timing of surgery. Withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers before major noncardiac surgery was associated with a lower risk of death and postoperative vascular events. A large randomized trial is needed to confirm this finding. In the interim, clinicians should consider recommending that patients withhold angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers 24 h before surgery.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velletri, P.A.; Aquilano, D.R.; Bruckwick, E.

Hypophysectomy of prepubescent (3-week-old) rats prevented the pubertal development of testicular, but not pulmonary, angiotensin-converting enzyme (EC 3.4.15.1). Additionally, hypophysectomy resulted in a loss of testicular converting enzyme activity in 10-week-old rats that had achieved puberty and had developed enzyme activity. Hormone regimens consisting of FSH/LH (7.5 U/rat X day), hCG (10 U/rat X day), or testosterone (1 mg/rat X day) were employed to ascertain their ability to maintain activity in hypophysectomized rats. All three of the above hormone regimens, if initiated on the first day after hypophysectomy of 10-week-old rats, were capable of maintaining testicular converting enzyme activity. Centrifugalmore » elutriation of dispersed testicular cells indicated that the majority of enzyme activity in mature rats was associated with the germinal cells, a result consistent with the data accumulated from the hormonal studies. Lastly, (/sup 3/H)captopril bound specifically to cellular fractions enriched in germinal cells. The above studies suggest that the pituitary gland is required for the development and maintenance of testicular angiotensin-converting enzyme in the rat by stimulating steroidogenesis in the testes. Furthermore, the sensitivity of converting enzyme activity to androgen coupled with the centrifugal elutriation and (/sup 3/H) captopril binding studies strongly support the notion that testicular converting enzyme is associated with germinal cells.« less

Biosynthesis of the enzymes of the cellulase system by T. Reesei QM 9414 in the presence of sophorose

NASA Astrophysics Data System (ADS)

Gritzali, M.

1982-12-01

As conventional, nonrenewable energy sources are rapidly depleted and it was necessary to search for alternative sources of energy. It was increasingly apparent that biomass and waste are alternatives well worth exploring. The sources of biomass and wastes that considered for conversion to useful products are quite diverse, but the most abundant constituent of almost every type is cellulose. Cellulose is cleanly converted to soluble fermentable sugars enzymatically, and cellulose enzymes were isolated from a number of microbial sources. It is generally agreed that the most effective system of enzymes for the conversion of cellulose to glucose is produced by species of the imperfect fungus Trichoderma. The mutant organism Trichoderma reesei QM 9414 is among the best producers of high levels of enzymes; these are extracellular and have carbonhydrate covalently bound to the peptide. Trichoderma produces three types of enzymes which, in a sequential and cooperative manner, convert cellulose to soluble oligosaccharides and glucose.

21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... high fructose corn syrup described in § 184.1866. They are derived from recognized species of precisely... ingredient is used as an enzyme, as defined in § 170.3(o)(9) of this chapter, to convert glucose to fructose. (2) The ingredient is used in high fructose corn syrup, at levels not to exceed current good...

21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... isomerase enzyme preparations are used in the production of high fructose corn syrup described in § 184.1866... defined in § 170.3(o)(9) of this chapter, to convert glucose to fructose. (2) The ingredient is used in high fructose corn syrup, at levels not to exceed current good manufacturing practice. [48 FR 5720, Feb...

21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... high fructose corn syrup described in § 184.1866. They are derived from recognized species of precisely... ingredient is used as an enzyme, as defined in § 170.3(o)(9) of this chapter, to convert glucose to fructose. (2) The ingredient is used in high fructose corn syrup, at levels not to exceed current good...

21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... high fructose corn syrup described in § 184.1866. They are derived from recognized species of precisely... ingredient is used as an enzyme, as defined in § 170.3(o)(9) of this chapter, to convert glucose to fructose. (2) The ingredient is used in high fructose corn syrup, at levels not to exceed current good...

21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

Code of Federal Regulations, 2012 CFR

2012-04-01

... high fructose corn syrup described in § 184.1866. They are derived from recognized species of precisely... ingredient is used as an enzyme, as defined in § 170.3(o)(9) of this chapter, to convert glucose to fructose. (2) The ingredient is used in high fructose corn syrup, at levels not to exceed current good...

Effects of Prolonged Angiotensin-converting Enzyme Inhibitor Treatment on Amyloid β-Protein Metabolism in Mouse Models of Alzheimer Disease

PubMed Central

Hemming, Matthew L.; Selkoe, Dennis J.; Farris, Wesley

2008-01-01

Genetic and pathologic studies have associated angiotensin-converting enzyme (ACE) with Alzheimer disease. Previously, we and others have reported that ACE degrades in vitro the amyloid β-protein (Aβ), a putative upstream initiator of Alzheimer disease. These studies support the hypothesis that deficiency in ACE-mediated Aβ proteolysis could increase Alzheimer disease risk, and raise the question of whether ACE inhibitors, a commonly prescribed class of anti-hypertensive medications, can elevate Aβ levels in vivo. To test this hypothesis, we administered the ACE inhibitor captopril to two lines of APP transgenic mice harboring either low levels of Aβ or high levels of Aβ with associated plaque deposition. In both models, we show that captopril does not affect cerebral Aβ levels in either soluble or insoluble pools. Further, we find no change in plaque deposition or in peripheral Aβ levels. Data from these Alzheimer models suggest that captopril and similar ACE inhibitors do not cause Aβ accumulation in vivo. PMID:17321748

Aβ degradation or cerebral perfusion? Divergent effects of multifunctional enzymes.

PubMed

Miners, J Scott; Palmer, Jennifer C; Tayler, Hannah; Palmer, Laura E; Ashby, Emma; Kehoe, Patrick G; Love, Seth

2014-01-01

There is increasing evidence that deficient clearance of β-amyloid (Aβ) contributes to its accumulation in late-onset Alzheimer disease (AD). Several Aβ-degrading enzymes, including neprilysin (NEP), endothelin-converting enzyme (ECE), and angiotensin-converting enzyme (ACE) reduce Aβ levels and protect against cognitive impairment in mouse models of AD. In post-mortem human brain tissue we have found that the activity of these Aβ-degrading enzymes rise with age and increases still further in AD, perhaps as a physiological response that helps to minimize the build-up of Aβ. ECE-1/-2 and ACE are also rate-limiting enzymes in the production of endothelin-1 (ET-1) and angiotensin II (Ang II), two potent vasoconstrictors, increases in the levels of which are likely to contribute to reduced blood flow in AD. This review considers the possible interdependence between Aβ-degrading enzymes, ischemia and Aβ in AD: ischemia has been shown to increase Aβ production both in vitro and in vivo, whereas increased Aβ probably enhances ischemia by vasoconstriction, mediated at least in part by increased ECE and ACE activity. In contrast, NEP activity may help to maintain cerebral perfusion, by reducing the accumulation of Aβ in cerebral blood vessels and lessening its toxicity to vascular smooth muscle cells. In assessing the role of Aβ-degrading proteases in the pathogenesis of AD and, particularly, their potential as therapeutic agents, it is important to bear in mind the multifunctional nature of these enzymes and to consider their effects on other substrates and pathways.

Role of serum angiotensin converting enzyme in sarcoidosis.

PubMed

Khan, A H; Ghani, F; Khan, A; Khan, M A; Khurshid, M

1998-05-01

This study was conducted to determine the role of Serum Angiotensin Converting Enzyme (SACE) as a marker in the differential diagnosis of pulmonary diseases and prognosis of sarcoidosis. A retrospective analysis of 113 medical records of patients at The Aga Khan University Hospital, with laboratory investigation for SACE was performed. Among 113 patients, 51 cases were found to have sarcoidosis, 44 of them had SACE levels greater than 52 IU/L (mean ACE 104.44). SACE levels were also found elevated in other clinical conditions like tuberculosis (mean 58.64 IU/L), but the enzyme level were less (p 0.04) than those found in sarcoidosis (mean (92.97 IU/L). SACE activity was found to be considerably lower in other chronic lung diseases such as, fibrosing alveolitis (mean 43.98 IU/L), interstitial lung disease (mean 42.11 IU/L) and chronic obstructive lung disease (mean 40.85 IU/L). Twenty patients of sarcoidosis, who received steroid treatment subsequently showed a decline in the SACE levels. SACE is a useful marker in differential diagnosis as 37.2% cases of sarcoidosis compared to only 9.09% of tuberculosis had SACE levels greater than 100 IU/L. In addition, our data also suggest that serum ACE is useful for the diagnosis as well as monitoring prognosis in sarcoidosis.

The effect of angiotensin-converting enzyme inhibition throughout a superovulation protocol in ewes.

PubMed

Pereira, Alécio Matos; de Souza Júnior, Antônio; Machado, Fernanda Brandão; Gonçalves, Gleisy Kelly Neves; Feitosa, Lauro César Soares; Reis, Adelina Martha; Santos, Robson Augusto Souza; Honorato-Sampaio, Kinulpe; Costa, Amilton Raposo

2015-12-01

Many studies identified new components of the renin–angiotensin system (RAS), such as Angiotensin-(1-7) [Ang-(1–7)] and Angiotensin-converting enzyme type 2 (ACE2), in mammalian ovaries.We previously showed Angiotensin-Converting Enzyme (ACE) inhibition, which increases the level of Ang-(1–7), stimulated ovarian estradiol output in ewe after estrous synchronization. Considering that Ang-(1–7) stimulates ovarian function and elevated estradiol before ovulation is associated with increased chance of achieving pregnancy, the present study investigated whether ACE inhibition throughout a superovulation protocol in ewe might improve ovulation outcome. At first, immunohistochemistry in ovaries of nonpregnant ewes revealed localization of Angiotensin II (Ang II), Ang-(1–7) and ACE2 in theca cells of antral follicles and in corpus luteum. Ang II and Ang-(1–7)were also detected in follicular fluid (FF) by Radioimmunoassay (RIA). Enalapril treatment throughout the superovulation protocol decreased 17β-estradiol (E2) output and raised progesterone:estradiol (P4:E2) ratio without a direct influence on ovulation and quality of embryos.

The effect of combination treatment with aliskiren and blockers of the renin-angiotensin system on hyperkalaemia and acute kidney injury: systematic review and meta-analysis

PubMed Central

Gilbert, Cameron; Wald, Ron; Bell, Chaim; Perl, Jeff; Juurlink, David; Beyene, Joseph; Shah, Prakesh S

2012-01-01

Objective To examine the safety of using aliskiren combined with agents used to block the renin-angiotensin system. Design Systematic review and meta-analysis of randomised controlled trials. Data sources Medline, Embase, the Cochrane Library, and two trial registries, published up to 7 May 2011. Study selection Published and unpublished randomised controlled trials that compared combined treatment using aliskiren and angiotensin converting enzyme inhibitors or angiotensin receptor blockers with monotherapy using these agents for at least four weeks and that provided numerical data on the adverse event outcomes of hyperkalaemia and acute kidney injury. A random effects model was used to calculate pooled risk ratios and 95% confidence intervals for these outcomes. Results 10 randomised controlled studies (4814 participants) were included in the analysis. Combination therapy with aliskiren and angiotensin converting enzyme inhibitors or angiotensin receptor blockers significantly increased the risk of hyperkalaemia compared with monotherapy using angiotensin converting enzymes or angiotensin receptor blockers (relative risk 1.58, 95% confidence interval 1.24 to 2.02) or aliskiren alone (1.67, 1.01 to 2.79). The risk of acute kidney injury did not differ significantly between the combined therapy and monotherapy groups (1.14, 0.68 to 1.89). Conclusion Use of aliskerin in combination with angiotensin converting enzyme inhibitors or angiotensin receptor blockers is associated with an increased risk for hyperkalaemia. The combined use of these agents warrants careful monitoring of serum potassium levels. PMID:22232539

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alhenc-Gelas, F.; Weare, J.A.; Johnson, R.L. Jr.

CE (converting enzyme) was purified from human lung, and antisera were raised in rabbits. Antisera inhibited the activity of the purified enzyme from lung and kidney and the plasma CE of normal persons and sarcoid patients. With antisera at a titer of 1:100,000, a sensitive, direct RIA was developed. CE purified from lung or kidney and CE present in normal and in sarcoid plasma gave parallel logit-log displacement lines, suggesting immunological identity. The level of CE in normal human plasma was 400 +/- 131 ng/ml. In untreated sarcoid patients, the enzyme level and activity increased in parallel. There was amore » negative correlation between enzyme level and diffusing capacity of the lung for CO in sarcoid patients. Synthetic inhibitors such as captopril or MK 421 did not interfere with the RIA, permitting enzyme levels to be monitored in patients undergoing acute inhibitor therapy. During administration of MK 421, CE activity was negligible and plasma levels of CE did not change. In contrast, renin activity increased eightfold during the inhibitor therapy.« less

[Effect of altitude chronic hypoxia on liver enzymes and its correlation with ACE/ACE2 in yak and migrated cattle].

PubMed

Liu, Feng-yun; Hu, Lin; Li, Yu-xian; Liu, Shi-ming; Tang, Yong-ping; Qi, Sheng-gui; Yang, Lei; Wu, Tian-yi

2015-05-01

To investigate the difference of liver enzyme levels and its correlation with serum ACE/ACE2 among yak and cattle on Qinghai-Tibetan plateau, and to further explore the biochemical mechanism of their liver of altitude adaptation. The serum samples of yak were collected at 3,000 m, 3,500 m, 4,000 m and 4,300 m respectively, meanwhile the serum samples of migrated cattle on plateau (2,500 m) and lowland cattle (1,300 m) were also collected. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholinesterase (CHE), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), serum lipase (LPS), angiotensin converting enzyme(ACE), angiotensin converting enzyme-2 (ACE2) in serum were measured by using fully automatic blood biochemcal analyzer. We analysed the differences of the above enzymes and its correlation with ACE/ACE2. We used one way analysis of variance (ANOVA). The levels of ALT in 4,000 m group and 4,300 m group of yak increased significantly compared with other groups, there were no statistically significant differences in AST, CHE, GGT, ACE/ACE2 levels of yaks at different altitudes. As compared to lowland cattle, the serum levels of AST and CHE were increased, the level of LPS and ACE was decreased significantly, respectively, and especially, the ratio of ACE/ACE2 of migranted cattle reduced nearly two times. The levels of LPS were significantly correlated to the ratio of ACE/ACE2 in yak (r = 0.357, P < 0.01), and a high correlation between ALP and ACE/ACE2 in lowland cattle( r = 0.418, P < 0.05), But the biggest contribution rate of the ratio of ACE/ACE2 was only 17.5% for the changes of the levels of liver enzyme. The results indicated that with the altitude increased did not significantly influence the changes of liver enzymes' activities in mountainous yaks but not in cattle. However, all above these changes weren't actually correlated to the ratio of ACE/ACE2.

27 CFR 24.246 - Materials authorized for the treatment of wine and juice.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (alpha-Amylase): To convert starches to fermentable carbohydrates The amylase enzyme activity shall be... 184.1027. Carbohydrase (beta-Amylase): To convert starches to fermentable carbohydrates The amylase... (Glucoamylase, Amylogluco-sidase): To convert starches to fermentable carbohydrates The amylase enzyme activity...

27 CFR 24.246 - Materials authorized for the treatment of wine and juice.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (alpha-Amylase): To convert starches to fermentable carbohydrates The amylase enzyme activity shall be... 184.1027. Carbohydrase (beta-Amylase): To convert starches to fermentable carbohydrates The amylase... (Glucoamylase, Amylogluco-sidase): To convert starches to fermentable carbohydrates The amylase enzyme activity...

27 CFR 24.246 - Materials authorized for the treatment of wine and juice.

Code of Federal Regulations, 2014 CFR

2014-04-01

... (alpha-Amylase): To convert starches to fermentable carbohydrates The amylase enzyme activity shall be... 184.1027. Carbohydrase (beta-Amylase): To convert starches to fermentable carbohydrates The amylase... (Glucoamylase, Amylogluco-sidase): To convert starches to fermentable carbohydrates The amylase enzyme activity...

27 CFR 24.246 - Materials authorized for the treatment of wine and juice.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (alpha-Amylase): To convert starches to fermentable carbohydrates The amylase enzyme activity shall be... 184.1027. Carbohydrase (beta-Amylase): To convert starches to fermentable carbohydrates The amylase... (Glucoamylase, Amylogluco-sidase): To convert starches to fermentable carbohydrates The amylase enzyme activity...

A re-evaluation of the final step of vanillin biosynthesis in the orchid Vanilla planifolia.

PubMed

Yang, Hailian; Barros-Rios, Jaime; Kourteva, Galina; Rao, Xiaolan; Chen, Fang; Shen, Hui; Liu, Chenggang; Podstolski, Andrzej; Belanger, Faith; Havkin-Frenkel, Daphna; Dixon, Richard A

2017-07-01

A recent publication describes an enzyme from the vanilla orchid Vanilla planifolia with the ability to convert ferulic acid directly to vanillin. The authors propose that this represents the final step in the biosynthesis of vanillin, which is then converted to its storage form, glucovanillin, by glycosylation. The existence of such a "vanillin synthase" could enable biotechnological production of vanillin from ferulic acid using a "natural" vanilla enzyme. The proposed vanillin synthase exhibits high identity to cysteine proteases, and is identical at the protein sequence level to a protein identified in 2003 as being associated with the conversion of 4-coumaric acid to 4-hydroxybenzaldehyde. We here demonstrate that the recombinant cysteine protease-like protein, whether expressed in an in vitro transcription-translation system, E. coli, yeast, or plants, is unable to convert ferulic acid to vanillin. Rather, the protein is a component of an enzyme complex that preferentially converts 4-coumaric acid to 4-hydroxybenzaldehyde, as demonstrated by the purification of this complex and peptide sequencing. Furthermore, RNA sequencing provides evidence that this protein is expressed in many tissues of V. planifolia irrespective of whether or not they produce vanillin. On the basis of our results, V. planifolia does not appear to contain a cysteine protease-like "vanillin synthase" that can, by itself, directly convert ferulic acid to vanillin. The pathway to vanillin in V. planifolia is yet to be conclusively determined. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gallium 67 citrate scanning and serum angiotensin converting enzyme levels in sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, R.G.; Bekerman, C.; Sicilian, L.

1982-09-01

Gallium 67 citrate scans and serum angiotension converting enzyme (ACE) levels were obtained in 54 patients with sarcoidosis and analyzed in relation to clinical manifestation. /sup 67/Ga scans were abnormal in 97% of patients with clinically active disease (n = 30) and in 71% of patients with inactive disease (n = 24). Serum ACE levels were abnormally high (2 standard deviations above the control mean) in 73% of patients with clinically active disease and in 54% of patients with inactive disease. Serum ACE levels correlated significantly with /sup 67/Ga uptake score (r = .436; p < .005). The frequency ofmore » abnormal /sup 67/Ga scans and elevated serum ACE levels suggests that inflammatory activity with little or no clinical expression is common in sarcoidosis. Abnormal /sup 67/Ga scans were highly sensitive (97%) but had poor specificity (29%) to clinical disease activity. The accuracy of negative prediction of clinical activity by normal scans (87%) was better than the accuracy of positive prediction of clinical activity by abnormal scans (63%). /sup 67/Ga scans can be used to support the clinical identification of inactive sarcoidosis.« less

Screening of Zulu medicinal plants for angiotensin converting enzyme (ACE) inhibitors.

PubMed

Duncan, A C; Jäger, A K; van Staden, J

1999-12-15

Twenty plants used by traditional healers in South Africa for the treatment of high blood pressure were investigated for their anti-hypertensive properties, utilizing the angiotensin converting enzyme assay. A hit rate of 65% was achieved, with the highest inhibition (97%) obtained by Adenopodia spicata leaves. A further seven plants exhibited an inhibition greater than 70% and five more over 50%. The leaves of the plants showed the greatest levels of inhibition. There was little difference in the overall hit rate between ethanolic and aqueous extracts, although in most cases there was a marked difference in activity between aqueous and ethanolic extracts from the same species. Plants exhibiting inhibition levels greater than 50% were further tested for the presence of tannins in order to eliminate possible false positives. Active plants that did not contain tannins were Agapanthus africanus, Agave americana, Clausena anisata, Dietes iridioides, Mesembruanthemum spp., Stangeria eriopus and Tulbaghia violacea.

Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment

PubMed Central

NEMETH, BALAZS; KISS, ISTVAN; JENCSIK, TIMEA; PETER, IVAN; KRESKA, ZITA; KOSZEGI, TAMAS; MISETA, ATTILA; KUSTAN, PETER; BONCZ, IMRE; LACZO, ANDREA; AJTAY, ZENO

2017-01-01

Aim: To study the effect of carbon dioxide (CO2) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Patients and Methods: Forty-seven hypertensive patients who underwent transcutaneous CO2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO2 treatment. Controls did not undergo CO2 treatment. Plasma ADMA levels were measured by ELISA. Results: ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). Conclusion: The short- and long-term decrease of ADMA levels suggests that CO2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO2 treatment. PMID:28438873

Degradation of neurotensin by rat brain synaptic membranes: involvement of a thermolysin-like metalloendopeptidase (enkephalinase), angiotensin-converting enzyme, and other unidentified peptidases.

PubMed

Checler, F; Vincent, J P; Kitabgi, P

1983-08-01

Neurotensin was inactivated by membrane-bound and soluble degrading activities present in purified preparations of rat brain synaptic membranes. Degradation products were identified by HPLC and amino acid analysis. The major points of cleavage of neurotensin were the Arg8-Arg9, Pro10-Tyr11, and Tyr11-Ile12 peptide bonds with the membrane-bound activity and the Arg8-Arg9 and Pro10-Tyr11 bonds with the soluble activity. Several lines of evidence indicated that the cleavage of the Arg8-Arg9 bond by the membrane-bound activity resulted mainly from the conversion of neurotensin1-10 to neurotensin1-8 by a dipeptidyl carboxypeptidase. In particular, captopril inhibited this cleavage with an IC50 (5.7 nM) close to its K1 (7 nM) for angiotensin-converting enzyme. Thiorphan inhibited the cleavage at the Tyr11-Ile12 bond by the membrane-bound activity with an IC50 (17 nM) similar to its K1 (4.7 nM) for enkephalinase. Both cleavages were inhibited by 1,10-phenanthroline. These and other data suggested that angiotensin-converting enzyme and a thermolysin-like metalloendopeptidase (enkephalinase) were the membrane-bound peptidases responsible for cleavages at the Arg8-Arg9 and Tyr11-Ile12 bonds, respectively. In contrast, captopril had no effect on the cleavage at the Arg8-Arg9 bond by the soluble activity, indicating that the enzyme responsible for this cleavage was different from angiotensin-converting enzyme. The cleavage at the Pro10-Tyr11 bond by both the membrane-bound and the soluble activities appeared to be catalyzed by an endopeptidase different from known brain proline endopeptidases. The possibility is discussed that the enzymes described here participate in physiological mechanisms of neurotensin inactivation at the synaptic level.

Perindopril

MedlinePlus

... in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It makes blood flow more smoothly ... if you are allergic to perindopril, angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin, in Lotrel), ...

Benazepril and Hydrochlorothiazide

MedlinePlus

... in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It works by decreasing certain chemicals ... benazepril (Lotensin); hydrochlorothiazide (HCTZ, Microzide, Oretic); angiotensin-converting enzyme (ACE) inhibitors such as captopril (Capoten), enalapril (Vasotec, ...

Lisinopril and Hydrochlorothiazide

MedlinePlus

... in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It works by decreasing certain chemicals ... to lisinopril; hydrochlorothiazide (HCTZ, Microzide, Oretic); angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), ...

Enalapril and Hydrochlorothiazide

MedlinePlus

... in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It works by decreasing certain chemicals ... in Vaseretic); hydrochlorothiazide (HCTZ, Microzide, Oretic); angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin, in Lotrel), ...

Effect of angiotensin-converting enzyme inhibitors on vascular endothelial function in hypertensive patients after intensive periodontal treatment.

PubMed

Rubio, María C; Lewin, Pablo G; De la Cruz, Griselda; Sarudiansky, Andrea N; Nieto, Mauricio; Costa, Osvaldo R; Nicolosi, Liliana N

2016-04-01

There is a relation between vascular endothelial function, atherosclerotic disease, and inflammation. Deterioration of endothelial function has been observed twenty-four hours after intensive periodontal treatment. This effect may be counteracted by the action of angiotensin-converting enzyme inhibitors, which improve endothelial function. The aim of the present study was to evaluate vascular endothelial function after intensive periodontal treatment, in hypertensive patients treated with angiotensinconverting enzyme inhibitors. A prospective, longitudinal, comparative study involving repeated measurements was conducted. Fifty-two consecutive patients with severe periodontal disease were divided into two groups, one comprising hypertensive patients treated with converting enzyme inhibitors and the other comprising patients with no clinical signs of pathology and not receiving angiotensin-converting enzyme inhibitors. Endothelial function was assessed by measuring postischemic dilation of the humeral artery (baseline echocardiography Doppler), and intensive periodontal treatment was performed 24h later. Endothelial function was re-assessed 24h and 15 days after periodontal treatment. Results were analyzed using the SPSS 20 statistical software package. Student's t test and MANOVA were calculated and linear regression analysis with 95% confidence intervals and α<0.05 was performed. Arterial dilation at 24 hours was lower compared to baseline in both groups; values corresponding to the groups receiving angiotensin-converting enzyme inhibitors were 11.89 ± 4.87 vs. 7.30 ± 2.90% (p<0.01) and those corresponding to the group not receiving ACE inhibitors were 12.72 ± 4.62 vs. 3.56 ± 2.39 (p<0.001). The differences between groups were statistically significant (p<0.001). The increase in endothelial dysfunction after intensive periodontal treatment was significantly lower in hypertensive patients treated with angiotensin-converting enzyme inhibitors. Endothelial function improved 15 days after periodontal treatment, reaching baseline values. These results support the protective effect of angiotensin converting enzyme inhibitors on the endothelial function after intensive periodontal treatment. Sociedad Argentina de Investigación Odontológica.

Angiotensin-converting enzyme genetic polymorphism: its impact on cardiac remodeling

PubMed Central

de Albuquerque, Felipe Neves; Brandão, Andréa Araujo; da Silva, Dayse Aparecida; Mourilhe-Rocha, Ricardo; Duque, Gustavo Salgado; Gondar, Alyne Freitas Pereira; Neves, Luiza Maceira de Almeida; Bittencourt, Marcelo Imbroinise; Pozzan, Roberto; de Albuquerque, Denilson Campos

2014-01-01

Background The role of angiotensin-converting enzyme genetic polymorphisms as a predictor of echocardiographic outcomes on heart failure is yet to be established. The local profile should be identified so that the impact of those genotypes on the Brazilian population could be identified. This is the first study on exclusively non-ischemic heart failure over a follow-up longer than 5 years. Objective To determine the distribution of angiotensin-converting enzyme genetic polymorphism variants and their relation with echocardiographic outcome of patients with non-ischemic heart failure. Methods Secondary analysis of the medical records of 111 patients and identification of the angiotensin-converting enzyme genetic polymorphism variants, classified as DD (Deletion/Deletion), DI (Deletion/Insertion) or II (Insertion/Insertion). Results The cohort means were as follows: follow-up, 64.9 months; age, 59.5 years; male sex, 60.4%; white skin color, 51.4%; use of beta-blockers, 98.2%; and use of angiotensin-converting-enzyme inhibitors or angiotensin receptor blocker, 89.2%. The angiotensin-converting enzyme genetic polymorphism distribution was as follows: DD, 51.4%; DI, 44.1%; and II, 4.5%. No difference regarding the clinical characteristics or treatment was observed between the groups. The final left ventricular systolic diameter was the only isolated echocardiographic variable that significantly differed between the angiotensin-converting enzyme genetic polymorphisms: 59.2 ± 1.8 for DD versus 52.3 ± 1.9 for DI versus 59.2 ± 5.2 for II (p = 0.029). Considering the evolutionary behavior, all echocardiographic variables (difference between the left ventricular ejection fraction at the last and first consultation; difference between the left ventricular systolic diameter at the last and first consultation; and difference between the left ventricular diastolic diameter at the last and first consultation) differed between the genotypes (p = 0.024; p = 0.002; and p = 0.021, respectively). Conclusion The distribution of the angiotensin-converting enzyme genetic polymorphisms differed from that of other studies with a very small number of II. The DD genotype was independently associated with worse echocardiographic outcome, while the DI genotype, with the best echocardiographic profile (increased left ventricular ejection fraction and decreased left ventricular diameters). PMID:24270863

Angiotensin-converting enzyme genetic polymorphism: its impact on cardiac remodeling.

PubMed

Albuquerque, Felipe Neves de; Brandão, Andréa Araujo; Silva, Dayse Aparecida da; Mourilhe-Rocha, Ricardo; Duque, Gustavo Salgado; Gondar, Alyne Freitas Pereira; Neves, Luiza Maceira de Almeida; Bittencourt, Marcelo Imbroinise; Pozzan, Roberto; Albuquerque, Denilson Campos de

2014-01-01

The role of angiotensin-converting enzyme genetic polymorphisms as a predictor of echocardiographic outcomes on heart failure is yet to be established. The local profile should be identified so that the impact of those genotypes on the Brazilian population could be identified. This is the first study on exclusively non-ischemic heart failure over a follow-up longer than 5 years. To determine the distribution of angiotensin-converting enzyme genetic polymorphism variants and their relation with echocardiographic outcome of patients with non-ischemic heart failure. Secondary analysis of the medical records of 111 patients and identification of the angiotensin-converting enzyme genetic polymorphism variants, classified as DD (Deletion/Deletion), DI (Deletion/Insertion) or II (Insertion/Insertion). The cohort means were as follows: follow-up, 64.9 months; age, 59.5 years; male sex, 60.4%; white skin color, 51.4%; use of beta-blockers, 98.2%; and use of angiotensin-converting-enzyme inhibitors or angiotensin receptor blocker, 89.2%. The angiotensin-converting enzyme genetic polymorphism distribution was as follows: DD, 51.4%; DI, 44.1%; and II, 4.5%. No difference regarding the clinical characteristics or treatment was observed between the groups. The final left ventricular systolic diameter was the only isolated echocardiographic variable that significantly differed between the angiotensin-converting enzyme genetic polymorphisms: 59.2 ± 1.8 for DD versus 52.3 ± 1.9 for DI versus 59.2 ± 5.2 for II (p = 0.029). Considering the evolutionary behavior, all echocardiographic variables (difference between the left ventricular ejection fraction at the last and first consultation; difference between the left ventricular systolic diameter at the last and first consultation; and difference between the left ventricular diastolic diameter at the last and first consultation) differed between the genotypes (p = 0.024; p = 0.002; and p = 0.021, respectively). The distribution of the angiotensin-converting enzyme genetic polymorphisms differed from that of other studies with a very small number of II. The DD genotype was independently associated with worse echocardiographic outcome, while the DI genotype, with the best echocardiographic profile (increased left ventricular ejection fraction and decreased left ventricular diameters).

The evolution of renin-angiotensin blockade: angiotensin-converting enzyme inhibitors as the starting point.

PubMed

Sica, Domenic A

2010-04-01

The renin-angiotensin system has been a target in the treatment of hypertension for close to three decades. Several medication classes that block specific aspects of this system have emerged as useful therapies, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and, most recently, direct renin inhibitors. There has been a natural history to the development of each of these three drug classes, starting with their use as antihypertensive agents; thereafter, in each case they have been employed as end-organ protective agents. To date, there has been scant evidence to favor angiotensin receptor blockers or direct renin inhibitors over angiotensin-converting enzyme inhibitors in treating hypertension or in affording end-organ protection; thus, angiotensin-converting enzyme inhibitors remain the standard of care when renin-angiotensin system blockade is warranted.

Substance P increases Sympathetic Activity during Combined Angiotensin Converting Enzyme and Dipeptidyl Peptidase-4 Inhibition

PubMed Central

Devin, Jessica K.; Pretorius, Mias; Nian, Hui; Yu, Chang; Billings, Frederic T.; Brown, Nancy J.

2014-01-01

Dipeptidyl peptidase-4 inhibitors prevent the degradation of incretin hormones and reduce post-prandial hyperglycemia in patients with type 2 diabetes mellitus. Dipeptidyl peptidase-4 degrades other peptides with a penultimate proline or alanine, including bradykinin and substance P, which are also substrates of angiotensin-converting enzyme. During angiotensin-converting enzyme inhibition, substance P is inactivated primarily by dipeptidyl peptidase-4, while bradykinin is first inactivated by aminopeptidase P. This study tested the hypothesis that dipeptidyl peptidase-4 inhibition potentiates vasodilator and fibrinolytic responses to substance P when angiotensin-converting enzyme is inhibited. Twelve healthy subjects participated in this randomized, double-blinded, placebo-controlled crossover study. On each study day, subjects received sitagliptin 200 mg p.o. or placebo. Substance P and bradykinin were infused via brachial artery before and during intra-arterial enalaprilat. Sitagliptin and enalaprilat each reduced forearm vascular resistance and increased forearm blood flow without affecting mean arterial pressure, but there was no interactive effect of the inhibitors. Enalaprilat increased bradykinin-stimulated vasodilation and tissue plasminogen activator release; sitagliptin did not affect these responses to bradykinin. The vasodilator response to substance P was unaffected by sitagliptin and enalaprilat, however, substance P increased heart rate and vascular release of norepinephrine during combined angiotensin-converting enzyme and dipeptidyl peptidase-4 inhibition. In women, sitagliptin diminished tissue plasminogen activator release in response to substance P both alone and during enalaprilat. Substance P increases sympathetic activity during combined angiotensin-converting enzyme and dipeptidyl peptidase-4 inhibition. PMID:24516103

Localization and characterization of angiotensin II receptor binding and angiotensin converting enzyme in the human medulla oblongata.

PubMed

Allen, A M; Chai, S Y; Clevers, J; McKinley, M J; Paxinos, G; Mendelsohn, F A

1988-03-08

Angiotensin II receptor and angiotensin converting enzyme distributions in the human medulla oblongata were localised by quantitative in vitro autoradiography. Angiotensin II receptors were labelled with the antagonist analogue 125I-[Sar1, Ile8] AII while angiotensin converting enzyme was labelled with 125I-351A, a derivative of the specific converting enzyme inhibitor, lisinopril. Angiotensin II receptor binding and angiotensin converting enzyme are present in high concentrations in the nucleus of the solitary tract, the dorsal motor nucleus of vagus, the rostral and caudal ventrolateral reticular nucleus, and in a band connecting the dorsal and ventral regions. In the rostral and caudal ventrolateral reticular nucleus, angiotensin II receptors are distributed in a punctate pattern that registers with neuronal cell bodies. The distribution and density of these cell bodies closely resemble those of catecholamine-containing neurones mapped by others. In view of the known interactions of angiotensin II with both central and peripheral catecholamine-containing neurons of laboratory animals, the current anatomical findings suggest similar interactions between these neuroactive compounds in the human central nervous system. The presence of angiotensin II receptors and angiotensin converting enzyme in the nucleus of the solitary tract, dorsal motor nucleus of vagus, and rostral and caudal ventrolateral reticular nucleus demonstrates sites for central angiotensin II to exert its known actions on vasopressin release and autonomic functions including blood pressure control. These data also suggest a possible interaction between angiotensin II and central catecholeminergic systems.

Role of Renin-Angiotensin-converting Enzyme Level and ACE Gene Polymorphism in Patients with Nonalcoholic Fatty Liver Disease.

PubMed

Tekatas, Demet D; Bahcecioglu, Ibrahim H; Ispiroglu, Murat; Sahin, Abdurrahman; Ilhan, Necip; Yalniz, Mehmet; Demirel, Ulvi

2016-01-01

In this study, we aimed to investigate the histological and clinical effect of angiotensin-converting enzyme (ACE) and ACE gene polymorphism in nonalcoholic fatty liver disease (NAFLD) and their roles in the progression of the disease. Liver function tests, body mass index, waist circumference, lipid parameters, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), homeostasis model assessment-IR (HOMA-IR), ACE, and ACE gene polymorphism were evaluated in the NAFLD group and control group. The study group was evaluated by dividing the group into four subgroups by ACE gene polymorphism (D/D homozygous, I/I homozygous, D/I heterozygous, I/D heterozygous). Liver biopsies were evaluated according to Brunt Classification. A total of 31 patients who were diagnosed with NAFLD and 40 healthy individuals were included in the study. The ACE level was found to be 11.69 ± 1.99 in the NAFLD group and 11.52 ± 1.72 in the control group (p = 0.70). There was a negative correlation between ACE levels and HOMA-IR levels (p = 0.008, r= -0.512). Biochemical parameters were not different among ACE gene polimorphism subgroups, except FBG (between D/D, I/D and D/I, I/D; p = 0.02). When the ACE levels were compared in terms of grade and stage, no significant difference was found (for stage and grade p = 0.68). The ACE gene polymorphism subgroups did not differ by histopathologic findings; grade and stage (for grade p = 0.42, for stage p = 0.92). In this study, we could not find a correlation of ACE and ACE gene polymorphism with metabolic risk factors and the disease severity in NAFLD. Tekatas DD, Bahcecioglu IH, Ispiroglu M, Sahin A, Ilhan N, Yalniz M, Demirel U. Role of Renin-Angiotensin-converting Enzyme Level and ACE Gene Polymorphism in Patients with Nonalcoholic Fatty Liver Disease. Euroasian J Hepato-Gastroenterol 2016;6(2):137-142.

The protective arm of the renin-angiotensin system may counteract the intense inflammatory process in fetuses with posterior urethral valves.

PubMed

Rocha, Natalia P; Bastos, Fernando M; Vieira, Érica L M; Prestes, Thiago R R; Silveira, Katia D da; Teixeira, Mauro M; Simões E Silva, Ana Cristina

2018-03-11

Posterior urethral valve is the most common lower urinary tract obstruction in male children. A high percentage of patients with posterior urethral valve evolve to end-stage renal disease. Previous studies showed that cytokines, chemokines, and components of the renin-angiotensin system contribute to the renal damage in obstructive uropathies. The authors recently found that urine samples from fetuses with posterior urethral valve have increased levels of inflammatory molecules. The aim of this study was to measure renin-angiotensin system molecules and to investigate their correlation with previously detected inflammatory markers in the same urine samples of fetuses with posterior urethral valve. Urine samples from 24 fetuses with posterior urethral valve were collected and compared to those from 22 healthy male newborns at the same gestational age (controls). Renin-angiotensin system components levels were measured by enzyme-linked immunosorbent assay. Fetuses with posterior urethral valve presented increased urinary levels of angiotensin (Ang) I, Ang-(1-7) and angiotensin-converting enzyme 2 in comparison with controls. ACE levels were significantly reduced and Ang II levels were similar in fetuses with posterior urethral valve in comparison with controls. Increased urinary levels of angiotensin-converting enzyme 2 and of Ang-(1-7) in fetuses with posterior urethral valve could represent a regulatory response to the intense inflammatory process triggered by posterior urethral valve. Copyright © 2018 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Focus on increased serum angiotensin-converting enzyme level: From granulomatous diseases to genetic mutations.

PubMed

Lopez-Sublet, Marilucy; di Lanzacco, Lorenzo Caratti; Jan Danser, A H; Lambert, Michel; Elourimi, Ghassan; Persu, Alexandre

2018-06-18

Angiotensin I-converting enzyme (ACE) is a well-known zinc-metallopeptidase that converts angiotensin I to the potent vasoconstrictor angiotensin II and degrades bradykinin, a powerful vasodilator, and as such plays a key role in the regulation of vascular tone and cardiac function. Increased circulating ACE (cACE) activity has been reported in multiple diseases, including but not limited to granulomatous disorders. Since 2001, genetic mutations leading to cACE elevation have also been described. This review takes advantage of the identification of a novel ACE mutation (25-IVS25 + 1G > A) in two Belgian pedigrees to summarize current knowledge about the differential diagnosis of cACE elevation, based on literature review and the experience of our centre. Furthermore, we propose a practical approach for the evaluation and management of patients with elevated cACE and discuss in which cases search for genetic mutations should be considered. Copyright © 2018. Published by Elsevier Inc.

/sup 67/Ga citrate scanning and serum angiotensin converting enzyme levels in sarcoidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, R.G.; Bekerman, C.; Sicilian, L.

1982-09-01

/sup 67/Ga citrate scans and serum angiotensin converting enzyme (ACE) levels were obtained in 54 patients with sarcoidosis and analyzed in relation to clinical manifestations. /sup 67/Ga scans were abnormal in 97% of patients with clinically active disease (n . 30) and in 71% of patients with inactive disease (n . 24). Serum ACE levels were abnormally high (2 standard deviations above the control mean) in 73% of patients with clinically active disease and in 54% of patients with inactive disease. Serum ACE levels correlated significantly with /sup 67/Ga uptake score (r..436; p less than .005). The frequency of abnormalmore » /sup 67/Ga scans and elevated serum ACE levels suggests that inflammatory activity with little or no clinical expression is common in sarcoidosis. Abnormal /sup 67/Ga scans were highly sensitive (97%) but had poor specificity (29%) to clinical disease activity. The accuracy of negative prediction of clinical activity by normal scans (87%) was better than the accuracy of positive prediction of clinical activity by abnormal scans (63%). /sup 67/Ga scans can be used to support the clinical indentification of inactive sacoidosis.« less

Is substance P released from slices of the rat spinal cord inactivated by peptidase(s) distinct from both 'enkephalinase' and 'angiotensin-converting enzyme'?

PubMed

Mauborgne, A; Bourgoin, S; Benoliel, J J; Hamon, M; Cesselin, F

1991-02-25

Studies on the effects of peptidase inhibitors on substance P-like immunoreactive material (SPLI) released by K(+)-induced depolarization from slices of the rat spinal cord showed that bacitracin was the most potent agent to protect SPLI from degradation. Captopril and thiorphan which inhibit, respectively, angiotensin I converting enzyme and endopeptidase-24.11 also protected SPLI from degradation. However other inhibitors of these two enzymes, kelatorphan for endopeptidase-24.11 and enalaprilat for angiotensin I converting enzyme were essentially inactive, indicating that both enzymes are probably not involved in the degradation of endogenous substance P. Instead, the non-additive protecting effect of bacitracin, captopril and thiorphan might be due to the blockade of some 'bacitracin-sensitive enzyme' playing a key role in the catabolism of SP within the rat spinal cord.

Tumor necrosis factor alpha converting enzyme: an encouraging target for various inflammatory disorders.

PubMed

Bahia, Malkeet S; Silakari, Om

2010-05-01

Tumor necrosis factor alpha is one of the most common pro-inflammatory cytokines responsible for various inflammatory disorders. It plays an important role in the origin and progression of rheumatoid arthritis and also in other autoimmune disease conditions. Some anti-tumor necrosis factor alpha antibodies like Enbrel, Humira and Remicade have been successfully used in these disease conditions as antagonists of tumor necrosis factor alpha. Inhibition of generation of active form of tumor necrosis factor alpha is a promising therapy for various inflammatory disorders. Therefore, the inhibition of an enzyme (tumor necrosis factor alpha converting enzyme), which is responsible for processing inactive form of tumor necrosis factor alpha into its active soluble form, is an encouraging target. Many tumor necrosis factor alpha converting enzyme inhibitors have been the candidates of clinical trials but none of them have reached in to the market because of their broad spectrum inhibitory activity for other matrix metalloproteases. Selectivity of tumor necrosis factor alpha converting enzyme inhibition over matrix metalloproteases is of utmost importance. If selectivity is achieved successfully, side-effects can be over-ruled and this approach may become a novel therapy for treatment of rheumatoid arthritis and other inflammatory disorders. This cytokine not only plays a pivotal role in inflammatory conditions but also in some cancerous conditions. Thus, successful targeting of tumor necrosis factor alpha converting enzyme may result in multifunctional therapy.

Active peptides from skate (Okamejei kenojei) skin gelatin diminish angiotensin-I converting enzyme activity and intracellular free radical-mediated oxidation.

PubMed

Ngo, Dai-Hung; Ryu, BoMi; Kim, Se-Kwon

2014-01-15

Skin gelatin of skate (Okamejei kenojei) was hydrolyzed using Alcalase, flavourzyme, Neutrase and protamex. It was found that the Alcalase hydrolysate exhibited the highest angiotensin-I converting enzyme (ACE) inhibitory activity. Then, Alcalase hydrolysate was further hydrolyzed with protease and separated by an ultrafiltration membrane system. Finally, two peptides responsible for ACE inhibitory activity were identified to be MVGSAPGVL (829Da) and LGPLGHQ (720Da), with IC50 values of 3.09 and 4.22μM, respectively. Moreover, the free radical-scavenging activity of the purified peptides was determined in human endothelial cells. In addition, the antioxidative mechanism of the purified peptides was evaluated by protein and gene expression levels of antioxidant enzymes. The current study demonstrated that the peptides derived from skate skin gelatin could be used in the food industry as functional ingredients with potent antihypertensive and antioxidant benefits. Copyright © 2013 Elsevier Ltd. All rights reserved.

Elevated serum angiotensin-converting enzyme (SACE) activity in acute pulmonary histoplasmosis.

PubMed

Davies, S F; Rohrbach, M S; Thelen, V; Kuritsky, J; Gruninger, R; Simpson, M L; DeRemee, R A

1984-03-01

Serum angiotensin-converting enzyme (SACE) levels were measured in 44 subjects six weeks after acute pulmonary histoplasmosis. All patients were infected in a common-source outbreak of histoplasmosis which occurred on one day. All patients had both strictly defined clinical and serologic evidence of infection. The SACE activity was elevated at six weeks compared to normal controls, and seven of the 44 had levels more than 2 SD above the normal mean. SACE levels were also measured at three and 24 weeks after acute infection in a smaller number of the same subjects. Serial observations demonstrated that all subjects (including those with normal and elevated SACE at six weeks) had a rise and fall in SACE activity following symptomatic acute pulmonary histoplasmosis. Our findings suggest that elevated SACE does not reliably separate sarcoidosis from histoplasmosis, although elevations in histoplasmosis are much less common and may occur only briefly following acute pulmonary histoplasmosis. More important, it seems that SACE activity rises acutely in all patients with symptomatic acute histoplasmosis and then falls gradually toward baseline over several months, coinciding temporally with the granulomatous response.

Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

PubMed

Nemeth, Balazs; Kiss, Istvan; Jencsik, Timea; Peter, Ivan; Kreska, Zita; Koszegi, Tamas; Miseta, Attila; Kustan, Peter; Boncz, Imre; Laczo, Andrea; Ajtay, Zeno

2017-01-01

To study the effect of carbon dioxide (CO 2 ) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Forty-seven hypertensive patients who underwent transcutaneous CO 2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO 2 treatment. Controls did not undergo CO 2 treatment. Plasma ADMA levels were measured by ELISA. ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). The short- and long-term decrease of ADMA levels suggests that CO 2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO 2 treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Efficacy of lycopene on modulation of renal antioxidant enzymes, ACE and ACE gene expression in hyperlipidaemic rats.

PubMed

Khan, Nazish Iqbal; Noori, Shafaq; Mahboob, Tabassum

2016-07-01

We aimed to evaluate the efficacy of lycopene on renal tissue antioxidant enzymes and angiotensin converting enzyme (ACE) gene expression and serum activity in diet-induced hyperlipidaemia. Thirty-two female Wistar albino rats (200-250 g weight), 5-6 months of age, were randomly selected and divided into four groups. Group I received normal diet; group II received 24 g high fat diet/100 g of daily diet; group III received 24 g high fat diet/100 g daily diet and 200 ml of lycopene extract (twice a week) for 8 weeks; and group IV received 200 ml oral lycopene extract twice a week for 8 weeks. A marked increase was observed in plasma urea and creatinine levels, serum C-reactive protein, kidney weight, tissue renal malonyldialdehyde level, ACE gene expression and serum level, while a decrease catalase level among hyperlipidaemic rats was observed. Histologically, interstitial inflammation and proliferation was seen. Lycopene supplementation significantly decreased plasma urea and creatinine, serum ACE, renal tissue malonyldialdehyde level and C-reactive protein level, while it increased tissue antioxidant enzymes level and total protein. Tissue inflammation and proliferation was improved. This finding suggests that supplementation of lycopene is effective for renal antioxidant enzymes, ACE gene expression and ACE serum level in hyperlipidaemic rats. © The Author(s) 2016.

Assay for Angiotensin-Converting Enzyme.

ERIC Educational Resources Information Center

Russo, Salvatore F.

1983-01-01

Describes a three-hour experiment designed to introduce students to chemistry of the angiotensis-converting enzyme, illustrate design of a quenched fluorescence substrate, and examine considerations necessary in designing a clinical assay. Includes background information on the biochemistry of hypertension, reagents/materials needed, procedures…

Plasma oxidative stress level of IgA nephropathy in children and the effect of early intervention with angiotensin-converting enzyme inhibitors.

PubMed

Pei, Yuxin; Xu, Yuanyuan; Ruan, Jingwei; Rong, Liping; Jiang, Mengjie; Mo, Ying; Jiang, Xiaoyun

2016-01-01

The purpose of this study was to investigate the change of the plasma oxidative stress level in children with IgA nephropathy (IgAN) and analyze its relativity to the clinical and pathological classification. To discuss the early effects of angiotensin-converting enzyme inhibitors (ACEIs) on the plasma oxidative stress level in children with IgA nephropathy. Thirty-eight children with IgAN were divided into groups according to their clinical features, pathologic grades, and treatments. Twenty healthy children were included in the control group. The plasma level of advanced oxidation protein products (AOPPs), malonaldehyde (MDA), and superoxide dismutase (SOD) were detected. The plasma level of oxidative stress was significantly increased in the IgAN group, including a higher plasma level of AOPP and MDA and a lower plasma level of SOD. After treatment, the plasma level of oxidative stress was significantly decreased in the ACEI group. The children with IgAN had an increase in the plasma level of oxidative stress, expressed as an increased plasma level of AOPP and MDA and a decreased plasma level of SOD. Oxidative stress was associated with the progression of IgAN in children. Early treatment with ACEI therapy can significantly reduce the plasma level of oxidative stress in children with IgAN. © The Author(s) 2016.

Sacubitril/Valsartan: The Newest Addition to the Toolbox for Guideline-Directed Medical Therapy of Heart Failure.

PubMed

Rodgers, Jo E

2017-06-01

Sacubitril/valsartan combines a neprilysin inhibitor with an angiotensin receptor blocker. As an inhibitor of neprilysin, an enzyme that degrades biologically active natriuretic peptides, this first-in-class therapy increases levels of circulating natriuretic peptides, resulting in natriuretic, diuretic, and vasodilatory effects. In patients with chronic New York Heart Association class II-IV heart failure with reduced ejection fraction, the PARADIGM-HF trial demonstrated that sacubitril/valsartan significantly reduced the primary endpoint of cardiovascular mortality and heart failure hospitalization, compared with enalapril. The rate of all-cause mortality was also significantly reduced. Subsequently, the American College of Cardiology/American Heart Association/Heart Failure Society of America recently updated guideline recommendations for Stage C patients with heart failure with reduced ejection fraction to recommend angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or sacubitril/valsartan in conjunction with other evidence-based therapies to reduce morbidity and mortality. Several analyses have suggested the cost-effectiveness of this new therapy. To ensure tolerability, initiating the lower dosage form of sacubitril/valsartan is warranted in patients with severe renal impairment, moderate hepatic impairment, and low blood pressure, and close monitoring is warranted in such patients. A 36-hour washout period is recommended when switching patients from an angiotensin-converting enzyme inhibitor to sacubitril/valsartan. Similarly, sacubitril/valsartan is contraindicated in patients receiving concomitant angiotensin-converting enzyme inhibitor or angiotensin receptor blocker and those with a history of angioedema. Copyright © 2017 Elsevier Inc. All rights reserved.

Prediction of therapeutic response in steroid-treated pulmonary sarcoidosis. Evaluation of clinical parameters, bronchoalveolar lavage, gallium-67 lung scanning, and serum angiotensin-converting enzyme levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollinger, W.M.; Staton, G.W. Jr.; Fajman, W.A.

1985-07-01

To find a pretreatment predictor of steroid responsiveness in pulmonary sarcoidosis the authors studied 21 patients before and after steroid treatment by clinical evaluation, pulmonary function tests, bronchoalveolar lavage (BAL), gallium-67 lung scan, and serum angiotensin-converting enzyme (SACE) level. Although clinical score, forced vital capacity (FVC), BAL percent lymphocytes (% lymphs), quantitated gallium-67 lung uptake, and SACE levels all improved with therapy, only the pretreatment BAL % lymphs correlated with the improvement in FVC (r = 0.47, p less than 0.05). Pretreatment BAL % lymphs of greater than or equal to 35% predicted improvement in FVC of 10/11 patients, whereasmore » among 10 patients with BAL % lymphs less than 35%, 5 patients improved and 5 deteriorated. Clinical score, pulmonary function parameters, quantitated gallium-67 lung uptake, and SACE level used alone, in combination with BAL % lymphs or in combination with each other, did not improve this predictive value. The authors conclude that steroid therapy improves a number of clinical and laboratory parameters in sarcoidosis, but only the pretreatment BAL % lymphs are useful in predicting therapeutic responsiveness.« less

Angiotensin-converting enzyme: I. New strategies for assay

PubMed Central

Ryan, James W.; Chung, Alfred; Ryan, Una S.

1980-01-01

The disposition of converting enzyme (kininase II) on the luminal surface of pulmonary endothelial cells is well established. Further, it is known that there is a net conversion of angiotensin I into angiotensin II as blood passes through the lungs. However, little is known about modulations of converting enzyme activity that may arise through, e.g., changes in the quality of inhalants, blood flow, or blood oxygenation. There are few data on the effects of lung disease. A major barrier to studies to examine for pathophysiologic modulations of converting enzyme is that of assay. The enzyme can be measured in terms of the rate of formation of angiotensin II from a known quantity of angiotensin I. However, both peptides are biologically active, and lungs contain other enzymes capable of degrading them. We have developed a series of radiolabeled, acylated tripeptides to improve our ability to examine for changes in the net converting enzyme of intact lungs. The enzyme, a dipeptidyl carboxypeptidase, is capable of removing C-terminal dipeptides from a variety of oligopeptides. We have prepared benzoyl-Gly-Gly-Gly (I), benzoyl-Pro-Phe-Arg (II), benzoyl-Gly-His-Leu (III), benzoyl-Phe-Ala-Pro (IV), and benzoyl-Phe-His-Leu (V), each containing a 3H-atom in the para position of the benzoyl moiety. Substrates I and III have been used previously in photometric assays of low sensitivity. II is the acylated C-terminal tripeptide of bradykinin, IV is an acylated tripeptide analog of BPP5a (

[Association between visual improvement after photocoagulation and the use of angiotensin converting enzyme inhibitors in diabetic macular oedema].

PubMed

Somilleda-Ventura, Selma Alin; García-Rubio, Yatzul Zuhaila; Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio

2016-01-01

Angiotensin converting enzyme inhibitors are effective in delaying the progression of diabetic retinopathy. It is unknown if their use is associated with a better visual outcome in patients with diabetic macular oedema. A non-experimental, comparative, longitudinal and retrospective study was performed on patients with diabetic macular oedema treated by focal photocoagulation, and with systemic arterial hypertension treated with angiotensin converting enzyme inhibitors (Group 1), and without hypertension (Group 2). The dependent variable was the proportion with visual improvement, operatively defined as the gain of one or more lines of vision three weeks after photocoagulation. The independent variable was the use of angiotensin converting enzyme inhibitors. The proportion of eyes with visual improvement after treatment was compared between groups using the Chi squared (χ(2)) test. A total of 33 eyes (51.6%) were assigned to group 1, and 31 (48.2%), to group 2. The mean of visual acuity improved after three weeks, compared with baseline (p=0.002). The proportion of eyes with visual improvement did not differ between patients treated with angiotensin converting enzyme inhibitors (45.5%) and those that did not use them (51.6%, p=0.4). There was no statistical difference in the proportion of eyes with visual improvement between patients treated with angiotensin converting enzyme inhibitors and in those where they were not used. There is no support for the inhibition of angiotensin II in addition to photocoagulation for improving the outcome in patients with diabetic macular oedema. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Discovery of piperonal-converting oxidase involved in the metabolism of a botanical aromatic aldehyde

PubMed Central

Doi, Shiori; Hashimoto, Yoshiteru; Tomita, Chiaki; Kumano, Takuto; Kobayashi, Michihiko

2016-01-01

Piperonal-catabolizing microorganisms were isolated from soil, the one (strain CT39-3) exhibiting the highest activity being identified as Burkholderia sp. The piperonal-converting enzyme involved in the initial step of piperonal metabolism was purified from strain CT39-3. Gene cloning of the enzyme and a homology search revealed that the enzyme belongs to the xanthine oxidase family, which comprises molybdoenzymes containing a molybdopterin cytosine dinucleotide cofactor. We found that the piperonal-converting enzyme acts on piperonal in the presence of O2, leading to formation of piperonylic acid and H2O2. The growth of strain CT39-3 was inhibited by higher concentrations of piperonal in the culture medium. Together with this finding, the broad substrate specificity of this enzyme for various aldehydes suggests that it would play an important role in the defense mechanism against antimicrobial compounds derived from plant species. PMID:27905507

Ultrasensitivity by Molecular Titration in Spatially Propagating Enzymatic Reactions

PubMed Central

Semenov, Sergey N.; Markvoort, Albert J.; Gevers, Wouter B.L.; Piruska, Aigars; de Greef, Tom F.A.; Huck, Wilhelm T.S.

2013-01-01

Delineating design principles of biological systems by reconstitution of purified components offers a platform to gauge the influence of critical physicochemical parameters on minimal biological systems of reduced complexity. Here we unravel the effect of strong reversible inhibitors on the spatiotemporal propagation of enzymatic reactions in a confined environment in vitro. We use micropatterned, enzyme-laden agarose gels which are stamped on polyacrylamide films containing immobilized substrates and reversible inhibitors. Quantitative fluorescence imaging combined with detailed numerical simulations of the reaction-diffusion process reveal that a shallow gradient of enzyme is converted into a steep product gradient by addition of strong inhibitors, consistent with a mathematical model of molecular titration. The results confirm that ultrasensitive and threshold effects at the molecular level can convert a graded input signal to a steep spatial response at macroscopic length scales. PMID:23972857

Identification of interleukin-8 converting enzyme as cathepsin L.

PubMed

Ohashi, Kensaku; Naruto, Masanobu; Nakaki, Toshio; Sano, Emiko

2003-06-26

IL-8 is produced by various cells, and the NH(2)-terminal amino acid sequence of IL-8 displays heterogeneity among cell types. The mature form of IL-8 has 72 amino acids (72IL-8), while a precursor form (77IL-8) of IL-8 has five additional amino acids to the 72IL-8 NH(2)-terminal. However, it has been unclear how IL-8 is processed to yield the mature form. In this study, converting enzyme was purified as a single 31-kDa band on silver-stained polyacrylamide gel from 160 l of cultured fibroblast supernatant by sequential chromatography. NH(2)-terminal amino acid sequence analysis revealed a sequence, EAPRSVDWRE, which was identified as a partial sequence of cathepsin L. Polyclonal antibodies raised against cathepsin L recognized the purified converting enzyme on Western blot. Moreover, human hepatic cathepsin L cleaved 77IL-8 between Arg(5) and Ser(6), which is the same cleavage site as the putative converting enzyme, resulting in 72IL-8 formation. These data indicate that the converting enzyme of the partially purified fraction of the human fibroblast culture supernatant was cathepsin L. Furthermore, 72IL-8 was sevenfold more potent than 77IL-8 in a neutrophil chemotaxis assay. These results show that cathepsin L is secreted from human fibroblasts in response to external stimuli and plays an important role in IL-8 processing in inflammatory sites.

Enzymes involved in branched-chain amino acid metabolism in humans.

PubMed

Adeva-Andany, María M; López-Maside, Laura; Donapetry-García, Cristóbal; Fernández-Fernández, Carlos; Sixto-Leal, Cristina

2017-06-01

Branched-chain amino acids (leucine, isoleucine and valine) are structurally related to branched-chain fatty acids. Leucine is 2-amino-4-methyl-pentanoic acid, isoleucine is 2-amino-3-methyl-pentanoic acid, and valine is 2-amino-3-methyl-butanoic acid. Similar to fatty acid oxidation, leucine and isoleucine produce acetyl-coA. Additionally, leucine generates acetoacetate and isoleucine yields propionyl-coA. Valine oxidation produces propionyl-coA, which is converted into methylmalonyl-coA and succinyl-coA. Branched-chain aminotransferase catalyzes the first reaction in the catabolic pathway of branched-chain amino acids, a reversible transamination that converts branched-chain amino acids into branched-chain ketoacids. Simultaneously, glutamate is converted in 2-ketoglutarate. The branched-chain ketoacid dehydrogenase complex catalyzes the irreversible oxidative decarboxylation of branched-chain ketoacids to produce branched-chain acyl-coA intermediates, which then follow separate catabolic pathways. Human tissue distribution and function of most of the enzymes involved in branched-chain amino acid catabolism is unknown. Congenital deficiencies of the enzymes involved in branched-chain amino acid metabolism are generally rare disorders. Some of them are associated with reduced pyruvate dehydrogenase complex activity and respiratory chain dysfunction that may contribute to their clinical phenotype. The biochemical phenotype is characterized by accumulation of the substrate to the deficient enzyme and its carnitine and/or glycine derivatives. It was established at the beginning of the twentieth century that the plasma level of the branched-chain amino acids is increased in conditions associated with insulin resistance such as obesity and diabetes mellitus. However, the potential clinical relevance of this elevation is uncertain.

Enzymes and Inhibitors in Neonicotinoid Insecticide Metabolism

PubMed Central

Shi, Xueyan; Dick, Ryan A.; Ford, Kevin A.; Casida, John E.

2009-01-01

Neonicotinoid insecticide metabolism involves considerable substrate specificity and regioselectivity of the relevant CYP450, aldehyde oxidase, and phase II enzymes. Human CYP450 recombinant enzymes carry out the following conversions: CYP3A4, 2C19 and 2B6 for thiamethoxam (TMX) to clothianidin (CLO); 3A4, 2C19 and 2A6 for CLO to desmethyl-CLO; 2C19 for TMX to desmethyl-TMX. Human liver aldehyde oxidase reduces the nitro substituent of CLO to nitroso much more rapidly than that of TMX. Imidacloprid (IMI), CLO and several of their metabolites do not give detectable N-glucuronides but 5-hydroxy-IMI, 4,5-diol-IMI and 4-hydroxy-thiacloprid are converted to O-glucuronides in vitro with mouse liver microsomes and UDP-glucuronic acid or in vivo in mice. Mouse liver cytosol with S-adenosylmethionine converts desmethyl-CLO to CLO but not desmethyl-TMX to TMX. Two organophosphorus CYP450 inhibitors partially block IMI, thiacloprid and CLO metabolism in vivo in mice, elevating the brain and liver levels of the parent compounds while reducing amounts of the hydroxylated metabolites. PMID:19391582

Long-Term Regulation of the Local Renin-Angiotensin System in the Myocardium of Spontaneously Hypertensive Rats by Feeding Bioactive Peptides Derived from Spirulina platensis.

PubMed

Pan, Huanglei; She, Xingxing; Wu, Hongli; Ma, Jun; Ren, Difeng; Lu, Jun

2015-09-09

This study investigated the long-term (8 weeks) anti-hypertensive effects of 10 mg/kg tripeptides isolated from Spirulina platensis, Ile-Gln-Pro (IQP) and Val-Glu-Pro (VEP), and S. platensis hydrolysates (SH) on spontaneously hypertensive rats. The treatment period was 6 weeks, and observation continued for another 2 weeks. After treatment, weighted systolic blood pressure, weighted diastolic blood pressure, left ventricular mass index, and right ventricular mass index of groups treated with IQP, VEP, and SH were significantly lower than those of the group treated with distilled water, even when the treatments had been withdrawn for 2 weeks. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting showed the mRNA expression levels and protein/peptide concentrations of the main components of the renin angiotensin system in myocardium were significantly affected by treatment: angiotensin converting enzyme, angiotensin II, and angiotensin type 1 receptor were down-regulated, whereas angiotensin type 2 receptor, angiotensin converting enzyme 2, angiotensin-(1-7), and Mas receptor were up-regulated.

Optimization of Bromelain-Aided Production of Angiotensin I-Converting Enzyme Inhibitory Hydrolysates from Stone Fish Using Response Surface Methodology.

PubMed

Muhammad Auwal, Shehu; Zarei, Mohammad; Abdul-Hamid, Azizah; Saari, Nazamid

2017-03-31

The stone fish is an under-utilized sea cucumber with many nutritional and ethno-medicinal values. This study aimed to establish the conditions for its optimum hydrolysis with bromelain to generate angiotensin I-converting enzyme (ACE)-inhibitory hydrolysates. Response surface methodology (RSM) based on a central composite design was used to model and optimize the degree of hydrolysis (DH) and ACE-inhibitory activity. Process conditions including pH (4-7), temperature (40-70 °C), enzyme/substrate (E/S) ratio (0.5%-2%) and time (30-360 min) were used. A pH of 7.0, temperature of 40 °C, E/S ratio of 2% and time of 240 min were determined using a response surface model as the optimum levels to obtain the maximum ACE-inhibitory activity of 84.26% at 44.59% degree of hydrolysis. Hence, RSM can serve as an effective approach in the design of experiments to improve the antihypertensive effect of stone fish hydrolysates, which can thus be used as a value-added ingredient for various applications in the functional foods industries.

Comparison of gallium-67 scanning, bronchoalveolar lavage, and serum angiotensin-converting enzyme levels in pulmonary sarcoidosis. Predicting response to therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baughman, R.P.; Fernandez, M.; Bosken, C.H.

1984-05-01

Patients with active pulmonary sarcoidosis underwent bronchoalveolar lavage, gallium scan, and serum angiotensin-converting enzyme (ACE) level determination prior to treatment with corticosteroids. Pulmonary function was tested before and after therapy. Increase in vital capacity after treatment ranged from 40 to 1,030 ml; 12 of the 16 patients studied had an increase of more than 200 ml. There was a close correlation between the percentage uptake of gallium scan and the increase of the vital capacity after therapy (r . 0.95, p less than 0.01). There was no relationship between the percentage of lymphocytes obtained on lavage and the changes inmore » vital capacity with therapy (r . 0.05). There was a positive correlation between the changes in vital capacity and the ratio of T4(+):T8(+)lymphocytes (r . 0.62, p less than 0.05) and number of T4 (+) lymphocytes (r . 0.92, p less than 0.01) in the bronchoalveolar fluid. There was a low correlation between the pretreatment ACE level and the change in vital capacity (r . 0.368, p greater than 0.05).« less

Application of liquid chromatography-electrospray ionization mass spectrometry for study of steroid-converting enzymes.

PubMed

Miksík, Ivan; Mikulíková, Katerina; Pácha, Jirí; Kucka, Marek; Deyl, Zdenek

2004-02-05

A high-performance liquid chromatography-atmospheric pressure ionization-electrospray ionization mass spectrometry (HPLC-API-ESI-MS) method was developed for the analysis of steroids in a study of steroid-converting enzymes. Separations ware done on a Zorbax Eclipse XDB-C18 column (eluted with a linear methanol-water-acetic acid gradient) and identification of the steroids involved was done by API-ESI-MS using positive ion mode and extracted ion analysis. The applicability of the present method for studying steroid metabolism was proven in assaying two steroid-converting enzymes (20beta-hydroxysteroid dehydrogenase and 11beta-hydroxysteroid dehydrogenase) in various biological samples (rat and chicken intestine, chicken oviduct).

Reduction of mean arterial pressure and proteinuria by the effect of ACEIs (Lisinopril) in Kurdish hypertensive patients in Hawler City.

PubMed

Muslih, A I

2012-06-30

The angiotensin converting enzyme inhibitors (ACEIs) are a group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure, in some cases as the drugs of first choice. The renin-angiotensin system is activated in response to hypotension, decreased sodium concentration in the distal tubule, decreased blood volume and in renal sympathetic nerve stimulation. This study examines the effects of angiotensin converting enzyme inhibitor (Lisinopril) on blood pressure (BP) 131 ± 2.4 and proteinuria 0.198 ± 0.005 in Kurd hypertensive patients, mean arterial blood pressure and proteinuria excretion were measured weekly along the period of 12 weeks. Lisinopril significantly reduced mean arterial blood pressure, and attenuated proteinuria level in patients subjected to this study in lisinopril 10mg dose dependent manner (p<0.05, n=24). In conclusion, lisinopril is of beneficial of renoprotection and in lowering BP.

Release of IL-1beta via IL-1beta-converting enzyme in a skin dendritic cell line exposed to 2,4-dinitrofluorobenzene.

PubMed

Matos, Teresa J; Jaleco, Sara P; Gonçalo, Margarida; Duarte, Carlos B; Lopes, M Celeste

2005-08-14

We used a mouse fetal skin dendritic cell line (FSDC) to study the effect of the strong allergen 2,4-dinitrofluorobenzene (DNFB) on interleukin (IL)-1beta release and IL-1beta receptor immunoreactivity. Stimulation with DNFB (30 minutes) increased IL-1 release without changing the mRNA levels of the protein. Furthermore, DNFB increased transiently the interleukin-1beta-converting enzyme (ICE) activity, as measured with its fluorogenic substrate Z-Tyr-Val-Ala-Asp-AFC. The ICE inhibitor Z-YVAD-FMK prevented the release of IL-1beta evoked by DNFB. Incubation of the cells with DNFB (30 minutes) strongly increased IL-1beta receptor immunoreactivity. The rapid effect of DNFB on the release of mature IL-1beta, without inducing an increase of IL-1beta mRNA in FSDC, suggests a posttranslational modification of pro-IL-1beta by ICE activity.

Angiotensin-converting enzyme activity in Cavalier King Charles Spaniels with an ACE gene polymorphism and myxomatous mitral valve disease.

PubMed

Meurs, Kathryn M; Olsen, Lisbeth H; Reimann, Maria J; Keene, Bruce W; Atkins, Clarke E; Adin, Darcy; Aona, Brent; Condit, Julia; DeFrancesco, Teresa; Reina-Doreste, Yamir; Stern, Joshua A; Tou, Sandra; Ward, Jessica; Woodruff, Kathleen

2018-02-01

Myxomatous mitral valve disease (MMVD) is the most common heart disease in the dog. It is particularly common in the Cavalier King Charles Spaniel (CKCS) breed and affected dogs are frequently managed with angiotensin-converting enzyme inhibitors (ACE-I). We have previously identified a canine ACE gene polymorphism associated with a decrease in angiotensin-converting enzyme (ACE) activity. The aim of this study was to evaluate for the prevalence of the ACE polymorphism in CKCS with mitral valve disease and to determine whether the presence of the polymorphism is associated with alterations in ACE activity at different stages of cardiac disease. Seventy-three dogs with a diagnosis of mitral valve disease were evaluated and a blood sample was drawn for ACE polymorphism genotyping and ACE activity measurement. Forty-three dogs were homozygous for the ACE polymorphism; five were heterozygous and 25 were homozygous wild type. The mean age and the median severity of disease were not different for dogs with the polymorphism and dogs with the wild-type sequence. The median baseline ACE activity was significantly lower for the ACE polymorphism (27.0 U/l) than the wild-type sequence dogs (31.0 U/l) (P=0.02). Dogs with more severe disease and the ACE polymorphism had significantly lower levels of ACE activity than dogs with the wild-type sequence (P=0.03). The CKCS appears to have a high prevalence of the ACE variant. Dogs with the ACE variant had lower levels of ACE activity even in more advanced mitral valve disease than dogs without the variant. The clinical significance of this finding and its impact on the need for ACE-I in dogs with the polymorphism and heart disease deserves further study.

21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Angiotensin converting enzyme (A.C.E.) test system. 862.1090 Section 862.1090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Angiotensin converting enzyme (A.C.E.) test system. 862.1090 Section 862.1090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Angiotensin converting enzyme (A.C.E.) test system. 862.1090 Section 862.1090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Angiotensin converting enzyme (A.C.E.) test system. 862.1090 Section 862.1090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

Biological production of organic compounds

DOEpatents

Yu, Jianping; Wang, Bo; Paddock, Troy; Carrieri, Damian; Maness, Pin-Ching; Seibert, Michael

2018-03-13

Methods of producing ethylene oxide and ethylene glycol are disclosed herein. Ethylene produced by cyanobacteria engineered to express ethylene-forming enzymes may be converted to ethylene oxide by bacteria engineered to express a monooxygenase enzyme. Ethylene oxide may be converted to ethylene glycol by exposure to an acidic solution. The methods may be performed in a bioreactor.

Depletion of angiotensin-converting enzyme 2 reduces brain serotonin and impairs the running-induced neurogenic response.

PubMed

Klempin, Friederike; Mosienko, Valentina; Matthes, Susann; Villela, Daniel C; Todiras, Mihail; Penninger, Josef M; Bader, Michael; Santos, Robson A S; Alenina, Natalia

2018-04-20

Physical exercise induces cell proliferation in the adult hippocampus in rodents. Serotonin (5-HT) and angiotensin (Ang) II are important mediators of the pro-mitotic effect of physical activity. Here, we examine precursor cells in the adult brain of mice lacking angiotensin-converting enzyme (ACE) 2, and explore the effect of an acute running stimulus on neurogenesis. ACE2 metabolizes Ang II to Ang-(1-7) and is essential for the intestinal uptake of tryptophan (Trp), the 5-HT precursor. In ACE2-deficient mice, we observed a decrease in brain 5-HT levels and no increase in the number of BrdU-positive cells following exercise. Targeting the Ang II/AT1 axis by blocking the receptor, or experimentally increasing Trp/5-HT levels in the brain of ACE2-deficient mice, did not rescue the running-induced effect. Furthermore, mice lacking the Ang-(1-7) receptor, Mas, presented a normal neurogenic response to exercise. Our results identify ACE2 as a novel factor required for exercise-dependent modulation of adult neurogenesis and essential for 5-HT metabolism.

Hypovolemic Shock Caused by Angiotensin-Converting Enzyme Inhibitor-Induced Visceral Angioedema: A Case Series and A Simple Method to Diagnose this Complication in the Emergency Department.

PubMed

Myslinski, Joseph; Heiser, Andrew; Kinney, Ashley

2018-03-01

Visceral angioedema is a rarely reported side effect of angiotensin-converting-enzyme inhibitors (ACEI). Because signs and symptoms tend to be nonspecific, the diagnosis is difficult to make, especially in the emergency department (ED). We describe 2 patients presenting with signs of hypovolemic shock, in which the diagnosis of ACEI-induced visceral angioedema was made in the ED. We surmise that patients with abdominal pain, who present with hypovolemic shock and are taking medications that can predispose to angioedema, may have this complication if their hemoglobin level is elevated compared with their previous levels. An abdominal computed tomography scan, if it does not identify any other significant etiology, will increase the probability that ACEI-induced visceral angioedema is the diagnosis when there is nonspecific bowel wall thickening or edema. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Identification of ACEI-induced visceral angioedema in the ED will avoid prolonged admissions, unnecessary procedures, and future recurrences. Copyright © 2017 Elsevier Inc. All rights reserved.

Possible identity of IL-8 converting enzyme in human fibroblasts as a cysteine protease.

PubMed

Ohashi, Kensaku; Sano, Emiko; Nakaki, Toshio; Naruto, Masanobu

2003-04-01

A converting activity was characterized in human diploid fibroblasts, which secrete 72IL-8 and 77IL-8 in treatment with IFN-beta and poly I: poly C. 77IL-8 was significantly converted to 72IL-8 by a partially purified fraction of the culture supernatant of human diploid fibroblasts. The converting activity, which was temperature-dependent and optimal at pH 6, was completely inhibited by cysteine protease inhibitors, antipain dihydrochloride and E-64, but not by other types of protease inhibitors. These data clearly show that human diploid fibroblasts are capable of processing IL-8 to produce a mature IL-8 and that the putative converting enzyme appears to be a cysteine protease.

[Prospective observational study of angiotensin converting enzyme inhibitors-induced hyperkalemia in hospitalized patients with chronic renal failure].

PubMed

Ben Mahmoud, Lobna; Ghozzi, Hanene; Kammoun, Khawla; Hakim, Ahmed; Kharrat, Mahmoud; Ben Hmida, Mohamed; Jarraya, Faical; Sahnoun, Zouheir; Zeghal, Khaled; Hachicha, Jamil

2013-04-01

To study the incidence and risk factors of angiotensin converting enzyme inhibitors-induced hyperkalemia in hospitalized patients with hypertension and preexisting chronic renal failure. Two-months prospective observational study was used including all hospitalized patients older than 18 years with a history of hypertension, non-dialyzed chronic renal failure and who had angiotensin converting enzyme prescription at the time of the admission. Hyperkalemia greater than or equal to 5 mmol/L was detected in these patients. The studied variables were demographic, clinical, biological and therapeutic. Eight patients, among 27 included, had a hyperkalemia (2963%). They were 73±15 years old. Factors that predispose to hyperkalemia were present in all patients. Hyperkalemia was associated in six cases with decompensation of renal function. The age was associated with hyperkalaemia in patients treated with angiotensin converting enzyme inhibitors (RC=1.21; IC95 1,11-1,46; P=0,021). Diabetes is a possible risk factor (OR=59 021 et, 95 0.93 to 2410, P=0.053). Compared with patients who did not develop hyperkalemia, the occurrence of hyperkalemia in patients included was associated with a longer duration of hospitalization (OR=130, 95 112 to 160, P=0. 022). The prescription of angiotensin converting enzyme inhibitors in the elderly with chronic renal failure and diabetes requires careful monitoring of serum potassium. Copyright © 2012 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

Angiotensin-converting enzyme inhibitors in patients with coronary artery disease and absence of heart failure or left ventricular systolic dysfunction: an overview of long-term randomized controlled trials.

PubMed

Danchin, Nicolas; Cucherat, Michel; Thuillez, Christian; Durand, Eric; Kadri, Zena; Steg, Philippe G

2006-04-10

Results of randomized trials of angiotensin-converting enzyme inhibitors in patients with coronary artery disease (CAD) and preserved left ventricular function are conflicting. We undertook this study to determine whether long-term prescription of angiotensin-converting enzyme inhibitors decreases major cardiovascular events and mortality in patients who have CAD and no evidence of left ventricular systolic dysfunction. We searched MEDLINE, EMBASE, and IPA databases, the Cochrane Controlled Trials Register (1990-2004), and reports from scientific meetings (2003-2004), and we reviewed secondary sources. Search terms included angiotensin-converting enzyme inhibitors, coronary artery disease, randomi(s)zed controlled trials, clinical trials, and myocardial infarction. Eligible studies included randomized controlled trials in patients who had CAD and no heart failure or left ventricular dysfunction, with follow-up omicronf 2 years or longer. Of 1146 publications screened, 7 met our selection criteria and included a total of 33 960 patients followed up for a mean of 4.4 years. Five trials included only patients with documented CAD. One trial included patients with documented CAD (80%) or patients who had diabetes mellitus and 1 or more additional risk factors, and another trial included patients who had CAD, a history of transient ischemic attack, or intermittent claudication. Treatment with angiotensin-converting enzyme inhibitors decreased overall mortality (odds ratio, 0.86; 95% confidence interval, 0.79-0.93), cardiovascular mortality (odds ratio, 0.81; 95% confidence interval, 0.73-0.90), myocardial infarction (odds ratio, 0.82; 95% confidence interval, 0.75-0.89), and stroke (odds ratio, 0.77; 95% confidence interval, 0.66-0.88). Other end points, including resuscitation after cardiac arrest, myocardial revascularization, and hospitalization because of heart failure, were also reduced. Angiotensin-converting enzyme inhibitors reduce total mortality and major cardiovascular end points in patients who have CAD and no left ventricular systolic dysfunction or heart failure.

Rapid conversion of angiotensin I to angiotensin II by neutrophil and mast cell proteinases.

PubMed

Reilly, C F; Tewksbury, D A; Schechter, N M; Travis, J

1982-08-10

Human neutrophil cathepsin G and human skin mast cell chymase rapidly convert angiotensin I to angiotensin II with only minor cleavage elsewhere in the molecule. The rate of cleavage is consistent with a potential role for either or both of these enzymes in an alternate pathway for angiotensin II synthesis. Since neither enzyme in inhibited by captopril, an angiotensin converting enzyme inactivator, it is possible that leukocyte and mast cell enzymes may play a significant role in the development of abnormally high local concentrations of angiotensin II, associated with various inflammatory processes.

Cloning and Characterization of the Glycoside Hydrolases That Remove Xylosyl Groups from 7-β-xylosyl-10-deacetyltaxol and Its Analogues*

PubMed Central

Cheng, Hai-Li; Zhao, Rui-Yu; Chen, Tian-Jiao; Yu, Wen-Bo; Wang, Fen; Cheng, Ke-Di; Zhu, Ping

2013-01-01

Paclitaxel, a natural antitumor compound, is produced by yew trees at very low concentrations, causing a worldwide shortage of this important anticancer medicine. These plants also produce significant amounts of 7-β-xylosyl-10-deacetyltaxol, which can be bio-converted into 10-deacetyltaxol for the semi-synthesis of paclitaxel. Some microorganisms can convert 7-β-xylosyl-10-deacetyltaxol into 10-deacetyltaxol, but the bioconversion yield needs to be drastically improved for industrial applications. In addition, the related β-xylosidases of these organisms have not yet been defined. We set out to discover an efficient enzyme for 10-deacetyltaxol production. By combining the de novo sequencing of β-xylosidase isolated from Lentinula edodes with RT-PCR and the rapid amplification of cDNA ends, we cloned two cDNA variants, Lxyl-p1–1 and Lxyl-p1–2, which were previously unknown at the gene and protein levels. Both variants encode a specific bifunctional β-d-xylosidase/β-d-glucosidase with an identical ORF length of 2412 bp (97% identity). The enzymes were characterized, and their 3.6-kb genomic DNAs (G-Lxyl-p1–1, G-Lxyl-p1–2), each harboring 18 introns, were also obtained. Putative substrate binding motifs, the catalytic nucleophile, the catalytic acid/base, and potential N-glycosylation sites of the enzymes were predicted. Kinetic analysis of both enzymes showed kcat/Km of up to 1.07 s−1mm−1 against 7-β-xylosyl-10-deacetyltaxol. Importantly, at substrate concentrations of up to 10 mg/ml (oversaturated), the engineered yeast could still robustly convert 7-β-xylosyl-10-deacetyltaxol into 10-deacetyltaxol with a conversion rate of over 85% and a highest yield of 8.42 mg/ml within 24 h, which is much higher than those reported previously. Therefore, our discovery might lead to significant progress in the development of new 7-β-xylosyl-10-deacetyltaxol-converting enzymes for more efficient use of 7-β-xylosyltaxanes to semi-synthesize paclitaxel and its analogues. This work also might lead to further studies on how these enzymes act on 7-β-xylosyltaxanes and contribute to the growing database of glycoside hydrolases. PMID:23665501

Renin-Angiotensin Inhibitors Decrease Recurrence after Transurethral Resection of Bladder Tumor in Patients with Nonmuscle Invasive Bladder Cancer.

PubMed

Blute, Michael L; Rushmer, Timothy J; Shi, Fangfang; Fuller, Benjamin J; Abel, E Jason; Jarrard, David F; Downs, Tracy M

2015-11-01

Prior reports suggest that renin-angiotensin system inhibition may decrease nonmuscle invasive bladder cancer recurrence. We evaluated whether angiotensin converting enzyme inhibitor or angiotensin receptor blocker treatment at initial surgery was associated with decreased recurrence or progression in patients with nonmuscle invasive bladder cancer. Using an institutional bladder cancer database we identified 340 patients with data available on initial transurethral resection of bladder tumor. Progression was defined as an increase to stage T2. Cox proportional hazards models were used to evaluate associations with recurrence-free and progression-free survival. Median patient age was 69.6 years. During a median followup of 3 years (IQR 1.3-6.1) 200 patients (59%) had recurrence and 14 (4.1%) had stage progression. Of those patients 143 were receiving angiotensin converting enzyme inhibitor/angiotensin receptor blockers at the time of the first transurethral resection. On univariate analysis factors associated with improved recurrence-free survival included carcinoma in situ (p = 0.040), bacillus Calmette-Guérin therapy (p = 0.003) and angiotensin converting enzyme inhibitor/angiotensin receptor blocker therapy (p = 0.009). Multivariate analysis demonstrated that patients treated with bacillus Calmette-Guérin therapy (HR 0.68, 95% CI 0.47-0.87, p = 0.002) or angiotensin converting enzyme inhibitor/angiotensin receptor blocker therapy (HR 0.61, 95% CI 0.45-0.84, p = 0.005) were less likely to experience tumor recurrence. The 5-year recurrence-free survival rate was 45.6% for patients treated with angiotensin converting enzyme inhibitor/angiotensin receptor blockers and 28.1% in those not treated with angiotensin converting enzyme inhibitor/angiotensin receptor blockers (p = 0.009). Subgroup analysis was performed to evaluate nonmuscle invasive bladder cancer pathology (Ta, T1 and carcinoma in situ) in 85 patients on bacillus Calmette-Guérin therapy alone and in 52 in whom it was combined with angiotensin converting enzyme inhibitor/angiotensin receptor blocker. Multivariate analysis revealed that patients treated with bacillus Calmette-Guérin alone (HR 2.19, 95% CI 1.01-4.77, p = 0.04) showed worse recurrence-free survival compared to patients treated with bacillus Calmette-Guérin and angiotensin converting enzyme inhibitor/angiotensin receptor blocker (stage Ta HR 0.45, 95% CI 0.21-0.98, p = 0.04). Pharmacological inhibition of the renin-angiotensin system is associated with improved outcomes in patients with bladder cancer. Renin-angiotensin system inhibitor administration in nonmuscle invasive bladder cancer cases should be studied in a prospective randomized trial. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Combined enzyme mediated fermentation of cellulous and xylose to ethanol by Schizosaccharoyces pombe, cellulase, .beta.-glucosidase, and xylose isomerase

DOEpatents

Lastick, Stanley M.; Mohagheghi, Ali; Tucker, Melvin P.; Grohmann, Karel

1994-01-01

A process for producing ethanol from mixed sugar streams from pretreated biomass comprising xylose and cellulose using enzymes to convert these substrates to fermentable sugars; selecting and isolating a yeast Schizosaccharomyces pombe ATCC No. 2476, having the ability to ferment these sugars as they are being formed to produce ethanol; loading the substrates with the fermentation mix composed of yeast, enzymes and substrates; fermenting the loaded substrates and enzymes under anaerobic conditions at a pH range of between about 5.0 to about 6.0 and at a temperature range of between about 35.degree. C. to about 40.degree. C. until the fermentation is completed, the xylose being isomerized to xylulose, the cellulose being converted to glucose, and these sugars being concurrently converted to ethanol by yeast through means of the anaerobic fermentation; and recovering the ethanol.

Combined enzyme mediated fermentation of cellulose and xylose to ethanol by Schizosaccharomyces pombe, cellulase, [beta]-glucosidase, and xylose isomerase

DOEpatents

Lastick, S.M.; Mohagheghi, A.; Tucker, M.P.; Grohmann, K.

1994-12-13

A process for producing ethanol from mixed sugar streams from pretreated biomass comprising xylose and cellulose using enzymes to convert these substrates to fermentable sugars; selecting and isolating a yeast Schizosaccharomyces pombe ATCC No. 2476, having the ability to ferment these sugars as they are being formed to produce ethanol; loading the substrates with the fermentation mix composed of yeast, enzymes and substrates; fermenting the loaded substrates and enzymes under anaerobic conditions at a pH range of between about 5.0 to about 6.0 and at a temperature range of between about 35 C to about 40 C until the fermentation is completed, the xylose being isomerized to xylulose, the cellulose being converted to glucose, and these sugars being concurrently converted to ethanol by yeast through means of the anaerobic fermentation; and recovering the ethanol. 2 figures.

Dipeptidyl peptidase-4 inhibitor induced angioedema - an overlooked and potentially lethal adverse drug reaction?

PubMed

Scott, Susanne Irene; Andersen, Michelle Fog; Aagaard, Lise; Buchwald, Christian Von; Rasmussen, Eva Rye

2017-02-14

Introduction Angioedema is a potentially fatal adverse drug reaction of some medications, as swellings of the upper airways can cause death by asphyxiation. Angiotensin converting enzyme-inhibitors are widely known to cause angioedema but less is known about the association between dipeptidyl peptidase-4 inhibitors (gliptins) and angioedema. Dipeptidyl peptidase-4 inhibitors are anti-diabetic drugs used to improve glycaemic control. They, as a class effect, inadvertently affect the degradation of the vasoactive kinins bradykinin and substance P, both of which can cause angioedema due to vasodilatation and increase in vascular permeability in the capillaries. Objective To assess the risk and pathomechanism of angioedema due to inhibition of dipeptidyl peptidase-4 inhibitors when used as monotherapy and in combination with angiotensin converting enzyme-inhibitors. Method PubMed, Embase, the Cochrane Library, PubMed Central, Web of Science, Google Scholar and clinicaltrials.gov were searched using different combinations of keywords "angioedema", "dipeptidyl peptidase 4", "dipeptidyl peptidase 4 inhibitors", "gliptins", "bradykinin", "substance P" and "angiotensin converting enzyme-inhibitors". Original research papers were preferably used as references and their bibliographies were used to further the search for original research results. Results Both angiotensin converting enzyme and dipeptidyl peptidase-4 are major enzymes in the degradation pathway of bradykinin and substance P, and when inhibited pharmacologically - especially at the same time - the theoretical risk of angioedema is increased due to accumulation of vasoactive kinins. Conclusion Treatment with dipeptidyl peptidase-4 inhibitors must be carefully considered and monitored especially during concurrent treatment with angiotensin converting enzyme-inhibitors or when treating patients with a known predisposition to angioedema. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Screening the ToxCast Phase 1, 2, and e1k Chemical Libraries for Inhibition of Deiodinase Type 1, 2 and 3 Enzyme Activity

EPA Science Inventory

Thyroid hormone (TH) homeostasis is dependent on multiple proteins for TH synthesis, transport, and peripheral metabolism and elimination. Deiodinase enzymes play an essential role in converting THs between active and inactive forms by converting the pro-hormone thyroxine (T4) to...

Angiotensin converting enzyme inhibitors and aortic arch obstructive malformations.

PubMed

Maliheh, Kadivar; Abdorrazagh, Kiani; Armen, Kocharian; Reza, Shabanian

2006-10-01

We describe two newborn infants with aortic arch obstructive malformations who became anuric after initiation of captopril. Since angiotensin converting enzyme inhibitors can alter renal blood flow by reduction in angiotensin II and blocking autoregulation phenomenon, it is important to use them with great caution in neonates with aortic arch obstructive malformations, while monitoring their renal function closely.

Enzyme Catalysis To Power Micro/Nanomachines

PubMed Central

2016-01-01

Enzymes play a crucial role in many biological processes which require harnessing and converting free chemical energy into kinetic forces in order to accomplish tasks. Enzymes are considered to be molecular machines, not only because of their capability of energy conversion in biological systems but also because enzymatic catalysis can result in enhanced diffusion of enzymes at a molecular level. Enlightened by nature’s design of biological machinery, researchers have investigated various types of synthetic micro/nanomachines by using enzymatic reactions to achieve self-propulsion of micro/nanoarchitectures. Yet, the mechanism of motion is still under debate in current literature. Versatile proof-of-concept applications of these enzyme-powered micro/nanodevices have been recently demonstrated. In this review, we focus on discussing enzymes not only as stochastic swimmers but also as nanoengines to power self-propelled synthetic motors. We present an overview on different enzyme-powered micro/nanomachines, the current debate on their motion mechanism, methods to provide motion and speed control, and an outlook of the future potentials of this multidisciplinary field. PMID:27666121

Enzyme Catalysis To Power Micro/Nanomachines.

PubMed

Ma, Xing; Hortelão, Ana C; Patiño, Tania; Sánchez, Samuel

2016-10-25

Enzymes play a crucial role in many biological processes which require harnessing and converting free chemical energy into kinetic forces in order to accomplish tasks. Enzymes are considered to be molecular machines, not only because of their capability of energy conversion in biological systems but also because enzymatic catalysis can result in enhanced diffusion of enzymes at a molecular level. Enlightened by nature's design of biological machinery, researchers have investigated various types of synthetic micro/nanomachines by using enzymatic reactions to achieve self-propulsion of micro/nanoarchitectures. Yet, the mechanism of motion is still under debate in current literature. Versatile proof-of-concept applications of these enzyme-powered micro/nanodevices have been recently demonstrated. In this review, we focus on discussing enzymes not only as stochastic swimmers but also as nanoengines to power self-propelled synthetic motors. We present an overview on different enzyme-powered micro/nanomachines, the current debate on their motion mechanism, methods to provide motion and speed control, and an outlook of the future potentials of this multidisciplinary field.

Clinical and biochemical presentation of sarcoidosis with high and normal serum angiotensin-converting enzyme.

PubMed

Sejdic, A; Graudal, N; Baslund, B

2018-06-22

The presentation of sarcoidosis can involve symptoms from all organs and the diagnosis is therefore often difficult. A raised serum level of serum angiotensin-converting enzyme (sACE) can be detected in 41-58% of patients. However, whether the sACE level per se reflects the severity of the sarcoid inflammation at the onset of the disease is not well described. The purpose of this study was to investigate the clinical and laboratory significance of high versus normal sACE levels in sarcoidosis. Journal data were retrospectively extracted from 101 patients from our clinic. Clinical and biochemical data were compared between patients with high sACE levels (> 115 U/L) on at least one occasion and normal sACE levels (< 115 U/L). In total, 48% (n = 48) of the patients had high ACE and 52% (n = 53) had normal ACE. The most common extrapulmonary manifestation for both groups was arthritis, followed by skin and eye involvement, but none of these differed between the two groups. Serum ionized calcium was significantly higher in the high sACE group, with a correlation coefficient of 0.112 (p = 0.460). Our study demonstrates that serum ionized calcium is significantly higher in the high sACE group but there was no statistical correlation to sACE. No other clinical or biochemical differences were observed.

Physiological effects of formulation containing tannase-converted green tea extract on skin care: physical stability, collagenase, elastase, and tyrosinase activities.

PubMed

Hong, Yang-Hee; Jung, Eun Young; Noh, Dong Ouk; Suh, Hyung Joo

2014-03-01

Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Physical stability was evaluated by measuring the pH, precipitation, and colors at 25 ± 2 °C/ambient humidity and at 40 ± 2 °C/70% ± 5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities ( p  < 0.05) compared with the formulation containing 5% normal green tea extract. The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.

Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

PubMed Central

Jaarin, Kamsiah; Foong, Wai Dic; Yeoh, Min Hui; Kamarul, Zaman Yusoff Nik; Qodriyah, Haji Mohd Saad; Azman, Abdullah; Zuhair, Japar Sidik Fadhlullah; Juliana, Abdul Hamid; Kamisah, Yusof

2015-01-01

OBJECTIVES This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers. METHODS: Twenty-four adult male Sprague-Dawley rats were divided equally into 4 groups. One group served as the control (group 1), whereas the other three groups (groups 2-4) were administered L-NAME (25 mg/kg, intraperitoneally). Groups 3 and 4 were given oral nicardipine daily at a dose of 3 mg/kg and Nigella sativa oil at a dose of 2.5 mg/kg for 8 weeks, respectively, concomitantly with L-NAME administration. RESULTS Nigella sativa oil prevented the increase in systolic blood pressure in the L-NAME-treated rats. The blood pressure reduction was associated with a reduction in cardiac lipid peroxidation product, NADPH oxidase, angiotensin-converting enzyme activity and plasma nitric oxide, as well as with an increase in heme oxygenase-1 activity in the heart. The effects of Nigella sativa on blood pressure, lipid peroxidation product, nicotinamide adenine dinucleotide phosphate oxidase and angiotensin-converting enzyme were similar to those of nicardipine. In contrast, L-NAME had opposite effects on lipid peroxidation, angiotensin-converting enzyme and NO. CONCLUSION: The antihypertensive effect of Nigella sativa oil appears to be mediated by a reduction in cardiac oxidative stress and angiotensin-converting enzyme activity, an increase in cardiac heme oxygenase-1 activity and a prevention of plasma nitric oxide loss. Thus, Nigella sativa oil might be beneficial for controlling hypertension. PMID:26602523

Inhibition of the renin-angiotensin-aldosterone system: is there room for dual blockade in the cardiorenal continuum?

PubMed

Volpe, Massimo; Danser, A H Jan; Menard, Joël; Waeber, Bernard; Mueller, Dominik N; Maggioni, Aldo P; Ruilope, Luis M

2012-04-01

Antagonism of renin-angiotensin-aldosterone system is exerted through angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, renin inhibitors and mineralocorticoid receptor antagonists. These drugs have been successfully tested in numerous trials and in different clinical settings. The original indications of renin-angiotensin-aldosterone system blockers have progressively expanded from the advanced stages to the earlier stages of cardiorenal continuum. To optimize the degree of blockade of renin-angiotensin-aldosterone system, dose uptitrations of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists or the use of a dual blockade, initially identified with the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists, have been proposed. The data from the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) study do not support this specific dual blockade approach. However, the dual blockade of angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists with direct renin inhibitors is currently under investigation while that based on an aldosterone blocker with any of the previous three drugs requires more evidence beyond heart failure. In this review, we revisited potential advantages of dual blockade of renin-angiotensin-aldosterone system in arterial hypertension and diabetes.

UDP-4-Keto-6-Deoxyglucose, a Transient Antifungal Metabolite, Weakens the Fungal Cell Wall Partly by Inhibition of UDP-Galactopyranose Mutase

PubMed Central

Ma, Liang; Salas, Omar; Bowler, Kyle

2017-01-01

ABSTRACT Can accumulation of a normally transient metabolite affect fungal biology? UDP-4-keto-6-deoxyglucose (UDP-KDG) represents an intermediate stage in conversion of UDP-glucose to UDP-rhamnose. Normally, UDP-KDG is not detected in living cells, because it is quickly converted to UDP-rhamnose by the enzyme UDP-4-keto-6-deoxyglucose-3,5-epimerase/-4-reductase (ER). We previously found that deletion of the er gene in Botrytis cinerea resulted in accumulation of UDP-KDG to levels that were toxic to the fungus due to destabilization of the cell wall. Here we show that these negative effects are at least partly due to inhibition by UDP-KDG of the enzyme UDP-galactopyranose mutase (UGM), which reversibly converts UDP-galactopyranose (UDP-Galp) to UDP-galactofuranose (UDP-Galf). An enzymatic activity assay showed that UDP-KDG inhibits the B. cinerea UGM enzyme with a Ki of 221.9 µM. Deletion of the ugm gene resulted in strains with weakened cell walls and phenotypes that were similar to those of the er deletion strain, which accumulates UDP-KDG. Galf residue levels were completely abolished in the Δugm strain and reduced in the Δer strain, while overexpression of the ugm gene in the background of a Δer strain restored Galf levels and alleviated the phenotypes. Collectively, our results show that the antifungal activity of UDP-KDG is due to inhibition of UGM and possibly other nucleotide sugar-modifying enzymes and that the rhamnose metabolic pathway serves as a shunt that prevents accumulation of UDP-KDG to toxic levels. These findings, together with the fact that there is no Galf in mammals, support the possibility of developing UDP-KDG or its derivatives as antifungal drugs. PMID:29162710

Optimization of Bromelain-Aided Production of Angiotensin I-Converting Enzyme Inhibitory Hydrolysates from Stone Fish Using Response Surface Methodology

PubMed Central

Auwal, Shehu Muhammad; Zarei, Mohammad; Abdul-Hamid, Azizah; Saari, Nazamid

2017-01-01

The stone fish is an under-utilized sea cucumber with many nutritional and ethno-medicinal values. This study aimed to establish the conditions for its optimum hydrolysis with bromelain to generate angiotensin I-converting enzyme (ACE)-inhibitory hydrolysates. Response surface methodology (RSM) based on a central composite design was used to model and optimize the degree of hydrolysis (DH) and ACE-inhibitory activity. Process conditions including pH (4–7), temperature (40–70 °C), enzyme/substrate (E/S) ratio (0.5%–2%) and time (30–360 min) were used. A pH of 7.0, temperature of 40 °C, E/S ratio of 2% and time of 240 min were determined using a response surface model as the optimum levels to obtain the maximum ACE-inhibitory activity of 84.26% at 44.59% degree of hydrolysis. Hence, RSM can serve as an effective approach in the design of experiments to improve the antihypertensive effect of stone fish hydrolysates, which can thus be used as a value-added ingredient for various applications in the functional foods industries. PMID:28362352

Antioxidation, angiotensin converting enzyme inhibition activity, nattokinase, and antihypertension of Bacillus subtilis (natto)-fermented pigeon pea.

PubMed

Lee, Bao-Hong; Lai, Yi-Syuan; Wu, She-Ching

2015-12-01

Because of the high incidence of cardiovascular diseases in Asian countries, traditional fermented foods from Asia have been increasingly investigated for antiatherosclerotic effects. This study investigated the production of nattokinase, a serine fibrinolytic enzyme, in pigeon pea by Bacillus subtilis fermentation. B. subtilis 14714, B. subtilis 14715, B. subtilis 14716, and B. subtilis 14718 were employed to produce nattokinase. The highest nattokinase activity in pigeon pea was obtained using B. subtilis 14715 fermentation for 32 hours. In addition, the levels of antioxidants (phenolics and flavonoids) and angiotensin converting enzyme inhibitory activity were increased in B. subtilis 14715-fermented pigeon pea, compared with those in nonfermented pigeon pea. In an animal model, we found that both water extracts of pigeon pea (100 mg/kg body weight) and water extracts of B. subtilis-fermented pigeon pea (100 mg/kg body weight) significantly improved systolic blood pressure (21 mmHg) and diastolic blood pressure (30 mmHg) in spontaneously hypertensive rats. These results suggest that Bacillus-fermented pigeon pea has benefits for cardiovascular health and can be developed as a new dietary supplement or functional food that prevents hypertension. Copyright © 2015. Published by Elsevier B.V.

Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil

PubMed Central

2010-01-01

Background Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil. Methods Forty-two male Sprague-Dawley rats were equally divided into six groups: Group I (control) - normal rat chow, Group II - fresh soy oil, Group III - soy oil heated once, Group IV - soy oil heated twice, Group V - soy oil heated five times, Group VI - soy oil heated ten times. Blood pressure was measured at the baseline level and at a monthly interval for six months. Plasma nitric oxide, heme oxygenase and angiotensin-converting enzyme levels were measured prior to treatment, at month-three and month-six later. At the end of treatment, the rats were sacrificed and thoracic aortas were taken for measurement of vascular reactivity. Results Blood pressure increased significantly (p < 0.01) in the repeatedly heated oil groups compared to the control and fresh soy oil groups. Consumption of diet containing repeatedly heated oil resulted higher plasma angiotensin-converting enzyme level and lower nitric oxide content and heme oxygenase concentration. Reheated soy oil groups exhibited attenuated relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine. Conclusion As a result of consumption of repeatedly heated soy oil, an elevation in blood pressure was observed which may be due to the quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure. PMID:20573259

Functional Activities and Immunohistochemical Distribution of Superoxide Dismutase in Normal, Dysplastic and Squamous Cell Carcinoma Oral Tissues

DTIC Science & Technology

2001-07-26

antioxidant enzymes: SOD, catalase ( CAT ), and glutathione peroxidase (GPO).2 ° SOD converts superoxide radical into hydrogen peroxide, while CAT and GPO convert...in endometriosis and adenomyosis. Fertility and Sterility 1999; 1:129-134. 45. Muse KE, Oberley TD, Sempf JM, Oberley LW. Immunolocalization of antioxidant enzymes in adult hamster kidney. Histochem J 1994;9:734-753. 43

Utilization of peptide carrier system to improve intestinal absorption: targeting prolidase as a prodrug-converting enzyme

NASA Technical Reports Server (NTRS)

Bai, J. P.; Hu, M.; Subramanian, P.; Mosberg, H. I.; Amidon, G. L.

1992-01-01

The feasibility of targeting prolidase as a peptide prodrug-converting enzyme has been examined. The enzymatic hydrolysis by prolidase of substrates for the peptide transporter L-alpha-methyldopa-pro and several dipeptide analogues without an N-terminal alpha-amino group (phenylpropionylproline, phenylacetylproline, N-benzoylproline, and N-acetylproline) was investigated. The Michaelis-Menten parameters Km and Vmax for L-alpha-methyldopa-pro are 0.09 +/- 0.02 mM and 3.98 +/- 0.25 mumol/min/mg protein, respectively. However, no hydrolysis of the dipeptide analogues without an N-terminal alpha-amino group is observed, suggesting that an N-terminal alpha-amino group is required for prolidase activity. These results demonstrate that prolidase may serve as a prodrug-converting enzyme for the dipeptide-type prodrugs, utilizing the peptide carrier for transport of prodrugs into the mucosal cells and prolidase, a cytosolic enzyme, to release the drug. However, a free alpha-amino group appears to be necessary for prolidase hydrolysis.

Molecular diversity of tuliposide B-converting enzyme in tulip (Tulipa gesneriana): identification of the third isozyme with a distinct expression profile.

PubMed

Nomura, Taiji; Kuchida, Ryo; Kitaoka, Naoki; Kato, Yasuo

2018-02-23

6-Tuliposide B (PosB), a major secondary metabolite that accumulates in tulip (Tulipa gesneriana), is converted to the antibacterial lactone, tulipalin B (PaB), by PosB-converting enzyme (TCEB). TgTCEB1 and TgTCEB-R, which encode TCEB, are specifically expressed in tulip pollen and roots, respectively, but are hardly expressed in other tissues (e.g. leaves) despite the presence of substantial PosB-converting activity, suggesting the existence of another TCEB isozyme. Here, we describe the identification of TgTCEB-L ("L" for leaf), a paralog of TgTCEB1 and TgTCEB-R, from leaves via native enzyme purification. The enzymatic characters of TgTCEB-L, including catalytic activity and subcellular localization, were substantially the same as those of TgTCEB1 and TgTCEB-R. However, TgTCEB-L did not exhibit tissue-specific expression. Identification of TgTCEB-L explains the PosB-converting activity detected in tissues where TgTCEB1 and TgTCEB-R transcripts could not be detected, indicating that tulip subtilizes the three TgTCEB isozymes depending on the tissue.

Activation of renin-angiotensin-aldosterone system (RAAS) in the lung of smoking-induced pulmonary arterial hypertension (PAH) rats.

PubMed

Yuan, Yi-Ming; Luo, Li; Guo, Zhen; Yang, Ming; Ye, Ren-Song; Luo, Chuan

2015-06-01

To explore the role of the renin-angiotensin-aldosterone system (RAAS) in the pathogenesis of pulmonary arterial hypertension (PAH) induced by chronic exposure to cigarette smoke. 48 healthy male SD rats were randomly divided into four groups (12/group): control group (group A); inhibitor alone group (group B); cigarette induction group (group C); cigarette induction + inhibitor group (group D). After the establishment of smoking-induced PAH rat model, the right ventricular systolic pressure (RVSP) was detected using an inserted catheter; western blotting was used to detect the protein expression of angiotensin-converting enzyme-2 (ACE2) and angiotensin-converting enzyme (ACE); expression levels of angiotensin II (AngII) in lung tissue were measured by radioimmunoassay. After six months of cigarette exposure, the RVSP of chronic cigarette induction group was significantly higher than that of the control group; expression levels of AngII and ACE increased in lung tissues, but ACE2 expression levels reduced. Compared with cigarette exposure group, after losartan treatment, RVSP, ACE and AngII obviously decreased (P<0.05), and ACE2 expression levels significantly increased. Chronic cigarette exposure may result in PAH and affect the protein expression of ACE2 and ACE in lung tissue, suggesting that ACE2 and ACE play an important role in the pathogenesis of smoking-induced PAH. © The Author(s) 2015.

Association of Angiotensin-Converting Enzyme ACE Gene Polymorphism with ACE Activity and Susceptibility to Vitiligo in Egyptian Population.

PubMed

Badran, Dahlia I; Nada, Hesham; Hassan, Ranya

2015-05-01

The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with vitiligo in the Indians and Koreans, but not in those of English or Turkish background. We investigated the ACE (I/D) polymorphism in vitiligo patients for the first time in Egypt and compared serum ACE levels between vitiligo patients and controls. The present study was carried out in 100 vitiligo patients (40 males and 60 females) and in 100 healthy controls of an Egyptian population using the polymerase chain reaction genotyping method. The ACE genotype and allele frequency was significantly different between vitiligo patients and controls. Our results revealed a significant increase in the frequency of the ACE I allele (p=0.002; odds ratio: 1.99; 95% confidence intervals: 1.207-3.284) with an overrepresentation of I/D genotype in the vitiligo patient group. Furthermore, there was a significant difference between the segmental, nonsegmental, and focal vitiligo in ACE gene genotype distribution. Serum ACE levels were significantly increased in vitiligo patients compared to controls (p=0.034). This study suggests that, for the first time, ACE gene polymorphism confers susceptibility to vitiligo in the Egyptian population.

Angiotensin-converting enzyme 2 activation improves endothelial function.

PubMed

Fraga-Silva, Rodrigo A; Costa-Fraga, Fabiana P; Murça, Tatiane M; Moraes, Patrícia L; Martins Lima, Augusto; Lautner, Roberto Q; Castro, Carlos H; Soares, Célia Maria A; Borges, Clayton L; Nadu, Ana Paula; Oliveira, Marilene L; Shenoy, Vinayak; Katovich, Michael J; Santos, Robson A S; Raizada, Mohan K; Ferreira, Anderson J

2013-06-01

Diminished release and function of endothelium-derived nitric oxide coupled with increases in reactive oxygen species production is critical in endothelial dysfunction. Recent evidences have shown that activation of the protective axis of the renin-angiotensin system composed by angiotensin-converting enzyme 2, angiotensin-(1-7), and Mas receptor promotes many beneficial vascular effects. This has led us to postulate that activation of intrinsic angiotensin-converting enzyme 2 would improve endothelial function by decreasing the reactive oxygen species production. In the present study, we tested 1-[[2-(dimetilamino)etil]amino]-4-(hidroximetil)-7-[[(4-metilfenil)sulfonil]oxi]-9H-xantona-9 (XNT), a small molecule angiotensin-converting enzyme 2 activator, on endothelial function to validate this hypothesis. In vivo treatment with XNT (1 mg/kg per day for 4 weeks) improved the endothelial function of spontaneously hypertensive rats and of streptozotocin-induced diabetic rats when evaluated through the vasorelaxant responses to acetylcholine/sodium nitroprusside. Acute in vitro incubation with XNT caused endothelial-dependent vasorelaxation in aortic rings of rats. This vasorelaxation effect was attenuated by the Mas antagonist D-pro7-Ang-(1-7), and it was reduced in Mas knockout mice. These effects were associated with reduction in reactive oxygen species production. In addition, Ang II-induced reactive oxygen species production in human aortic endothelial cells was attenuated by preincubation with XNT. These results showed that chronic XNT administration improves the endothelial function of hypertensive and diabetic rat vessels by attenuation of the oxidative stress. Moreover, XNT elicits an endothelial-dependent vasorelaxation response, which was mediated by Mas. Thus, this study indicated that angiotensin-converting enzyme 2 activation promotes beneficial effects on the endothelial function and it is a potential target for treating cardiovascular disease.

In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean

PubMed Central

Ademosun, Ayokunle O.; Ademiluyi, Adedayo O.; Omojokun, Olasunkanmi S.; Nwanna, Esther E.; Longe, Kuburat O.

2014-01-01

Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension. PMID:25295218

In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean.

PubMed

Oboh, Ganiyu; Ademosun, Ayokunle O; Ademiluyi, Adedayo O; Omojokun, Olasunkanmi S; Nwanna, Esther E; Longe, Kuburat O

2014-01-01

Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension.

Genetic variation of the angiotensin-converting enzyme gene: increased frequency of the insertion allele in Koreans.

PubMed

Hong, S H; Kang, B Y; Park, W H; Kim, J Q; Lee, C C

1997-01-01

In view of the clinical importance of angiotensin-converting enzyme (ACE) as a major marker for cardiovascular diseases, we investigated insertion/deletion (I/D) polymorphism of the ACE gene in Koreans. Genotype frequencies were examined by polymerase chain reaction in 171 patients with coronary artery disease (CAD) and 120 healthy subjects. Allele frequencies of ACE polymorphism in Koreans were not significantly different between patient and control groups. In addition, association between ACE genotypes and the number of stenosed coronary arteries was not detected. ACE genotypes in the CAD group were not associated with body mass index and plasma lipid levels. Thus, our results suggest that, at least in Koreans, I/D polymorphism of the gene is unlikely to be a useful marker for CAD subjects. However, the I allele frequency of Koreans (0.58) was higher than that of Caucasian populations (0.47) but lower than that of Samoan (0.91) and Yanomami (0.85) populations. Here, we discuss the clinical and ethnic importance of ACE polymorphism.

Separation and Characterization of Angiotensin I Converting Enzyme (ACE) Inhibitory Peptides from Saurida elongata Proteins Hydrolysate by IMAC-Ni2.

PubMed

Sun, Lixia; Wu, Shanguang; Zhou, Liqin; Wang, Feng; Lan, Xiongdiao; Sun, Jianhua; Tong, Zhangfa; Liao, Dankui

2017-02-15

Lizard fish protein hydrolysates (LFPH) were prepared from Lizard fish ( Saurida elongata ) proteins possessing powerful angiotensin I converting enzyme (ACE) inhibitory activity and the fraction (LFPH-I) with high ACE inhibitory activity was obtained through ultrafiltration. The active Fraction (F2) was isolated from LFPH-I using immobilized metal affinity chromatography (IMAC - Ni 2+ ). Analysis of amino acid levels revealed that F2 eluted from IMAC was enriched in Met, His, Tyr, Pro, Ile, and Leu compared to the crude peptide LFPH-I. F2 with the high ACE inhibitory activity (IC 50 of 0.116 mg·mL -1 ) was further separated by a reverse-phase column to yield a novel ACE inhibitory peptide with IC 50 value of 52 μM. The ACE inhibitory peptide was identified as Arg-Tyr-Arg-Pro, RYRP. The present study demonstrated that IMAC may be a useful tool for the separation of ACE inhibitory peptides from protein hydrolysate.

Angiotensin converting enzyme (ACE) inhibitory, antihypertensive and antihyperlipidaemic activities of protein hydrolysates from Rhopilema esculentum.

PubMed

Liu, Xin; Zhang, Miansong; Zhang, Chao; Liu, Changheng

2012-10-15

Angiotensin-converting enzyme (ACE) inhibitory, antihypertensive and antihyperlipidaemic activities of protein hydrolysates (RPH) from the jellyfish Rhopilema esculentum were investigated. R. esculentum was hydrolysed sequentially with pepsin and papain, and then the hydrolysate was ultrafiltered with a 2000 Da cut-off membrane. It was found that RPH contained high levels of Gly, Glu, Pro, Asp and Ala, having potential ACE inhibitory activity in vitro with an IC(50) of 1.28 mg/ml. It was also found that systolic blood pressure was reduced markedly in spontaneously hypertensive rats after single and chronic oral administration of RPH, indicating that RPH had an antihypertensive effect. In addition, oral administration of RPH decreased total serum cholesterol and triglyceride, and increased high-density lipoprotein cholesterol in rats fed with high-fat diet. These results indicate that RPH may prove to be a promising functional food for the prevention and treatment of hypertension and hyperlipidaemia. Copyright © 2012 Elsevier Ltd. All rights reserved.

Angiotensin-I converting enzyme inhibitory peptides from antihypertensive skate (Okamejei kenojei) skin gelatin hydrolysate in spontaneously hypertensive rats.

PubMed

Ngo, Dai-Hung; Kang, Kyong-Hwa; Ryu, BoMi; Vo, Thanh-Sang; Jung, Won-Kyo; Byun, Hee-Guk; Kim, Se-Kwon

2015-05-01

The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate (Okamejei kenojei) skin gelatin. The Alcalase/protease gelatin hydrolysate below 1 kDa (SAP) exhibited the highest angiotensin-I converting enzyme (ACE) inhibition compared to other hydrolysates. SAP can decrease systolic blood pressure significantly in spontaneously hypertensive rats. SAP inhibited vasoconstriction via PPAR-γ expression, activation and phosphorylation of eNOS in lungs. Moreover, the expression levels of endothelin-1, RhoA, α-smooth muscle actin, cleaved caspase 3 and MAPK were decreased by SAP in lungs. Vascularity, muscularization and cellular proliferation in lungs were detected by immunohistochemical staining. Finally, two purified peptides (LGPLGHQ, 720Da and MVGSAPGVL, 829Da) showed potent ACE inhibition with IC50 values of 4.22 and 3.09 μM, respectively. These results indicate that bioactive peptides isolated from skate skin gelatin may serve as candidates against hypertension and could be used as functional food ingredients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Release of IL-1β via IL-1β-Converting Enzyme in a Skin Dendritic Cell Line Exposed to 2,4-Dinitrofluorobenzene

PubMed Central

Matos, Teresa J.; Jaleco, Sara P.; Gonçalo, Margarida; Duarte, Carlos B.; Lopes, M. Celeste

2005-01-01

We used a mouse fetal skin dendritic cell line (FSDC) to study the effect of the strong allergen 2,4-dinitrofluorobenzene (DNFB) on interleukin (IL)-1β release and IL-1β receptor immunoreactivity. Stimulation with DNFB (30 minutes) increased IL-1β release without changing the mRNA levels of the protein. Furthermore, DNFB increased transiently the interleukin-1β-converting enzyme (ICE) activity, as measured with its fluorogenic substrate Z-Tyr-Val-Ala-Asp-AFC. The ICE inhibitor Z-YVAD-FMK prevented the release of IL-1β evoked by DNFB. Incubation of the cells with DNFB (30 minutes) strongly increased IL-1β receptor immunoreactivity. The rapid effect of DNFB on the release of mature IL-1β, without inducing an increase of IL-1β mRNA in FSDC, suggests a posttranslational modification of pro-IL-1β by ICE activity. PMID:16106098

A novel lactone-forming carboxylesterase: molecular identification of a tuliposide A-converting enzyme in tulip.

PubMed

Nomura, Taiji; Ogita, Shinjiro; Kato, Yasuo

2012-06-01

Tuliposides, the glucose esters of 4-hydroxy-2-methylenebutanoate and 3,4-dihydroxy-2-methylenebutanoate, are major secondary metabolites in tulip (Tulipa gesneriana). Their lactonized aglycons, tulipalins, function as defensive chemicals due to their biological activities. We recently found that tuliposide-converting enzyme (TCE) purified from tulip bulbs catalyzed the conversion of tuliposides to tulipalins, but the possibility of the presence of several TCE isozymes was raised: TCE in tissues other than bulbs is different from bulb TCE. Here, to prove this hypothesis, TCE was purified from petals, which have the second highest TCE activity after bulbs. The purified enzyme, like the bulb enzyme, preferentially accepted tuliposides as substrates, with 6-tuliposide A the best substrate, which allowed naming the enzyme tuliposide A-converting enzyme (TCEA), but specific activity and molecular mass differed between the petal and bulb enzymes. After peptide sequencing, a novel cDNA (TgTCEA) encoding petal TCEA was isolated, and the functional characterization of the recombinant enzyme verified that TgTCEA catalyzes the conversion of 6-tuliposide A to tulipalin A. TgTCEA was transcribed in all tulip tissues but not in bulbs, indicating the presence of a bulb-specific TgTCEA, as suggested by the distinct enzymatic characters between the petal and bulb enzymes. Plastidial localization of TgTCEA enzyme was revealed, which allowed proposing a cytological mechanism of TgTCE-mediated tulipalin formation in the tulip defensive strategy. Site-directed mutagenesis of TgTCEA suggested that the oxyanion hole and catalytic triad characteristic of typical carboxylesterases are essential for the catalytic process of TgTCEA enzyme. To our knowledge, TgTCEA is the first identified member of the lactone-forming carboxylesterases, specifically catalyzing intramolecular transesterification.

A Novel Lactone-Forming Carboxylesterase: Molecular Identification of a Tuliposide A-Converting Enzyme in Tulip1[W

PubMed Central

Nomura, Taiji; Ogita, Shinjiro; Kato, Yasuo

2012-01-01

Tuliposides, the glucose esters of 4-hydroxy-2-methylenebutanoate and 3,4-dihydroxy-2-methylenebutanoate, are major secondary metabolites in tulip (Tulipa gesneriana). Their lactonized aglycons, tulipalins, function as defensive chemicals due to their biological activities. We recently found that tuliposide-converting enzyme (TCE) purified from tulip bulbs catalyzed the conversion of tuliposides to tulipalins, but the possibility of the presence of several TCE isozymes was raised: TCE in tissues other than bulbs is different from bulb TCE. Here, to prove this hypothesis, TCE was purified from petals, which have the second highest TCE activity after bulbs. The purified enzyme, like the bulb enzyme, preferentially accepted tuliposides as substrates, with 6-tuliposide A the best substrate, which allowed naming the enzyme tuliposide A-converting enzyme (TCEA), but specific activity and molecular mass differed between the petal and bulb enzymes. After peptide sequencing, a novel cDNA (TgTCEA) encoding petal TCEA was isolated, and the functional characterization of the recombinant enzyme verified that TgTCEA catalyzes the conversion of 6-tuliposide A to tulipalin A. TgTCEA was transcribed in all tulip tissues but not in bulbs, indicating the presence of a bulb-specific TgTCEA, as suggested by the distinct enzymatic characters between the petal and bulb enzymes. Plastidial localization of TgTCEA enzyme was revealed, which allowed proposing a cytological mechanism of TgTCE-mediated tulipalin formation in the tulip defensive strategy. Site-directed mutagenesis of TgTCEA suggested that the oxyanion hole and catalytic triad characteristic of typical carboxylesterases are essential for the catalytic process of TgTCEA enzyme. To our knowledge, TgTCEA is the first identified member of the lactone-forming carboxylesterases, specifically catalyzing intramolecular transesterification. PMID:22474185

Reducing Enzyme Costs Increases Market Potential of Biofuels; The Spectrum of Clean Energy Innovation (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Fact sheet describing NREL's work with enzyme producers Novozymes and Genencor to engineer new cellulase enzymes to breakdown cellulosic ethanol into fermentable sugars that can be converted into biofuels.

Pharmacologic modulation of ACE2 expression.

PubMed

Soler, María José; Barrios, Clara; Oliva, Raymond; Batlle, Daniel

2008-10-01

Angiotensin-converting enzyme 2 (ACE2) is an enzymatically active homologue of angiotensin-converting enzyme that degrades angiotensin I, angiotensin II, and other peptides. Recent studies have shown that under pathologic conditions, ACE2 expression in the kidney is altered. In this review, we briefly summarize recent studies dealing with pharmacologic interventions that modulate ACE2 expression. ACE2 amplification may have a potential therapeutic role for kidney disease and hypertension.

Rediscovering ACE: Novel insights into the many roles of the angiotensin-converting enzyme

PubMed Central

Gonzalez-Villalobos, Romer A.; Shen, Xiao Z.; Bernstein, Ellen A.; Janjulia, Tea; Taylor, Brian; Giani, Jorge F.; Blackwell, Wendell-Lamar B.; Shah, Kandarp H.; Shi, Peng D.; Fuchs, Sebastien; Bernstein, Kenneth E.

2013-01-01

Angiotensin converting enzyme (ACE) is best known for the catalytic conversion of angiotensin I to angiotensin II. However, the use of gene-targeting techniques has led to mouse models highlighting many other biochemical properties and actions of this enzyme. This review discusses recent studies examining the functional significance of ACE tissue-specific expression and the presence in ACE of two independent catalytic sites with distinct substrates and biological effects. It is these features which explain why ACE makes important contributions to many different physiological processes including renal development, blood pressure control, inflammation and immunity. PMID:23686164

Production of Glucaric Acid from Hemicellulose Substrate by Rosettasome Enzyme Assemblies.

PubMed

Lee, Charles C; Kibblewhite, Rena E; Paavola, Chad D; Orts, William J; Wagschal, Kurt

2016-07-01

Hemicellulose biomass is a complex polymer with many different chemical constituents that can be utilized as industrial feedstocks. These molecules can be released from the polymer and transformed into value-added chemicals through multistep enzymatic pathways. Some bacteria produce cellulosomes which are assemblies composed of lignocellulolytic enzymes tethered to a large protein scaffold. Rosettasomes are artificial engineered ring scaffolds designed to mimic the bacterial cellulosome. Both cellulosomes and rosettasomes have been shown to facilitate much higher rates of biomass hydrolysis compared to the same enzymes free in solution. We investigated whether tethering enzymes involved in both biomass hydrolysis and oxidative transformation to glucaric acid onto a rosettasome scaffold would result in an analogous production enhancement in a combined hydrolysis and bioconversion metabolic pathway. Three different enzymes were used to hydrolyze birchwood hemicellulose and convert the substituents to glucaric acid, a top-12 DOE value added chemical feedstock derived from biomass. It was demonstrated that colocalizing the three different enzymes to the synthetic scaffold resulted in up to 40 % higher levels of product compared to uncomplexed enzymes.

Murine recombinant angiotensin-converting enzyme 2 attenuates kidney injury in experimental Alport syndrome.

PubMed

Bae, Eun Hui; Fang, Fei; Williams, Vanessa R; Konvalinka, Ana; Zhou, Xiaohua; Patel, Vaibhav B; Song, Xuewen; John, Rohan; Oudit, Gavin Y; Pei, York; Scholey, James W

2017-06-01

Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase in the renin-angiotensin system that catalyzes the breakdown of angiotensin II to angiotensin 1-7. We have reported that ACE2 expression in the kidney is reduced in experimental Alport syndrome but the impact of this finding on disease progression has not been studied. Accordingly, we evaluated effects of murine recombinant ACE2 treatment in Col4a3 knockout mice, a model of Alport syndrome characterized by proteinuria and progressive renal injury. Murine recombinant ACE2 (0.5 mg/kg/day) was administered from four to seven weeks of age via osmotic mini-pump. Pathological changes were attenuated by murine recombinant ACE2 treatment which ameliorated kidney fibrosis as shown by decreased expression of COL1α1 mRNA, less accumulation of extracellular matrix proteins, and inhibition of transforming growth factor-β signaling. Further, increases in proinflammatory cytokine expression, macrophage infiltration, inflammatory signaling pathway activation, and heme oxygenase-1 levels in Col4a3 knockout mice were also reduced by murine recombinant ACE2 treatment. Lastly, murine recombinant ACE2 influenced the turnover of renal ACE2, as it suppressed the expression of tumor necrosis factor-α converting enzyme, a negative regulator of ACE2. Thus, treatment with exogenous ACE2 alters angiotensin peptide metabolism in the kidneys of Col4a3 knockout mice and attenuates the progression of Alport syndrome nephropathy. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Antihypertensive Medications and the Prevalence of Hyperkalemia in a Large Health System.

PubMed

Chang, Alex R; Sang, Yingying; Leddy, Julia; Yahya, Taher; Kirchner, H Lester; Inker, Lesley A; Matsushita, Kunihiro; Ballew, Shoshana H; Coresh, Josef; Grams, Morgan E

2016-06-01

Little is known about the frequency and patterns of hyperkalemia in clinical settings. We evaluated the association between baseline antihypertensive medications that may affect potassium levels (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, loop/thiazide diuretics, and potassium-sparing diuretics) and hyperkalemia, defined by potassium >5 mEq/L and >5.5 mEq/L, over a 3-year time period in 194 456 outpatients in the Geisinger Health System, as well as actions taken after an episode of hyperkalemia. The proportions of patients with 0, <2, 2 to 4, and ≥4 potassium measurements per year were 20%, 58%, 16%, and 6%. Potassium levels >5 mEq/L and >5.5 mEq/L occurred in 10.8% and 2.3% of all patients over the 3-year period; among patients with ≥4 measurements per year, corresponding values were 39.4% and 14.6%. Most cases of hyperkalemia occurred only once during follow-up. The antihypertensive medication class most strongly associated with hyperkalemia was angiotensin-converting enzyme inhibitors. Among patients with a measurement of potassium >5.5 mEq/L, only 24% were seen by a nephrologist and 5.2% were seen by a dietician during the 3-year period. Short-term actions after a potassium measurement >5.5 mEq/L included emergency room visit (3.1% within 7 days), remeasurement of potassium (44.3% with 14 days), and change in a potassium-altering medication (26.4% within 60 days). The most common medication changes were discontinuation/dose reduction of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or potassium-sparing diuretic, which occurred in 29.1% and 49.6% of people taking these medications, respectively. In conclusion, hyperkalemia is common. Future research may enable optimal renin-angiotensin-aldosterone system inhibitor use with improved management of hyperkalemia. © 2016 American Heart Association, Inc.

ADAM17_i33780A>G polymorphism interacts with dietary n-6 polyunsaturated fatty acids to modulate obesity risk in the genetics of lipid lowering drugs and diet network study

USDA-ARS?s Scientific Manuscript database

The disintegrin and metalloproteinase ADAM17, also known as tumor necrosis factor alpha converting enzyme, is expressed in adipocytes, and elevated levels of expression have been linked to obesity and insulin resistance. This study evaluated the association of six ADAM17 single nucleotide polymorphi...

Glutamic acid is an active site residue of angiotensin I-converting enzyme. Use of the Lossen rearrangement for identification of dicarboxylic acid residues.

PubMed

Harris, R B; Wilson, I B

1983-01-25

A set of chemical reactions was used to show that one glutamic acid residue at the active site of bovine lung angiotensin I-converting enzyme is esterified with the alkylating agent p-[N,N-bis(chloroethyl)amino] phenylbutyryl-L-Pro (chlorambucyl-L-Pro), an affinity label for this enzyme (Harris, R. B., and Wilson, I. B. (1982) J. Biol. Chem. 257, 811-815). The same procedure was used to confirm that a glutamic acid residue of carboxypeptidase A alpha is esterified by reaction with bromoacetyl-N-methyl-L-phenylalanine (Haas, G. M., and Neurath, H. (1971) Biochemistry 10, 3535-3546). In the procedure described in this paper, the esterified residue at the active site is converted to the hydroxamic acid by reaction with hydroxylamine and the hydroxamic acid is subject to the Lossen rearrangement. If a glutamic acid residue was esterified, 1 eq of 2,4-diaminobutyric acid will be formed. Aspartyl esters will give 2,3-diaminopropionic acid. The diamino acids can be quantitatively measured using the short column of an amino acid analyzer if the amount of lysine and histidine is largely decreased by modification with suitable side chain protecting groups. With carboxypeptidase A, the reactions were done on the whole undigested enzyme. With the converting enzyme, we first cleaved the esterified enzyme with cyanogen bromide. Twenty-nine cleavage peptides were separated on high performance liquid chromatography and one of these contained all of the bound radioactive inhibitor. This active site peptide was then subjected to the derivatization and Lossen procedures, and 1 eq of 2,4-diaminobutyric acid was obtained.

Synthesis and evaluation of chalcone analogues based pyrimidines as angiotensin converting enzyme inhibitors.

PubMed

Bukhari, S N A; Butt, A M; Amjad, M W B; Ahmad, W; Shah, V H; Trivedi, A R

2013-11-01

Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.

The Effect Enzymes Have On Bodies Of Water

NASA Astrophysics Data System (ADS)

Igiebor, I. W.; Murray, P.; Montes, D. R.

2017-12-01

With our ongoing research and studies of extracellular enzymes, we have gathered that the enzymes have a process in which they convert organic matter into CO2. Therefore, one of our goals is to find out how much and at what rate the organic matter was being transformed into CO2 so that we or others may somehow make this into a tool to reduce CO2 levels in Earth's atmosphere. Although, to find an answer or learn more about it, we needed to continue to test different water samples and see which enzymes were active, under what conditions, and at what rates. Currently I am testing enzymes in new water sources in and around the Newark, NJ area. The ultimate goal is to find out why and how the conversion of organic matter to carbon occurs, still not having a clear answer on why it does happen, but realizing that continuing to accumulate data for the scientific community to examine is the path forward to solving the atmospheric CO2 problem.

Serum angiotensin-converting enzyme (SACE) activity as an indicator of total body granuloma load and prognosis in sarcoidosis.

PubMed

Muthuswamy, P P; Lopez-Majano, V; Ranginwala, M; Trainor, W D

1987-09-01

The relationship between the level of serum angiotensin converting enzyme (SACE) and the total body granuloma load in patients with sarcoidosis was studied in two groups using SACE levels and total body gallium67 scans. The study group consisted of 22 patients with SACE levels greater than or equal to 100 U/ml (EH-SACE group) and the control group consisted of 24 patients consecutively diagnosed to have sarcoidosis in a one year period with SACE level of less than 80 U/ml. The average number of organs involved in the EH-SACE group was 3.9 +/- 1 compared to 2.3 +/- 1 in the control group (p less than 0.0001). The incidence of extra pulmonary organ involvement in the EH-SACE group was 2.2 +/- 1 organs compared to 1.0 + 0.8 in the control group (p less than 0.0002). The SACE level was correlated with the number of organs involved for all patients with sarcoidosis (r = .55; p less than .0001). Following corticosteroid therapy for 39 +/- 41 weeks the SACE dropped to 64 +/- 45 units in the EH-SACE group. But it took only 13 +/- 10 weeks to normalize the SACE level to 27 +/- 9 units in the control group. The EH-SACE group patients were followed for 114 +/- 64 weeks and 73% of them still have active sarcoidosis requiring repeated cycles of corticosteroid therapy, while after 42 +/- 23 weeks of follow up only 10% of patients from the control group were still on therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor necrosis factor-alpha converting enzyme in the human placenta throughout gestation.

PubMed

Hung, Tai-Ho; Chen, Szu-Fu; Hsieh, Ching-Chang; Hsu, Jenn-Jeih; Li, Meng-Jen; Yeh, Yi-Lin; Hsieh, T'sang-T'ang

2008-02-01

Ectodomain shedding of epidermal growth factor receptor ligands such as transforming growth factor- alpha (TGF-alpha), heparin-binding epidermal growth factor-like growth factor (HBEGF), and amphiregulin (AREG) is considered to be important during implantation. Tumor necrosis factor-alpha converting enzyme (TACE) has been suggested as the major sheddase for these molecules. The objectives of this study are (1) to characterize the expression of TACE in the human placenta throughout gestation; (2) to determine the association between the expression of TACE with TGF-alpha, HBEGF, and AREG; (3) to ascertain whether TACE mediates TGF-alpha, HBEGF, and AREG shedding; and (4) to examine the effect of hypoxia on the expression of TACE. By analyzing a total of 55 villous samples representing different gestational ages, the authors found that TACE was continuously expressed in the placentas throughout gestation and that the levels of TACE were positively correlated with the levels of TGF-alpha, HBEGF, and AREG. Preadministration of a TACE inhibitor in villous explant cultures or transfection of cytotrophoblastic cells with TACE-specific small interference RNA decreased the shedding of HBEGF and AREG. Moreover, hypoxia (2% O(2)) caused an increase in the levels of TACE mRNA and protein in villous explants and primary cytotrophoblastic cells in vitro. These results indicate that oxygen regulates the expression of TACE and that TACE may be important for placental development during human pregnancy.

Substance P stimulates endothelin 1 secretion via endothelin-converting enzyme 1 and promotes melanogenesis in human melanocytes.

PubMed

Park, Phil June; Lee, Tae Ryong; Cho, Eun-Gyung

2015-02-01

Substance P (SP) is a well-known neuropeptide implicated in the wound-healing process. The wound occasionally causes a pigmented scar. In the present study, we examined whether increased levels of SP affected melanogenesis. When human melanocytes were treated with SP, the melanin content increased and the pigmentation process accelerated in a dose-dependent manner. In addition to melanogenesis-related genes, the expression of neurokinin 1 receptor, endothelin 1 (EDN1), and EDN receptor type B (EDNRB) also increased at both the messenger RNA and protein levels. Interestingly, secreted EDN1 was observed in the melanocyte culture medium, and this phenomenon was significantly enhanced by SP treatment. Through knockdown experiments using small interfering RNAs (siRNAs), we confirmed that endothelin-converting enzyme 1 (ECE1), EDN1, and EDNRB were involved in SP-induced pigmentation and found that EDN1 secretion was affected by ECE1 and EDN1 siRNAs, but not by EDNRB siRNA. These findings indicate that ECE1 is essential for EDN1 secretion in melanocytes and that EDNRB functions downstream of secreted EDN1 to increase the cAMP levels and activate the melanogenesis-related phosphorylation cascade. This study provides in vitro evidence for a melanogenic function of SP in the skin and suggests that the SP-related signal is a potent target for regulating stress- or wound-induced pigmentation.

Enzymatic conversion of sucrose to glucose and its anomerization by quantitative NMR spectroscopy: Application of a simple consecutive reaction rates approach

NASA Astrophysics Data System (ADS)

Singh, Jaideep; Her, Cheenou; Krishnan, V. V.

2018-02-01

The anomerization of carbohydrates is an essential process that determines the relative stabilization of stereoisomers in an aqueous solution. In a typical real-time enzyme kinetics experiment, the substrate (sucrose) is converted to glucose and fructose by the enzyme invertase. The product (α-D-glucose) starts to convert to β-D-glucose immediately by hydrolysis. Though the anomerization process is independent of the enzyme catalysis, the progress curve describing the production of β-D-glucose from α-D-glucose is directly affected by the kinetics of consecutive reactions. When α-D-glucose is continually converted to β-D-glucose, by the enzymatic action, the time course of both α- and β-D-glucose is influenced by the enzyme kinetics. Thus, a reversible first-order rate equation is not adequate to model the reaction mechanism, leading to erroneous results on the rates of formation of the glucose anomers. In this manuscript, we incorporate an approximate method to address consecutive general reactions involving enzyme kinetics and first-order reaction processes. The utility of the approach is demonstrated in the real-time NMR measurement of the anomerization process of α-D-glucose (enzymatically produced from sucrose) to β-D-glucose, as a function of invertase enzyme concentration. Variable temperature experiments were used to estimate the thermodynamic parameters of the anomerization process and are consistent with literature values.

Pathway for biodegradation of p-nitrophenol in a Moraxella sp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spain, J.C.; Gibson, D.T.

1991-03-01

A Moraxella strain grew on p-nitrophenol with stoichiometric release of nitrite. During induction of the enzymes for growth on p-nitrophenol, traces of hydroquinone accumulated in the medium. In the presence of 2,2{prime}-dipyidyl, p-nitrophenol, was converted stoichiometrically to hydroquinone. Particulate enzymes catalyzed the conversion of p-nitrophenol to hydroquinone in the presence of NADPH and oxygen. Soluble enzymes catalyzed the conversion of hydroquinone to {gamma}-hydroxymuconic semialdehyde, which was identified by high-performance liquid chromatography (HPLC)-mass spectroscopy. Upon addition of catalytic amounts of NAD{sup +}, {gamma}-hydroxymuconic semialdehyde was converted to {beta}-ketoadipic acid. In the presence of pyruvate and lactic dehydrogenase, substrate amounts of NADmore » were required and {gamma}-hydroxymuconic semialdehyde was converted to maleylacetic acid, which was identified by HPLC-mass spectroscopy. Similar results were obtained when the reaction was carried out in the presence of potassium ferricyanide. Extracts prepared from p-nitrophenol-grown cells also contained an enzyme that catalyzed the oxidation of 1,2,4-benzenetriol to maleylacetic acid. The enzyme responsible for the oxidation of 1,2,4-benzenetriol was separated from the enzyme responsible for hydroquinone oxidation by DEAE-cellulose chromatography. The results indicate that the pathway for biodegradation of p-nitrophenol involves the initial removal of the nitro group as nitrite and formation of hydroquinone.« less

Toward solar biodiesel production from CO2 using engineered cyanobacteria.

PubMed

Woo, Han Min; Lee, Hyun Jeong

2017-05-01

Metabolic engineering of cyanobacteria has received attention as a sustainable strategy to convert carbon dioxide to various biochemicals including fatty acid-derived biodiesel. Recently, Synechococcus elongatus PCC 7942, a model cyanobacterium, has been engineered to convert CO2 to fatty acid ethyl esters (FAEEs) as biodiesel. Modular pathway has been constructed for FAEE production. Several metabolic engineering strategies were discussed to improve the production levels of FAEEs, including host engineering by improving CO2 fixation rate and photosynthetic efficiency. In addition, protein engineering of key enzyme in S. elongatus PCC 7942 was implemented to address issues on FAEE secretions toward sustainable FAEE production from CO2. Finally, advanced metabolic engineering will promote developing biosolar cell factories to convert CO2 to feasible amount of FAEEs toward solar biodiesel. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Central nervous system considerations in the use of beta-blockers, angiotensin-converting enzyme inhibitors, and thiazide diuretics in managing essential hypertension.

PubMed

Gengo, F M; Gabos, C

1988-07-01

The most common mild side effects occurring with use of beta-blockers, thiazide diuretics, and angiotensin-converting enzyme inhibitors for blood pressure control are central nervous system symptoms, specifically lethargy, sedation, and fatigue. These symptoms affect 5% to 10% of patients taking these drugs. The mechanism by which beta-blockers may induce central nervous system effects is uncertain. Relative lipophilicity as a factor affecting penetrance of the blood-brain barrier has not proved to be a reliable predictor of whether the drug will cause such disturbances. Comparisons of atenolol (hydrophilic) and metoprolol (lipophilic) have shown no differences between these drugs with respect to side effects of the central nervous system. The incidence of central nervous system effects with angiotensin-converting enzyme inhibitors is similar to that for most beta-blockers. The precise role of the angiotensin-converting enzyme in the central nervous system is not well defined. Most thiazide diuretics are not associated with major complications of the central nervous system, although electrolyte imbalance may occasionally lead to complaints of neurologic symptoms. Because the incidence of central nervous system effects with these three classes of drugs is so low, concern for the side effects of the central nervous system is not a prime consideration in the choice of an initial antihypertensive agent.

Molecular and catalytic properties of 2,4'-dihydroxyacetophenone dioxygenase from Burkholderia sp. AZ11.

PubMed

Enya, Mayu; Aoyagi, Keiko; Hishikawa, Yoshihiro; Yoshimura, Azusa; Mitsukura, Koichi; Maruyama, Kiyofumi

2012-01-01

The gene dad encoding 2,4'-dihydroxyacetophenone (DHAP) dioxygenase was cloned from Burkholderia sp. AZ11. The initiation codon GTG was converted to ATG for high-level expression of the enzyme in Escherichia coli. The enzyme was moderately thermostable, and the recombinant enzyme was briefly purified. The enzyme (M(r)=90 kDa) was a homotetramer with a subunit M(r) of 23 kDa. It contained 1.69 mol of non-heme iron, and had a dark gray color. On anaerobic incubation of it with DHAP, the absorption at around 400 nm increased due to the formation of an enzyme-DHAP complex. Multiple sequence alignment suggested that His77, His79, His115, and Glu96 in the cupin fold were possible metal ligands. The apparent K(m) for DHAP and the apparent V(max) were estimated to be 1.60 µM and 6.28 µmol/min/mg respectively. 2-Hydroxyacetophenone was a poor substrate. CuCl(2) and HgCl(2) strongly inhibited the enzyme, while FeSO(4) weakly activated it.

Aβ-degrading enzymes: potential for treatment of Alzheimer disease.

PubMed

Miners, James Scott; Barua, Neil; Kehoe, Patrick Gavin; Gill, Steven; Love, Seth

2011-11-01

There is increasing evidence that deficient clearance of β-amyloid (Aβ) contributes to its accumulation in late-onset Alzheimer disease (AD). Several Aβ-degrading enzymes, including neprilysin (NEP), insulin-degrading enzyme, and endothelin-converting enzyme reduce Aβ levels and protect against cognitive impairment in mouse models of AD. The activity of several Aβ-degrading enzymes rises with age and increases still further in AD, perhaps as a physiological response to minimize the buildup of Aβ. The age- and disease-related changes in expression of more recently recognized Aβ-degrading enzymes (e.g. NEP-2 and cathepsin B) remain to be investigated, and there is strong evidence that reduced NEP activity contributes to the development of cerebral amyloid angiopathy. Regardless of the role of Aβ-degrading enzymes in the development of AD, experimental data indicate that increasing the activity of these enzymes (NEP in particular) has therapeutic potential in AD, although targeting their delivery to the brain remains a major challenge. The most promising current approaches include the peripheral administration of agents that enhance the activity of Aβ-degrading enzymes and the direct intracerebral delivery of NEP by convection-enhanced delivery. In the longer term, genetic approaches to increasing the intracerebral expression of NEP or other Aβ-degrading enzymes may offer advantages.

Childhood Sarcoidosis Presenting as Recurrent Facial Palsy.

PubMed

Passi, Gouri Rao; Arora, Kriti; Gokhale, Narendra

2018-04-15

Recurrent facial palsy in a patient merits investigation for underlying etiology. 8-year-old boy with erythematous itchy skin lesion and recurrent facial palsy. He had a past history of aseptic meningitis and nephrocalcinosis. Raised angiotensin converting enzyme levels, interstitial lung disease on CT chest, and non caseating granulomas on skin biopsy clinched the diagnosis of sarcoidosis. Multisystem involvement and recurrent lower motor facial nerve palsy is a clinical clue for sarcoidosis.

Renal Angiotensin-Converting Enzyme Is Essential for the Hypertension Induced by Nitric Oxide Synthesis Inhibition

PubMed Central

Giani, Jorge F.; Janjulia, Tea; Kamat, Nikhil; Seth, Dale M.; Blackwell, Wendell-Lamar B.; Shah, Kandarp H.; Shen, Xiao Z.; Fuchs, Sebastien; Delpire, Eric; Toblli, Jorge E.; Bernstein, Kenneth E.; McDonough, Alicia A.

2014-01-01

The kidney is an important source of angiotensin-converting enzyme (ACE) in many species, including humans. However, the specific effects of local ACE on renal function and, by extension, BP control are not completely understood. We previously showed that mice lacking renal ACE, are resistant to the hypertension induced by angiotensin II infusion. Here, we examined the responses of these mice to the low-systemic angiotensin II hypertensive model of nitric oxide synthesis inhibition with L-NAME. In contrast to wild-type mice, mice without renal ACE did not develop hypertension, had lower renal angiotensin II levels, and enhanced natriuresis in response to L-NAME. During L-NAME treatment, the absence of renal ACE was associated with blunted GFR responses; greater reductions in abundance of proximal tubule Na+/H+ exchanger 3, Na+/Pi co-transporter 2, phosphorylated Na+/K+/Cl− cotransporter, and phosphorylated Na+/Cl− cotransporter; and greater reductions in abundance and processing of the γ isoform of the epithelial Na+ channel. In summary, the presence of ACE in renal tissue facilitates angiotensin II accumulation, GFR reductions, and changes in the expression levels and post-translational modification of sodium transporters that are obligatory for sodium retention and hypertension in response to nitric oxide synthesis inhibition. PMID:25012170

Reduced endothelin converting enzyme-1 and endothelin-3 mRNA in the developing bowel of male mice may increase expressivity and penetrance of Hirschsprung disease-like distal intestinal aganglionosis.

PubMed

Vohra, Bhupinder P S; Planer, William; Armon, Jennifer; Fu, Ming; Jain, Sanjay; Heuckeroth, Robert O

2007-01-01

Hirschsprung disease (distal intestinal aganglionosis, HSCR) is a multigenic disorder with incomplete penetrance, variable expressivity, and a strong male gender bias. Recent studies demonstrated that these genetic patterns arise because gene interactions determine whether enteric nervous system (ENS) precursors successfully proliferate and migrate into the distal bowel. We now demonstrate that male gender bias in the extent of distal intestinal aganglionosis occurs in mice with Ret dominant-negative mutations (RetDN) that mimic human HSCR. We hypothesized that male gender bias could result from reduced expression of a gene already known to be essential for ENS development. Using quantitative real-time polymerase chain reaction (PCR) we demonstrated reduced levels of endothelin converting enzyme-1 and endothelin-3 mRNA in the male mouse bowel at the time that ENS precursors migrate into the colon. Other HSCR-associated genes are expressed at comparable levels in male and female mice. Testosterone and Mullerian inhibiting substance had no deleterious effect on ENS precursor development, but adding EDN3 peptide to E11.5 male RetDN heterozygous mouse gut explants in organ culture significantly increased the rate of ENS precursor migration through the bowel.

Molecular identification of tuliposide B-converting enzyme: a lactone-forming carboxylesterase from the pollen of tulip.

PubMed

Nomura, Taiji; Murase, Tatsunori; Ogita, Shinjiro; Kato, Yasuo

2015-07-01

6-Tuliposides A (PosA) and B (PosB), which are the major secondary metabolites in tulip (Tulipa gesneriana), are enzymatically converted to the antimicrobial lactonized aglycons, tulipalins A (PaA) and B (PaB), respectively. We recently identified a PosA-converting enzyme (TCEA) as the first reported member of the lactone-forming carboxylesterases. Herein, we describe the identification of another lactone-forming carboxylesterase, PosB-converting enzyme (TCEB), which preferentially reacts with PosB to give PaB. This enzyme was isolated from tulip pollen, which showed high PosB-converting activity. Purified TCEB exhibited greater activity towards PosB than PosA, which was contrary to that of the TCEA. Novel cDNA (TgTCEB1) encoding the TCEB was isolated from tulip pollen. TgTCEB1 belonged to the carboxylesterase family and was approximately 50% identical to the TgTCEA polypeptides. Functional characterization of the recombinant enzyme verified that TgTCEB1 catalyzed the conversion of PosB to PaB with an activity comparable with the native TCEB. RT-qPCR analysis of each part of plant revealed that TgTCEB1 transcripts were limited almost exclusively to the pollen. Furthermore, the immunostaining of the anther cross-section using anti-TgTCEB1 polyclonal antibody verified that TgTCEB1 was specifically expressed in the pollen grains, but not in the anther cells. N-terminal transit peptide of TgTCEB1 was shown to function as plastid-targeted signal. Taken together, these results indicate that mature TgTCEB1 is specifically localized in plastids of pollen grains. Interestingly, PosB, the substrate of TgTCEB1, accumulated on the pollen surface, but not in the intracellular spaces of pollen grains. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Phenylalanine ammonia lyase, enzyme substitution therapy for phenylketonuria, where are we now?

PubMed

Sarkissian, Christineh N; Gámez, Alejandra

2005-12-01

Phenylketonuria (PKU) is an autosomal recessive genetic disorder in which mutations in the phenylalanine-4-hydroxylase (PAH) gene result in an inactive enzyme (PAH, EC 1.14.16.1). The effect is an inability to metabolize phenylalanine (Phe), translating into elevated levels of Phe in the bloodstream (hyperphenylalaninemia). If therapy is not implemented at birth, mental retardation can occur. PKU patients respond to treatment with a low-phenylalanine diet, but compliance with the diet is difficult, therefore the development of alternative treatments is desirable. Enzyme substitution therapy with a recombinant phenylalanine ammonia lyase (PAL) is currently being explored. This enzyme converts Phe to the harmless metabolites, trans-cinnamic acid and trace ammonia. Taken orally and when non-absorbable and protected, PAL lowers plasma Phe in mutant hyperphenylalaninemic mouse models. Subcutaneous administration of PAL results in more substantial lowering of plasma and significant reduction in brain Phe levels, however the metabolic effect is not sustained following repeated injections due to an immune response. We have chemically modified PAL by pegylation to produce a protected form of PAL that possesses better specific activity, prolonged half-life, and reduced immunogenicity in vivo. Subcutaneous administration of pegylated molecules to PKU mice has the desired metabolic response (prolonged reduction in blood Phe levels) with greatly attenuated immunogenicity.

Gestational Protein Restriction Increases Angiotensin II Production in Rat Lung1

PubMed Central

Gao, Haijun; Yallampalli, Uma; Yallampalli, Chandra

2013-01-01

ABSTRACT Gestational protein restriction (PR) alters the renin-angiotensin system in uterine arteries and placentas and elevates plasma levels of angiotensin II in pregnant rats. To date, how PR increases maternal plasma levels of angiotensin II remains unknown. In this study, we hypothesize that the expression and/or the activity of angiotensin I converting enzyme (peptidyl-dipeptidase A) 1 (ACE) in lungs, but not kidneys and blood, largely contribute to elevated plasma angiotensin II levels in pregnant rats subject to gestational PR. Time-scheduled pregnant Sprague-Dawley rats were fed a normal or low-protein diet from Day 3 of pregnancy until euthanized at Day 19 or 22. Expressions of Ace and Ace2 (angiotens in I converting enzyme [peptidyl-dipeptidase A] 2) in lungs and kidneys from pregnant rats by quantitative real-time PCR and Western blotting, and the activities of these proteins in lungs, kidneys, and plasma, were measured. The mRNA levels of Ace and Ace2 in lungs were elevated by PR at both Days 19 and 22 of pregnancy. The abundance of ACE protein in lungs was increased, but ACE2 protein was decreased, by PR. The activities of ACE, but not ACE2, in lungs were increased by PR. PR did not change expressions of Ace and Ace2, the activities of both ACE and ACE2 in kidneys, and the abundance and activity of plasma ACE. These findings suggest that maternal lungs contribute to the elevated plasma levels of angiotensin II by increasing both the expression and the activity of ACE in response to gestational PR. PMID:23365412

EI-2128-1, a novel interleukin-1beta converting enzyme inhibitor produced by Penicillium sp. E-2128.

PubMed

Koizumi, Fumito; Agatsuma, Tsutomu; Ando, Katsuhiko; Kondo, Hidemasa; Saitoh, Yutaka; Matsuda, Yuzuru; Nakanishi, Satoshi

2003-11-01

EI-2128-1, a novel interleukin-1beta converting enzyme (ICE) inhibitor, was isolated from the culture broths of Penicillium sp. E-2128. EI-2128-1 selectively inhibited human recombinant ICE activity with IC50 value of 0.59 microM, without inhibiting elastase and cathepsin B. EI-2128-1 also inhibited mature interleukin-1beta secretion from THP-1 cells induced by LPS with IC50 value of 0.28 microM.

Imbalanced plasma ACE and ACE2 level in the uremic patients with cardiovascular diseases and its change during a single hemodialysis session.

PubMed

Yang, Chung-Wei; Lu, Li-Che; Chang, Chia-Chu; Cho, Ching-Chang; Hsieh, Wen-Yeh; Tsai, Chin-Hung; Lin, Yi-Chang; Lin, Chih-Sheng

2017-11-01

The renin-angiotensin system (RAS) has significant influences on heart and renal disease progression. Angiotensin converting enzyme (ACE) and angiotensin converting enzyme II (ACE2) are major peptidases of RAS components and play counteracting functions through angiotensin II (Ang II)/ATIR and angiotensin-(1-7) (Ang-(1-7))/Mas axis, respectively. There were 360 uremic patients on regular hemodialysis (HD) treatment (inclusive of 119 HD patients with cardiovascular diseases (CVD) and 241 HD patients without CVD and 50 healthy subjects were enrolled in this study. Plasma ACE, ACE2, Ang II and Ang-(1-7) levels of the HD patients were determined. We compared pre-HD levels of plasma ACE, ACE2, Ang II and Ang-(1-7) in the HD patients with and without CVD to those of the controls. The HD patients, particularly those with CVD, showed a significant increase in the levels of ACE and Ang II, whereas ACE2 and Ang-(1-7) levels were lower than those in the healthy controls. Therefore, imbalanced ACE/ACE2 was observed in the HD patients with CVD. In the course of a single HD session, the plasma ACE, ACE/ACE2 and Ang II levels in the HD patients with CVD were increased from pre-HD to post-HD. On the contrary, ACE2 levels were decreased after the HD session. These changes were not detected in the HD patients without CVD. Pathogenically imbalanced circulating ACE/ACE2 was detected in the HD patients, particularly those with CVD. HD session could increase ACE/Ang II/AT1R axis and decrease ACE2/Ang-(1-7)/Mas axis activity in the circulation of HD patients with CVD.

Increased ophthalmic acid production is supported by amino acid catabolism under fasting conditions in mice.

PubMed

Kobayashi, Sho; Lee, Jaeyong; Takao, Toshifumi; Fujii, Junichi

2017-09-23

Glutathione (GSH) plays pivotal roles in antioxidation and detoxification. The transsulfuration pathway, in conjunction with methionine metabolism, produces equimolar amounts of cysteine (Cys) and 2-oxobutyric acid (2OB). The resulting 2OB is then converted into 2-aminobutyric acid (2AB) by a transaminase and is utilized as a substitute for Cys by the GSH-synthesizing machinery to produce ophthalmic acid (OPT). By establishing a method for simultaneously measuring Cys, GSH, and OPT by liquid chromatography-mass spectrometry, we found that fasting causes an elevation in OPT levels in the liver and blood plasma, even though the levels of Cys and GSH are decreased. Autophagy was activated, but the levels of GSH/OPT-synthesizing enzymes remained unchanged. After 6 h of fasting, the mice were given 1% 2AB and/or 5% glucose in the drinking water for an additional 24 h and the above metabolites analyzed. 2AB administration caused an increase in OPT levels, and, when glucose was co-administered with 2AB, the levels of OPT were elevated further but GSH levels were decreased somewhat. These results suggest that, while Cys is utilized for glyconeogenesis under fasting conditions, reaching levels that were insufficient for the synthesis of GSH, 2OB was preferentially converted to 2AB via amino acid catabolism and was utilized as a building block for OPT. Thus the consumption of Cys and the parallel elevation of 2AB under fasting conditions appeared to force γ-glutamylcysteine synthetase to form γ-glutamyl-2AB, despite the fact that the enzyme has a higher Km value for 2AB than Cys. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal oxygen content is increased in healthy subjects after angiotensin-converting enzyme inhibition.

PubMed

Stein, Anna; Goldmeier, Silvia; Voltolini, Sarah; Setogutti, Enio; Feldman, Carlos; Figueiredo, Eduardo; Eick, Renato; Irigoyen, Maria; Rigatto, Katya

2012-07-01

The association between renal hypoxia and the development of renal injury is well established. However, no adequate method currently exists to non-invasively measure functional changes in renal oxygenation in normal and injured patients. R2* quantification was performed using renal blood oxygen level-dependent properties. Five healthy normotensive women (50 ± 5.3 years) underwent magnetic resonance imaging in a 1.5T Signa Excite HDx scanner (GE Healthcare, Waukesha, WI). A multiple fast gradient-echo sequence was used to acquire R2*/T2* images (sixteen echoes from 2.1 ms/slice to 49.6 ms/slice in a single breath hold per location). The images were post-processed to generate R2* maps for quantification. Data were recorded before and at 30 minutes after the oral administration of an angiotensin II-converting enzyme inhibitor (captopril, 25 mg). The results were compared using an ANOVA for repeated measurements (mean + standard deviation) followed by the Tukey test. ClinicalTrials.gov: NCT01545479. A significant difference (p<0.001) in renal oxygenation (R2*) was observed in the cortex and medulla before and after captopril administration: right kidney, cortex = 11.08 ± 0.56 ms, medulla = 17.21 ± 1.47 ms and cortex = 10.30 ± 0.44 ms, medulla = 16.06 ± 1.74 ms, respectively; and left kidney, cortex= 11.79 ± 1.85 ms, medulla = 17.03 ± 0.88 ms and cortex = 10.89 ± 0.91 ms, medulla = 16.43 ± 1.49 ms, respectively. This result suggests that the technique efficiently measured alterations in renal blood oxygenation after angiotensin II-converting enzyme inhibition and that it may provide a new strategy for identifying the early stages of renal disease and perhaps new therapeutic targets.

ANGIOTENSIN CONVERTING ENZYME INHIBITION AND NOVEL CARDIOVASCULAR RISK BIOMARKERS

PubMed Central

Cesari, Matteo; Kritchevsky, Stephen B.; Atkinson, Hal H.; Penninx, Brenda W.; Di Bari, Mauro; Tracy, Russell P.; Pahor, Marco

2015-01-01

Background Beneficial effects of angiotensin converting enzyme (ACE) inhibitors seem to be mediated by mechanisms that are partly independent of blood pressure lowering. The present study evaluates effects of an ACE-inhibitor (i.e. fosinopril) intervention on novel cardiovascular risk factors. Methods Data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN), a double-blind, crossover, randomized, placebo-controlled trial enrolling subjects aged ≥55 years and older with high cardiovascular disease risk profile. Biomarkers of hemostasis (i.e. plasminogen activator inhibitor-1 [PAI-1], D-dimer), inflammation (i.e. C-reactive protein [CRP], interleukin-6 [IL-6]), and endothelial function (i.e. endothelin-1, vascular cell adhesion molecule-1 [VCAM-1]) were measured at the baseline, at the mid-term, and at end of follow-up (after one year) clinic visits. Paired t-test analyses (after Sidak’s adjustment, p value<0.009) were performed to compare biomarkers modifications after fosinopril/placebo interventions. Results Mean age of the sample (n=290, women 43.4%) was 66.0 years old. No significant differences were reported for CRP, IL-6, PAI-1, VCAM-1, and endothelin-1 levels in the comparisons between fosinopril and placebo interventions. D-Dimer was the only biomarker showing a significant difference between fosinopril intervention (median 0.32 [interquartile range, IQR 0.22–0.52] µg/mL) and placebo (median 0.29 [IQR 0.20–0.47] µg/mL, p=0.007) when analyses were restricted to participants with higher compliance to treatment and receiving the maximum ACE-inhibitor dosage. Conclusions ACE-inhibition does not significantly modify major biomarkers of inflammation, hemostasis, and endothelial function. Further studies should confirm the possible effect of ACE-inhibitors on the fibrinolysis pathway. PMID:19185642

Prescribing patterns and adherence to medication among South-Asian, Chinese and white people with type 2 diabetes mellitus: a population-based cohort study.

PubMed

Chong, E; Wang, H; King-Shier, K M; Quan, H; Rabi, D M; Khan, N A

2014-12-01

To determine the prescribing of and adherence to oral hypoglycaemic agents, insulin, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and statin therapy among South-Asian, Chinese and white people with newly diagnosed diabetes. The present study was a population-based cohort study using administrative and pharmacy databases to include all South-Asian, Chinese and white people aged ≥ 35 years with diabetes living in British Columbia, Canada (1997-2006). Adherence to each class of medication was measured using proportion of days covered over 1 year with optimum adherence defined as ≥ 80%. The study population included 9529 South-Asian, 14 084 Chinese and 143 630 white people with diabetes. The proportion of people who were prescribed angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statin or oral hypoglycaemic agents was ≤ 50% for all groups. South-Asian and Chinese people had significantly lower adherence for all medications than white people, with the lowest adherence to angiotensin-converting enzyme inhibitor treatment (South-Asian people: adjusted odds ratio 0.37, 95% CI 0.34-0.39; P<0.0001; Chinese people: adjusted odds ratio 0.50, 95% CI 0.47-0.54; P<0.0001) and statin therapy (South-Asian people: adjusted odds ratio 0.47, 95% CI 0.41 - 0.53, P < 0.0001; Chinese people: adjusted odds ratio 0.72, 95% CI 0.67 - 0.77; P<0.0001) compared with white people. Adherence to evidence-based pharmacotherapy was substantially worse among the South-Asian and Chinese populations. Care providers need to be alerted to the high levels of non-adherence in these groups and the underlying causes need to be investigated. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

Polymorphisms of apolipoprotein E and angiotensin-converting enzyme genes and carotid atherosclerosis in heavy drinkers.

PubMed

Bednarska-Makaruk, Małgorzata; Rodo, Maria; Markuszewski, Cezary; Rozenfeld, Anna; Swiderska, Malgorzata; Habrat, Bogusław; Wehr, Hanna

2005-01-01

To investigate the influence of apolipoprotein E (APOE) and angiotensin-converting enzyme (ACE) gene polymorphisms on carotid artery atherosclerosis in alcoholism. Polymorphism of both genes was identified by DNA analysis in 130 male alcohol-dependent patients. Intima-media thickness (IMT) was measured ultrasonographically. Multivariate regression analysis showed that of all the known risk factors the greatest impact on carotid atherosclerosis in alcoholics was exerted by age, hypertension, LDL cholesterol and fasting plasma glucose levels. Subjects carrying the APO E epsilon4 allele were more liable to develop atherosclerotic changes in carotid arteries compared with subjects with the epsilon3/3 genotype, which showed statistical significance in patients under 50 years of age. No association was shown between ACE I/D polymorphism and carotid atherosclerosis. APO E polymorphism can increase the risk of carotid atherosclerosis development in an alcoholic subject. The association of the APO E epsilon4 allele with carotid atherosclerosis was significant in younger patients. Since the elevated carotid IMT is considered to be a good marker of increased risk of generalized atherosclerosis the consequences could involve both cardiac and cerebrovascular events.

The angiotensin-converting-enzyme insertion/deletion polymorphism is not related to venous thrombosis.

PubMed

Köppel, Herwig; Renner, Wilfried; Gugl, Alexander; Cichocki, Lisa; Gasser, Robert; Wascher, Thomas C; Pilger, Ernst

2004-01-01

The insertion/deletion (I/D) polymorphism of the gene for angiotensin-converting-enzyme (ACE) is associated with ACE plasma levels and activity. Conflicting results have been reported about the relevance of this polymorphism for venous thrombosis. The aim of the present study was to analyze the role of this polymorphism for deep venous thrombosis. The study was designed as a case-control study, including 330 patients with documented deep venous thrombosis and 354 controls. ACE genotype was determined by size-analysis of polymerase chain reaction products. Results showed that, ACE genotype frequencies were similar between patients (II: 24.8%; ID: 43.3%; DD: 31.8%) and controls (II: 22.9%; ID: 50.6%; DD: 26.6%, P = 0.15). The adjusted odds ratio of carriers of the DD geno-type for venous thrombosis was 1.24 (95% confidence interval 0.90-1.80). The polymorphism was furthermore not associated with age at first thromboembolic event or the occurrence of pulmonary embolism. From these results, we can conclude that the ACE I/D polymorphism is not a significant risk factor for deep venous thrombosis.

Angiotensin-converting enzyme gene polymorphisms and hypertension in occupational noise exposure in Egypt

PubMed Central

Zawilla, Nermin; Shaker, Dalia; Abdelaal, Amaal; Aref, Wael

2014-01-01

Background: The gene–environment interaction in the pathogenesis of hypertension has not been extensively studied in occupational noise. Objectives: The aim of this study was to determine the relationship between noise and hypertension in Egyptian workers, the interaction of angiotensin-converting enzyme (ACE) gene polymorphisms as modifiers, and the possible relationship between noise hearing impairment and hypertension. Methods: Study subjects were divided into two groups depending on noise exposure level. The control group (n = 161) was exposed to noise intensity <85 dB and the exposed group (n = 217) was exposed to noise intensity ≧85 dB. A polymerase chain reaction was used to differentiate the various genotypes of ACE insertion/deletion (I/D) and ACE G2350A. Results: Noise significantly increased the likelihood of hypertension. Carriers of the genotypes AG, GG, and DD were vulnerable to hypertension on noise exposure. No association between hypertension and hearing impairment or noise-induced hearing loss (NIHL) was found. Conclusion: Our results support the association between ACE gene polymorphisms and occurrence of hypertension in noise-exposed workers. PMID:25000107

21 CFR 184.1388 - Lactase enzyme preparation from Kluyveromyces lactis.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) This enzyme preparation is derived from the nonpathogenic, nontoxicogenic yeast Kluyveromyces lactis... 683), which converts lactose to glucose and galactose. It is prepared from yeast that has been grown...

More Nuts and Bolts of Michaelis-Menten Enzyme Kinetics

ERIC Educational Resources Information Center

Lechner, Joseph H.

2011-01-01

Several additions to a classroom activity are proposed in which an "enzyme" (the student) converts "substrates" (nut-bolt assemblies) into "products" (separated nuts and bolts) by unscrewing them. (Contains 1 table.)

Non-specific activities of the major herbicide-resistance gene BAR.

PubMed

Christ, Bastien; Hochstrasser, Ramon; Guyer, Luzia; Francisco, Rita; Aubry, Sylvain; Hörtensteiner, Stefan; Weng, Jing-Ke

2017-12-01

Bialaphos resistance (BAR) and phosphinothricin acetyltransferase (PAT) genes, which convey resistance to the broad-spectrum herbicide phosphinothricin (also known as glufosinate) via N-acetylation, have been globally used in basic plant research and genetically engineered crops 1-4 . Although early in vitro enzyme assays showed that recombinant BAR and PAT exhibit substrate preference toward phosphinothricin over the 20 proteinogenic amino acids 1 , indirect effects of BAR-containing transgenes in planta, including modified amino acid levels, have been seen but without the identification of their direct causes 5,6 . Combining metabolomics, plant genetics and biochemical approaches, we show that transgenic BAR indeed converts two plant endogenous amino acids, aminoadipate and tryptophan, to their respective N-acetylated products in several plant species. We report the crystal structures of BAR, and further delineate structural basis for its substrate selectivity and catalytic mechanism. Through structure-guided protein engineering, we generated several BAR variants that display significantly reduced non-specific activities compared with its wild-type counterpart in vivo. The transgenic expression of enzymes can result in unintended off-target metabolism arising from enzyme promiscuity. Understanding such phenomena at the mechanistic level can facilitate the design of maximally insulated systems featuring heterologously expressed enzymes.

Investigation into the Mechanism of Homo- and Heterodimerization of Angiotensin-Converting Enzyme.

PubMed

Abrie, J Albert; Moolman, Wessel J A; Cozier, Gyles E; Schwager, Sylva L; Acharya, K Ravi; Sturrock, Edward D

2018-04-01

Angiotensin-converting enzyme (ACE) plays a central role in the renin-angiotensin system (RAS), which is primarily responsible for blood pressure homeostasis. Studies have shown that ACE inhibitors yield cardiovascular benefits that cannot be entirely attributed to the inhibition of ACE catalytic activity. It is possible that these benefits are due to interactions between ACE and RAS receptors that mediate the protective arm of the RAS, such as angiotensin II receptor type 2 (AT 2 R) and the receptor MAS. Therefore, in this study, we investigated the molecular interactions of ACE, including ACE homodimerization and heterodimerization with AT 2 R and MAS, respectively. Molecular interactions were assessed by fluorescence resonance energy transfer and bimolecular fluorescence complementation in human embryonic kidney 293 cells and Chinese hamster ovary-K1 cells transfected with vectors encoding fluorophore-tagged proteins. The specificity of dimerization was verified by competition experiments using untagged proteins. These techniques were used to study several potential requirements for the germinal isoform of angiotensin-converting enzyme expressed in the testes (tACE) dimerization as well as the effect of ACE inhibitors on both somatic isoforms of angiotensin-converting enzyme expressed in the testes (sACE) and tACE dimerization. We demonstrated constitutive homodimerization of sACE and of both of its domains separately, as well as heterodimerization of both sACE and tACE with AT 2 R, but not MAS. In addition, we investigated both soluble sACE and the sACE N domain using size-exclusion chromatography-coupled small-angle X-ray scattering and we observed dimers in solution for both forms of the enzyme. Our results suggest that ACE homo- and heterodimerization does occur under physiologic conditions. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

Systematic comparison of co-expression of multiple recombinant thermophilic enzymes in Escherichia coli BL21(DE3).

PubMed

Chen, Hui; Huang, Rui; Zhang, Y-H Percival

2017-06-01

The precise control of multiple heterologous enzyme expression levels in one Escherichia coli strain is important for cascade biocatalysis, metabolic engineering, synthetic biology, natural product synthesis, and studies of complexed proteins. We systematically investigated the co-expression of up to four thermophilic enzymes (i.e., α-glucan phosphorylase (αGP), phosphoglucomutase (PGM), glucose 6-phosphate dehydrogenase (G6PDH), and 6-phosphogluconate dehydrogenase (6PGDH)) in E. coli BL21(DE3) by adding T7 promoter or T7 terminator of each gene for multiple genes in tandem, changing gene alignment, and comparing one or two plasmid systems. It was found that the addition of T7 terminator after each gene was useful to decrease the influence of the upstream gene. The co-expression of the four enzymes in E. coli BL21(DE3) was demonstrated to generate two NADPH molecules from one glucose unit of maltodextrin, where NADPH was oxidized to convert xylose to xylitol. The best four-gene co-expression system was based on two plasmids (pET and pACYC) which harbored two genes. As a result, apparent enzymatic activities of the four enzymes were regulated to be at similar levels and the overall four-enzyme activity was the highest based on the formation of xylitol. This study provides useful information for the precise control of multi-enzyme-coordinated expression in E. coli BL21(DE3).

EFFECT OF SYSTEMIC BETA-BLOCKERS, ACE INHIBITORS, AND ANGIOTENSIN RECEPTOR BLOCKERS ON DEVELOPMENT OF CHOROIDAL NEOVASCULARIZATION IN PATIENTS WITH AGE-RELATED MACULAR DEGENERATION.

PubMed

Thomas, Akshay S; Redd, Travis; Hwang, Thomas

2015-10-01

Recent studies have suggested that the use of systemic beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers can induce regression of choroidal neovascularization in rodent models. The purpose of this study is to evaluate if these agents have a protective effect against the development of choroidal neovascularization in patients with age-related macular degeneration. In this single-center retrospective case-control study, the charts of 250 patients with neovascular age-related macular degeneration were compared with those of 250 controls with dry age-related macular degeneration. Charts were reviewed for current and past use of beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers. Frequency tables were generated, and associations were examined using chi-square tests, t-tests, and multivariate logistic regression. There was no statistically significant difference between rates of beta-blocker use (P = 0.57), angiotensin-converting enzyme inhibitors use (P = 0.20), or angiotensin receptor blockers use (P = 0.61) between the 2 groups. Additionally, there was no statistically significant difference between rates of use of combinations of the above drugs between the two groups. Although there is growing evidence that beta-blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers can induce regression of choroidal neovascularization in rodent models, these medications do not seem to confer a protective effect against the development of choroidal neovascularization in patients with age-related macular degeneration.

Polymorphism of angiotensin-converting enzyme gene in sarcoidosis.

PubMed

Arbustini, E; Grasso, M; Leo, G; Tinelli, C; Fasani, R; Diegoli, M; Banchieri, N; Cipriani, A; Gorrini, M; Semenzato, G; Luisetti, M

1996-02-01

Sarcoidosis is the disease in which increased levels of serum Angiotensin-converting enzyme (sACE) are most often detected. It has recently been shown that the deletion (D) or the insertion (I) of a 250bp-DNA fragment in the ACE gene accounts for three main ACE genotypes (i.e., II, ID, and DD) and for 47% of total phenotypic variance in sACE level. The aim of our work was to investigate whether or not patients with sarcoidosis have an increased incidence of those ACE genotypes coding for highest sACE levels and to investigate whether or not sACE level in sarcoidosis is related to ACE genotypes. We studied 61 unrelated patients with sarcoidosis (test group) and 80 unrelated healthy control subjects (control group). The ACE I and D alleles were detected with polymerase chain reaction on genomic DNA. In the control group we found an ACE genotype distribution that agreed with the Hardy-Weinberg proportion. The ACE genotype distribution was not significantly different in the test group. There was no correlation between ACE genotype and roentgenologic stage of sarcoidosis. Plotting the sACE level in the control group against ACE genotype, we found a trend of increasing mean sACE value according to the order II < ID < DD. The same trend for ACE genotype was found in the test group, in which it also paralleled the trend of sACE values plotted against roentgenologic stage, according to the order Stage I < Stage II < Stage III. We conclude that in sarcoidosis the ACE genotype distribution is not altered. The trends for increasing sACE values in sarcoidosis according to both ACE genotype and roentgenologic stage would suggest that both mechanisms play a role in determining sACE level.

Serum soluble interleukin-2 receptor level is more sensitive than angiotensin-converting enzyme or lysozyme for diagnosis of sarcoidosis and may be a marker of multiple organ involvement.

PubMed

Thi Hong Nguyen, Chuyen; Kambe, Naotomo; Kishimoto, Izumi; Ueda-Hayakawa, Ikuko; Okamoto, Hiroyuki

2017-07-01

Skin lesions in sarcoidosis are often the initial symptoms that enable the dermatologist to be the first to diagnose this granulomatosis. However, diagnosis is sometimes very problematic. In 2015, the diagnostic criteria for sarcoidosis were updated in Japan, with elevated serum soluble interleukin-2 receptor (sIL-2R) replacing negative tuberculin reaction. Therefore, we assessed the clinical utility of sIL-2R compared with two other common markers, angiotensin-converting enzyme (ACE) and lysozyme, in patients who visited the dermatology clinic. Data from 72 patients showed that sIL-2R was more sensitive than both ACE and lysozyme in supporting a diagnosis of sarcoidosis (52.8%) compared with ACE (29%) and lysozyme (26.4%). Additionally, the sIL-2R level was significantly higher in patients with multiple organ involvement and parenchymal infiltration. Patients with elevated sIL-2R levels had higher serum ACE and lysozyme levels, a higher incidence of pulmonary involvement, more severe chest radiographic stage and a high incidence of expression-specific signs by imaging analysis. Receiver-operator curve analysis showed that sIL-2R was a better marker at the threshold cut-off point compared with ACE and lysozyme for identifying patients with multiple organ involvement, detecting patients with pulmonary disease and parenchymal infiltration as well as predicting the presence of specific signs in the diagnosis of sarcoidosis. Moreover, the kinetics of sIL-2R levels correlated closely with clinical manifestations, in contrast to the modest changes of ACE and lysozyme levels during the follow-up period. In conclusion, sIL-2R may be considered a good marker for diagnosis and a potential indicator of disease activity. © 2017 Japanese Dermatological Association.

21 CFR 184.1387 - Lactase enzyme preparation from Candida pseudotropicalis.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., nontoxicogenic yeast C. pseudotropicalis. It contains the enzyme lactase (β-D-galactoside galactohydrolase, EC 3.2.1.23), which converts lactose to glucose and galactose. It is prepared from yeast that has been...

21 CFR 184.1387 - Lactase enzyme preparation from Candida pseudotropicalis.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., nontoxicogenic yeast C. pseudotropicalis. It contains the enzyme lactase (β-D-galactoside galactohydrolase, EC 3.2.1.23), which converts lactose to glucose and galactose. It is prepared from yeast that has been...

Genetics Home Reference: Crigler-Najjar syndrome

MedlinePlus

... from the body only after it undergoes a chemical reaction in the liver, which converts the toxic form ... the body. The bilirubin-UGT enzyme performs a chemical reaction called glucuronidation. During this reaction, the enzyme transfers ...

Penicillium subrubescens is a promising alternative for Aspergillus niger in enzymatic plant biomass saccharification.

PubMed

Mäkelä, Miia R; Mansouri, Sadegh; Wiebenga, Ad; Rytioja, Johanna; de Vries, Ronald P; Hildén, Kristiina S

2016-12-25

In industrial applications, efficient mixtures of polysaccharide-degrading enzymes are needed to convert plant biomass into fermentable sugars. Most of the commercially produced lignocellulolytic enzymes are from a limited number of filamentous fungi, such as Trichoderma and Aspergillus species. In contrast, the plant biomass-degrading capacity of Penicillia has been less explored. We performed growth profiling of several Penicillia on diverse plant biomass-related substrates demonstrating the capacity particularly of Penicillium subrubescens to degrade crude lignocellulose feedstock, as well as polysaccharides, and metabolise their monomeric components. We focussed on the lignocellulolytic potential of P. subrubescens FBCC1632, which produced a variable set of (hemi-)cellulolytic activities on plant biomass substrates with activity levels comparable to those of Aspergillus niger. The good ability of the extracellular enzyme mixtures produced by P. subrubescens to saccharify complex plant biomasses, wheat bran and sugar beet pulp, indicated a high potential for this strain as a producer of industrial enzyme cocktails. Copyright © 2016 Elsevier B.V. All rights reserved.

In silico prediction of potential chemical reactions mediated by human enzymes.

PubMed

Yu, Myeong-Sang; Lee, Hyang-Mi; Park, Aaron; Park, Chungoo; Ceong, Hyithaek; Rhee, Ki-Hyeong; Na, Dokyun

2018-06-13

Administered drugs are often converted into an ineffective or activated form by enzymes in our body. Conventional in silico prediction approaches focused on therapeutically important enzymes such as CYP450. However, there are more than thousands of different cellular enzymes that potentially convert administered drug into other forms. We developed an in silico model to predict which of human enzymes including metabolic enzymes as well as CYP450 family can catalyze a given chemical compound. The prediction is based on the chemical and physical similarity between known enzyme substrates and a query chemical compound. Our in silico model was developed using multiple linear regression and the model showed high performance (AUC = 0.896) despite of the large number of enzymes. When evaluated on a test dataset, it also showed significantly high performance (AUC = 0.746). Interestingly, evaluation with literature data showed that our model can be used to predict not only enzymatic reactions but also drug conversion and enzyme inhibition. Our model was able to predict enzymatic reactions of a query molecule with a high accuracy. This may foster to discover new metabolic routes and to accelerate the computational development of drug candidates by enabling the prediction of the potential conversion of administered drugs into active or inactive forms.

Targeted enzyme prodrug therapies.

PubMed

Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

2010-09-01

The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

Identification of amino acid residues in Streptococcus mutans glucosyltransferases influencing the structure of the glucan product.

PubMed Central

Shimamura, A; Nakano, Y J; Mukasa, H; Kuramitsu, H K

1994-01-01

The glucosyltransferases (GTFs) of mutans streptococci are important virulence factors in the sucrose-dependent colonization of tooth surfaces by these organisms. To investigate the structure-function relationship of the GTFs, an approach was initiated to identify amino acid residues of the GTFs which affect the incorporation of glucose residues into the glucan polymer. Conserved amino acid residues were identified in the GTF-S and GTF-I enzymes of the mutans streptococci and were selected for site-directed mutagenesis in the corresponding enzymes from Streptococcus mutans GS5. Conversion of six amino acid residues of the GTF-I enzyme to those present at the corresponding positions in GTF-S, either singly or in multiple combinations, resulted in enzymes synthesizing increased levels of soluble glucans. The enzyme containing six alterations synthesized 73% water-soluble glucan in the absence of acceptor dextran T10, while parental enzyme GTF-I synthesized no such glucan product. Conversely, when residue 589 of the GTF-S enzyme was converted from Thr to either Asp or Glu, the resulting enzyme synthesized primarily water-insoluble glucan in the absence of the acceptor. Therefore, this approach has identified several amino acid positions which influence the nature of the glucan product synthesized by GTFs. PMID:8050997

Potential utility of natural products as regulators of breast cancer-assoicated aromatase promoters

USDA-ARS?s Scientific Manuscript database

Aromatase, the key enzyme in estrogen biosynthesis, converts androstenedione to estrone and testosterone to estradiol. The enzyme is expressed in various tissues such as ovary, placenta, bone, brain, skin, and adipose tissue. Aromatase enzyme is encoded by a single gene CYP 19A1 and its expression i...

The Nuts and Bolts of Michaelis-Menten Enzyme Kinetics: Suggestions and Clarifications

ERIC Educational Resources Information Center

Silverstein, Todd

2011-01-01

Matthew Junker's recent article describes a useful and effective enzyme kinetics application and analogy in which students simulate enzyme activity by unscrewing nut-bolt "substrate molecules", thus, converting them into separate nuts and bolts "products". A number of suggestions and corrections are presented that improve the clarity and accuracy…

Efficient conversion of mannitol derived from brown seaweed to fructose for fermentation with a thraustochytrid.

PubMed

Tajima, Takahisa; Tomita, Kousuke; Miyahara, Hiroyuki; Watanabe, Kenshi; Aki, Tsunehiro; Okamura, Yoshiko; Matsumura, Yukihiko; Nakashimada, Yutaka; Kato, Junichi

2018-02-01

Macroalgae are a promising biomass feedstock for energy and valuable chemicals. Mannitol and alginate are the major carbohydrates found in the microalga Laminaria japonica (Konbu). To convert mannitol to fructose for its utilization as a carbon source in mannitol non-assimilating bacteria, a psychrophile-based simple biocatalyst (PSCat) was constructed using a psychrophile as a host by expressing mesophilic enzymes, including mannitol 2-dehydrogenase for mannitol oxidation, and NADH oxidase and alkyl hydroxyperoxide reductase for NAD + regeneration. PSCat was treated at 40 °C to inactivate the psychrophilic enzymes responsible for byproduct formation and to increase the membrane permeability of the substrate. PSCat efficiently converted mannitol to fructose with high conversion yield without additional input of NAD + . Konbu extract containing mannitol was converted to fructose with hydroperoxide scavenging, inhibiting the mannitol dehydrogenase activity. Auranthiochytrium sp. could grow well in the presence of fructose converted by PSCat. Thus, PSCat is a potential carbohydrate converter for mannitol non-assimilating microorganism. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Association between angiotensin II receptor gene polymorphism and serum angiotensin converting enzyme (SACE) activity in patients with sarcoidosis.

PubMed

Takemoto, Y; Sakatani, M; Takami, S; Tachibana, T; Higaki, J; Ogihara, T; Miki, T; Katsuya, T; Tsuchiyama, T; Yoshida, A; Yu, H; Tanio, Y; Ueda, E

1998-06-01

Serum angiotensin converting enzyme (SACE) is considered to reflect disease activity in sarcoidosis. SACE activity is increased in many patients with active sarcoid lesions. The mechanism for the increased SACE activity in this disease has not been clarified. ACE insertion/deletion (I/D) gene polymorphism has been reported to have an association with SACE levels in sarcoidosis, but no evidence of an association between angiotensin II receptor gene polymorphism and SACE in this disease has been found. A study of the association of angiotensin II receptor gene polymorphisms with sarcoidosis was therefore undertaken. ACE (I/D), angiotensin II type 1 receptor (AGTR1), and angiotensin II type 2 receptor (AGTR2) gene polymorphisms were investigated by polymerase chain reaction (PCR) and SACE levels were measured in three groups of patients: those with sarcoidosis or tuberculosis and normal controls. There was no difference in allele frequency of AGTR1 and AGTR2 polymorphism among the three groups. Neither AGTR1 nor AGTR2 polymorphisms were associated with sarcoidosis. SACE activity was higher in patients with sarcoidosis with the AGTR1 A/C genotype than in others. However, this tendency was not detected in patients with tuberculosis. The AGTR1 allele C is associated with high activity of SACE in patients with sarcoidosis. It is another predisposing factor for high levels of SACE in patients with sarcoidosis and is considered to be an independent factor from the ACE D allele for high levels of SACE in sarcoidosis. This fact could be one of the explanations for the increased SACE activity in sarcoidosis.

Angiotensin converting enzyme (ACE) gene expression in experimentally induced liver cirrhosis in rats.

PubMed

Shahid, Syed Muhammad; Fatima, Syeda Nuzhat; Mahboob, Tabassum

2013-09-01

Angiotensin converting enzyme (ACE) is a key player of Renin Angiotensin System (RAS), involved in conversion of active product, angiotensin-II. Alterations in RAS have been implicated in the pathophysiology of various diseases involving heart, kidney, lung and liver. This study is designed to investigate the association of ACE gene expression in induction of liver cirrhosis in rats. Total 12 male albino Wistar rats were selected and divided in two groups. Control group received 0.9% NaCl, where as Test group received thioacidamide (TAA), dissolved in 0.9%NaCl, injected intraperitoneally at a dosage of 200mg/Kg of body weight, twice a week for 12 weeks. The rats were decapitated and blood sample was collected at the end of experimental period and used for liver functions, enzyme activity, antioxidant enzymes and lipid peroxidation estimations. Genomic DNA was isolated from excised tissue determine the ACE genotypes using specific primers. The ACE gene expression in liver tissue was assessed using the quantitative RT-PCR method. The activity of ALT, total and direct bilirubin, SOD and CAT levels were significantly high (p<0.05) and level of MDA was significantly low (p<0.05) in TAA treated rats as compared to control rats. The ACE gene expression after 12 weeks TAA treatment in cirrhotic rats was significantly increased (p<0.05) in comparison to controls. This study describes the importance of RAS in the development of hepatic fibrosis and the benefits of modulation of this system ACE gene expression. The finding of major up-regulation of ACE in the experimental rat liver provides further insight into the complexities of the RAS and its regulation in liver injury. The development of specific modulators of ACE activity and function, in future, will help determine the role of ACE and its genetic variants in the pathophysiology of liver disease.

Improvement on sugar cane bagasse hydrolysis using enzymatic mixture designed cocktail.

PubMed

Bussamra, Bianca Consorti; Freitas, Sindelia; Costa, Aline Carvalho da

2015-01-01

The aim of this work was to study cocktail supplementation for sugar cane bagasse hydrolysis, where the enzymes were provided from both commercial source and microorganism cultivation (Trichoderma reesei and genetically modified Escherichia coli), followed by purification. Experimental simplex lattice mixture design was performed to optimize the enzymatic proportion. The response was evaluated through hydrolysis microassays validated here. The optimized enzyme mixture, comprised of T. reesei fraction (80%), endoglucanase (10%) and β-glucosidase (10%), converted, theoretically, 72% of cellulose present in hydrothermally pretreated bagasse, whereas commercial Celluclast 1.5L converts 49.11%±0.49. Thus, a rational enzyme mixture designed by using synergism concept and statistical analysis was capable of improving biomass saccharification. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigating a Bio-Engineered Enzyme.

ERIC Educational Resources Information Center

Bullerwell, Lornie; And Others

1994-01-01

Describes science experiments with the enzyme lactose, which is available commercially as Lactaid and Dairy Ease. Experiments show how the rate of reaction of lactose converted to glucose and galactose is influenced by temperature, pH, and substrate concentration. (PR)

Enzymatic activity and partial purification of solanapyrone synthase: first enzyme catalyzing Diels-Alder reaction.

PubMed

Katayama, K; Kobayashi, T; Oikawa, H; Honma, M; Ichihara, A

1998-05-19

In cell-free extracts of Alternaria solani, an enzymatic activity converting prosolanapyrone II to solanapyrones A and D via oxidation and subsequent Diels-Alder reaction has been found. Chromatography with DEAE-Sepharose provided two active fractions, pools 1 and 2. The former fraction converted prosolanapyrone II to solanapyrones A and D in a ratio of 2.2:1 with optical purities of 99% and 45% ee, respectively. The latter fraction did so in a ratio of 7.6:1 with 99% and nearly 0% ee, respectively. The enzyme partially purified from pool 2 native molecular weight of 40-62 kD and a pl of 4.25. The high reactivity of prosolanapyrone III in aqueous solution and the chromatographic behavior of the enzyme in pool 2 suggest that a single enzyme catalyzes both the oxidation and Diels-Alder reaction.

Biocatalysis for the production of industrial products and functional foods from rice and other agricultural produce.

PubMed

Akoh, Casimir C; Chang, Shu-Wei; Lee, Guan-Chiun; Shaw, Jei-Fu

2008-11-26

Many industrial products and functional foods can be obtained from cheap and renewable raw agricultural materials. For example, starch can be converted to bioethanol as biofuel to reduce the current demand for petroleum or fossil fuel energy. On the other hand, starch can also be converted to useful functional ingredients, such as high fructose and high maltose syrups, wine, glucose, and trehalose. The conversion process involves fermentation by microorganisms and use of biocatalysts such as hydrolases of the amylase superfamily. Amylases catalyze the process of liquefaction and saccharification of starch. It is possible to perform complete hydrolysis of starch by using the fusion product of both linear and debranching thermostable enzymes. This will result in saving energy otherwise needed for cooling before the next enzyme can act on the substrate, if a sequential process is utilized. Recombinant enzyme technology, protein engineering, and enzyme immobilization are powerful tools available to enhance the activity of enzymes, lower the cost of enzyme through large scale production in a heterologous host, increase their thermostability, improve pH stability, enhance their productivity, and hence making it competitive with the chemical processes involved in starch hydrolysis and conversions. This review emphasizes the potential of using biocatalysis for the production of useful industrial products and functional foods from cheap agricultural produce and transgenic plants. Rice was selected as a typical example to illustrate many applications of biocatalysis in converting low-value agricultural produce to high-value commercial food and industrial products. The greatest advantages of using enzymes for food processing and for industrial production of biobased products are their environmental friendliness and consumer acceptance as being a natural process.

A human lung mast cell chymotrypsin-like enzyme. Identification and partial characterization.

PubMed

Wintroub, B U; Kaempfer, C E; Schechter, N M; Proud, D

1986-01-01

We have used a high performance liquid chromatography assay, which detects chymotryptic cleavage of the phe8-his9 bond of angiotensin I to yield angiotensin II, in order to examine human lung mast cells for the presence of chymotryptic activity. Mast cells, purified from human lung by enzymatic dispersion, countercurrent elutriation, and Percoll gradient centrifugation, were lysed or challenged with goat anti-human IgE. In multiple experiments angiotensin II-converting activity was detected in lysates of 10-99% pure mast cell preparations. Regression analysis of net percent release values of histamine and the angiotensin I-converting activity from dose-response experiments demonstrated a correlation between the two parameters, indicating that the chymotrypsin-like enzyme is a constituent of the mast cell secretory granule. The chymotryptic activity was completely inhibited by 10(-3) M phenylmethylsulfonylfluoride but not by 10(-3) M Captopril, and the pH optimum of activity was 7.5-9.5. Gel filtration of released material separated the activity from tryptase and demonstrated an approximate molecular weight of 30-35,000. The mast cell enzyme, like a human skin chymotrypsin-like proteinase, can be distinguished from leukocyte cathepsin G by lack of susceptibility to inhibition by bovine pancreatic trypsin inhibitor. Thus, an enzyme with limited chymotryptic specificity is present in human lung mast cells. The Michaelis constant of the enzyme for angiotensin I of 6.0 X 10(-5) M is similar to that of endothelial cell angiotensin-converting enzyme and is consistent with a reaction of physiologic importance.

Relation of Angiotensin-Converting Enzyme Inhibitor Treatment to Insulin-Like Growth Factor-1 Serum Levels in Subjects >65 Years of Age (the InCHIANTI Study)

PubMed Central

Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Pahor, Marco; Bandinelli, Stefania; Najjar, Samer S.; Ling, Shari M.; Basaria, Shehzad; Ruggiero, Carmelinda; Valenti, Giorgio; Ferrucci, Luigi

2009-01-01

Observational studies have shown that the use of angiotensin-converting enzyme (ACE) inhibitors is associated with the maintenance of greater muscle strength and physical performance in older subjects. However, the mechanism that underlies these beneficial effects remains poorly understood. Because ACE inhibitors block the production of angiotensin II, which is a potent inhibitor of insulin-like growth factor-1 (IGF-1) production, it was hypothesized that treatment with ACE inhibitors is associated with higher levels of IGF-1. This hypothesis was tested in 745 subjects (417 women, 328 men) enrolled in the Invecchiare in Chianti study. Of these, 160 were receiving ACE inhibitors. The association between ACE inhibitor use and serum IGF-1 was tested by linear regression models. After adjusting for multiple potential confounders, serum levels of total IGF-1 were significantly higher in participants receiving ACE inhibitors (mean ± SD 129.0 ± 56.1 ng/ml) compared with the rest of the study population (mean ± SD 116.5 ± 54.8 ng/ml) (p <0.001). Participants with short (<3 years) and long (3 to 9 years) treatment durations had higher serum IGF-1 levels than participants who were not receiving ACE inhibitor treatment, but the difference was statistically significant only for the short-duration group (p <0.05). In conclusion, in older subjects, treatment with ACE inhibitors for <3 years is associated with significantly higher levels of IGF-1. This may be 1 of the mechanisms by which ACE inhibitors might slow the decreases in muscle strength and physical function that are often observed in older subjects. PMID:16679098

Relation of angiotensin-converting enzyme inhibitor treatment to insulin-like growth factor-1 serum levels in subjects >65 years of age (the InCHIANTI study).

PubMed

Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Pahor, Marco; Bandinelli, Stefania; Najjar, Samer S; Ling, Shari M; Basaria, Shehzad; Ruggiero, Carmelinda; Valenti, Giorgio; Ferrucci, Luigi

2006-05-15

Observational studies have shown that the use of angiotensin-converting enzyme (ACE) inhibitors is associated with the maintenance of greater muscle strength and physical performance in older subjects. However, the mechanism that underlies these beneficial effects remains poorly understood. Because ACE inhibitors block the production of angiotensin II, which is a potent inhibitor of insulin-like growth factor-1 (IGF-1) production, it was hypothesized that treatment with ACE inhibitors is associated with higher levels of IGF-1. This hypothesis was tested in 745 subjects (417 women, 328 men) enrolled in the Invecchiare in Chianti study. Of these, 160 were receiving ACE inhibitors. The association between ACE inhibitor use and serum IGF-1 was tested by linear regression models. After adjusting for multiple potential confounders, serum levels of total IGF-1 were significantly higher in participants receiving ACE inhibitors (mean +/- SD 129.0 +/- 56.1 ng/ml) compared with the rest of the study population (mean +/- SD 116.5 +/- 54.8 ng/ml) (p <0.001). Participants with short (<3 years) and long (3 to 9 years) treatment durations had higher serum IGF-1 levels than participants who were not receiving ACE inhibitor treatment, but the difference was statistically significant only for the short-duration group (p <0.05). In conclusion, in older subjects, treatment with ACE inhibitors for <3 years is associated with significantly higher levels of IGF-1. This may be 1 of the mechanisms by which ACE inhibitors might slow the decreases in muscle strength and physical function that are often observed in older subjects.

Enalapril protects against myocardial ischemia/reperfusion injury in a swine model of cardiac arrest and resuscitation

PubMed Central

Wang, Guoxing; Zhang, Qian; Yuan, Wei; Wu, Junyuan; Li, Chunsheng

2016-01-01

There is strong evidence to suggest that angiotensin-converting enzyme inhibitors (ACEIs) protect against local myocardial ischemia/reperfusion (I/R) injury. This study was designed to explore whether ACEIs exert cardioprotective effects in a swine model of cardiac arrest (CA) and resuscitation. Male pigs were randomly assigned to three groups: sham-operated group, saline treatment group and enalapril treatment group. Thirty minutes after drug infusion, the animals in the saline and enalapril groups were subjected to ventricular fibrillation (8 min) followed by cardiopulmonary resuscitation (up to 30 min). Cardiac function was monitored, and myocardial tissue and blood were collected for analysis. Enalapril pre-treatment did not improve cardiac function or the 6-h survival rate after CA and resuscitation; however, this intervention ameliorated myocardial ultrastructural damage, reduced the level of plasma cardiac troponin I and decreased myocardial apoptosis. Plasma angiotensin (Ang) II and Ang-(1–7) levels were enhanced in the model of CA and resuscitation. Enalapril reduced the plasma Ang II level at 4 and 6 h after the return of spontaneous circulation whereas enalapril did not affect the plasma Ang-(1–7) level. Enalapril pre-treatment decreased the myocardial mRNA and protein expression of angiotensin-converting enzyme (ACE). Enalapril treatment also reduced the myocardial ACE/ACE2 ratio, both at the mRNA and the protein level. Enalapril pre-treatment did not affect the upregulation of ACE2, Ang II type 1 receptor (AT1R) and MAS after CA and resuscitation. Taken together, these findings suggest that enalapril protects against ischemic injury through the attenuation of the ACE/Ang II/AT1R axis after CA and resuscitation in pigs. These results suggest the potential therapeutic value of ACEIs in patients with CA. PMID:27633002

TSC1 and TSC2 Gene Homologs in Schizosaccharomyces Pombe

DTIC Science & Technology

2005-04-01

arginine metabolism in B C S. pombe. Enzymes are in italic. Arginase converts arginine into ornithine, a precur- pyroglutamic acid sor of polyamines. 5...both Atscl and Atsc2. 5-Oxoprolinase hydro- 12. Yang, W., Tabancay, A. P., Jr., Urano, J., and Tamanoi, F. (2001) Mol. Micro- lyzed pyroglutamic acid to...relationship of the S. pombe model to human TSC. The transcriptional expression profile and intracellular amino acid levels associated with Atscl and Atsc2

Impact of angiotensin-converting enzyme gene polymorphism on neurohormonal responses to high- versus low-dose enalapril in advanced heart failure.

PubMed

Tang, W H Wilson; Vagelos, Randall H; Yee, Yin-Gail; Fowler, Michael B

2004-11-01

The impact of angiotensin-converting enzyme (ACE) gene polymorphism on neurohormonal dose response to ACE inhibitor therapy is unclear. ACE Insertion (I) or Deletion (D) genotype was determined in 74 patients with chronic heart failure who were randomly assigned to receive either high-dose or low-dose enalapril over a period of 6 months. Monthly pre-enalapril and post-enalapril neurohormone levels (serum ACE activity (sACE), plasma angiotensin II (A-II), plasma renin activity (PRA), and serum aldosterone (ALDO) were compared between genotype subgroups and between patients who received high- or low-dose enalapril within each genotype subgroup. At baseline, predose/postdose sACE and postdose PRA were significantly higher in the DD genotype. At 6-month follow-up, postdose sACE was reduced in a dose-dependent fashion in all three genotypes (P < .05). However, predose and postdose ALDO and A-II levels did not differ between each genotype subgroup at baseline or by enalapril dose within each genotype subgroup. ALDO escape and A-II reactivation were not affected by ACE genotype or enalapril dosage. Predose sACE were consistently higher in the DD genotype when compared with ID or II subgroups. Despite a dose-dependent suppression of sACE, there were no observed statistically significant differences in ALDO and A-II suppression or escape with escalating doses of enalapril within each subgroup.

The hemodynamic effects of methylene blue when administered at the onset of cardiopulmonary bypass.

PubMed

Maslow, Andrew D; Stearns, Gary; Butala, Parag; Batula, Parag; Schwartz, Carl S; Gough, Jeffrey; Singh, Arun K

2006-07-01

Hypotension occurs during cardiopulmonary bypass (CPB), in part because of induction of the inflammatory response, for which nitric oxide and guanylate cyclase play a central role. In this study we examined the hemodynamic effects of methylene blue (MB), an inhibitor of guanylate cyclase, administered during cardiopulmonary bypass (CPB) to patients taking angiotensin-converting enzyme inhibitors. Thirty patients undergoing cardiac surgery were randomized to receive either MB (3 mg/kg) or saline (S) after institution of CPB and cardioplegic arrest. CPB was managed similarly for all study patients. Hemodynamic data were assessed before, during, and after CPB. The use of vasopressors was recorded. All study patients experienced a similar reduction in mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) with the onset of CPB and cardioplegic arrest. MB increased MAP and SVR and this effect lasted for 40 minutes. The saline group demonstrated a persistently reduced MAP and SVR throughout CPB. The saline group received phenylephrine more frequently during CPB, and more norepinephrine after CPB to maintain a desirable MAP. The MB group recorded significantly lower serum lactate levels despite equal or greater MAP and SVR. In conclusion, administration of MB after institution of CPB for patients taking angiotensin-converting enzyme inhibitors increased MAP and SVR and reduced the need for vasopressors. Furthermore, serum lactate levels were lower in MB patients, suggesting more favorable tissue perfusion.

Assessment of the rs4340 ACE gene polymorphism in acute coronary syndrome in a Western Mexican population.

PubMed

Valdez-Haro, A; Valle, Y; Valdes-Alvarado, E; Casillas-Muñoz, F; Muñoz-Valle, J F; Reynoso-Villalpando, G L; Flores-Salinas, H E; Padilla-Gutiérrez, J R

2017-09-27

Acute coronary syndrome (ACS) is considered one of the main causes of death worldwide. Contradictory findings concerning the impact of the angiotensin-converting enzyme (ACE) gene on cardiovascular diseases have been reported. Previous conclusions point out that the variability in results depends on ethnicity and genetic polymorphisms to determine the association of rs4340 polymorphisms of the ACE gene and ACE circulating levels in ACS. Genotyping of rs4340 polymorphisms was performed in a total of 600 individuals from Western Mexico divided into two groups: the ACS and the control group (CG). The polymorphisms were identified by polymerase chain reaction. Serum ACE concentration was determined by enzyme-linked immunosorbent assay. D/D carriers had higher ACE levels than I/I carriers (3.6 vs 2.8 ng/mL, P < 0.0021) in the CG. The D/D genotype of the rs4340 polymorphism is associated with higher ACE concentration levels; however, the polymorphism was not associated with ACS.

Aedes aegypti juvenile hormone acid methyl transferase, the ultimate enzyme in the biosynthetic pathway of juvenile hormone III, exhibits substrate control

USDA-ARS?s Scientific Manuscript database

We report on the cloning, sequencing, characterization, 3D modeling and docking of Aedes aegypti juvenile hormone acid methyl transferase (AeaJHAMT), the enzyme that converts juvenile hormone acid (JHA) into juvenile hormone (JH). Purified recombinant AeaJHAMT was extensively characterized for enzym...

Arginine production in the neonate

USDA-ARS?s Scientific Manuscript database

Endogenous arginine synthesis in adults is a complex multiorgan process, in which citrulline is synthesized in the gut, enters the general circulation, and is converted into arginine in the kidney, by what is known as the intestinal-renal axis. In neonates, the enzymes required to convert citrulline...

Budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme upon high-altitude exposure.

PubMed

Li, Hui-Jie; Zheng, Cheng-Rong; Chen, Guo-Zhu; Qin, Jun; Zhang, Ji-Hang; Yu, Jie; Zhang, En-Hao; Huang, Lan

2016-01-01

Inhaled budesonide is a novel approach to prevent acute mountain sickness (AMS). However, its mechanism is not completely understood. We aimed to investigate the effects of budesonide and dexamethasone on renin-angiotensin-aldosterone system in AMS prevention. Data were obtained from a randomised controlled trial including 138 participants. The participants were randomly assigned to receive budesonide, dexamethasone or placebo as prophylaxis before they travelled to 3450 m altitude from 400 m by car. Their plasma concentrations of renin, angiotensin-converting enzyme (ACE) and aldosterone were measured at both altitudes. All parameters were comparable among the three groups at 400 m. After high-altitude exposure of 3450, renin in all groups increased significantly; the ACE, aldosterone concentrations, as well as the aldosterone/renin ratio, rose markedly in the dexamethasone and placebo groups but not in the budesonide group. Moreover, the aldosterone/renin ratio correlated closely with ACE concentration. Upon acute high-altitude exposure, budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme. © The Author(s) 2016.

Measurement of crude-cell-extract glycerol dehydratase activity in recombinant Escherichia coli using coupled-enzyme reactions.

PubMed

Sankaranarayanan, Mugesh; Seol, Eunhee; Kim, Yeonhee; Chauhan, Ashish Singh; Park, Sunghoon

2017-03-01

Glycerol dehydratase (GDHt), which converts glycerol to 3-hydroxypropionaldehyde, is essential to the production of 1,3-propanediol (1,3-PDO) or 3-hydroxypropionic acid (3-HP). A reliable GDHt activity assay in crude-cell extract was developed. In the assay, GDHt converted 1,2-propanediol (1,2-PDO) to propionaldehyde, which was further converted to 1-propionic acid by aldehyde dehydrogenase (KGSADH) or to 1-propanol by yeast-alcohol dehydrogenase (yADH), while the NADH concentration change was monitored spectrophotometrically. Cells should be disintegrated by Bead Beater/French Press, not by chemical methods (BugBuster ® /B-PER™), because the reagents significantly inactivated GDHt and coupling enzymes. Furthermore, in the assay mixture, a much higher activity of KGSADH (>200-fold) or yADH (>400-fold) than that of GDHt should have been maintained. Under optimal conditions, both KGSADH and yADH showed practically the same activity. The coupled-enzyme assay method established here should prove to be applicable to recombinant strains developed for the production of 3-HP and/or 1,3-PDO from glycerol.

Analysis and Evaluation of the Inhibitory Mechanism of a Novel Angiotensin-I-Converting Enzyme Inhibitory Peptide Derived from Casein Hydrolysate.

PubMed

Tu, Maolin; Liu, Hanxiong; Zhang, Ruyi; Chen, Hui; Mao, Fengjiao; Cheng, Shuzhen; Lu, Weihong; Du, Ming

2018-04-25

Casein hydrolysates exert various biological activities, and the responsible functional peptides are being identified from them continuously. In this study, the tryptic casein hydrolysate was fractionated by an ultrafiltration membrane (3 kDa), and the peptides were identified by capillary electrophoresis-quadrupole-time-of-flight-tandem mass spectrometry. Meanwhile, in silico methods were used to analyze the toxicity, solubility, stability, and affinity between the peptides and angiotensin-I-converting enzyme (ACE). Finally, a new angiotensin-I-converting enzyme inhibitory (ACEI) peptide, EKVNELSK, derived from α s1 -casein (fragment 35-42) was screened. The half maximal inhibitory concentration value of the peptide is 5.998 mM, which was determined by a high-performance liquid chromatography method. The Lineweaver-Burk plot indicated that this peptide is a mixed-type inhibitor against ACE. Moreover, Discovery Studio 2017 R2 software was adopted to perform molecular docking to propose the potential mechanisms underlying the ACEI activity of the peptide. These results indicated that EKVNELSK is a new ACEI peptide identified from casein hydrolysate.

Ontogenetic role of angiontensin-converting enzyme in rats: thirst and sodium appetite evaluation.

PubMed

Mecawi, André S; Araujo, Iracema G; Rocha, Fábio F; Coimbra, Terezila M; Antunes-Rodrigues, José; Reis, Luís C

2010-01-12

We investigated the influence of captopril (an angiotensin converting enzyme inhibitor) treatment during pregnancy and lactation period on hydromineral balance of the male adult offspring, particularly, concerning thirst and sodium appetite. We did not observe significant alterations in basal hydromineral (water intake, 0.3M NaCl intake, volume and sodium urinary concentration) or cardiovascular parameters in adult male rats perinatally treated with captopril compared to controls. However, male offspring rats that perinatally exposed to captopril showed a significant attenuation in water intake induced by osmotic stimulation, extracellular dehydration and beta-adrenergic stimulation. Moreover, captopril treatment during perinatal period decreased the salt appetite induced by sodium depletion. This treatment also attenuated thirst and sodium appetite aroused during inhibition of peripheral angiotensin II generation raised by low concentration of captopril in the adult offspring. Interestingly, perinatal exposure to captopril did not alter water or salt intake induced by i.c.v. administration of angiotensin I or angiotensin II. These results showed that chronic inhibition of angiotensin converting enzyme during pregnancy and lactation modifies the regulation of induced thirst and sodium appetite in adulthood.

Budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme upon high-altitude exposure

PubMed Central

Li, Hui-Jie; Zheng, Cheng-Rong; Chen, Guo-Zhu; Qin, Jun; Zhang, Ji-Hang; Yu, Jie; Zhang, En-Hao; Huang, Lan

2016-01-01

Introduction: Inhaled budesonide is a novel approach to prevent acute mountain sickness (AMS). However, its mechanism is not completely understood. We aimed to investigate the effects of budesonide and dexamethasone on renin–angiotensin–aldosterone system in AMS prevention. Materials and methods: Data were obtained from a randomised controlled trial including 138 participants. The participants were randomly assigned to receive budesonide, dexamethasone or placebo as prophylaxis before they travelled to 3450 m altitude from 400 m by car. Their plasma concentrations of renin, angiotensin-converting enzyme (ACE) and aldosterone were measured at both altitudes. Results: All parameters were comparable among the three groups at 400 m. After high-altitude exposure of 3450, renin in all groups increased significantly; the ACE, aldosterone concentrations, as well as the aldosterone/renin ratio, rose markedly in the dexamethasone and placebo groups but not in the budesonide group. Moreover, the aldosterone/renin ratio correlated closely with ACE concentration. Conclusions: Upon acute high-altitude exposure, budesonide, but not dexamethasone, blunted the response of aldosterone to renin elevation by suppressing angiotensin converting enzyme. PMID:27317302

Effect of SQ29,852, a new angiotensin converting enzyme (ACE) inhibitor with a phosphonic acid group, on the activity of angiotensin converting enzyme from human kidney.

PubMed

Hiwada, K; Inoue, Y; Kokubu, T

1990-01-01

1. An in vitro experiment was carried out to compare the inhibitory effect of SQ29,852 on human renal angiotensin converting enzyme (ACE) with those of captopril, enalapril and enalaprilat. 2. SQ29,852 strongly inhibited human renal ACE; its IC50 value was 1.5 x 10(-8) M. In terms of the IC50, SQ29,852's efficacy was about 1/10 of that of captopril and 1/28 of that of enalaprilat, but it was about 14 times more potent than enalapril. 3. SQ29,852 showed no inhibitory effects on cathepsin D, urinary kallikrein, renal renin, pepsin, trypsin and chymotrypsin. Its ACE-specificity was higher than that of captopril. 4. ACE inhibition by SQ29,852 was shown to be competitive, as revealed by Lineweaver-Burk plots. The affinity of SQ29,852 to ACE was shown to be high by a Ki value of 1.2 x 10(-8) M.

Analysis of ATP-citrate lyase and malic enzyme mutants of Yarrowia lipolytica points out the importance of mannitol metabolism in fatty acid synthesis.

PubMed

Dulermo, Thierry; Lazar, Zbigniew; Dulermo, Rémi; Rakicka, Magdalena; Haddouche, Ramedane; Nicaud, Jean-Marc

2015-09-01

The role of the two key enzymes of fatty acid (FA) synthesis, ATP-citrate lyase (Acl) and malic enzyme (Mae), was analyzed in the oleaginous yeast Yarrowia lipolytica. In most oleaginous yeasts, Acl and Mae are proposed to provide, respectively, acetyl-CoA and NADPH for FA synthesis. Acl was mainly studied at the biochemical level but no strain depleted for this enzyme was analyzed in oleaginous microorganisms. On the other hand the role of Mae in FA synthesis in Y. lipolytica remains unclear since it was proposed to be a mitochondrial NAD(H)-dependent enzyme and not a cytosolic NADP(H)-dependent enzyme. In this study, we analyzed for the first time strains inactivated for corresponding genes. Inactivation of ACL1 decreases FA synthesis by 60 to 80%, confirming its essential role in FA synthesis in Y. lipolytica. Conversely, inactivation of MAE1 has no effects on FA synthesis, except in a FA overaccumulating strain where it improves FA synthesis by 35%. This result definitively excludes Mae as a major key enzyme for FA synthesis in Y. lipolytica. During the analysis of both mutants, we observed a negative correlation between FA and mannitol level. As mannitol and FA pathways may compete for carbon storage, we inactivated YlSDR, encoding a mannitol dehydrogenase converting fructose and NADPH into mannitol and NADP+. The FA content of the resulting mutant was improved by 60% during growth on fructose, demonstrating that mannitol metabolism may modulate FA synthesis in Y. lipolytica. Copyright © 2015. Published by Elsevier B.V.

The Effects of Angiotensin Converting Enzyme Inhibitors (ACE-I) on Human N-Acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) Levels: A Systematic Review and Meta-Analysis.

PubMed

Mnguni, Ayanda Trevor; Engel, Mark E; Borkum, Megan S; Mayosi, Bongani M

2015-01-01

Tuberculous pericardial effusion is a pro-fibrotic condition that is complicated by constrictive pericarditis in 4% to 8% of cases. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a ubiquitous tetrapeptide with anti-fibrotic properties that is low in tuberculous pericardial effusion, thus providing a potential mechanism for the heightened fibrotic state. Angiotensin-converting enzyme inhibitors (ACE-I), which increase Ac-SDKP levels with anti-fibrotic effects in animal models, are candidate drugs for preventing constrictive pericarditis if they can be shown to have similar effects on Ac-SDKP and fibrosis in human tissues. To systematically review the effects of ACE-Is on Ac-SDKP levels in human tissues. We searched five electronic databases (1996 to 2014) and conference abstracts with no language restrictions. Two reviewers independently selected studies, extracted data and assessed methodological quality. The protocol was registered in PROSPERO. Four studies with a total of 206 participants met the inclusion criteria. Three studies (106 participants) assessed the change in plasma levels of Ac-SDKP following ACE-I administration in healthy humans. The administration of an ACE-I was associated with an increase in Ac-SDKP levels (mean difference (MD) 5.07 pmol/ml (95% confidence intervals (CI) 0.64 pmol/ml to 9.51 pmol/ml)). Two studies with 100 participants further assessed the change in Ac-SDKP level in humans with renal failure using ACE-I. The administration of an ACE-I was associated with a significant increase in Ac-SDKP levels (MD 8.94 pmol/ml; 95% CI 2.55 to 15.33; I2 = 44%). ACE-I increased Ac-SDKP levels in human plasma. These findings provide the rationale for testing the impact of ACE-I on Ac-SDKP levels and fibrosis in tuberculous pericarditis.

Genetics Home Reference: Bietti crystalline dystrophy

MedlinePlus

... broken down and converted into energy, but the enzyme's specific function is not well understood. CYP4V2 gene mutations that cause Bietti crystalline dystrophy impair or eliminate the function of this enzyme and are believed to affect lipid breakdown. However, ...

Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction.

PubMed

Duan, Yaqian; Beli, Eleni; Li Calzi, Sergio; Quigley, Judith L; Miller, Rehae C; Moldovan, Leni; Feng, Dongni; Salazar, Tatiana E; Hazra, Sugata; Al-Sabah, Jude; Chalam, Kakarla V; Le Phuong Trinh, Thao; Meroueh, Marya; Markel, Troy A; Murray, Matthew C; Vyas, Ruchi J; Boulton, Michael E; Parsons-Wingerter, Patricia; Oudit, Gavin Y; Obukhov, Alexander G; Grant, Maria B

2018-05-15

Angiotensin-converting enzyme 2 (ACE2) is the primary enzyme of the vasoprotective axis of the renin angiotensin system (RAS). We tested the hypothesis that loss of ACE2 would exacerbate diabetic retinopathy by promoting bone marrow dysfunction. ACE2 -/y were crossed with Akita mice, a model of type 1 diabetes. When comparing the bone marrow of the ACE2 -/y -Akita mice to that of Akita mice, we observed a reduction of both short-term and long-term repopulating hematopoietic stem cells, a shift of hematopoiesis towards myelopoiesis, and an impairment of lineage - c-kit + hematopoietic stem/progenitor cell (HS/PC) migration and proliferation. Migratory and proliferative dysfunction of these cells was corrected by exposure to angiotensin-1-7 (Ang-1-7), the protective peptide generated by ACE2. Over the duration of diabetes examined, ACE2 deficiency led to progressive reduction in electrical responses assessed by electroretinography and to increases in neural infarcts observed by fundus photography. Compared to Akita mice, ACE2 -/y -Akita at 9-months of diabetes showed an increased number of acellular capillaries indicative of more severe diabetic retinopathy. In diabetic and control human subjects, CD34 + cells, a key bone marrow HS/PC population, were assessed for changes in mRNA levels for MAS, the receptor for Ang-1-7. Levels were highest in CD34 + cells from diabetics without retinopathy. Higher serum Ang-1-7 levels predicted protection from development of retinopathy in diabetics. Treatment with Ang-1-7 or alamandine restored the impaired migration function of CD34 + cells from subjects with retinopathy. These data support that activation of the protective RAS within HS/PCs may represent a therapeutic strategy for prevention of diabetic retinopathy. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

Renal tubular angiotensin converting enzyme is responsible for nitro-L-arginine methyl ester (L-NAME)-induced salt sensitivity

PubMed Central

Giani, Jorge F.; Eriguchi, Masahiro; Bernstein, Ellen A.; Katsumata, Makoto; Shen, Xiao Z.; Li, Liang; McDonough, Alicia A.; Fuchs, Sebastien; Bernstein, Kenneth E.; Gonzalez-Villalobos, Romer A.

2017-01-01

Renal parenchymal injury predisposes to salt-sensitive hypertension, but how this occurs is not known. Here we tested whether renal tubular angiotensin converting enzyme (ACE), the main site of kidney ACE expression, is central to the development of salt sensitivity in this setting. Two mouse models were used: it-ACE mice in which ACE expression is selectively eliminated from renal tubular epithelial cells; and ACE 3/9 mice, a compound heterozygous mouse model that makes ACE only in renal tubular epithelium from the ACE 9 allele, and in liver hepatocytes from the ACE 3 allele. Salt sensitivity was induced using a post L-NAME salt challenge. While both wild-type and ACE 3/9 mice developed arterial hypertension following three weeks of high salt administration, it-ACE mice remained normotensive with low levels of renal angiotensin II. These mice displayed increased sodium excretion, lower sodium accumulation, and an exaggerated reduction in distal sodium transporters. Thus, in mice with renal injury induced by L-NAME pretreatment, renal tubular epithelial ACE, and not ACE expression by renal endothelium, lung, brain, or plasma, is essential for renal angiotensin II accumulation and salt-sensitive hypertension. PMID:27988209

Endotoxin reduces specific pulmonary uptake of radiolabeled monoclonal antibody to angiotensin-converting enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzykantov, V.R.; Puchnina, E.A.; Atochina, E.N.

The biodistribution of radiolabeled monoclonal antibody (Mab) to angiotensin-converting enzyme (ACE) was examined in normal and endotoxin-treated rats. Endotoxin administration at a dose of 4 mg/kg induced mild or middle pulmonary edema. The ACE activity in lung homogenate remained virtually unchanged, while the activity of serum ACE increased 15 hr after endotoxin infusion. In normal rats, anti-ACE Mab accumulates specifically in the lung after i.v. injection. Endotoxin injection induces reduction of specific pulmonary uptake of this antibody. Even in non-edematous endotoxemia, the accumulation of anti-ACE Mab antibody (Mab 9B9) decreased from 19.02 to 11.91% of ID/g of tissue without anymore » change in accumulation of control nonspecific IgG. The antibody distribution in other organs and its blood level were almost the same as in the control. In a case of endotoxemia accompanied by increased microvascular permeability, the lung accumulation of Mab 9B9 was reduced to 9.17% of ID/g of tissue, while the accumulation of nonspecific IgG increased to 1.44% versus 0.89% in the control.« less

OptSSeq: High-throughput sequencing readout of growth enrichment defines optimal gene expression elements for homoethanologenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Indro Neil; Landick, Robert

The optimization of synthetic pathways is a central challenge in metabolic engineering. OptSSeq (Optimization by Selection and Sequencing) is one approach to this challenge. OptSSeq couples selection of optimal enzyme expression levels linked to cell growth rate with high-throughput sequencing to track enrichment of gene expression elements (promoters and ribosomebinding sites) from a combinatorial library. OptSSeq yields information on both optimal and suboptimal enzyme levels, and helps identify constraints that limit maximal product formation. Here we report a proof-of-concept implementation of OptSSeq using homoethanologenesis, a two-step pathway consisting of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (Adh) that converts pyruvate tomore » ethanol and is naturally optimized in the bacterium Zymomonas mobilis. We used OptSSeq to determine optimal gene expression elements and enzyme levels for Z. mobilis Pdc, AdhA, and AdhB expressed in Escherichia coli. By varying both expression signals and gene order, we identified an optimal solution using only Pdc and AdhB. We resolved current uncertainty about the functions of the Fe 2+-dependent AdhB and Zn 2+- dependent AdhA by showing that AdhB is preferred over AdhA for rapid growth in both E. coli and Z. mobilis. Finally, by comparing predictions of growth-linked metabolic flux to enzyme synthesis costs, we established that optimal E. coli homoethanologenesis was achieved by our best pdc-adhB expression cassette and that the remaining constraints lie in the E. coli metabolic network or inefficient Pdc or AdhB function in E. coli. Furthermore, OptSSeq is a general tool for synthetic biology to tune enzyme levels in any pathway whose optimal function can be linked to cell growth or survival.« less

OptSSeq: High-throughput sequencing readout of growth enrichment defines optimal gene expression elements for homoethanologenesis

DOE PAGES

Ghosh, Indro Neil; Landick, Robert

2016-07-16

The optimization of synthetic pathways is a central challenge in metabolic engineering. OptSSeq (Optimization by Selection and Sequencing) is one approach to this challenge. OptSSeq couples selection of optimal enzyme expression levels linked to cell growth rate with high-throughput sequencing to track enrichment of gene expression elements (promoters and ribosomebinding sites) from a combinatorial library. OptSSeq yields information on both optimal and suboptimal enzyme levels, and helps identify constraints that limit maximal product formation. Here we report a proof-of-concept implementation of OptSSeq using homoethanologenesis, a two-step pathway consisting of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (Adh) that converts pyruvate tomore » ethanol and is naturally optimized in the bacterium Zymomonas mobilis. We used OptSSeq to determine optimal gene expression elements and enzyme levels for Z. mobilis Pdc, AdhA, and AdhB expressed in Escherichia coli. By varying both expression signals and gene order, we identified an optimal solution using only Pdc and AdhB. We resolved current uncertainty about the functions of the Fe 2+-dependent AdhB and Zn 2+- dependent AdhA by showing that AdhB is preferred over AdhA for rapid growth in both E. coli and Z. mobilis. Finally, by comparing predictions of growth-linked metabolic flux to enzyme synthesis costs, we established that optimal E. coli homoethanologenesis was achieved by our best pdc-adhB expression cassette and that the remaining constraints lie in the E. coli metabolic network or inefficient Pdc or AdhB function in E. coli. Furthermore, OptSSeq is a general tool for synthetic biology to tune enzyme levels in any pathway whose optimal function can be linked to cell growth or survival.« less

Personal glucose meters for detection and quantification of a broad range of analytes

DOEpatents

Lu, Yi; Xiang, Yu

2015-02-03

A general methodology for the development of highly sensitive and selective sensors that can achieve portable, low-cost and quantitative detection of a broad range of targets using only a personal glucose meter (PGM) is disclosed. The method uses recognition molecules that are specific for a target agent, enzymes that can convert an enzyme substrate into glucose, and PGM. Also provided are sensors, which can include a solid support to which is attached a recognition molecule that permits detection of a target agent, wherein the recognition molecule specifically binds to the target agent in the presence of the target agent but not significantly to other agents as well as an enzyme that can catalyze the conversion of a substance into glucose, wherein the enzyme is attached directly or indirectly to the recognition molecule, and wherein in the presence of the target agent the enzyme can convert the substance into glucose. The disclosed sensors can be part of a lateral flow device. Methods of using such sensors for detecting target agents are also provided.

Pie waste - A component of food waste and a renewable substrate for producing ethanol.

PubMed

Magyar, Margaret; da Costa Sousa, Leonardo; Jayanthi, Singaram; Balan, Venkatesh

2017-04-01

Sugar-rich food waste is a sustainable feedstock that can be converted into ethanol without an expensive thermochemical pretreatment that is commonly used in first and second generation processes. In this manuscript we have outlined the pie waste conversion to ethanol through a two-step process, namely, enzyme hydrolysis using commercial enzyme products mixtures and microbial fermentation using yeast. Optimized enzyme cocktail was found to be 45% alpha amylase, 45% gamma amylase, and 10% pectinase at 2.5mg enzyme protein/g glucan produced a hydrolysate with high glucose concentration. All three solid loadings (20%, 30%, and 40%) produced sugar-rich hydrolysates and ethanol with little to no enzyme or yeast inhibition. Enzymatic hydrolysis and fermentation process mass balance was carried out using pie waste on a 1000g dry weight basis that produced 329g ethanol at 20% solids loading. This process clearly demonstrate how food waste could be efficiently converted to ethanol that could be used for making biodiesel by reacting with waste cooking oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative study on the conventional and non thermal simultaneous saccharification and fermentation of Manihot glaziovii root starch

NASA Astrophysics Data System (ADS)

Hargono, Kumoro, Andri Cahyo; Jos, Bakti

2015-12-01

Inconventional ethanol production process, starch is converted into dextrins via liquefaction using α-amylase enzyme at high temperature (90-120°C). Then, dextrins are saccharified by glucoamylase to obtain to monomeric sugars (glucose). Recently, a granular starch hydrolyzing enzymes (GSHE), Stargen 002, was developed to convert starch into dextrins at low temperature (< 32°C) and hydrolyzes dextrins into glucose. The subject of this research was to compare ethanol production using a granular starch hydrolyzing enzymes and conventional enzymatic liquefaction and saccharification in cassava starch processing. Starch slurry concentrations were 20% w/v, and dosage of enzymes 0.50, 1.0 and 2%, respectively, were studied. After 48 hr process the final ethanol concentration for the respective enzyme concentration for conventional process were 34.90, 36.16 and 42.10 g/L, whereas for the non-thermal treatment, final ethanol concentration were 46.4, 57.62 and 59.65 g/L, respectively. By implementation of this non thermal process, the use of energy can be saved by carrying out saccharification step at lower temperature (30°C) could be realized.

Human recombinant arginase enzyme reduces plasma arginine in mouse models of arginase deficiency

PubMed Central

Burrage, Lindsay C.; Sun, Qin; Elsea, Sarah H.; Jiang, Ming-Ming; Nagamani, Sandesh C.S.; Frankel, Arthur E.; Stone, Everett; Alters, Susan E.; Johnson, Dale E.; Rowlinson, Scott W.; Georgiou, George; Lee, Brendan H.

2015-01-01

Arginase deficiency is caused by deficiency of arginase 1 (ARG1), a urea cycle enzyme that converts arginine to ornithine. Clinical features of arginase deficiency include elevated plasma arginine levels, spastic diplegia, intellectual disability, seizures and growth deficiency. Unlike other urea cycle disorders, recurrent hyperammonemia is typically less severe in this disorder. Normalization of plasma arginine levels is the consensus treatment goal, because elevations of arginine and its metabolites are suspected to contribute to the neurologic features. Using data from patients enrolled in a natural history study conducted by the Urea Cycle Disorders Consortium, we found that 97% of plasma arginine levels in subjects with arginase deficiency were above the normal range despite conventional treatment. Recently, arginine-degrading enzymes have been used to deplete arginine as a therapeutic strategy in cancer. We tested whether one of these enzymes, a pegylated human recombinant arginase 1 (AEB1102), reduces plasma arginine in murine models of arginase deficiency. In neonatal and adult mice with arginase deficiency, AEB1102 reduced the plasma arginine after single and repeated doses. However, survival did not improve likely, because this pegylated enzyme does not enter hepatocytes and does not improve hyperammonemia that accounts for lethality. Although murine models required dosing every 48 h, studies in cynomolgus monkeys indicate that less frequent dosing may be possible in patients. Given that elevated plasma arginine rather than hyperammonemia is the major treatment challenge, we propose that AEB1102 may have therapeutic potential as an arginine-reducing agent in patients with arginase deficiency. PMID:26358771

Sarcoidosis Presenting Addison's Disease.

PubMed

Takahashi, Kentaro; Kagami, Shin-Ichiro; Kawashima, Hirotoshi; Kashiwakuma, Daisuke; Suzuki, Yoshio; Iwamoto, Itsuo

2016-01-01

We herein describe a second Japanese case of sarcoidosis presenting Addison's disease. A 52-year-old man was diagnosed with sarcoidosis based on clinical and laboratory findings, including bilateral hilar lymphadenopathy and elevated levels of serum angiotensin-converting enzyme and lysozyme, as well as the presence of noncaseating epithelioid granulomas. The patient also exhibited general fatigue, pigmentation, weight loss, hypotension and hyponatremia, suggestive of chronic adrenocortical insufficiency. An endocrine examination confirmed primary adrenocortical insufficiency. This case suggests the direct involvement of sarcoid granuloma in the adrenal glands.

Angiotensin II-producing enzyme III from acidified serum of nephrectomized dogs.

PubMed

Haas, E; Lewis, L; Koshy, T J; Varde, A U; Renerts, L; Bagai, R C

1989-09-01

A highly active angiotensin-producing enzyme (enzyme III) was obtained from the serum of bilaterally nephrectomized dogs by acid treatment and ammonium sulfate fractionation. An inactive precursor (proenzyme III) was converted to enzyme III during prolonged storage (or by treatment with acid or with cathepsin G or by incubation at 38 degrees C as described in the following paper). Enzyme III reacted maximally at pH 7.7 and it produced up to 400 ng of angiotensin II/mL serum/h (i.e., amounts 4000 times higher than that generated by the endogenous renin present in serum after bilateral nephrectomy). Enzyme III produced angiotensin II at identical rates when either dog angiotensinogen or angiotensin I was used as substrate, but the rate was 710 times higher with synthetic tetradecapeptide renin substrate. Enzyme III is not identical to renin, cathepsin G, tonin, enzyme I, enzyme II, the calcium-dependent angiotensin I-converting enzyme, or the calcium-independent carboxy peptidase, which acts by sequential cleavage of angiotensin I. Enzyme III was inhibited by alpha-1-antitrypsin, diisopropyl fluorophosphate, and lima bean trypsin inhibitor (hence it is a serine proteinase). It was not inhibited by Captopril, Teprotide, or Enalapril. It had been reported previously that cathepsin G released from neutrophil granulocytes, by producing high local concentrations of angiotensin II, may provide a mobile means for modulating blood flow in tissue microvasculature during the inflammatory response. The present study offers a new, additional pathway, by enzyme III, for a similar rapid formation of angiotensin II from serum protein substrate or angiotensin I.

Serum levels of angiotensin converting enzyme as a biomarker of liver fibrosis

PubMed Central

Miranda, Aline Silva; Simões e Silva, Ana Cristina

2017-01-01

The renin angiotensin system (RAS) is classically conceived as a circulating hormonal system involved in blood pressure control and hydroelectrolyte balance. The discovery that RAS components are locally expressed in a wide range of organs and tissues, including the liver, pointed to a role for this system in the pathogenesis of several conditions including hepatic fibrosis and cirrhosis. It has been widely reported that the classical RAS axis composed by the angiotensin converting enzyme (ACE)-angiotensin (Ang) II-Ang type 1 (AT1) receptor mediates pro-inflammatory, pro-thrombotic, and pro-fibrotic processes. On the other hand, the alternative axis comprising ACE2-Ang-(1-7)-Mas receptor seems to play a protective role by frequently opposing Ang II action. Chronic hepatitis B (CHB) is one of the leading causes of liver fibrosis, accounting for the death of nearly one million people worldwide. Liver fibrosis is a key factor to determine therapeutic interventions for patients with CHB. However, the establishment of non-invasive and accurate methods to detect reversible stages of liver fibrosis is still a challenge. In an elegant study published in the 36th issue of the World Journal of Gastroenterology, Noguchi et al showed the predictive value of serum ACE levels in detecting not only advanced stages of liver fibrosis but also initial and intermediate fibrotic stages. The serum levels of ACE might represent an accurate, non-invasive, widely available, and easy method to evaluate fibrosis related to CHB. Moreover, therapies involving the inhibition of the classical RAS axis components might be promising in the control of CHB-related liver fibrosis. PMID:29358853

Angiotensin-(1-9) reverses experimental hypertension and cardiovascular damage by inhibition of the angiotensin converting enzyme/Ang II axis.

PubMed

Ocaranza, Maria Paz; Moya, Jackeline; Barrientos, Victor; Alzamora, Rodrigo; Hevia, Daniel; Morales, Cristobal; Pinto, Melissa; Escudero, Nicolás; García, Lorena; Novoa, Ulises; Ayala, Pedro; Díaz-Araya, Guillermo; Godoy, Ivan; Chiong, Mario; Lavandero, Sergio; Jalil, Jorge E; Michea, Luis

2014-04-01

Little is known about the biological effects of angiotensin-(1-9), but available evidence shows that angiotensin-(1-9) has beneficial effects in preventing/ameliorating cardiovascular remodeling. In this study, we evaluated whether angiotensin-(1-9) decreases hypertension and reverses experimental cardiovascular damage in the rat. Angiotensin-(1-9) (600  ng/kg per min for 2 weeks) reduced already-established hypertension in rats with early high blood pressure induced by angiotensin II infusion or renal artery clipping. Angiotensin-(1-9) also improved cardiac (assessed by echocardiography) and endothelial function in small-diameter mesenteric arteries, cardiac and aortic wall hypertrophy, fibrosis, oxidative stress, collagen and transforming growth factor type β - 1 protein expression (assessed by western blot). The beneficial effect of angiotensin-(1-9) was blunted by coadministration of the angiotensin type 2(AT2) receptor blocker PD123319 (36  ng/kg per min) but not by coadministration of the Mas receptor blocker A779 (100  ng/kg per min). Angiotensin-(1-9) treatment also decreased circulating levels of Ang II, angiotensin-converting enzyme activity and oxidative stress in aorta and left ventricle. Whereas, Ang-(1-9) increased endothelial nitric oxide synthase mRNA levels in aorta as well as plasma nitrate levels. Angiotensin-(1-9) reduces hypertension, ameliorates structural alterations (hypertrophy and fibrosis), oxidative stress in the heart and aorta and improves cardiac and endothelial function in hypertensive rats. These effects were mediated by the AT2 receptor but not by the angiotensin-(1-7)/Mas receptor axis.

Enhanced angiotensin-converting enzyme activity and systemic reactivity to angiotensin II in normotensive rats exposed to a high-sodium diet

PubMed Central

Crestani, Sandra; Júnior, Arquimedes Gasparotto; Marques, Maria C.A.; Sullivan, Jennifer C.; Webb, R. Clinton; da Silva-Santos, J. Eduardo

2016-01-01

A high salt diet is associated with reduced activity of the renin–angiotensin–aldosterone system (RAAS). However, normotensive rats exposed to high sodium do not show changes in systemic arterial pressure. We hypothesized that, despite the reduced circulating amounts of angiotensin II induced by a high salt diet, the cardiovascular system’s reactivity to angiotensin II is increased in vivo, contributing to maintain arterial pressure at normal levels. Male Wistar rats received chow containing 0.27% (control), 2%, 4%, or 8% NaCl for six weeks. The high-sodium diet did not lead to changes in arterial pressure, although plasma levels of angiotensin II and aldosterone were reduced in the 4% and 8% NaCl groups. The 4% and 8% NaCl groups showed enhanced pressor responses to angiotensin I and II, accompanied by unchanged and increased angiotensin-converting enzyme activity, respectively. The 4% NaCl group showed increased expression of angiotensin II type 1 receptors and reduced expression of angiotensin II type 2 receptors in the aorta. In addition, the hypotensive effect of losartan was reduced in both 4% and 8% NaCl groups. In conclusion these results explain, at least in part, why the systemic arterial pressure is maintained at normal levels in non-salt sensitive and healthy rats exposed to a high salt diet, when the functionality of RAAS appears to be blunted, as well as suggest that angiotensin II has a crucial role in the vascular dysfunction associated with high salt intake, even in the absence of hypertension. PMID:24321189

Serum levels of angiotensin converting enzyme as a biomarker of liver fibrosis.

PubMed

Miranda, Aline Silva; Simões E Silva, Ana Cristina

2017-12-28

The renin angiotensin system (RAS) is classically conceived as a circulating hormonal system involved in blood pressure control and hydroelectrolyte balance. The discovery that RAS components are locally expressed in a wide range of organs and tissues, including the liver, pointed to a role for this system in the pathogenesis of several conditions including hepatic fibrosis and cirrhosis. It has been widely reported that the classical RAS axis composed by the angiotensin converting enzyme (ACE)-angiotensin (Ang) II-Ang type 1 (AT1) receptor mediates pro-inflammatory, pro-thrombotic, and pro-fibrotic processes. On the other hand, the alternative axis comprising ACE2-Ang-(1-7)-Mas receptor seems to play a protective role by frequently opposing Ang II action. Chronic hepatitis B (CHB) is one of the leading causes of liver fibrosis, accounting for the death of nearly one million people worldwide. Liver fibrosis is a key factor to determine therapeutic interventions for patients with CHB. However, the establishment of non-invasive and accurate methods to detect reversible stages of liver fibrosis is still a challenge. In an elegant study published in the 36 th issue of the World Journal of Gastroenterology , Noguchi et al showed the predictive value of serum ACE levels in detecting not only advanced stages of liver fibrosis but also initial and intermediate fibrotic stages. The serum levels of ACE might represent an accurate, non-invasive, widely available, and easy method to evaluate fibrosis related to CHB. Moreover, therapies involving the inhibition of the classical RAS axis components might be promising in the control of CHB-related liver fibrosis.

Effects of replacing groundnut cake with rumen content supplemented with or without enzyme in the diet of weaner rabbits.

PubMed

Adeniji, A A; Rumak, S; Oluwafemi, R A

2015-12-18

Rabbits are also herbivores which efficiently convert fodder to food. They are prolific and converter of plant proteins of little or no use to people as food into high-value animal protein. Rabbit meat is high in protein, low in calories and low in fat and cholesterol contents, being considered as a delicacy and a healthy food product. Feeding rabbits with concentrates is expensive and therefore in order to reduce cost of production, hence the use of rumen content in this study as alternative feedstuff without competition. A total of thirty six (36) weaner rabbits (oryctalagus cuniculus) of different body weight and age where use in this experiment to determine the effects of replacing rumen content with or without enzyme supplementation for groundnut cake. This feeding trial which lasted for 8 weeks was carried out in order to determine the replacement value of groundnut cake with rumen content with or without enzyme in the diet of weaner rabbit. A 3x2 factorial experiment was adopted such that there where three (3) replacement level of rumen content (0, 25 and 50 %) for groundnut cake by two supplemental level (no enzyme and enzyme supplement). The results showed that increased inclusion level of rumen content has significant effects (p < 0.05) on daily feed intake, rate of weight gain, feed to gain ratio, nitrogen retention, faecal nitrogen, total nitrogen output and nitrogen digestibility. The weight gained by rabbits fed on 0, 25 and 50 % were all comparable (p > 0.05) with weight gained value of 7.62,7.44 and 7.36 g respectively. Similarly there was a significant (p < 0.05) effect of supplement added on the body weight gain of the experimental animals. There was significant effect (p < 0.05) of the diet on the obtained feed to gain ratio. However, there was no significant effect (p > 0.05) of the treatment on urinary nitrogen. Significant (p < 0.05) effects of supplementation was observed on the feed intake, weight gain, feed to gain ratio, faecal nitrogen, nitrogen retention and nitrogen digestibility but there was no significant effects (p > 0.05) of the supplementation on the nitrogen intake. The interaction between the varying levels of rumen content supplementation had significant effects (p < 0.05) on the feacal nitrogen, feed intake and feed to gain ratio but no significant (p < 0.05) effects on interaction of nitrogen intake. In conclusion, since the results from this study showed no negative effects on the performance of the experimental animals, the test ingredient can be used as alternative feedstuff at a lower inclusion level so as to reduce production cost and expand rabbit production.

Association between angiotensin II receptor gene polymorphism and serum angiotensin converting enzyme (SACE) activity in patients with sarcoidosis

PubMed Central

Takemoto, Y.; Sakatani, M.; Takami, S.; Tachibana, T.; Higaki, J.; Ogihara, T.; Miki, T.; Katsuya, T.; Tsuchiyama, T.; Yoshida, A.; Yu, H.; Tanio, Y.; Ueda, E.

1998-01-01

BACKGROUND—Serum angiotensin converting enzyme (SACE) is considered to reflect disease activity in sarcoidosis. SACE activity is increased in many patients with active sarcoid lesions. The mechanism for the increased SACE activity in this disease has not been clarified. ACE insertion/deletion (I/D) gene polymorphism has been reported to have an association with SACE levels in sarcoidosis, but no evidence of an association between angiotensin II receptor gene polymorphism and SACE in this disease has been found. A study of the association of angiotensin II receptor gene polymorphisms with sarcoidosis was therefore undertaken.
METHODS—ACE (I/D), angiotensin II type 1 receptor (AGTR1), and angiotensin II type 2 receptor (AGTR2 ) gene polymorphisms were investigated by polymerase chain reaction (PCR) and SACE levels were measured in three groups of patients: those with sarcoidosis or tuberculosis and normal controls.
RESULTS—There was no difference in allele frequency of AGTR1 and AGTR2 polymorphism among the three groups. Neither AGTR1 nor AGTR2 polymorphisms were associated with sarcoidosis. SACE activity was higher in patients with sarcoidosis with the AGTR1 A/C genotype than in others. However, this tendency was not detected in patients with tuberculosis.
CONCLUSIONS—The AGTR1 allele C is associated with high activity of SACE in patients with sarcoidosis. It is another predisposing factor for high levels of SACE in patients with sarcoidosis and is considered to be an independent factor from the ACE D allele for high levels of SACE in sarcoidosis. This fact could be one of the explanations for the increased SACE activity in sarcoidosis.

 PMID:9713444

A Novel Splice-Site Mutation in Angiotensin I-Converting Enzyme (ACE) Gene, c.3691+1G>A (IVS25+1G>A), Causes a Dramatic Increase in Circulating ACE through Deletion of the Transmembrane Anchor

PubMed Central

Persu, Alexandre; Lambert, Michel; Deinum, Jaap; Cossu, Marta; de Visscher, Nathalie; Irenge, Leonid; Ambroise, Jerôme; Minon, Jean-Marc; Nesterovitch, Andrew B.; Churbanov, Alexander; Popova, Isolda A.; Danilov, Sergei M.; Danser, A. H. Jan; Gala, Jean-Luc

2013-01-01

Background Angiotensin-converting enzyme (ACE) (EC 4.15.1) metabolizes many biologically active peptides and plays a key role in blood pressure regulation and vascular remodeling. Elevated ACE levels are associated with different cardiovascular and respiratory diseases. Methods and Results Two Belgian families with a 8-16-fold increase in blood ACE level were incidentally identified. A novel heterozygous splice site mutation of intron 25 - IVS25+1G>A (c.3691+1G>A) - cosegregating with elevated plasma ACE was identified in both pedigrees. Messenger RNA analysis revealed that the mutation led to the retention of intron 25 and Premature Termination Codon generation. Subjects harboring the mutation were mostly normotensive, had no left ventricular hypertrophy or cardiovascular disease. The levels of renin-angiotensin-aldosterone system components in the mutated cases and wild-type controls were similar, both at baseline and after 50 mg captopril. Compared with non-affected members, quantification of ACE surface expression and shedding using flow cytometry assay of dendritic cells derived from peripheral blood monocytes of affected members, demonstrated a 50% decrease and 3-fold increase, respectively. Together with a dramatic increase in circulating ACE levels, these findings argue in favor of deletion of transmembrane anchor, leading to direct secretion of ACE out of cells. Conclusions We describe a novel mutation of the ACE gene associated with a major familial elevation of circulating ACE, without evidence of activation of the renin-angiotensin system, target organ damage or cardiovascular complications. These data are consistent with the hypothesis that membrane-bound ACE, rather than circulating ACE, is responsible for Angiotensin II generation and its cardiovascular consequences. PMID:23560051

Convergent evidences from human and animal studies implicate angiotensin I-converting enzyme activity in cognitive performance in schizophrenia.

PubMed

Gadelha, A; Vendramini, A M; Yonamine, C M; Nering, M; Berberian, A; Suiama, M A; Oliveira, V; Lima-Landman, M T; Breen, G; Bressan, R A; Abílio, V; Hayashi, M A F

2015-12-08

In schizophrenia (SCZ), higher angiotensin I-converting enzyme (ACE) levels have been reported in patient's blood and cerebrospinal fluid (CSF). Hereby, we propose to explore whether the ACE activity levels are associated to cognitive performance in SCZ. Seventy-two patients with SCZ or schizoaffective disorder diagnosis, and 69 healthy controls (HCs) underwent a cognitive battery with parallel collection of peripheral blood samples to measure ACE activity. Significant higher ACE activity levels were confirmed in the plasma of SCZ patients compared with HCs (Student's t=-5.216; P<0.001). ACE activity significantly correlated to Hopkins delayed recall measures (r=-0.247; P=0.004) and Hopkins total (r=-0.214; P=0.012). Subjects grouped as high ACE activity (above average) had worse performance compared with low ACE activity level group for Hopkins delayed recall measure, even after correction for clinical condition, age, gender and years of education (P=0.029). The adjusted R squared for this final model was 0.343. This result was evident only comparing extreme groups for ACE activity, when splitting the sample in three groups with similar number of subjects. To clarify this finding, we performed an evaluation of the cognitive performance of transgenic mice with three copies of ACE gene in novel object recognition (NOR) test, which showed that such animals presented impairment in NOR (P<0.05) compared with two copies of wild-type animals. The results observed in SCZ patients and animal model suggest both the association of ACE to cognitive deficits in SCZ. This finding may support the evaluation of novel treatment protocols and/or of innovative drugs for specific intervention of cognitive deficits in SCZ envisioning concomitant ACE activity and behavior evaluations.

Valsartan attenuates intimal hyperplasia in balloon-injured rat aortic arteries through modulating the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis.

PubMed

Li, Yonghong; Cai, Shanglang; Wang, Qixin; Zhou, Jingwei; Hou, Bo; Yu, Haichu; Ge, Zhiming; Guan, Renyan; Liu, Xu

2016-05-15

The role of the Mas receptor in the activity of valsartan against intimal hyperplasia is unclear. Herein, we investigated the role of the angiotensin-converting enzyme 2 (ACE2)-angiotensin-(1-7)-Mas receptor axis on the activity of valsartan against intimal hyperplasiain balloon-injured rat aortic arteries. Wistar rats were randomized equally into the sham control group, injured group, and injured plus valsartan (20 mg/kg/d)-treated group. Valsartan significantly attenuated the vascular smooth muscle cell proliferation and intimal and medial thickening on days 14 and 28 after injury. The angiotensin-(1-7) levels as well as ACE2 and Mas receptor mRNA/protein expression were significantly decreased in the injured rats, compared to the uninjured rats; meanwhile, the angiotensin II level as well as the ACE and AT1 receptor mRNA/protein expression were increased (all P < 0.05 or < 0.01). Additionally, the p-ERK protein expression was increased (P < 0.01). Treatment with valsartan significantly increased the angiotensin-(1-7) levels as well as ACE2 and Mas receptor mRNA/protein expression but decreased the angiotensin II level, ACE and AT1 receptor mRNA/protein expression, as well as the p-ERK protein expression, compared to the injured group (all P < 0.05 or < 0.01). These results suggest that valsartan attenuates neointimal hyperplasiain balloon-injured rat aortic arteries through activation of the ACE2-angiotensin-(1-7)-Mas axis as well as inhibition of the ACE-angiotensin II-AT1 and p-ERK pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

Acute kidney injury post-major orthopaedic surgery: A single-Centre case-control study.

PubMed

Ying, Tracey; Chan, Samantha; Lane, Stephen; Somerville, Christine

2018-02-01

To identify risk factors for acute kidney injury following major orthopaedic surgery. We included all patients undergoing major orthopaedic surgery at University Hospital Geelong between 2008 and 2014 in the study. Out of 2188 surgeries audited, we identified cases of acute kidney injury using the RIFLE criteria and matched those to controls 2:1 for age, sex, procedure and chronic kidney disease stage. We reviewed their records for risk factors of postoperative acute kidney injury, including medications such as gentamicin, diuretics, non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use. We reviewed the patients' history of cardiovascular disease, chronic liver disease, hypertension and diabetes mellitus along with presence of sepsis and obesity. Associations of hypothetical risk factors were estimated using conditional logistic regression. We identified 164 cases of AKI in an elderly cohort (median age = 73 years). Controlling for baseline comorbidities, both diuretic and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use were found to be associated with a twofold risk of acute kidney injury (diuretic - OR 2.06 95% CI:1.30-3.26, P < 0.005, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use OR 2.09 95% CI:1.31-3.32, P < 0.005). A dose-effect model accounting for perioperative nonsteroidal anti-inflammatory drug administration demonstrated a linear relationship between the number of times these drugs were given and postoperative acute kidney injury risk (OR 1.35 95% CI:1.05-1.73, P = 0.02). We identified perioperative diuretics, non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker to be significantly associated with postoperative AKI. Further prospective studies are required to confirm this. © 2016 Asian Pacific Society of Nephrology.

Peptidases in dog-ileum circular and longitudinal smooth-muscle plasma membranes. Their relative contribution to the metabolism of neurotensin.

PubMed

Checler, F; Ahmad, S; Kostka, P; Barelli, H; Kitabgi, P; Fox, J A; Kwan, C Y; Daniel, E E; Vincent, J P

1987-07-15

We established the content in neuropeptide-metabolizing peptidases present in highly purified plasma membranes prepared from the circular and longitudinal muscles of dog ileum. Activities were measured by the use of fluorigenic substrates and the identities of enzymes were confirmed by the use of specific peptidase inhibitors. Endopeptidase 24.11, angiotensin-converting enzyme, post-proline dipeptidyl aminopeptidase and aminopeptidases were found in both membrane preparations. Proline endopeptidase was only detected in circular smooth muscle plasma membranes while pyroglutamyl-peptide hydrolase was not observed in either tissue. The relative contribution of these peptidases to the inactivation of neurotensin was assessed. The enzymes involved in the primary inactivating cleavages occurring on the neurotensin molecule were as follows. In both membrane preparations, endopeptidase 24.11 was responsible for the formation of neurotensin-(1-11) and contributed to the formation of neurotensin-(1-10); a recently purified neurotensin-degrading neutral metallopeptidase was also involved in the formation of neurotensin-(1-10). A carboxypeptidase-like activity hydrolysed neurotensin at the Ile12-Leu13 peptide bond, leading to the formation of neurotensin-(1-12). Proline endopeptidase and endopeptidase 24.15 only occurred in circular muscle plasma membranes, yielding neurotensin-(1-7) and neurotensin-(1-8), respectively. In addition, the secondary processing of neurotensin degradation products was catalyzed by the following peptidases. In circular and longitudinal muscle membranes, angiotensin-converting enzyme converted neurotensin-(1-10) into neurotensin-(1-8) and tyrosine resulted from the rapid hydrolysis of neurotensin-(11-13) by bestatin-sensitive aminopeptidases. A post-proline dipeptidyl aminopeptidase activity converted neurotensin-(9-13) into neurotensin-(11-13) in circular muscle plasma membranes. The mechanism of neurotensin inactivation occurring in these membranes will be compared to that previously established for membranes from central origin.

Purification and characterization of a tuliposide-converting enzyme from bulbs of Tulipa gesneriana.

PubMed

Kato, Yasuo; Shoji, Kazuaki; Ubukata, Makoto; Shigetomi, Kengo; Sato, Yukio; Nakajima, Noriyuki; Ogita, Shinjiro

2009-08-01

An enzyme that catalyzes the stoichiometric conversion of 6-tuliposide into tulipalin was purified and characterized from bulbs of Tulipa gesneriana. The enzyme appeared to be a dimer, the relative molecular mass (Mr) of each subunit being 34,900; it had maximum activity and stability at neutral pH and moderate temperature. The enzyme preferentially acted on such glucose esters as 6-tuliposides, and to a lesser extent on p-nitrophenylacetate.

Genetics Home Reference: combined malonic and methylmalonic aciduria

MedlinePlus

... acids are building blocks used to make fats (lipids). The ACSF3 enzyme performs a chemical reaction that converts malonic acid to malonyl-CoA, which is the first step of fatty acid synthesis in cellular structures called mitochondria . Based on this activity, the enzyme ...

Efficient, environmentally-friendly and specific valorization of lignin: promising role of non-radical lignolytic enzymes.

PubMed

Wang, Wenya; Zhang, Chao; Sun, Xinxiao; Su, Sisi; Li, Qiang; Linhardt, Robert J

2017-06-01

Lignin is the second most abundant bio-resource in nature. It is increasingly important to convert lignin into high value-added chemicals to accelerate the development of the lignocellulose biorefinery. Over the past several decades, physical and chemical methods have been widely explored to degrade lignin and convert it into valuable chemicals. Unfortunately, these developments have lagged because of several difficulties, of which high energy consumption and non-specific cleavage of chemical bonds in lignin remain the greatest challenges. A large number of enzymes have been discovered for lignin degradation and these are classified as radical lignolytic enzymes and non-radical lignolytic enzymes. Radical lignolytic enzymes, including laccases, lignin peroxidases, manganese peroxidases and versatile peroxidases, are radical-based bio-catalysts, which degrade lignins through non-specific cleavage of chemical bonds but can also catalyze the radical-based re-polymerization of lignin fragments. In contrast, non-radical lignolytic enzymes selectively cleave chemical bonds in lignin and lignin model compounds and, thus, show promise for use in the preparation of high value-added chemicals. In this mini-review, recent developments on non-radical lignolytic enzymes are discussed. These include recently discovered non-radical lignolytic enzymes, their metabolic pathways for lignin conversion, their recent application in the lignin biorefinery, and the combination of bio-catalysts with physical/chemical methods for industrial development of the lignin refinery.

Angiotensin-I converting enzyme (ACE): structure, biological roles, and molecular basis for chloride ion dependence.

PubMed

Masuyer, Geoffrey; Yates, Christopher J; Sturrock, Edward D; Acharya, K Ravi

2014-10-01

Somatic angiotensin-I converting enzyme (sACE) has an essential role in the regulation of blood pressure and electrolyte fluid homeostasis. It is a zinc protease that cleaves angiotensin-I (AngI), bradykinin, and a broad range of other signalling peptides. The enzyme activity is provided by two homologous domains (N- and C-), which display clear differences in substrate specificities and chloride activation. The presence of chloride ions in sACE and its unusual role in activity was identified early on in the characterisation of the enzyme. The molecular mechanisms of chloride activation have been investigated thoroughly through mutagenesis studies and shown to be substrate-dependent. Recent results from X-ray crystallography structural analysis have provided the basis for the intricate interactions between ACE, its substrate and chloride ions. Here we describe the role of chloride ions in human ACE and its physiological consequences. Insights into the chloride activation of the N- and C-domains could impact the design of improved domain-specific ACE inhibitors.

Molecular diversity of tuliposide B-converting enzyme in tulip (Tulipa gesneriana): identification of the root-specific isozyme.

PubMed

Nomura, Taiji; Ueno, Ayaka; Ogita, Shinjiro; Kato, Yasuo

2017-06-01

6-Tuliposide B (PosB) is a glucose ester accumulated in tulip (Tulipa gesneriana) as a major secondary metabolite. PosB serves as the precursor of the antimicrobial lactone tulipalin B (PaB), which is formed by PosB-converting enzyme (TCEB). The gene TgTCEB1, encoding a TCEB, is transcribed in tulip pollen but scarcely transcribed in other tissues (e.g. roots) even though those tissues show high TCEB activity. This led to the prediction of the presence of a TCEB isozyme with distinct tissue specificity. Herein, we describe the identification of the TgTCEB-R gene from roots via native enzyme purification; this gene is a paralog of TgTCEB1. Recombinant enzyme characterization verified that TgTCEB-R encodes a TCEB. Moreover, TgTCEB-R was localized in tulip plastids, as found for pollen TgTCEB1. TgTCEB-R is transcribed almost exclusively in roots, indicating a tissue preference for the transcription of TCEB isozyme genes.

Redirection of pyruvate flux toward desired metabolic pathways through substrate channeling between pyruvate kinase and pyruvate-converting enzymes in Saccharomyces cerevisiae.

PubMed

Kim, Sujin; Bae, Sang-Jeong; Hahn, Ji-Sook

2016-04-07

Spatial organization of metabolic enzymes allows substrate channeling, which accelerates processing of intermediates. Here, we investigated the effect of substrate channeling on the flux partitioning at a metabolic branch point, focusing on pyruvate metabolism in Saccharomyces cerevisiae. As a platform strain for the channeling of pyruvate flux, PYK1-Coh-Myc strain was constructed in which PYK1 gene encoding pyruvate kinase is tagged with cohesin domain. By using high-affinity cohesin-dockerin interaction, the pyruvate-forming enzyme Pyk1 was tethered to heterologous pyruvate-converting enzymes, lactate dehydrogenase and α-acetolactate synthase, to produce lactic acid and 2,3-butanediol, respectively. Pyruvate flux was successfully redirected toward desired pathways, with a concomitant decrease in ethanol production even without genetic attenuation of the ethanol-producing pathway. This pyruvate channeling strategy led to an improvement of 2,3-butanediol production by 38%, while showing a limitation in improving lactic acid production due to a reduced activity of lactate dehydrogenase by dockerin tagging.

Angiotensin-converting enzyme in epithelial and neuroepithelial cells.

PubMed

Defendini, R; Zimmerman, E A; Weare, J A; Alhenc-Gelas, F; Erdös, E G

1983-07-01

Angiotensin-converting enzyme (CE) occurs in three types of cell: endothelial, epithelial, and neuroepithelial. In all three, it appears to be bound to plasma membrane. With antisera to the human enzyme, CE is demonstrated in paraffin sections on the apical surface of epithelial cells in the proximal tubule of the kidney, the mucosa of the small intestine, the syncytial trophoblast of the placenta, and the choroid plexus. Epithelial CE is characteristically found on microvillous surfaces in contact with an effluent, well placed to act on substrate in flux. In the brain, CE occurs in nerve fibers and terminals, mainly mesiobasally and in basal ganglia. Mesiobasal CE coincides with other components of the renin-angiotensin system (RAS) in the choroid/ventricular fluid, the subfornical organ, and the magnocellular neurosecretory system of the hypothalamus. Extrapyramidal CE, however, may not be related to the RAS. In the substantia nigra and the globus pallidus, the enzyme has the same cellular distribution as two putative neuromodulators, substance P and enkephalin, the latter a known substrate of CE.

Quality improvement in coronary care: analysis of sustainability and impact on adjacent clinical measures after a Swedish controlled, multicenter quality improvement collaborative.

PubMed

Carlhed, Rickard; Bellman, Christina; Bojestig, Mats; Bojö, Leif; Peterson, Anette; Lindahl, Bertil

2012-08-01

Quality Improvement in Coronary Care, a Swedish multicenter, controlled quality-improvement (QI) collaborative, has shown significant improvements in adherence to national guidelines for acute myocardial infarction, as well as improved clinical outcome. The objectives of this report were to describe the sustainability of the improvements after withdrawal of study support and a consolidation period of 3 months and to report whether improvements were disseminated to treatments and diagnostic procedures other than those primarily targeted. Multidisciplinary teams from 19 Swedish hospitals were educated in basic QI methodologies. Another 19 matched hospitals were included as blinded controls. All evaluations were made on the hospital level, and data were obtained from a national quality registry, Swedish Register of Information and Knowledge About Swedish Heart Intensive Care Admissions (RIKS-HIA). Sustainability indicators consisted of use of angiotensin-converting enzyme inhibitors, lipid-lowering therapy, clopidogrel, low-molecular weight heparin, and coronary angiography. Dissemination indicators were use of echocardiography, stress tests, and reperfusion therapy; time delays; and length of stay. At the reevaluation period of 6 months, the improvements at the QI intervention hospitals were sustained in all indicators but 1 (angiotensin-converting enzyme inhibitor). Between the 2 measurements, the control group improved significantly in all but 1 indicator (angiotensin-converting enzyme inhibitor). However, at the second measurement, the absolute adherence rates of the intervention hospitals were still numerically higher in all 5 indicators, and significantly so in 1 (clopidogrel). No significant changes were observed for the dissemination indicators. The combination of a systematic QI collaborative with a national, interactive quality registry might lead to substantial and sustained improvements in the quality of acute myocardial infarction care. However, to achieve disseminated improvements in adjacent clinical measures, those adjacent measures probably should be made explicit before any QI intervention. (J Am Heart Assoc. 2012;1:e000737 doi: 10.1161/JAHA.112.000737.).

Angiotensin converting enzyme 2 activity and human atrial fibrillation: increased plasma angiotensin converting enzyme 2 activity is associated with atrial fibrillation and more advanced left atrial structural remodelling.

PubMed

Walters, Tomos E; Kalman, Jonathan M; Patel, Sheila K; Mearns, Megan; Velkoska, Elena; Burrell, Louise M

2017-08-01

Angiotensin converting enzyme 2 (ACE2) is an integral membrane protein whose main action is to degrade angiotensin II. Plasma ACE2 activity is increased in various cardiovascular diseases. We aimed to determine the relationship between plasma ACE2 activity and human atrial fibrillation (AF), and in particular its relationship to left atrial (LA) structural remodelling. One hundred and three participants from a tertiary arrhythmia centre, including 58 with paroxysmal AF (PAF), 20 with persistent AF (PersAF), and 25 controls, underwent clinical evaluation, echocardiographic analysis, and measurement of plasma ACE2 activity. A subgroup of 20 participants underwent invasive LA electroanatomic mapping. Plasma ACE2 activity levels were increased in AF [control 13.3 (9.5-22.3) pmol/min/mL; PAF 16.9 (9.7-27.3) pmol/min/mL; PersAF 22.8 (13.7-33.4) pmol/min/mL, P = 0.006]. Elevated plasma ACE2 was associated with older age, male gender, hypertension and vascular disease, elevated left ventricular (LV) mass, impaired LV diastolic function and advanced atrial disease (P < 0.05 for all). Independent predictors of elevated plasma ACE2 activity were AF (P = 0.04) and vascular disease (P < 0.01). There was a significant relationship between elevated ACE2 activity and low mean LA bipolar voltage (adjusted R2 = 0.22, P = 0.03), a high proportion of complex fractionated electrograms (R2 = 0.32, P = 0.009) and a long LA activation time (R2 = 0.20, P = 0.04). Plasma ACE2 activity is elevated in human AF. Both AF and vascular disease predict elevated plasma ACE2 activity, and elevated plasma ACE2 is significantly associated with more advanced LA structural remodelling. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

An in vitro synthetic biology platform for the industrial biomanufacturing of myo-inositol from starch.

PubMed

You, Chun; Shi, Ting; Li, Yunjie; Han, Pingping; Zhou, Xigui; Zhang, Yi-Heng Percival

2017-08-01

Myo-Inositol (vitamin B8) is widely used in the drug, cosmetic, and food & feed industries. Here, we present an in vitro non-fermentative enzymatic pathway that converts starch to inositol in one vessel. This in vitro pathway is comprised of four enzymes that operate without ATP or NAD + supplementation. All enzyme BioBricks are carefully selected from hyperthermophilic microorganisms, that is, alpha-glucan phosphorylase from Thermotoga maritima, phosphoglucomutase from Thermococcus kodakarensis, inositol 1-phosphate synthase from Archaeoglobus fulgidus, and inositol monophosphatase from T. maritima. They were expressed efficiently in high-density fermentation of Escherichia coli BL21(DE3) and easily purified by heat treatment. The four-enzyme pathway supplemented with two other hyperthermophilic enzymes (i.e., 4-α-glucanotransferase from Thermococcus litoralis and isoamylase from Sulfolobus tokodaii) converts branched or linear starch to inositol, accomplishing a very high product yield of 98.9 ± 1.8% wt./wt. This in vitro (aeration-free) biomanufacturing has been successfully operated on 20,000-L reactors. Less costly inositol would be widely added in heath food, low-end soft drink, and animal feed, and may be converted to other value-added biochemicals (e.g., glucarate). This biochemical is the first product manufactured by the in vitro synthetic biology platform on an industrial scale. Biotechnol. Bioeng. 2017;114: 1855-1864. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

[Angiotensin converting enzyme 2 and its emerging role in the regulation of the renin angiotensin system].

PubMed

Soler, María José; Lloveras, Josep; Batlle, Daniel

2008-07-12

The renin-angiotensin system (RAS) plays a key role in the regulation of cardiovascular and renal function. Thus, RAS blockade with an angiotensin-converting enzyme (ACE) and/or angiotensin receptor blocker decreases blood pressure, cardiovascular events, and delays the progression of kidney disease. The discovery of ACE2, a homologue of ACE, capable of degrading angiotensin II to angiotensin 1-7, may offer new insights into the RAS. In this review we discuss the possible protective role of ACE2 in different organs, namely heart, lungs and kidneys. The role of this enzyme is inferred from recent studies performed using genetically manipulated mice that lack the ACE2 gene and also mice treated with pharmacological ACE2 inhibitors. These results suggest that ACE2 might be a new therapeutic target within the RAS.

Molecular imprinting of enzymes with water-insoluble ligands for nonaqueous biocatalysis.

PubMed

Rich, Joseph O; Mozhaev, Vadim V; Dordick, Jonathan S; Clark, Douglas S; Khmelnitsky, Yuri L

2002-05-15

Attaining higher levels of catalytic activity of enzymes in organic solvents is one of the major challenges in nonaqueous enzymology. One of the most successful strategies for enhancing enzyme activity in organic solvents involves tuning the enzyme active site by molecular imprinting with substrates or their analogues. Unfortunately, numerous imprinters of potential importance are poorly soluble in water, which significantly limits the utility of this method. In the present study, we have developed strategies that overcome this limitation of the molecular-imprinting technique and that thus expand its applicability beyond water-soluble ligands. The solubility problem can be addressed either by converting the ligands into a water-soluble form or by adding relatively high concentrations of organic cosolvents, such as tert-butyl alcohol and 1,4-dioxane, to increase their solubility in the lyophilization medium. We have succeeded in applying both of these strategies to produce imprinted thermolysin, subtilisin, and lipase TL possessing up to 26-fold higher catalytic activity in the acylation of paclitaxel and 17beta-estradiol compared to nonimprinted enzymes. Furthermore, we have demonstrated for the first time that molecular imprinting and salt activation, applied in combination, produce a strong additive activation effect (up to 110-fold), suggesting different mechanisms of action involved in these enzyme activation techniques.

Allosteric Inhibition of the Neuropeptidase Neurolysin*

PubMed Central

Hines, Christina S.; Ray, Kallol; Schmidt, Jack J.; Xiong, Fei; Feenstra, Rolf W.; Pras-Raves, Mia; de Moes, Jan Peter; Lange, Jos H. M.; Melikishvili, Manana; Fried, Michael G.; Mortenson, Paul; Charlton, Michael; Patel, Yogendra; Courtney, Stephen M.; Kruse, Chris G.; Rodgers, David W.

2014-01-01

Neuropeptidases specialize in the hydrolysis of the small bioactive peptides that play a variety of signaling roles in the nervous and endocrine systems. One neuropeptidase, neurolysin, helps control the levels of the dopaminergic circuit modulator neurotensin and is a member of a fold group that includes the antihypertensive target angiotensin converting enzyme. We report the discovery of a potent inhibitor that, unexpectedly, binds away from the enzyme catalytic site. The location of the bound inhibitor suggests it disrupts activity by preventing a hinge-like motion associated with substrate binding and catalysis. In support of this model, the inhibition kinetics are mixed, with both noncompetitive and competitive components, and fluorescence polarization shows directly that the inhibitor reverses a substrate-associated conformational change. This new type of inhibition may have widespread utility in targeting neuropeptidases. PMID:25378390

Assimilation of nicotinamide mononucleotide requires periplasmic AphA phosphatase in Salmonella enterica.

PubMed

Grose, Julianne H; Bergthorsson, Ulfar; Xu, Yaping; Sterneckert, Jared; Khodaverdian, Behzad; Roth, John R

2005-07-01

Salmonella enterica can obtain pyridine from exogenous nicotinamide mononucleotide (NMN) by three routes. In route 1, nicotinamide is removed from NMN in the periplasm and enters the cell as the free base. In route 2, described here, phosphate is removed from NMN in the periplasm by acid phosphatase (AphA), and the produced nicotinamide ribonucleoside (NmR) enters the cell via the PnuC transporter. Internal NmR is then converted back to NMN by the NmR kinase activity of NadR. Route 3 is seen only in pnuC* transporter mutants, which import NMN intact and can therefore grow on lower levels of NMN. Internal NMN produced by either route 2 or route 3 is deamidated to nicotinic acid mononucleotide and converted to NAD by the biosynthetic enzymes NadD and NadE.

Serum angiotensin-1 converting enzyme activity processes a human immunodeficiency virus 1 gp160 peptide for presentation by major histocompatibility complex class I molecules

PubMed Central

1992-01-01

T cell stimulation by the human immunodeficiency virus 1 gp160-derived peptide p18 presented by H-2Dd class I major histocompatibility complex molecules in a cell-free system was found to require proteolytic cleavage. This extracellular processing was mediated by peptidases present in fetal calf serum. In vitro processing of p18 resulted in a distinct reverse phase high performance liquid chromatography profile, from which a biologically active product was isolated and sequenced. This peptide processing can be specifically blocked by the angiotensin- 1 converting enzyme (ACE) inhibitor captopril, and can occur by exposing p18 to purified ACE. The ability of naturally occurring extracellular proteases to convert inactive peptides to T cell antigens has important implications for understanding cytotoxic T lymphocyte responses in vivo, and for rational peptide vaccine design. PMID:1316930

21 CFR 184.1388 - Lactase enzyme preparation from Kluyveromyces lactis.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-galactoside galactohydrase (CAS Reg. No. CBS 683), which converts lactose to glucose and galactose. It is... in § 170.3(o)(9) of this chapter to convert lactose to glucose and galactose. (2) The ingredient is... practice is to use this ingredient in milk to produce lactase-treated milk, which contains less lactose...

21 CFR 184.1388 - Lactase enzyme preparation from Kluyveromyces lactis.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-galactoside galactohydrase (CAS Reg. No. CBS 683), which converts lactose to glucose and galactose. It is... in § 170.3(o)(9) of this chapter to convert lactose to glucose and galactose. (2) The ingredient is... practice is to use this ingredient in milk to produce lactase-treated milk, which contains less lactose...

Renin-angiotensin-aldosterone system inhibition: overview of the therapeutic use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, mineralocorticoid receptor antagonists, and direct renin inhibitors.

PubMed

Mercier, Kelly; Smith, Holly; Biederman, Jason

2014-12-01

Angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy in hypertensive diabetic patients with macroalbuminuria, microalbuminuria, or normoalbuminuria has been repeatedly shown to improve cardiovascular mortality and reduce the decline in glomerular filtration rate. Renin-angiotensin-aldosterone system (RAAS) blockade in normotensive diabetic patients with normoalbuminuria or microalbuminuria cannot be advocated at present. Dual RAAS inhibition with ACE inhibitors plus ARBs or ACE inhibitors plus direct renin inhibitors has failed to improve cardiovascular or renal outcomes but has predisposed patients to serious adverse events. Copyright © 2014 Elsevier Inc. All rights reserved.

Angiotensin converting enzyme over expression in myelocytes enhances the immune response

PubMed Central

Bernstein, Kenneth E.; Gonzalez-Villalobos, Romer A.; Giani, Jorge F.; Shah, Kandarp; Bernstein, Ellen; Janjulia, Tea; Koronyo, Yosef; Shi, Peng D.; Koronyo-Hamaoui, Maya; Fuchs, Sebastien; Shen, Xiao Z.

2015-01-01

Angiotensin converting enzyme (ACE) plays an important role in blood pressure control. ACE also has effects on renal function, reproduction, hematopoiesis and several aspects of the immune response. ACE 10/10 mice over express ACE in monocytic cells; macrophages from ACE 10/10 mice demonstrate increased polarization towards a proinflammatory phenotype. As a result, ACE 10/10 mice have a highly effective immune response following challenge with either melanoma, bacterial infection or Alzheimer’s disease. The ACE 10/10 mice suggest that enhanced monocytic function greatly contributes to the ability of the immune response to defend against a wide variety of antigenic and non-antigenic challenges. PMID:24633750

Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora) Hydrolysates

PubMed Central

Ghanbari, Raheleh; Zarei, Mohammad; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

2015-01-01

In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions. PMID:26690117

Necessity of angiotensin-converting enzyme-related gene for cardiac functions and longevity of Drosophila melanogaster assessed by optical coherence tomography

NASA Astrophysics Data System (ADS)

Liao, Fang-Tsu; Chang, Cheng-Yi; Su, Ming-Tsan; Kuo, Wen-Chuan

2014-01-01

Prior studies have established the necessity of an angiotensin-converting enzyme-related (ACER) gene for heart morphogenesis of Drosophila. Nevertheless, the physiology of ACER has yet to be comprehensively understood. Herein, we employed RNA interference to down-regulate the expression of ACER in Drosophila's heart and swept source optical coherence tomography to assess whether ACER is required for cardiac functions in living adult flies. Several contractile parameters of Drosophila heart, including the heart rate (HR), end-diastolic diameter (EDD), end-systolic diameter (ESD), percent fractional shortening (%FS), and stress-induced cardiac performance, are shown, which are age dependent. These age-dependent cardiac functions declined significantly when ACER was down-regulated. Moreover, the lifespans of ACER knock-down flies were significantly shorter than those of wild-type control flies. Thus, we posit that ACER, the Drosophila ortholog of mammalian angiotensin-converting enzyme 2 (ACE2), is essential for both heart physiology and longevity of animals. Since mammalian ACE2 controls many cardiovascular physiological features and is implicated in cardiomyopathies, our findings that ACER plays conserved roles in genetically tractable animals will pave the way for uncovering the genetic pathway that controls the renin-angiotensin system.

Production of angiotensin I converting enzyme inhibitory (ACE-I) peptides during milk fermentation and their role in reducing hypertension.

PubMed

Rai, Amit Kumar; Sanjukta, Samurailatpam; Jeyaram, Kumaraswamy

2017-09-02

Fermented milk is a potential source of various biologically active peptides with specific health benefits. Angiotensin converting enzyme inhibitory (ACE-I) peptides are one of the most studied bioactive peptides produced during milk fermentation. The presence of these peptides is reported in various fermented milk products such as, yoghurt, cheese, sour milk, etc., which are also available as commercial products. Many of the ACE-I peptides formed during milk fermentation are resistant to gastrointestinal digestion and inhibit angiotensin converting enzyme (ACE) in the rennin angiotension system (RAS). There are various factors, which affect the formation ACE-I peptides and their ability to reach the target tissue in active form, which includes type of starters (lactic acid bacteria (LAB), yeast, etc.), substrate composition (casein type, whey protein, etc.), composition of ACE-I peptide, pre and post-fermentation treatments, and its stability during gastrointestinal digestion. The antihypertensive effect of fermented milk products has also been proved by various in vitro and in vivo (animal and human trials) experiments. This paper reviews the literature on fermented milk products as a source of ACE-I peptides and various factors affecting the production and activity of ACE-I peptides.

Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos.

PubMed

Smolikova, Galina; Dolgikh, Elena; Vikhnina, Maria; Frolov, Andrej; Medvedev, Sergei

2017-09-16

The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN ( SGR ) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds.

Genetic and Hormonal Regulation of Chlorophyll Degradation during Maturation of Seeds with Green Embryos

PubMed Central

Dolgikh, Elena; Vikhnina, Maria; Frolov, Andrej

2017-01-01

The embryos of some angiosperms (usually referred to as chloroembryos) contain chlorophylls during the whole period of embryogenesis. Developing embryos have photochemically active chloroplasts and are able to produce assimilates, further converted in reserve biopolymers, whereas at the late steps of embryogenesis, seeds undergo dehydration, degradation of chlorophylls, transformation of chloroplast in storage plastids, and enter the dormancy period. However, in some seeds, the process of chlorophyll degradation remains incomplete. These residual chlorophylls compromise the quality of seed material in terms of viability, nutritional value, and shelf life, and represent a serious challenge for breeders and farmers. The mechanisms of chlorophyll degradation during seed maturation are still not completely understood, and only during the recent decades the main pathways and corresponding enzymes could be characterized. Among the identified players, the enzymes of pheophorbide a oxygenase pathway and the proteins encoded by STAY GREEN (SGR) genes are the principle ones. On the biochemical level, abscisic acid (ABA) is the main regulator of seed chlorophyll degradation, mediating activity of corresponding catabolic enzymes on the transcriptional level. In general, a deep insight in the mechanisms of chlorophyll degradation is required to develop the approaches for production of chlorophyll-free high quality seeds. PMID:28926960

Glutamine Transport and Mitochondrial Metabolism in Cancer Cell Growth

PubMed Central

Scalise, Mariafrancesca; Pochini, Lorena; Galluccio, Michele; Console, Lara; Indiveri, Cesare

2017-01-01

The concept that cancer is a metabolic disease is now well acknowledged: many cancer cell types rely mostly on glucose and some amino acids, especially glutamine for energy supply. These findings were corroborated by overexpression of plasma membrane nutrient transporters, such as the glucose transporters (GLUTs) and some amino acid transporters such as ASCT2, LAT1, and ATB0,+, which became promising targets for pharmacological intervention. On the basis of their sodium-dependent transport modes, ASCT2 and ATB0+ have the capacity to sustain glutamine need of cancer cells; while LAT1, which is sodium independent will have the role of providing cancer cells with some amino acids with plausible signaling roles. According to the metabolic reprogramming of many types of cancer cells, glucose is mainly catabolized by aerobic glycolysis in tumors, while the fate of Glutamine is completed at mitochondrial level where the enzyme Glutaminase converts Glutamine to Glutamate. Glutamine rewiring in cancer cells is heterogeneous. For example, Glutamate is converted to α-Ketoglutarate giving rise to a truncated form of Krebs cycle. This reprogrammed pathway leads to the production of ATP mainly at substrate level and regeneration of reducing equivalents needed for cells growth, redox balance, and metabolic energy. Few studies on hypothetical mitochondrial transporter for Glutamine are reported and indirect evidences suggested its presence. Pharmacological compounds able to inhibit Glutamine metabolism may represent novel drugs for cancer treatments. Interestingly, well acknowledged targets for drugs are the Glutamine transporters of plasma membrane and the key enzyme Glutaminase. PMID:29376023

Role of mesenchymal stem cells versus angiotensin converting enzyme inhibitor in kidney repair.

PubMed

Ahmed, Hanaa H; Toson, Elshahat A; El-Mezayen, Hatem A; Rashed, Laila A; Elsherbiny, Eslam S

2017-07-01

The current study sought to clarify the role of bone marrow derived mesenchymal stem cells (BM-MSCs) and adipose tissue derived mesenchymal stem cells (AD-MSCs) in repressing nephropathy in the experimental model. Moreover, the aim of this work was extended to compare between stem cells role and angiotensin converting enzyme inhibitor in kidney repair. Isolation and preparation of MSCs culture, flow cytometry using CD34, CD44 and CD105 cell surface markers, biochemical analyses for determination of serum creatinine, urea, transforming growth factor β (TGF-β), cystatin C (CYS-C) and urinary N-Acetyl-ß-D-Glucosaminidase (UNAG), and histopathological investigation of kidney tissue sections were performed. The results of the present study revealed that single intravenous infusion of MSCs either derived from bone marrow or adipose tissue was able to enhance renal reparative processes through significantly decreased serum creatinine, urea, TGF-β and CYS-C levels as well as UNAG level and significantly increase glomerular filtration rate. Additionally, the histopathological investigations of kidney tissues showed that MSCs have significant regenerative effects as evidenced by the decrease in focal inflammatory cells infiltration, focal interstitial nephritis and congested glomeruli as well as degenerated tubules. The current data provided distinct evidence about the favourable impact of AD-MSCs and BM-MSCs in attenuation of cyclosporine-induced nephropathy in rats through their ability to promote functional and structural kidney repair via transdifferentiation. © 2016 Asian Pacific Society of Nephrology.

Transdermal delivery of angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs) and others for management of hypertension.

PubMed

Ahad, Abdul; Al-Mohizea, Abdullah Mohammed; Al-Jenoobi, Fahad Ibrahim; Aqil, Mohd

2016-01-01

Angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs) are some of the most commonly prescribed medications for hypertension. Most of all conventional dosage forms of ARBs and ACEIs undergo extensive first-pass metabolism, which significantly reduces bioavailability. Majority of ARBs and ACEIs are inherently short acting due to a rapid elimination half-life. In addition, oral dosage forms of ARBs and ACEIs have many high incidences of adverse effects due to variable absorption profiles, higher frequency of administration and poor patient compliance. Many attempts have been made globally at the laboratory level to investigate the skin permeation and to develop transdermal therapeutic systems of various ARBs, ACEIs and other anti-hypertensives, to circumvent the drawbacks associated with their conventional dosage form. This manuscript presents an outline of the transdermal research specifically in the area of ARBs, ACEIs and other anti-hypertensives reported in various pharmaceutical journals. The transdermal delivery has gained a significant importance for systemic treatment as it is able to avoid first-pass metabolism and major fluctuations of plasma levels typical of repeated oral administration. As we can experience from this review article that transdermal delivery of different ARBs and ACEIs improves bioavailability as well as patient compliance by many folds. In fact, the rationale development of some newer ARBs, ACEIs and other anti-hypertensives transdermal systems will provide new ways of treatment, circumventing current limitations for conventional dosage forms.

Relationship of quadriceps muscle power and optimal shortening velocity with angiotensin-converting enzyme activity in older women.

PubMed

Kostka, Joanna; Sikora, Joanna; Kostka, Tomasz

2017-01-01

The goal of this study was to assess whether angiotensin-converting enzyme (ACE) activity is related to muscle function (strength, power and velocity), as well as to assess if ACE inhibitors (ACEIs) and other angiotensin system blocking medications (ASBMs) influence muscle performance in elderly women. Ninety-five community-dwelling elderly women took part in this study. Anthropometric data, blood ACE activity analysis, maximum power (P max ) and optimal shortening velocity (υ opt ) of the knee extensor muscles, handgrip strength, physical activity (PA) and functional performance were measured. Women taking ACEI were on average almost 2 years older than the women who did not take ACEI. They took more medicines and were also characterized by significantly lower level of ACE, but they did not differ in terms of PA level, results of functional performance and parameters characterizing muscle functions. No correlations of ACE activity with P max and handgrip strength, as well as with PA or functional performance were found. Higher ACE activity was connected with lower υ opt for women who did not take any ASBMs (rho =-0.37; p =0.01). Serum ACE activity was not associated with muscle strength, power and functional performance in both ASBM users and nonusers, but was associated with optimal shortening velocity of quadriceps muscles in older women. Further prospective studies are needed to assess if ACEIs or other ASBMs may slow down the decline in muscle function and performance.

Common genetic variations of the renin-angiotensin-aldosterone system and response to acute angiotensin I-converting enzyme inhibition in essential hypertension.

PubMed

Hannila-Handelberg, Tuula; Kontula, Kimmo K; Paukku, Kirsi; Lehtonen, Jukka Y; Virtamo, Jarmo; Tikkanen, Ilkka; Hiltunen, Timo P

2010-04-01

In order to get insight into possible genetic determinants of antihypertensive drug action, we analysed the relations between polymorphisms of the genes of the renin-angiotensin-aldosterone system and acute effects of ACE inhibition on blood pressure as well as circulating renin and aldosterone levels in hypertensive patients. A total of 315 hypertensive patients referred for problems in drug treatment were given a single 50 mg dose of captopril. Plasma renin and aldosterone were measured before and 60 min after the drug administration. Four DNA variants, including angiotensin type I receptor (AGTR1) 1166 A/C, angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T and AGT -217 G/A, were genotyped in the patients and normotensive men (n = 175). A replication study on the relation between AGTR1 1166 A/C and plasma renin and aldosterone levels was carried out in the 244 hypertensive men of the pharmacogenetic GENRES Study. Referred hypertensive patients with the AGTR1 CC genotype had higher aldosterone at baseline (P = 0.02) and after 60 min of captopril administration (P = 0.01) compared with the AA genotype. Replicate analysis in the GENRES patients showed a similar trend. When the two studies were combined (315 and 244 patients, respectively), plasma aldosterone level (P = 0.007) as well as aldosterone/renin ratio (P = 0.04) were significantly higher in the CC genotype (n = 13) than in the AA genotype (n = 370). Transfection studies in cultured HEK293 cells indicated that the 1166C allele was associated with higher mRNA levels than the 1166A allele. The AGTR1 1166C allele when present in homozygous form may be associated with a form of essential hypertension characterized by high plasma aldosterone and low plasma renin levels, possibly due to increased AGTR1 mRNA levels and augmented angiotensin II action.

Angiotensin converting enzyme gene polymorphism is associated with severity of coronary artery disease in men with high total cholesterol levels.

PubMed

Borzyszkowska, Joanna; Stanislawska-Sachadyn, Anna; Wirtwein, Marcin; Sobiczewski, Wojciech; Ciecwierz, Dariusz; Targonski, Radoslaw; Gruchala, Marcin; Rynkiewicz, Andrzej; Limon, Janusz

2012-05-01

This study examines whether renin-angiotensin-aldosterone system gene polymorphisms: ACE (encoding for angiotensin converting enzyme) c.2306-117_404 I/D, AGTR1 (encoding for angiotensin II type-1 receptor) c.1080*86A>C and CYP11B2 (encoding for aldosterone synthase) c.-344C>T are associated with the extension of coronary atherosclerosis in a group of 647 patients who underwent elective coronary angiography. The extension of CAD was evaluated using the Gensini score. The polymorphisms were determined by PCR and RFLP assays. The associations between genotypes and the extent of coronary atherosclerosis were tested by the Kruskal-Wallis test, followed by pairwise comparisons using Wilcoxon test. The population has been divided into groups defined by: sex, smoking habit, past myocardial infarction, BMI (>, ≤ 25), age (>, ≤ 55), diabetes mellitus, level of total cholesterol (>, ≤ 200 mg/dl), LDL cholesterol (>, ≤ 130 mg/dl), HDL cholesterol (>, ≤ 40 mg/dl), triglycerides (>, ≤ 150 mg/dl). Significant associations between the ACE c.2306-117_404 I/D polymorphism and the Gensini score in men with high total cholesterol levels (P(Kruskal-Wallis) = 0.008; P(adjusted) = 0.009), high level of LDL cholesterol (P(Kruskal-Wallis) = 0.016; P(adjusted) = 0.028) and low level of HDL cholesterol (P(Kruskal-Wallis) = 0.04; P(adjusted) = 0.055) have been found. No association between the AGTR1 c.1080*86A>C and CYP11B2 c.-344C>T and the Gensini score has been found. These results suggest that men who carry ACE c.2306-117_404 DD genotype and have high total cholesterol, high LDL cholesterol and low HDL cholesterol levels may be predisposed to the development of more severe CAD.

Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration

PubMed Central

Carvalho, Clarissa Coelho; Florentino, Rodrigo Machado; França, Andressa; Matias, Eveline; Guimarães, Paola Bianchi; Batista, Carolina; Freire, Valder; Carmona, Adriana Karaoglanovic; Pesquero, João Bosco; de Paula, Ana Maria; Foureaux, Giselle; Leite, Maria de Fatima

2016-01-01

Background The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. Aim Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. Results We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. Conclusion ACE activation regulates melanoma cell proliferation and migration. PMID:27992423

Zeaxanthin epoxidation - an in vitro approach.

PubMed

Kuczyńska, Paulina; Latowski, Dariusz; Niczyporuk, Sylvia; Olchawa-Pajor, Monika; Jahns, Peter; Gruszecki, Wiesław I; Strzałka, Kazimierz

2012-01-01

Zeaxanthin epoxidase (ZE) is an enzyme operating in the violaxanthin cycle, which is involved in photoprotective mechanisms. In this work model systems to study zeaxanthin (Zx) epoxidation were developed. Two assay systems are presented in which epoxidation of Zx was observed. In these assays two mutants of Arabidopsis thaliana which have active only one of the two xanthophyll cycle enzymes were used. The npq1 mutant possesses an active ZE and is thus able to convert Zx to violaxanthin (Vx) but the violaxanthin de-epoxidase (VDE) is inactive, so that Vx cannot be converted to Zx. The other mutant, npq2, possesses an active VDE and can convert exogenous Vx to Zx under strong light conditions but reverse reaction is not possible. The first assay containing thylakoids from npq1 and npq2 mutants of A. thaliana gave positive results and high efficiency of epoxidation reaction was observed. The amount of Zx was reduced by 25%. To optimize high efficiency of epoxidation reaction additional factors facilitating both fusion of the two types of thylakoids and incorporation of Zx to their membranes were also studied. The second kind of assay contained npq1 mutant thylakoids of A. thaliana supplemented with exogenous Zx and monogalactosyldiacylglycerol (MGDG). Experiments with different proportions of Zx and MGDG showed that their optimal ratio is 1:60. In such system, due to epoxidation, the amount of Zx was reduced by 38% of its initial level. The in vitro systems of Zx epoxidation described in this paper enable analysis some properties of the ZE without necessity of its isolation.

Identification of amino acids conferring chain length substrate specificities on fatty alcohol-forming reductases FAR5 and FAR8 from Arabidopsis thaliana.

PubMed

Chacón, Micaëla G; Fournier, Ashley E; Tran, Frances; Dittrich-Domergue, Franziska; Pulsifer, Ian P; Domergue, Frédéric; Rowland, Owen

2013-10-18

Fatty alcohols play a variety of biological roles in all kingdoms of life. Fatty acyl reductase (FAR) enzymes catalyze the reduction of fatty acyl-coenzyme A (CoA) or fatty acyl-acyl carrier protein substrates to primary fatty alcohols. FAR enzymes have distinct substrate specificities with regard to chain length and degree of saturation. FAR5 (At3g44550) and FAR8 (At3g44560) from Arabidopsis thaliana are 85% identical at the amino acid level and are of equal length, but they possess distinct specificities for 18:0 or 16:0 acyl chain length, respectively. We used Saccharomyces cerevisiae as a heterologous expression system to assess FAR substrate specificity determinants. We identified individual amino acids that affect protein levels or 16:0-CoA versus 18:0-CoA specificity by expressing in yeast FAR5 and FAR8 domain-swap chimeras and site-specific mutants. We found that a threonine at position 347 and a serine at position 363 were important for high FAR5 and FAR8 protein accumulation in yeast and thus are likely important for protein folding and stability. Amino acids at positions 355 and 377 were important for dictating 16:0-CoA versus 18:0-CoA chain length specificity. Simultaneously converting alanine 355 and valine 377 of FAR5 to the corresponding FAR8 residues, leucine and methionine, respectively, almost fully converted FAR5 specificity from 18:0-CoA to 16:0-CoA. The reciprocal amino acid conversions, L355A and M377V, made in the active FAR8-S363P mutant background converted its specificity from 16:0-CoA to 18:0-CoA. This study is an important advancement in the engineering of highly active FAR proteins with desired specificities for the production of fatty alcohols with industrial value.

Major amyloid-β-degrading enzymes, endothelin-converting enzyme-2 and neprilysin, are expressed by distinct populations of GABAergic interneurons in hippocampus and neocortex.

PubMed

Pacheco-Quinto, Javier; Eckman, Christopher B; Eckman, Elizabeth A

2016-12-01

Impaired clearance of amyloid-β peptide (Aβ) has been postulated to significantly contribute to the amyloid accumulation typical of Alzheimer's disease. Among the enzymes known to degrade Aβ in vivo are endothelin-converting enzyme (ECE)-1, ECE-2, and neprilysin (NEP), and evidence suggests that they regulate independent pools of Aβ that may be functionally significant. To better understand the differential regulation of Aβ concentration by its physiological degrading enzymes, we characterized the cell and region-specific expression pattern of ECE-1, ECE-2, and NEP by in situ hybridization and immunohistochemistry in brain areas relevant to Alzheimer's disease. In contrast to the broader distribution of ECE-1, ECE-2 and NEP were found enriched in GABAergic neurons. ECE-2 was majorly expressed by somatostatin-expressing interneurons and was active in isolated synaptosomes. NEP messenger RNA was found mainly in parvalbumin-expressing interneurons, with NEP protein localized to perisomatic parvalbuminergic synapses. The identification of somatostatinergic and parvalbuminergic synapses as hubs for Aβ degradation is consistent with the possibility that Aβ may have a physiological function related to the regulation of inhibitory signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of gossypol biosynthetic pathway

PubMed Central

Tian, Xiu; Ruan, Ju-Xin; Huang, Jin-Quan; Fang, Xin; Chen, Zhi-Wen; Hong, Hui; Wang, Ling-Jian; Mao, Ying-Bo; Lu, Shan; Zhang, Tian-Zhen; Chen, Xiao-Ya

2018-01-01

Gossypol and related sesquiterpene aldehydes in cotton function as defense compounds but are antinutritional in cottonseed products. By transcriptome comparison and coexpression analyses, we identified 146 candidates linked to gossypol biosynthesis. Analysis of metabolites accumulated in plants subjected to virus-induced gene silencing (VIGS) led to the identification of four enzymes and their supposed substrates. In vitro enzymatic assay and reconstitution in tobacco leaves elucidated a series of oxidative reactions of the gossypol biosynthesis pathway. The four functionally characterized enzymes, together with (+)-δ-cadinene synthase and the P450 involved in 7-hydroxy-(+)-δ-cadinene formation, convert farnesyl diphosphate (FPP) to hemigossypol, with two gaps left that each involves aromatization. Of six intermediates identified from the VIGS-treated leaves, 8-hydroxy-7-keto-δ-cadinene exerted a deleterious effect in dampening plant disease resistance if accumulated. Notably, CYP71BE79, the enzyme responsible for converting this phytotoxic intermediate, exhibited the highest catalytic activity among the five enzymes of the pathway assayed. In addition, despite their dispersed distribution in the cotton genome, all of the enzyme genes identified show a tight correlation of expression. Our data suggest that the enzymatic steps in the gossypol pathway are highly coordinated to ensure efficient substrate conversion. PMID:29784821

Pharmacokinetic interaction between cefdinir and two angiotensin-converting enzyme inhibitors in rats.

PubMed Central

Jacolot, A; Tod, M; Petitjean, O

1996-01-01

The pharmacokinetic interaction between cefdinir and an angiotensin-converting enzyme inhibitor (captopril or quinapril) was investigated in rats. The linearity of cefdinir pharmacokinetics was demonstrated in three groups of rats receiving 10, 20, or 40 mg of cefdinir per kg of body weight intravenously. Then, three other groups of rats were established as follows: group 1 (n = 5) received cefdinir (10 mg/kg) intravenously, and 12 blood samples per rat were drawn between 0 and 8 h after injection of the dose; group 2 (n = 5) was treated in the same way as group 1, but captopril (0.8 mg/kg) was coadministered by intraintestinal injection into all animals; group 3 (n = 6) was treated in the same way as group 2, but quinapril (0.8 mg/kg) replaced captopril. Plasma cefdinir concentrations were measured by liquid chromatography, and the data were analyzed by a noncompartmental method. Finally, three groups of four or five rats each were set up as described above, but the cefdinir dose was 20 mg/kg and the animals were sacrificed 1 h after drug injection to collect blood to determine the unbound cefdinir fraction (fu) by ultrafiltration. The angiotensin-converting enzyme inhibitors increased the mean cefdinir area under the concentration-time curve up to 8 h by a factor of 1.8 (captopril; P < 0.05) and a factor of 3.5 (quinapril; P < 0.05). With captopril, mean cefdinir clearance was decreased by a factor of 2, and the volume of distribution increased by the same factor, while the fu increased from 15.4% +/- 3.0% (cefdinir alone) to 22.8% +/- 10.9% (cefdinir plus captopril). Captopril increased the cefdinir half-life from 0.62 +/- 0.17 to 2.92 +/- 0.95 h. With quinapril, the interaction was so strong that no elimination phase was detectable in four of the six rats, and therefore, no pharmacokinetic parameter values other than the cefdinir fu could be calculated; the cefdinir fu increased to 25.1% +/- 11.1%. It is concluded that captopril and quinapril (and/or their metabolites) have a major impact on the disposition of cefdinir in rats, probably by competition at the plasma protein-binding level and at the tubular anionic carrier level. This latter mechanism should also be relevant in humans. PMID:8849263

Targeting of antibody-conjugated plasminogen activators to the pulmonary vasculature.

PubMed

Muzykantov, V R; Barnathan, E S; Atochina, E N; Kuo, A; Danilov, S M; Fisher, A B

1996-11-01

Thrombolytic therapy has not been widely used for pulmonary embolism due to less than optimal results with conventional plasminogen activators. We propose a new approach to deliver plasminogen activators to the luminal surface of the pulmonary vasculature to potentially improve dissolution of pulmonary thromboemboli. Our previous studies have documented that a monoclonal antibody (mAb) to angiotensin-converting enzyme (anti-angiotensin-converting enzyme mAb 9B9) accumulates in the lungs of various animal species after systemic administration. We coupled 125I-labeled biotinylated plasminogen activators (single-chain urokinase plasminogen activator, tissue-type plasminogen activator and streptokinase) to biotinylated mAb 9B9, using streptavidin as a cross-linker. The fibrinolytic activity of plasminogen activators was not changed significantly by either biotinylation or by coupling to streptavidin. Antibody-conjugated plasminogen activators bind to the antigen immobilized in plastic wells and provide lysis of fibrin clots formed in these wells. Therefore, antibody-conjugated plasminogen activators bound to their target antigen retain their capacity to activate plasminogen. One hour after i.v. injection of mAb 9B9-conjugated radiolabeled biotinylated single-chain urokinase plasminogen activator, biotinylated tissue-type plasminogen activator or biotinylated-streptokinase in rats, the level of radiolabel was 7.4 +/- 0.8, 5.9 +/- 0.4 and 3.6 +/- 0.4% of injected dose/g (ID/g) of lung tissue vs. 0.5 +/- 0.01, 0.3 +/- 0.01 and 0.6 +/- 0.3% ID/g after injection of the same activators conjugated with control mouse IgG (P < .01 in all cases). Injection of mAb 9B9-conjugated radiolabeled plasminogen activator led to its rapid pulmonary uptake with a peak value 6.2 +/- 1.2% ID/g attained 3 hr after injection. One day later, 2.2 +/- 0.5% of the injected radioactivity was found per gram of lung tissue, although the blood level was 0.13 +/- 0.03% ID/g (lung/blood ratio 16.7 +/- 0.3). Therefore, conjugation of plasminogen activators with anti-angiotensin-converting enzyme mAb 9B9 provides their specific targeting to and prolonged association with the pulmonary vasculature. These results provide a basis for study of the local pulmonary fibrinolysis by mAb 9B9-conjugated plasminogen activators.

Porcine pulmonary angiotensin I-converting enzyme--biochemical characterization and spatial arrangement of the N- and C-domains by three-dimensional electron microscopic reconstruction.

PubMed

Chen, Hui-Ling; Lünsdorf, Heinrich; Hecht, Hans-Jürgen; Tsai, Hsin

2010-08-01

The somatic angiotensin I-converting enzyme (sACE; peptidyl-dipeptidase A; EC 3.4.15.1) was isolated from pig lung and purified to homogeneity. The purified enzyme has a molecular mass of about 180 kDa. Upon proteolytic cleavage, two approximately 90 kDa fragments were obtained and identified by amino-terminal sequence analysis as the N- and C-domains of sACE. Both purified domains were shown to be catalytically active. A 2.3 nm resolution model of sACE was obtained by three-dimensional electron microscopic reconstruction of negatively stained sACE particles, based on atomic X-ray data fitting. Our model shows for the first time the relative orientation of the sACE catalytically active domains and their spatial distance. (c) 2010 Elsevier Ltd. All rights reserved.

An Enzyme-Catalyzed Multistep DNA Refolding Mechanism in Hairpin Telomere Formation

PubMed Central

Shi, Ke; Huang, Wai Mun; Aihara, Hideki

2013-01-01

Hairpin telomeres of bacterial linear chromosomes are generated by a DNA cutting–rejoining enzyme protelomerase. Protelomerase resolves a concatenated dimer of chromosomes as the last step of chromosome replication, converting a palindromic DNA sequence at the junctions between chromosomes into covalently closed hairpins. The mechanism by which protelomerase transforms a duplex DNA substrate into the hairpin telomeres remains largely unknown. We report here a series of crystal structures of the protelomerase TelA bound to DNA that represent distinct stages along the reaction pathway. The structures suggest that TelA converts a linear duplex substrate into hairpin turns via a transient strand-refolding intermediate that involves DNA-base flipping and wobble base-pairs. The extremely compact di-nucleotide hairpin structure of the product is fully stabilized by TelA prior to strand ligation, which drives the reaction to completion. The enzyme-catalyzed, multistep strand refolding is a novel mechanism in DNA rearrangement reactions. PMID:23382649

21 CFR 184.1387 - Lactase enzyme preparation from Candida pseudotropicalis.

Code of Federal Regulations, 2010 CFR

2010-04-01

....2.1.23), which converts lactose to glucose and galactose. It is prepared from yeast that has been... defined in § 170.3(o)(9) of this chapter, to convert lactose to glucose and galactose. (2) The ingredient... manufacturing practice is limited to use of this ingredient to reduce the lactose content in milk and milk...

21 CFR 184.1387 - Lactase enzyme preparation from Candida pseudotropicalis.

Code of Federal Regulations, 2011 CFR

2011-04-01

....2.1.23), which converts lactose to glucose and galactose. It is prepared from yeast that has been... defined in § 170.3(o)(9) of this chapter, to convert lactose to glucose and galactose. (2) The ingredient... manufacturing practice is limited to use of this ingredient to reduce the lactose content in milk and milk...

Pomegranate peel extract attenuates oxidative stress by decreasing coronary angiotensin-converting enzyme (ACE) activity in hypertensive female rats.

PubMed

Dos Santos, Roger L; Dellacqua, Lais O; Delgado, Nathalie T B; Rouver, Wender N; Podratz, Priscila L; Lima, Leandro C F; Piccin, Mariela P C; Meyrelles, Silvana S; Mauad, Helder; Graceli, Jones B; Moyses, Margareth R

2016-01-01

Based on the antioxidant properties of pomegranate, this study was designed to investigate the effects of pomegranate peel extract on damage associated with hypertension and aging in a spontaneously hypertensive rat (SHR) model. The influence of pomegranate consumption was examined on systolic blood pressure (SBP), angiotensin-converting enzyme (ACE) coronary activity, oxidative stress, and vascular morphology. Four- or 28-wk-old SHR model rats were treated for 30 d, with terminal experimental animal age being 8 and 32 wk, respectively, with either pomegranate extract (SHR-PG) or filtered water (SHR). Data showed significant reduction in SBP and coronary ACE activity in both age groups. The levels of superoxide anion, a measure of oxidative stress, were significantly lower in animals in the SHR-PG group compared to SHR alone. Coronary morphology demonstrated total increases in vascular wall areas were in the SHR group, and pomegranate peel extract diminished this effect. Pomegranate peel extract consumption conferred protection against hypertension in the SHR model. This finding was demonstrated by marked reduction in coronary ACE activity, oxidative stress, and vascular remodelling. In addition, treatment was able to reduce SBP in both groups. Evidence indicates that the use of pomegranate peel extract may prove beneficial in alleviating coronary heart disease.

Angiotensin-converting Enzyme as a Predictor of Extrathoracic Involvement of Sarcoidosis.

PubMed

Yasar, Zehra; Özgül, Mehmet Akif; Cetinkaya, Erdoğan; Kargi, Aysel; Gül, Şule; Talay, Fahrettin; Tanriverdi, Elif; Dincer, H Erhan

2016-01-18

Sarcoidosis is a multisystem disease, with extrathoracic involvement occurring in 25-50% of patients. Multi-organ involvement is often associated with a more chronic and severe course. The value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in diagnosing extrathoracic involvement in sarcoidosis has been demonstrated; however, because of the radiation dose and high cost, indications for its use must be well defined. Angiotensin-converting enzyme (ACE) is produced by active granuloma cells; thus, serum ACE (sACE) levels may reflect the total granuloma load. In this retrospective study, we evaluated the diagnostic value of sACE in the detection of extrathoracic involvement in sarcoidosis. 43 patients with biopsy-proven sarcoidosis underwent FDG-PET/CT during the initial workup. Positive findings were classified as thoracic and/or extrathoracic. The diagnostic value of sACE was estimated using sensitivity, specificity, and area under the receiver operating characteristic curves (AUCs). Of the 43 patients studied, 17 (39.7%) had extrathoracic involvement. In this group, sACE values were higher than in patients without extrathoracic involvement (331 vs. 150, p=0.002) and correlated positively with extrathoracic involvement (R:0.532 p=0.02). Receiver operator characteristic curve analysis revealed an AUC of 0.816 [95% confidence interval: 0.669-0.963, p=0.002], 70.6% sensitivity and 80% specificity at the sACE cut-off value. In sarcoidosis, extrathoracic involvement may be life threatening or indicative of poor outcome. sACE levels are easily determined and may predict extrathoracic involvement. In patients with sarcoidosis, sACE levels can be used to better define those who would benefit from FDG-PET/CT examination to detect extrathoracic involvement.

Insertion/Deletion Polymorphisms and Serum Angiotensin-converting Enzyme Levels in Iranian Patients with Sarcoidosis

PubMed Central

JAVADI, Alireza; SHAMAEI, Masoud; ZAREI, Masoud; REZAEIAN, Lida; KIANI, Arda; ABEDINI, Atefeh

2016-01-01

Background: Sarcoidosis is a multisystem inflammatory disease of unknown origin with characterization of small granulomas. Angiotensin-converting enzyme (ACE) is a pathophysiologic marker of sarcoidosis. We present the ACE insertion/deletion (I/D) polymorphism in correlation with serum ACE level in Iranian patients with sarcoidosis. Methods: From Jan 2014 to Jan 2015, 102 Iranian patients who histopathologically diagnosed for sarcoidosis and 192 healthy age and sex-matched controls were recruited. PCR was used for detection of I/D polymorphism in ACE gene. Results: Frequency of II/ID/DD genotype in sarcoidosis disease was 17%, 35.5%, and 47.1%, respectively. The frequency of D allele was 0.65. A significant association between I/D genotypes and mean of sACE level was seen (DD=85.2±22.9, P<0.001). More frequent genotype in sarcoidosis patients was DD (47%), ID genotype (45.9%) was found more in controls. Logistic regression analysis adjusting age and sex showed that ID to II (OR=0.35, 95%CI=0.17–0.73, P=0.005) and DD to II (OR=2.11, 95%CI=0.98–4.54, P=0.05) could be considered as a predictor factor for the disease activity. No significant model for men in sarcoidosis group was seen, while women with II/ID were associated with a reduced risk for the disease. Conclusion: Although more regional studies with appropriate statistical scale must be done to provide a better diagnosis and prognostic tool for this disease, this study demonstrates that ID and DD genotype could be predictive factors for sarcoidosis. PMID:28032065

Pharmacogenetic effects of angiotensin-converting enzyme inhibitors over age-related urea and creatinine variations in patients with dementia due to Alzheimer disease.

PubMed

Ferreira de Oliveira, Fabricio; Berretta, Juliana Marília; Suchi Chen, Elizabeth; Cardoso Smith, Marilia; Ferreira Bertolucci, Paulo Henrique

2016-06-30

Renal function declines according to age and vascular risk factors, whereas few data are available regarding genetically-mediated effects of anti-hypertensives over renal function. To estimate urea and creatinine variations in dementia due to Alzheimer disease (AD) by way of a pharmacogenetic analysis of the anti-hypertensive effects of angiotensin-converting enzyme inhibitors (ACEis). Consecutive outpatients older than 60 years-old with AD and no history of kidney transplant or dialytic therapy were recruited for prospective correlations regarding variations in fasting blood levels of urea and creatinine in one year, considering ACE genotypes of rs1800764 and rs4291 and their respective haplotypes, and treatment with ACEis along with blood pressure variations. For 190 patients, 152 had arterial hypertension, and 122 used ACEis. Minor allele frequencies were 0.492 for rs1800764-C and 0.337 for rs4291-T, both in Hardy-Weinberg equilibrium. There were no overall significant yearly variations in levels of urea and creatinine, but their concurrent variations were positively correlated (ρ <0.0001). Each A allele of rs4291 led to an yearly urea increase of 3,074 mg/dL, and an yearly creatinine increase of 0.044 mg/dL, while the use of ACEis was protective regarding creatinine variations. The use of ACEis was also protective for carriers of rs1800764-CT/rs4291-AA, while carriers of rs1800764-CT/rs4291-AT had steeper reductions in creatinine levels, particularly when they were treated with ACEis. Effects of ACEis over creatinine variations are genetically mediated and independent of blood pressure variations in older people with AD.

Effect of peptide aldehydes with IL-1 beta converting enzyme inhibitory properties on IL-1 alpha and IL-1 beta production in vitro.

PubMed

Németh, K; Patthy, M; Fauszt, I; Széll, E; Székely, J I; Bajusz, S

1995-12-01

Tripeptide and pentapeptide aldehydes as substrate-base inhibitors of cysteine proteases were designed in our laboratory for the inhibition of interleukin-1 beta converting enzyme (ICE), a recently described cysteine protease responsible for the processing of IL-1 beta. The biological effectivity of the peptide aldehydes was studied in THP-1 cells and human whole blood. The released and cell-associated IL-1 alpha and IL-1 beta levels were determined by ELISA from the supernatants and cell lysates, respectively. The total IL-1 like bioactivity was assayed by the D10 G4.1 cell proliferation method. The tripeptide aldehyde (Z-Val-His-Asp-H) and pentapeptide aldehyde (Eoc-Ala-Tyr-Val-Ala-Asp-H) significantly reduced IL-1 beta levels in the supernatants in relatively high concentrations (10-100 microM), but the IL-1 alpha release was unaffected by these peptides. However, a considerable decrease in the cell-associated IL-1 beta and IL-1 alpha levels was observed. N-terminal extension of the tripeptide aldehyde yielded even more potent inhibitors. Amino acid substitution at the P2 position did not cause considerable changes in the inhibitory activity. The peptide aldehydes suppressed the IL-1 beta production in a reversible manner, whereas dexamethasone, a glucocorticoid, had a prolonged inhibitory effect. The inhibitory effect of these peptides and that of dexamethasone appeared to be additive. These findings indicate that these peptide aldehydes might be used as IL-beta inhibitory agents in experimental models in which IL-1 beta is a key mediator or ICE is implicated.

Angiotensin-converting enzyme gene polymorphism (insertion/deletion) and liver fibrosis in Turkish patients from the western Black Sea region, Turkey.

PubMed

Turhan, N K; Ilikhan, S Uygun; Hamamcioglu, A C; Ustundag, Y; Dursun, A; Kokturk, F

2015-12-16

Chronic viral hepatitis B, chronic viral hepatitis C, non-alcoholic steatohepatitis, alcoholic liver disease, autoimmune hepatitis, primary biliary cirrhosis, and secondary biliary cirrhosis are important health issues worldwide. While an association between angiotensin-converting enzyme gene insertion/deletion (ACE gene I/D) polymorphism and liver fibrosis has been demonstrated in rat studies, the results of clinical studies area have been contradictory. The aim of this study was to assess the possible association between ACE gene I/D polymorphism and liver fibrosis in a large group of Turkish patients from the western Black Sea region. In 418 patients with different etiologies, ACE gene I/D polymorphism and serum ACE levels were investigated. The distribution of the "DD", "ID", "II" genotypes of the ACE gene were 32.5, 48.8, and 18.7% in the mild to moderate fibrosis group (N = 246, F:1-3 according to Ishak's score) and 39.0, 44.2, and 16.9% in the advanced fibrosis group (N = 172, F:4-6 according to Ishak's score). A significant correlation between serum ACE levels and ACE gene alleles was identified (P < 0.001): serum ACE levels of patients with D alleles were higher than those of patients with I alleles [44 (min 7-max 101) versus 29 (min 7-max 96)]. Patients with advanced fibrosis were also found to be older than those with mild to moderate fibrosis (P < 0.001). No significant association was noted between the patient gender and fibrosis severity. We conclude that ACE I/D polymorphism is not associated with the degree of liver fibrosis.

Pharmacogenetic effects of angiotensin-converting enzyme inhibitors over age-related urea and creatinine variations in patients with dementia due to Alzheimer disease

PubMed Central

Berretta, Juliana Marília; Suchi Chen, Elizabeth; Cardoso Smith, Marilia; Ferreira Bertolucci, Paulo Henrique

2016-01-01

Background: Renal function declines according to age and vascular risk factors, whereas few data are available regarding genetically-mediated effects of anti-hypertensives over renal function. Objective: To estimate urea and creatinine variations in dementia due to Alzheimer disease (AD) by way of a pharmacogenetic analysis of the anti-hypertensive effects of angiotensin-converting enzyme inhibitors (ACEis). Methods: Consecutive outpatients older than 60 years-old with AD and no history of kidney transplant or dialytic therapy were recruited for prospective correlations regarding variations in fasting blood levels of urea and creatinine in one year, considering ACE genotypes of rs1800764 and rs4291 and their respective haplotypes, and treatment with ACEis along with blood pressure variations. Results: For 190 patients, 152 had arterial hypertension, and 122 used ACEis. Minor allele frequencies were 0.492 for rs1800764-C and 0.337 for rs4291-T, both in Hardy-Weinberg equilibrium. There were no overall significant yearly variations in levels of urea and creatinine, but their concurrent variations were positively correlated (ρ <0.0001). Each A allele of rs4291 led to an yearly urea increase of 3,074 mg/dL, and an yearly creatinine increase of 0.044 mg/dL, while the use of ACEis was protective regarding creatinine variations. The use of ACEis was also protective for carriers of rs1800764-CT/rs4291-AA, while carriers of rs1800764-CT/rs4291-AT had steeper reductions in creatinine levels, particularly when they were treated with ACEis. Conclusions: Effects of ACEis over creatinine variations are genetically mediated and independent of blood pressure variations in older people with AD. PMID:27546928

Mining novel starch-converting Glycoside Hydrolase 70 enzymes from the Nestlé Culture Collection genome database: The Lactobacillus reuteri NCC 2613 GtfB.

PubMed

Gangoiti, Joana; van Leeuwen, Sander S; Meng, Xiangfeng; Duboux, Stéphane; Vafiadi, Christina; Pijning, Tjaard; Dijkhuizen, Lubbert

2017-08-30

The Glycoside hydrolase (GH) family 70 originally was established for glucansucrases of lactic acid bacteria (LAB) converting sucrose into α-glucan polymers. In recent years we have identified 3 subfamilies of GH70 enzymes (designated GtfB, GtfC and GtfD) as 4,6-α-glucanotransferases, cleaving (α1 → 4)-linkages in maltodextrins/starch and synthesizing new (α1 → 6)-linkages. In this work, 106 putative GtfBs were identified in the Nestlé Culture Collection genome database with ~2700 genomes, and the L. reuteri NCC 2613 one was selected for further characterization based on variations in its conserved motifs. Using amylose the L. reuteri NCC 2613 GtfB synthesizes a low-molecular-mass reuteran-like polymer consisting of linear (α1 → 4) sequences interspersed with (α1 → 6) linkages, and (α1 → 4,6) branching points. This product specificity is novel within the GtfB subfamily, mostly comprising 4,6-α-glucanotransferases synthesizing consecutive (α1 → 6)-linkages. Instead, its activity resembles that of the GtfD 4,6-α-glucanotransferases identified in non-LAB strains. This study demonstrates the potential of large-scale genome sequence data for the discovery of enzymes of interest for the food industry. The L. reuteri NCC 2613 GtfB is a valuable addition to the starch-converting GH70 enzyme toolbox. It represents a new evolutionary intermediate between families GH13 and GH70, and provides further insights into the structure-function relationships of the GtfB subfamily enzymes.

Production of 2-deoxyribose 5-phosphate from fructose to demonstrate a potential of artificial bio-synthetic pathway using thermophilic enzymes.

PubMed

Honda, Kohsuke; Maya, Shohei; Omasa, Takeshi; Hirota, Ryuichi; Kuroda, Akio; Ohtake, Hisao

2010-08-02

Six thermophilic enzymes from Thermus thermophilus were used to construct an 'artificial bio-synthetic pathway' for the production of 2-deoxyribose 5-phosphate from fructose. By a simple operation using six recombinant Escherichia coli strains producing the thermophilic enzymes, respectively, fructose was converted to 2-deoxyribose 5-phosphate with a molar yield of 55%. Copyright 2010 Elsevier B.V. All rights reserved.

Screening the ToxCast Phase I, II, and e1K Chemical Libraries for Inhibition of Deiodinase Type 1,2 and 3 Enzyme Activity

EPA Science Inventory

Thyroid hormone (TH) signaling and homeostasis is dependent upon coordination of multiple key events including thyroidal iodide uptake and hormone synthesis, and peripheral metabolism and elimination. Deiodinase enzymes play an essential role in converting the pro-hormone thyroxi...

Characterization of Enzymes Catalyzing Transformations of Cysteine S-Conjugated Intermediates in the Lincosamide Biosynthetic Pathway.

PubMed

Ushimaru, Richiro; Lin, Chia-I; Sasaki, Eita; Liu, Hung-Wen

2016-09-02

Lincosamides such as lincomycin A, celesticetin, and Bu-2545, constitute an important group of antibiotics. These natural products are characterized by a thiooctose linked to a l-proline residue, but they differ with regards to modifications of the thioacetal moiety, the pyrrolidine ring, and the octose core. Here we report that the pyridoxal 5'-phosphate-dependent enzyme CcbF (celesticetin biosynthetic pathway) is a decarboxylating deaminase that converts a cysteine S-conjugated intermediate into an aldehyde. In contrast, the homologous enzyme LmbF (lincomycin biosynthetic pathway) catalyzes C-S bond cleavage of the same intermediate to afford a thioglycoside. We show that Ccb4 and LmbG (downstream methyltransferases) convert the aldehyde and thiol intermediates into a variety of methylated lincosamide compounds including Bu-2545. The substrates used in these studies are the β-anomers of the natural substrates. The findings not only provide insight into how the biosynthetic pathway of lincosamide antibiotics can bifurcate to generate different lincosamides, but also reveal the promiscuity of the enzymes involved. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immobilized enzymes to convert N-sulfo, N-acetyl heparosan to a critical intermediate in the production of bioengineered heparin.

PubMed

Xiong, Jian; Bhaskar, Ujjwal; Li, Guoyun; Fu, Li; Li, Lingyun; Zhang, Fuming; Dordick, Jonathan S; Linhardt, Robert J

2013-09-10

Heparin is a critically important anticoagulant drug that is prepared from pig intestine. In 2007-2008, there was a crisis in the heparin market when the raw material was adulterated with the toxic polysaccharide, oversulfated chondroitin sulfate, which was associated with 100 deaths in the U.S. alone. As the result of this crisis, our laboratory and others have been actively pursuing alternative sources for this critical drug, including synthetic heparins and bioengineered heparin. In assessing the bioengineering processing costs it has become clear that the use of both enzyme-catalyzed cofactor recycling and enzyme immobilization will be needed for commercialization. In the current study, we examine the use of immobilization of C₅-epimerase and 2-O-sulfotransferase involved in the first enzymatic step in the bioengineered heparin process, as well as arylsulfotransferase-IV involved in cofactor recycling in all three enzymatic steps. We report the successful immobilization of all three enzymes and their use in converting N-sulfo, N-acetyl heparosan into N-sulfo, N-acetyl 2-O-sulfo heparin. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantitative Structure-Activity Relationship Modeling Coupled with Molecular Docking Analysis in Screening of Angiotensin I-Converting Enzyme Inhibitory Peptides from Qula Casein Hydrolysates Obtained by Two-Enzyme Combination Hydrolysis.

PubMed

Lin, Kai; Zhang, Lanwei; Han, Xue; Meng, Zhaoxu; Zhang, Jianming; Wu, Yifan; Cheng, Dayou

2018-03-28

In this study, Qula casein derived from yak milk casein was hydrolyzed using a two-enzyme combination approach, and high angiotensin I-converting enzyme (ACE) inhibitory activity peptides were screened by quantitative structure-activity relationship (QSAR) modeling integrated with molecular docking analysis. Hydrolysates (<3 kDa) derived from combinations of thermolysin + alcalase and thermolysin + proteinase K demonstrated high ACE inhibitory activities. Peptide sequences in hydrolysates derived from these two combinations were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). On the basis of the QSAR modeling prediction, a total of 16 peptides were selected for molecular docking analysis. The docking study revealed that four of the peptides (KFPQY, MPFPKYP, MFPPQ, and QWQVL) bound the active site of ACE. These four novel peptides were chemically synthesized, and their IC 50 was determined. Among these peptides, KFPQY showed the highest ACE inhibitory activity (IC 50 = 12.37 ± 0.43 μM). Our study indicated that Qula casein presents an excellent source to produce ACE inhibitory peptides.

Inhibition of angiotensin I converting enzyme by subtilisin NAT (nattokinase) in natto, a Japanese traditional fermented food.

PubMed

Murakami, Keiko; Yamanaka, Naoki; Ohnishi, Katsunori; Fukayama, Minoru; Yoshino, Masataka

2012-06-01

Angiotensin I converting enzyme (ACE) was inhibited by the culture medium of Bacillus subtilis subsp. natto, which ferments boiled soy beans to natto, a Japanese traditional food. Subtilisin NAT (nattokinase) produced by B. subtilis also inhibited ACE, and the inhibition was markedly stimulated by heat treatment of subtilisin at 120 °C for 15 min. Inhibition of ACE by subtilisin was of a mixed type: the decrease in V(max) and the increase in K(m) value. SDS-polyacrylamide gel electrophoresis showed that heat treatment of subtilisin caused inactivation with fragmentation of the enzyme protein into small peptides. The inhibitory action of subtilisin was not due to an enzymatic action of protease, but may be ascribed to the potent ACE-inhibitory peptides such as LY and FY, amino acid sequences in subtilisin. HPLC-MS analysis of heat-inactivated subtilisin confirmed that LY and FY were liberated by fragmentation of the enzyme. Inhibition of ACE by subtilisin and its degradation peptides such as LY and FY may participate in the suppression of blood pressure by ingestion of natto.

Conversion of 2-chloro-cis,cis-muconate and its metabolites 2-chloro- and 5-chloromuconolactone by chloromuconate cycloisomerases of pJP4 and pAC27.

PubMed Central

Vollmer, M D; Schlömann, M

1995-01-01

2-Chloro-cis,cis-muconate, the product of ortho-cleavage of 3-chlorocatechol, was converted by purified preparations of the pJP4- and pAC27-encoded chloromuconate cycloisomerases (EC 5.5.1.7) to trans-dienelactone (trans-4-carboxymethylenebut-2-en-4-olide). The same compound was also formed when (+)-2-chloro- and (+)-5-chloromuconolactone were substrates of these enzyme preparations. Thus, the pJP4- and pAC27-encoded chloromuconate cycloisomerases are able to catalyze chloride elimination from (+)-5-chloromuconolactone. The ability to convert (+)-2-chloromuconolactone differentiates these enzymes from other groups of cycloisomerases. PMID:7751312

The linkage disequilibrium pattern of the angiotensin converting enzyme gene in Arabic and Asian population groups.

PubMed

Kharrat, Najla; Abdelmouleh, Wafa; Abdelhedi, Rania; Alfadhli, Suad; Rebai, Ahmed

2012-01-01

DNA variations within the Angiotensin-Converting Enzyme (ACE) gene have been shown to be involved in the aetiology of several common diseases and the therapeutic response. This study reports a comparison of haplotype analysis of five SNPs in the ACE gene region using a sample of 100 healthy subjects derived from five different populations (Tunisian, Iranian, Kuwaiti, Bahraini and Indian). Strong linkage disequilibrium was found among all SNPs studied for all populations. Two SNPs (rs1800764 and rs4340) were identified as key SNPs for all populations. These SNPs will be valuable for future effective association studies of the ACE gene polymorphisms in Arab and Asian populations.

Screening the Brazilian flora for antihypertensive plant species for in vitro angiotensin-I-converting enzyme inhibiting activity.

PubMed

Castro Braga, F; Wagner, H; Lombardi, J A; de Oliveira, A B

2000-06-01

The evaluation of several antihypertensive activity of Brazilian plant species was performed using in vitro inhibition of the angiotensin I-converting enzyme (ACE). Nineteen species belonging to 13 families were investigated. Plants were selected based on their use as diuretics and on a chemosystematic consideration. Extracts of the following species presented the highest ACE inhibition rate, at concentrations of 0.33 mg/ml: Ouratea semiserrata (Mart. & Nees) Engl. stems (68%), Cuphea cartagenesis (Jacq.) Macbride leaves (50%) and Mansoa hirsuta DC. leaves (54%). Some hypotheses about the nature of the compounds that may be responsible for the activity of these species are discussed in the paper.

Tetraterpene Synthase Substrate and Product Specificity in the Green Microalga Botryococcus braunii Race L.

PubMed

Thapa, Hem R; Tang, Su; Sacchettini, James C; Devarenne, Timothy P

2017-09-15

Recently, the biosynthetic pathway for lycopadiene, a C 40 tetraterpenoid hydrocarbon, was deciphered from the L race of Botryococcus braunii, an alga that produces hydrocarbon oils capable of being converted into combustible fuels. The lycopadiene pathway is initiated by the squalene synthase (SS)-like enzyme lycopaoctaene synthase (LOS), which catalyzes the head-to-head condensation of two C 20 geranylgeranyl diphosphate (GGPP) molecules to produce C 40 lycopaoctaene. LOS shows unusual substrate promiscuity for SS or SS-like enzymes by utilizing C 15 farnesyl diphosphate (FPP) and C 20 phytyl diphosphate in addition to GGPP as substrates. These three substrates can be combined by LOS individually or in combinations to produce six different hydrocarbons of C 30 , C 35 , and C 40 chain lengths. To understand LOS substrate and product specificity, rational mutagenesis experiments were conducted based on sequence alignment with several SS proteins as well as a structural comparison with the human SS (HSS) crystal structure. Characterization of the LOS mutants in vitro identified Ser276 and Ala288 in the LOS active site as key amino acids responsible for controlling substrate binding, and thus the promiscuity of this enzyme. Mutating these residues to those found in HSS largely converted LOS from lycopaoctaene production to C 30 squalene production. Furthermore, these studies were confirmed in vivo by expressing LOS in E. coli cells metabolically engineered to produce high FPP and GGPP levels. These studies also offer insights into tetraterpene hydrocarbon metabolism in B. braunii and provide a foundation for engineering LOS for robust production of specific hydrocarbons of a desired chain length.

β-Glucuronidase from Lactobacillus brevis useful for baicalin hydrolysis belongs to glycoside hydrolase family 30.

PubMed

Sakurama, Haruko; Kishino, Shigenobu; Uchibori, Yoshie; Yonejima, Yasunori; Ashida, Hisashi; Kita, Keiko; Takahashi, Satomi; Ogawa, Jun

2014-05-01

Baicalin (baicalein 7-O-β-D-glucuronide) is one of the major flavonoid glucuronides found in traditional herbal medicines. Because its aglycone, baicalein, is absorbed more quickly and shows more effective properties than baicalin, the conversion of baicalin into baicalein by β-glucuronidase (GUS) has drawn the attention of researchers. Recently, we have found that Lactobacillus brevis subsp. coagulans can convert baicalin to baicalein. Therefore, we aimed to identify and characterize the converting enzyme from L. brevis subsp. coagulans. First, we purified this enzyme from the cell-free extracts of L. brevis subsp. coagulans and cloned its gene. Surprisingly, this enzyme was found to be a GUS belonging to glycoside hydrolase (GH) family 30 (designated as LcGUS30), and its amino acid sequence has little similarity with any GUS belonging to GH families 1, 2, and 79 that have been reported so far. We then established a high-level expression and simple purification system of the recombinant LcGUS30 in Escherichia coli. The detailed analysis of the substrate specificity revealed that LcGUS30 has strict specificity toward glycon but not toward aglycones. Interestingly, LcGUS30 prefers baicalin rather than estrone 3-(β-D-glucuronide), one of the human endogenous steroid hormones. These results indicated that L. brevis subsp. coagulans and LcGUS30 should serve as powerful tools for the construction of a safe bioconversion system for baicalin. In addition, we propose that this novel type of GUS forms a new group in subfamily 3 of GH family 30.

Impact of Renin-Angiotensin Aldosterone System Inhibition on Serum Potassium Levels among Peritoneal Dialysis Patients.

PubMed

Ribeiro, Silvia Carreira; Figueiredo, Ana Elizabeth; Barretti, Pasqual; Pecoits-Filho, Roberto; de Moraes, Thyago Proença

2017-01-01

The chronic use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blocker has been associated with hyperkalemia in patients with reduced renal function even after the initiation of hemodialysis. Whether such medications may cause a similar effect in peritoneal dialysis patients is not well established. So, the aim of our study was to analyze the impact of renin-angiotensin-aldosterone inhibitors on the serum levels of potassium in a national cohort of peritoneal dialysis patients. A prospective, observational, nationwide cohort study was conducted. We identified all incident patients on peritoneal dialysis that had angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) prescribed for at least 3 months and a similar period of time without these medications. Patients were divided into 4 groups: Groups I and III correspond to patients using, respectively, an ACEi or ARB and then got the drug suspended; Groups II and IV started peritoneal dialysis without the use of any renin-angiotensin aldosterone system inhibitor and then got, respectively, an ACEi or ARB introduced. Changes in potassium serum levels were compared using 2 statistical approaches: (1) the non-parametric Wilcoxon test for repeated measures and (2) a crossover analysis. Mean potassium serum levels at the first phase of the study for Groups I, II, III, and IV were, respectively, 4.46 ± 0.79, 4.33 ± 0.78, 4.41 ± 0.63, and 4.44 ± 0.56. Changes in mean potassium serum levels for Groups I, II, III, and IV were -0.10 ± 0.60, 0.02 ± 0.56, -0.06 ± 0.46, and 0.03 ± 0.50, respectively. The use of ACEi and ARB was not associated with a greater risk for hyperkalemia in stable peritoneal dialysis patients independently of residual renal function. © 2017 S. Karger AG, Basel.

LECITHINASE AND LYSOLECITHINASE ACTIVITY OF RAT INTESTINAL MUCOSA AFTER WHOLE-BODY X-IRRADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ottolenghi, A.; Bernheim, F.

1961-11-01

Twenty-four hours after whole-body x irradiation the lecithinase activity of rat intestinal mucosa has markedly decreased and the lysolecithinase activity has decreasecp to a lesser extent. Addition of normal mucosa or chyi'otrypsin to the irradiated mucosa restores the activity of both enzymes. This indicates that irradiation eithei produces an inhibitor or inactivates a mechanism necessarly to convert pro-enzymes into active enzymes. Since chymo trypsin can increase to some extent the activity of the enzymes in normal mucosa, the second possibility seems more probable. (auth)

Expression Patterns of Genes Involved in Sugar Metabolism and Accumulation during Apple Fruit Development

PubMed Central

Cheng, Lailiang

2012-01-01

Both sorbitol and sucrose are imported into apple fruit from leaves. The metabolism of sorbitol and sucrose fuels fruit growth and development, and accumulation of sugars in fruit is central to the edible quality of apple. However, our understanding of the mechanisms controlling sugar metabolism and accumulation in apple remains quite limited. We identified members of various gene families encoding key enzymes or transporters involved in sugar metabolism and accumulation in apple fruit using homology searches and comparison of their expression patterns in different tissues, and analyzed the relationship of their transcripts with enzyme activities and sugar accumulation during fruit development. At the early stage of fruit development, the transcript levels of sorbitol dehydrogenase, cell wall invertase, neutral invertase, sucrose synthase, fructokinase and hexokinase are high, and the resulting high enzyme activities are responsible for the rapid utilization of the imported sorbitol and sucrose for fruit growth, with low levels of sugar accumulation. As the fruit continues to grow due to cell expansion, the transcript levels and activities of these enzymes are down-regulated, with concomitant accumulation of fructose and elevated transcript levels of tonoplast monosaccharide transporters (TMTs), MdTMT1 and MdTMT2; the excess carbon is converted into starch. At the late stage of fruit development, sucrose accumulation is enhanced, consistent with the elevated expression of sucrose-phosphate synthase (SPS), MdSPS5 and MdSPS6, and an increase in its total activity. Our data indicate that sugar metabolism and accumulation in apple fruit is developmentally regulated. This represents a comprehensive analysis of the genes involved in sugar metabolism and accumulation in apple, which will serve as a platform for further studies on the functions of these genes and subsequent manipulation of sugar metabolism and fruit quality traits related to carbohydrates. PMID:22412983

HPLC-DAD Analysis and In-Vitro Property of Polyphenols Extracts from (Solanum Aethiopium) Fruits on α -Amylase, α -Glucosidase and Angiotensin - 1- Converting Enzyme Activities

PubMed Central

Nwanna, E. E; Ibukun, E. O; Oboh, G.; Ademosun, A. O.; Boligon, A. A.; Athayde, M.

2014-01-01

AIM: Garden egg (Solanum aethiopium) is an edible fruits vegetable with  different species.This study investigated characterisation and the effect of the phenolics extracts from S. aethiopium species with enzymes linked with type -2-diabetes (α-amylase and α-glucosidase) and hypertension [Angiotensin-1-converting enzyme (ACE)]. METHODS: Fresh samples of the 5 species of the garden egg namely, [Solanum gilo (PW), Solanum torvum (TWS), Solanum kumba (PGR), Solanum incanum (GSB), and Solanum indicum (WSB)] were oven-dried at 50°C and milled into flour. The aqueous extracts were prepared (1:50 w/v). The phenolic contents (total phenol and total flavonoid), vitamin C and 1,1-diphenyl–2-picrylhydrazyl (DPPH), the antioxidant activities of the extracts were evaluated. The ability of the extracts to inhibit diabetes enzymes in rat pancreas as well as the inhibition of angiotensin-1-converting (ACE) enzyme in lungs homogenates in vitro were investigated. Furthermore, the fruits polyphenols were identified and quantified using HPLC-DAD. RESULTS: The phenolic contents ranged from 2.70-3.76 mgGAE/g, while there were no significant (P>0.05) differences in their flavonoid content and ability to reduce Fe3+ to Fe2+. The vitamin C contents of the species ranged from 4.01-6.52 mg/ml. The extracts scavenged DPPH in a dose dependent manner with the IC50 values ranging from 3.23-4.20 mg/ml. Furthermore, the extracts showed strong inhibition of α-glucosidase, mild inhibition of α-amylase and strong inhibition of ACE activities. CONCLUSION: This study showed that the inhibition of the key enzymes relevant to type-2 diabetes and hypertension could be part of the mechanisms by which garden egg manage/prevent the degenerative conditions. PMID:25598760

Functional characterization of proanthocyanidin pathway enzymes from tea and their application for metabolic engineering.

PubMed

Pang, Yongzhen; Abeysinghe, I Sarath B; He, Ji; He, Xianzhi; Huhman, David; Mewan, K Mudith; Sumner, Lloyd W; Yun, Jianfei; Dixon, Richard A

2013-03-01

Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (-)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (-)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols.

A Modern Understanding of the Traditional and Nontraditional Biological Functions of Angiotensin-Converting Enzyme

PubMed Central

Ong, Frank S.; Blackwell, Wendell-Lamar B.; Shah, Kandarp H.; Giani, Jorge F.; Gonzalez-Villalobos, Romer A.; Shen, Xiao Z.; Fuchs, Sebastien

2013-01-01

Angiotensin-converting enzyme (ACE) is a zinc-dependent peptidase responsible for converting angiotensin I into the vasoconstrictor angiotensin II. However, ACE is a relatively nonspecific peptidase that is capable of cleaving a wide range of substrates. Because of this, ACE and its peptide substrates and products affect many physiologic processes, including blood pressure control, hematopoiesis, reproduction, renal development, renal function, and the immune response. The defining feature of ACE is that it is composed of two homologous and independently catalytic domains, the result of an ancient gene duplication, and ACE-like genes are widely distributed in nature. The two ACE catalytic domains contribute to the wide substrate diversity of ACE and, by extension, the physiologic impact of the enzyme. Several studies suggest that the two catalytic domains have different biologic functions. Recently, the X-ray crystal structure of ACE has elucidated some of the structural differences between the two ACE domains. This is important now that ACE domain-specific inhibitors have been synthesized and characterized. Once widely available, these reagents will undoubtedly be powerful tools for probing the physiologic actions of each ACE domain. In turn, this knowledge should allow clinicians to envision new therapies for diseases not currently treated with ACE inhibitors. PMID:23257181

The angiotensin converting enzyme inhibitor captopril protects nigrostriatal dopamine neurons in animal models of parkinsonism

PubMed Central

Sonsalla, Patricia K.; Coleman, Christal; Wong, Lai-Yoong; Harris, Suzan L.; Richardson, Jason R.; Gadad, Bharathi S.; Li, Wenhao; German, Dwight C.

2013-01-01

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by a prominent loss of nigrostriatal dopamine (DA) neurons with an accompanying neuroinflammation. The peptide angiotensin II (AngII) plays a role in oxidative-stress induced disorders and is thought to mediate its detrimental actions via activation of AngII AT1 receptors. The brain renin-angiotensin system is implicated in neurodegenerative disorders including PD. Blockade of the angiotensin converting enzyme or AT1 receptors provides protection in acute animal models of parkinsonism. We demonstrate here that treatment of mice with the angiotensin converting enzyme inhibitor captopril protects the striatum from acutely administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrine (MPTP), and that chronic captopril protects the nigral DA cell bodies from degeneration in a progressive rat model of parkinsonism created by the chronic intracerebral infusion of 1-methyl-4-phenylpyridinium (MPP+). The accompanying activation of microglia in the substantia nigra of MPP+-treated rats was reduced by the chronic captopril treatment. These findings indicate that captopril is neuroprotective for nigrostriatal DA neurons in both acute and chronic rodent PD models. Targeting the brain AngII pathway may be a feasible approach to slowing neurodegeneration in PD. PMID:24184050

Production of high concentration of L-lactic acid from cellobiose by thermophilic Bacillus coagulans WCP10-4.

PubMed

Ong, Shufen Angeline; Ng, Zhi Jian; Wu, Jin Chuan

2016-07-01

Thermophilic Bacillus coagulans WCP10-4 is found to be able to convert cellobiose to optically pure L-lactic acid. Its β-glucosidase activity is detected in whole cells (7.3 U/g dry cells) but not in culture medium, indicating the intracellular location of the enzyme. Its β-glucosidase activity is observed only when cultured using cellobiose as the sole carbon source, indicating that the expression of this enzyme is tightly regulated in cells. The enzyme is most active at 50 °C and pH 7.0. The supplement of external β-glucosidase during fermentation of cellobiose (106 g/l) by B. coagulans WCP10-4 increased the fermentation time from 21 to 23 h and decreased the lactic acid yield from 96.1 to 92.9 % compared to the control without β-glucosidase supplementation. B. coagulans WCP10-4 converted 200 g/l of cellobiose to 196.3 g/l of L-lactic acid at a yield of 97.8 % and a productivity of 7.01 g/l/h. This result shows that B. coagulans WCP10-4 is a highly efficient strain for converting cellobiose to L-lactic acid without the need of supplementing external β-glucosidases.

Discovery and structural characterisation of new fold type IV-transaminases exemplify the diversity of this enzyme fold

PubMed Central

Pavkov-Keller, Tea; Strohmeier, Gernot A.; Diepold, Matthias; Peeters, Wilco; Smeets, Natascha; Schürmann, Martin; Gruber, Karl; Schwab, Helmut; Steiner, Kerstin

2016-01-01

Transaminases are useful biocatalysts for the production of amino acids and chiral amines as intermediates for a broad range of drugs and fine chemicals. Here, we describe the discovery and characterisation of new transaminases from microorganisms which were enriched in selective media containing (R)-amines as sole nitrogen source. While most of the candidate proteins were clearly assigned to known subgroups of the fold IV family of PLP-dependent enzymes by sequence analysis and characterisation of their substrate specificity, some of them did not fit to any of these groups. The structure of one of these enzymes from Curtobacterium pusillum, which can convert d-amino acids and various (R)-amines with high enantioselectivity, was solved at a resolution of 2.4 Å. It shows significant differences especially in the active site compared to other transaminases of the fold IV family and thus indicates the existence of a new subgroup within this family. Although the discovered transaminases were not able to convert ketones in a reasonable time frame, overall, the enrichment-based approach was successful, as we identified two amine transaminases, which convert (R)-amines with high enantioselectivity, and can be used for a kinetic resolution of 1-phenylethylamine and analogues to obtain the (S)-amines with e.e.s >99%. PMID:27905516

Purification and characterization of a bacterial nitrophenol oxygenase which converts ortho-nitrophenol to catechol and nitrite.

PubMed Central

Zeyer, J; Kocher, H P

1988-01-01

A nitrophenol oxygenase which stoichiometrically converted ortho-nitrophenol (ONP) to catechol and nitrite was isolated from Pseudomonas putida B2 and purified. The substrate specificity of the enzyme was broad and included several halogen- and alkyl-substituted ONPs. The oxygenase consisted of a single polypeptide chain with a molecular weight of 58,000 (determined by gel filtration) or 65,000 (determined on a sodium dodecyl sulfate-polyacrylamide gel). The enzymatic reaction was NADPH dependent, and one molecule of oxygen was consumed per molecule of ONP converted. Enzymatic activity was stimulated by magnesium or manganese ions, whereas the addition of flavin adenine dinucleotide, flavin mononucleotide, or reducing agents had no effect. The apparent Kms for ONP and NADPH were 8 and 140 microM, respectively. 2,4-Dinitrophenol competitively (Ki = 0.5 microM) inhibited ONP turnover. The optimal pH for enzyme stability and activity was in the range of 7.5 to 8.0. At 40 degrees C, the enzyme was totally inactivated within 2 min; however, in the presence of 1 mM ONP, 40% of the activity was recovered, even after 10 min. Enzymatic activity was best preserved at -20 degrees C in the presence of 50% glycerol. Images PMID:3350791

Exercise training modulates the hepatic renin-angiotensin system in fructose-fed rats.

PubMed

Frantz, Eliete Dalla Corte; Medeiros, Renata Frauches; Giori, Isabele Gomes; Lima, Juliana Bittencourt Silveira; Bento-Bernardes, Thais; Gaique, Thaiane Gadioli; Fernandes-Santos, Caroline; Fernandes, Tiago; Oliveira, Edilamar Menezes; Vieira, Carla Paulo; Conte-Junior, Carlos Adam; Oliveira, Karen Jesus; Nobrega, Antonio Claudio Lucas

2017-09-01

What is the central question of this study? What are the effects of exercise training on the hepatic renin-angiotensin system and their contribution to damage resulting from fructose overload in rats? What is the main finding and its importance? Exercise training attenuated the deleterious actions of the angiotensin-converting enzyme/angiotensin II/angiotensin II type 1 receptor axis and increased expression of the counter-regulatory (angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor) axis in the liver. Therefore, our study provides evidence that exercise training modulates the hepatic renin-angiotensin system, which contributes to reducing the progression of metabolic dysfunction and non-alcoholic fatty liver disease in fructose-fed rats. The renin-angiotensin system (RAS) has been implicated in the development of metabolic syndrome. We investigated whether the hepatic RAS is modulated by exercise training and whether this modulation improves the deleterious effects of fructose overload in rats. Male Wistar rats were divided into (n = 8 each) control (CT), exercise control (CT-Ex), high-fructose (HFr) and exercise high-fructose (HFr-Ex) groups. Fructose-drinking rats received d-fructose (100 g l -1 ). After 2 weeks, CT-Ex and HFr-Ex rats were assigned to a treadmill training protocol at moderate intensity for 8 weeks (60 min day -1 , 4 days per week). We assessed body mass, glucose and lipid metabolism, hepatic histopathology, angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity, the angiotensin concentration and the expression profile of proteins affecting the hepatic RAS, gluconeogenesis and inflammation. Neither fructose overload nor exercise training influenced body mass gain and serum ACE and ACE2 activity. The HFr group showed hyperinsulinaemia, but exercise training normalized this parameter. Exercise training was effective in preventing hepatic steatosis and in preventing triacylglycerol and glycogen accumulation. Furthermore, exercise improved the response to the deleterious effects of HFr overload by normalizing the gluconeogenesis pathway and the protein levels of interleukin-6 and tumour necrosis factor-α. The HFr rats displayed increased hepatic ACE activity and protein expression and angiotensin II concentration, which were attenuated by exercise training. Exercise training restored the ACE2/angiotensin-(1-7)/Mas receptor axis. Exercise training may favour the counter-regulatory ACE2/angiotensin-(1-7)/Mas receptor axis over the classical RAS (ACE/angiotensin II/angiotensin II type 1 receptor axis), which could be responsible for the reduction of metabolic dysfunction and the prevention of non-alcoholic fatty liver disease. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

A futile cycle, formed between two ATP-dependant gamma-glutamyl cycle enzymes, gamma-glutamyl cysteine synthetase and 5-oxoprolinase: the cause of cellular ATP depletion in nephrotic cystinosis?

PubMed

Kumar, Akhilesh; Bachhawat, Anand Kumar

2010-03-01

Cystinosis, an inherited disease caused by a defect in the lysosomal cystine transporter (CTNS), is characterized by renal proximal tubular dysfunction. Adenosine triphosphate (ATP) depletion appears to be a key event in the pathophysiology of the disease, even though the manner in which ATP depletion occurs is still a puzzle. We present a model that explains how a futile cycle that is generated between two ATP-utilizing enzymes of the gamma-glutamyl cycle leads to ATP depletion. The enzyme gamma-glutamyl cysteine synthetase (gamma-GCS), in the absence of cysteine, forms 5-oxoproline (instead of the normal substrate, gamma-glutamyl cysteine) and the 5-oxoproline is converted into glutamate by the ATP-dependant enzyme, 5-oxoprolinase. Thus, in cysteine-limiting conditions, glutamate is cycled back into glutamate via 5-oxoproline at the cost of two ATP molecules without production of glutathione and is the cause of the decreased levels of glutathione synthesis, as well as the ATP depletion observed in these cells. The model is also compatible with the differences seen in the human patients and the mouse model of cystinosis, where renal failure is not observed.

Blockade of the angiotensin system improves mental health domain of quality of life: A meta-analysis of randomized clinical trials.

PubMed

Brownstein, Daniel J; Salagre, Estela; Köhler, Cristiano; Stubbs, Brendon; Vian, João; Pereira, Ciria; Chavarria, Victor; Karmakar, Chandan; Turner, Alyna; Quevedo, João; Carvalho, André F; Berk, Michael; Fernandes, Brisa S

2018-01-01

It is unclear whether blockade of the angiotensin system has effects on mental health. Our objective was to determine the impact of angiotensin converting enzyme inhibitors and angiotensin II type 1 receptor (AT1R) blockers on mental health domain of quality of life. Meta-analysis of published literature. PubMed and clinicaltrials.gov databases. The last search was conducted in January 2017. Randomized controlled trials comparing any angiotensin converting enzyme inhibitor or AT1R blocker versus placebo or non-angiotensin converting enzyme inhibitor or non-AT1R blocker were selected. Study participants were adults without any major physical symptoms. We adhered to meta-analysis reporting methods as per PRISMA and the Cochrane Collaboration. Eleven studies were included in the analysis. When compared with placebo or other antihypertensive medications, AT1R blockers and angiotensin converting enzyme inhibitors were associated with improved overall quality of life (standard mean difference = 0.11, 95% confidence interval = [0.08, 0.14], p < 0.0001), positive wellbeing (standard mean difference = 0.11, 95% confidence interval = [0.05, 0.17], p < 0.0001), mental (standard mean difference = 0.15, 95% confidence interval = [0.06, 0.25], p < 0.0001), and anxiety (standard mean difference = 0.08, 95% confidence interval = [0.01, 0.16], p < 0.0001) domains of QoL. No significant difference was found for the depression domain (standard mean difference = 0.05, 95% confidence interval = [0.02, 0.12], p = 0.15). Use of angiotensin blockers and inhibitors for the treatment of hypertension in otherwise healthy adults is associated with improved mental health domains of quality of life. Mental health quality of life was a secondary outcome in the included studies. Research specifically designed to analyse the usefulness of drugs that block the angiotensin system is necessary to properly evaluate this novel psychiatric target.

Response to angiotensin-converting enzyme inhibition is selectively blunted by high sodium in angiotensin-converting enzyme DD genotype: evidence for gene-environment interaction in healthy volunteers.

PubMed

Lely, A Titia; Heerspink, Hiddo J Lambers; Zuurman, Mike; Visser, Folkert W; Kocks, Menno J A; Boomsma, Frans; Navis, Gerjan

2010-12-01

Renin-angiotensin-aldosterone system blockade is a cornerstone in cardiovascular protection. Angiotensin-converting enzyme (ACE)-DD genotype has been associated with resistance to angiotensin-converting enzyme inhibition (ACEi), but data are conflicting. As sodium intake modifies the effect of ACEi as well as the genotype-phenotype relationship, we hypothesize gene-environment interaction between sodium-status, the response to ACEi, and ACE genotype. Thirty-five male volunteers (26 ± 9 years; II n = 6, ID n = 18, DD n = 11) were studied during placebo and ACEi (double blind, enalapril 20 mg/day) on low [7 days 50 mmol Na/day (low salt)] and high [7 days 200 mmol Na/day (high salt)] sodium, with a washout of 6 weeks in-between. After each period mean arterial pressure (MAP) was measured before and during graded infusion of angiotensin II (Ang II). During high salt, ACEi reduced MAP in II and ID, but not in DD [II: 88 (78-94) versus 76 (72-88); ID: 87 (84-91) versus 83 (79-87); both P < 0.05 and DD: 86 (82-96) versus 88 (80-90); ns, P < 0.05 between genotypes]. However, during low salt, ACEi reduced MAP in all genotype groups [II: 83 (78-89) versus 77 (72-83); ID: 88 (84-91) versus 82 (78-86); DD: 84 (80-91) versus 81 (75-85); all P < 0.05]. During high salt + ACEi, the Ang II response was blunted in DD, with an 18% rise in MAP during the highest dose versus 22 and 31% in ID and II (P < 0.05). Low salt annihilated these differences. In healthy participants, the MAP response to ACEi is selectively blunted in DD genotype during high salt, accompanied by blunted sensitivity to Ang II. Low salt corrects both abnormalities. Further analysis of this gene-environment interaction in patients may contribute to strategies for improvement of individual treatment efficacy.

Impact of Empagliflozin on Blood Pressure in Patients With Type 2 Diabetes Mellitus and Hypertension by Background Antihypertensive Medication.

PubMed

Mancia, Giuseppe; Cannon, Christopher P; Tikkanen, Ilkka; Zeller, Cordula; Ley, Ludwin; Woerle, Hans J; Broedl, Uli C; Johansen, Odd Erik

2016-12-01

In the EMPA-REG BP trial, empagliflozin 10 mg and 25 mg once daily reduced glycohemoglobin, blood pressure (BP), and weight versus placebo in patients with type 2 diabetes mellitus and hypertension. Patients received placebo (n=271), empagliflozin 10 mg (n=276), or empagliflozin 25 mg (n=276) for 12 weeks (n=full analysis set). This present analysis investigated changes from baseline to week 12 in mean 24-hour systolic BP (SBP) and diastolic BP (DBP) in patients receiving 0, 1, or ≥2 antihypertensive medications and patients receiving/not receiving diuretics or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. Compared with placebo, empagliflozin 10 mg and 25 mg reduced mean 24-hour SBP/DBP in patients receiving 0 (10 mg: -3.89/-2.58 mm Hg; 25 mg: -3.77/-2.45 mm Hg), 1 (10 mg: -4.74/-1.97 mm Hg; 25 mg: -4.27/-1.81 mm Hg), or ≥2 (10 mg: -2.36/-0.68 mm Hg; 25 mg: -4.17/-1.54 mm Hg) antihypertensives. The effect of empagliflozin was not significantly different between subgroups by number of antihypertensives for changes in SBP (interaction P value 0.448) or DBP (interaction P value 0.498). Empagliflozin reduced 24-hour mean SBP/DBP irrespective of diuretic or angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use, with no significant difference between subgroups by use/no use of diuretics (interaction P values 0.380 [systolic]; 0.240 [diastolic]) or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (interaction P values 0.900 [systolic]; 0.359 [diastolic]). In conclusion, in patients with type 2 diabetes mellitus and hypertension, empagliflozin for 12 weeks reduced SBP and DBP versus placebo, irrespective of the number of antihypertensives and use of diuretics or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers. URL: https://clinicaltrials.gov. Unique identifier: NCT01370005. © 2016 American Heart Association, Inc.

Amyloid-clearing proteins and their epigenetic regulation as a therapeutic target in Alzheimer’s disease

PubMed Central

Nalivaeva, Natalia N.; Belyaev, Nikolai D.; Kerridge, Caroline; Turner, Anthony J.

2014-01-01

Abnormal elevation of amyloid β-peptide (Aβ) levels in the brain is the primary trigger for neuronal cell death specific to Alzheimer’s disease (AD). It is now evident that Aβ levels in the brain are manipulable due to a dynamic equilibrium between its production from the amyloid precursor protein (APP) and removal by amyloid clearance proteins. Clearance can be either enzymic or non-enzymic (binding/transport proteins). Intriguingly several of the main amyloid-degrading enzymes (ADEs) are members of the M13 peptidase family (neprilysin (NEP), NEP2 and the endothelin converting enzymes (ECE-1 and -2)). A distinct metallopeptidase, insulin-degrading enzyme (IDE), also contributes to Aβ degradation in the brain. The ADE family currently embraces more than 20 members, both membrane-bound and soluble, and of differing cellular locations. NEP plays an important role in brain function terminating neuropeptide signals. Its decrease in specific brain areas with age or after hypoxia, ischaemia or stroke contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP (and other genes) by the APP intracellular domain (AICD) and its dependence on the cell type and APP isoform expression suggest possibilities for selective manipulation of NEP gene expression in neuronal cells. We have also observed that another amyloid-clearing protein, namely transthyretin (TTR), is also regulated in the neuronal cell by a mechanism similar to NEP. Dependence of amyloid clearance proteins on histone deacetylases and the ability of HDAC inhibitors to up-regulate their expression in the brain opens new avenues for developing preventive strategies in AD. PMID:25278875

Discovery of novel hydroxamates as highly potent tumor necrosis factor-[alpha] converting enzyme inhibitors. Part II: Optimization of the S3′ pocket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazzola Jr., Robert D.; Zhu, Zhaoning; Sinning, Lisa

2010-10-01

A series of cyclopropyl hydroxamic acids were prepared. Many of the compounds displayed picomolar affinity for the TACE enzyme while maintaining good to excellent selectivity profiles versus MMP-1, -2, -3, -7, -14, and ADAM-10. X-ray analysis of an inhibitor in the TACE active site indicated that the molecules bound to the enzyme in the S1{prime}-S3{prime} pocket.

Angiotensin converting enzyme immobilized on magnetic beads as a tool for ligand fishing.

PubMed

de Almeida, Fernando G; Vanzolini, Kenia L; Cass, Quezia B

2017-01-05

Angiotensin converting enzyme (ACE) presents an important role in blood pressure regulation, since that converts angiotensin I to the vasoconstrictor angiotensin II. Some commercially available ACE inhibitors are captopril, lisinopril and enalapril; due to their side effects, naturally occurring inhibitors have been prospected. In order to endorse this research field we have developed a new tool for ACE ligand screening. To this end, ACE was extracted from bovine lung, purified and chemically immobilized in modified ferrite magnetic beads (ACE-MBs). The ACE-MBs have shown a Michaelian kinetic behavior towards hippuryl-histidyl-leucine. Moreover, as proof of concept, the ACE-MBs was inhibited by lisinopril with a half maximal inhibitory concentration (IC 50 ) of 10nM. At the fishing assay, ACE-MBs were able not only to fish out the reference inhibitor, but also one peptide from a pool of tryptic digested BSA. In conclusion, ACE-MBs emerge as new straightforward tool for ACE kinetics determination, inhibition and binder screening. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation of progenin III from total steroidal saponins of Dioscorea nipponica Makino using a crude enzyme from Aspergillus oryzae strain.

PubMed

Liu, Tingqiang; Yu, Hongshan; Liu, Chunying; Bao, Yongming; Hu, Xiangchun; Wang, Yuanhao; Liu, Bing; Fu, Yaoyao; Tang, Sihui; Jin, Fengxie

2013-05-01

Progenin III, one of the most active spirostanol saponins, is a potential candidate for anti-cancer therapy due to its strong antitumor activity and low hemolytic activity. However, the concentration of progenin III is extremely low in natural Dioscorea plants. In this paper, the progenin III production from total steroidal saponins of Dioscorea nipponica Makino was studied using the crude enzyme from Aspergillus oryzae DLFCC-38. The crude enzyme converting total steroidal saponins into progenin III was obtained from the A. oryzae DLFCC-38 culture. For enzyme production, the strain was cultured for 72 h at 30 °C with shaking at 150 rpm in 5 % (w/v) malt extract medium containing 2 % (v/v) extract of D. nipponica as the enzyme inducer. The crude enzyme converted total steroidal saponins into major progenin III with a high yield when the reaction was carried out for 9 h at 50 °C and pH 5.0 with the 20 mg/ml of substrate. In the preparation of progenin III, 117 g of crude progenin III was obtained from 160 g of substrate, and the crude product was purified with silica gel column to obtain 60.3 g progenin III of 93.4 % purity.

Effect of small hairpin RNA targeting endothelin-converting enzyme-1 in monocrotaline-induced pulmonary hypertensive rats.

PubMed

Son, Jae Sung; Kim, Kwan Chang; Kim, Bo Kyung; Cho, Min-Sun; Hong, Young Mi

2012-12-01

The purpose of this study was to investigate the therapeutic effects of small hairpin RNA (shRNA) targeting endothelin-converting enzyme (ECE)-1 in monocrotaline (MCT)-induced pulmonary hypertensive rats. Ninty-four Sprague-Dawley rats were divided into three groups: control (n = 24), MCT (n = 35) and shRNA (n = 35). Four-week survival rate in the shRNA group was significantly increased compared to that in the MCT group. The shRNA group showed a significant improvement of right ventricular (RV) pressure compared with the MCT group. The MCT and shRNA groups also showed an increase in RV/(left ventricle + septum) ratio and lung/body weight. Plasma endothelin (ET)-1 concentrations in the shRNA group were lower than those in the MCT group. Medial wall thickness of pulmonary arterioles were increased after MCT injection and was significantly decreased in the shRNA group. The number of intra-acinar muscular pulmonary arteries was decreased in the shRNA group. The mRNA expressions of ET-1 and ET receptor A (ET(A)) were significantly decreased in the shRNA group in week 4. The protein levels of ET(A) were decreased in the shRNA group in week 2. The protein levels of tumor necrosis factor-α and vascular endothelial growth factor were decreased in the shRNA group in week 4. In conclusion, the gene silencing with lentiviral vector targeting ECE-1 could be effective against hemodynamic, histopathological and gene expression changes in pulmonary hypertension.

Respiratory epithelial cells convert inactive vitamin D to its active form: potential effects on host defense.

PubMed

Hansdottir, Sif; Monick, Martha M; Hinde, Sara L; Lovan, Nina; Look, Dwight C; Hunninghake, Gary W

2008-11-15

The role of vitamin D in innate immunity is increasingly recognized. Recent work has identified a number of tissues that express the enzyme 1alpha-hydroxylase and are able to activate vitamin D. This locally produced vitamin D is believed to have important immunomodulatory effects. In this paper, we show that primary lung epithelial cells express high baseline levels of activating 1alpha-hydroxylase and low levels of inactivating 24-hydroxylase. The result of this enzyme expression is that airway epithelial cells constitutively convert inactive 25-dihydroxyvitamin D(3) to the active 1,25-dihydroxyvitamin D(3). Active vitamin D that is generated by lung epithelium leads to increased expression of vitamin D-regulated genes with important innate immune functions. These include the cathelicidin antimicrobial peptide gene and the TLR coreceptor CD14. dsRNA increases the expression of 1alpha-hydroxylase, augments the production of active vitamin D, and synergizes with vitamin D to increase expression of cathelicidin. In contrast to induction of the antimicrobial peptide, vitamin D attenuates dsRNA-induced expression of the NF-kappaB-driven gene IL-8. We conclude that primary epithelial cells generate active vitamin D, which then influences the expression of vitamin D-driven genes that play a major role in host defense. Furthermore, the presence of vitamin D alters induction of antimicrobial peptides and inflammatory cytokines in response to viruses. These observations suggest a novel mechanism by which local conversion of inactive to active vitamin D alters immune function in the lung.

Similar efficacy from specific and non-specific mineralocorticoid receptor antagonist treatment of muscular dystrophy mice.

PubMed

Lowe, Jeovanna; Floyd, Kyle T; Rastogi, Neha; Schultz, Eric J; Chadwick, Jessica A; Swager, Sarah A; Zins, Jonathan G; Kadakia, Feni K; Smart, Suzanne; Gomez-Sanchez, Elise P; Gomez-Sanchez, Celso E; Raman, Subha V; Janssen, Paul M L; Rafael-Fortney, Jill A

2016-01-01

Combined treatment with an angiotensin-converting enzyme inhibitor and a mineralocorticoid receptor (MR) antagonist improved cardiac and skeletal muscle function and pathology in a mouse model of Duchenne muscular dystrophy. MR is present in limb and respiratory skeletal muscles and functions as a steroid hormone receptor. The goals of the current study were to compare the efficacy of the specific MR antagonist eplerenone with the non-specific MR antagonist spironolactone, both in combination with the angiotensin-converting enzyme inhibitor lisinopril. Three groups of n=18 dystrophin-deficient, utrophin-haploinsufficient male mice were given chow containing: lisinopril plus spironolactone, lisinopril plus eplerenone, or no drug, from four to 20 weeks-of-age. Eighteen C57BL/10 male mice were used as wild-type controls. In vivo measurements included cardiac magnetic resonance imaging, conscious electrocardiography, and grip strength. From each mouse in the study, diaphragm, extensor digitorum longus , and cardiac papillary muscle force was measured ex vivo , followed by histological quantification of muscle damage in heart, diaphragm, quadriceps, and abdominal muscles. MR protein levels were also verified in treated muscles. Treatment with specific and non-specific MR antagonists did not result in any adverse effects to dystrophic skeletal muscles or heart. Both treatments resulted in similar functional and pathological improvements across a wide array of parameters. MR protein levels were not reduced by treatment. These data suggest that spironolactone and eplerenone show similar effects in dystrophic mice and support the clinical development of MR antagonists for treating skeletal muscles in Duchenne muscular dystrophy.

Effects of the angiotensin-converting enzyme inhibitor alacepril in dogs with mitral valve disease.

PubMed

Hori, Yasutomo; Nakamura, Kensuke; Kanno, Nobuyuki; Hitomi, Makoto; Yamashita, Yohei; Hosaka, Satoshi; Isayama, Noriko; Mimura, Takahiro

2018-06-22

Alacepril is a relatively novel angiotensin-converting enzyme inhibitor; however, the safety, tolerance, and efficacy of alacepril in terms of cough suppression in dogs with mitral valve disease (MVD) remain unknown. The aim of this study was to investigate the safety, tolerance, and cough suppression efficacy of alacepril in dogs with MVD. This was a multi-center, prospective study. Forty-two dogs with echocardiographic or radiographic evidence of cardiac enlargement in addition to cough were enrolled. Dogs were treated with alacepril (1.0-3.0 mg/kg/day) for at least 4 weeks. One dog (2.4%) developed complications, including appetite loss, lethargy, and vomiting. Thirty-six dogs were re-evaluated after 4 weeks of treatment. Cough resolved or improved in 20 dogs (55.6%) after treatment. Based on the efficacy of alacepril, the dogs were divided into an effective group (n=20) and an ineffective group (n=16). After treatment, the left ventricular end-diastolic internal diameter corrected for body weight was significantly increased from baseline in the ineffective group but was significantly decreased in the effective group. Univariate binomial logistic regression analyses showed that high atrial natriuretic peptide level, N-terminal pro-B-type natriuretic peptide level, and E wave velocity at baseline were significantly correlated with alacepril inefficacy. Alacepril as treatment for MVD is well tolerated in most dogs, and different conditions of cardiac loading may influence the effect of the drug. Alacepril is expected to improve the quality of life of dogs with early stage MVD.

Screening the ToxCast Phase 1, 2, and e1k chemical libraries for inhibition of Deiodinase Types 1, 2 and 3 enzyme activity

EPA Science Inventory

Thyroid hormone (TH) homeostasis is dependent on multiple proteins for TH synthesis, transport, and peripheral metabolism and elimination. Deiodinase enzymes play an essential role in converting THs between active and inactive forms by deiodinating the pro-hormone thyroxine (T4) ...

Serine proteases as candidates for proteolytic processing of angiotensin-I converting enzyme.

PubMed

Aragão, Danielle S; de Andrade, Maria Claudina C; Ebihara, Fabiana; Watanabe, Ingrid K M; Magalhães, Dayane C B P; Juliano, Maria Aparecida; Hirata, Izaura Yoshico; Casarini, Dulce Elena

2015-01-01

Somatic angiotensin-I converting enzyme (sACE) is a broadly distributed peptidase which plays a role in blood pressure and electrolyte homeostasis by the conversion of angiotensin I into angiotensin II. N-domain isoforms (nACE) with 65 and 90 kDa have been described in body fluids, tissues and mesangial cells (MC), and a 90 kDa nACE has been described only in spontaneously hypertensive rats. The aim of this study was to investigate the existence of proteolytic enzymes that may act in the hydrolysis of sACE generating nACEs in MC. After the confirmation of the presence of ACE sheddases in Immortalized MC (IMC), we purified and characterized these enzymes using fluorogenic substrates specifically designed for ACE sheddases. Purified enzyme identified as a serine protease by N-terminal sequence was able to generate nACE. In the present study, we described for the first time the presence of ACE sheddases in IMC, identified as serine proteases able to hydrolyze sACE in vitro. Further investigations are necessary to elucidate the mechanisms responsible for the expression and regulation of ACE sheddases in MC and their roles in the generation of nACEs, especially the 90 kDa form possibly related to hypertension. Copyright © 2014 Elsevier B.V. All rights reserved.

Back-reactions, short-circuits, leaks and other energy wasteful reactions in biological electron transfer: redox tuning to survive life in O(2).

PubMed

Rutherford, A William; Osyczka, Artur; Rappaport, Fabrice

2012-03-09

The energy-converting redox enzymes perform productive reactions efficiently despite the involvement of high energy intermediates in their catalytic cycles. This is achieved by kinetic control: with forward reactions being faster than competing, energy-wasteful reactions. This requires appropriate cofactor spacing, driving forces and reorganizational energies. These features evolved in ancestral enzymes in a low O(2) environment. When O(2) appeared, energy-converting enzymes had to deal with its troublesome chemistry. Various protective mechanisms duly evolved that are not directly related to the enzymes' principal redox roles. These protective mechanisms involve fine-tuning of reduction potentials, switching of pathways and the use of short circuits, back-reactions and side-paths, all of which compromise efficiency. This energetic loss is worth it since it minimises damage from reactive derivatives of O(2) and thus gives the organism a better chance of survival. We examine photosynthetic reaction centres, bc(1) and b(6)f complexes from this view point. In particular, the evolution of the heterodimeric PSI from its homodimeric ancestors is explained as providing a protective back-reaction pathway. This "sacrifice-of-efficiency-for-protection" concept should be generally applicable to bioenergetic enzymes in aerobic environments. Copyright © 2012 Federation of European Biochemical Societies. All rights reserved.

Morphine biosynthesis in opium poppy involves two cell types: sieve elements and laticifers.

PubMed

Onoyovwe, Akpevwe; Hagel, Jillian M; Chen, Xue; Khan, Morgan F; Schriemer, David C; Facchini, Peter J

2013-10-01

Immunofluorescence labeling and shotgun proteomics were used to establish the cell type-specific localization of morphine biosynthesis in opium poppy (Papaver somniferum). Polyclonal antibodies for each of six enzymes involved in converting (R)-reticuline to morphine detected corresponding antigens in sieve elements of the phloem, as described previously for all upstream enzymes transforming (S)-norcoclaurine to (S)-reticuline. Validated shotgun proteomics performed on whole-stem and latex total protein extracts generated 2031 and 830 distinct protein families, respectively. Proteins corresponding to nine morphine biosynthetic enzymes were represented in the whole stem, whereas only four of the final five pathway enzymes were detected in the latex. Salutaridine synthase was detected in the whole stem, but not in the latex subproteome. The final three enzymes converting thebaine to morphine were among the most abundant active latex proteins despite a limited occurrence in laticifers suggested by immunofluorescence labeling. Multiple charge isoforms of two key O-demethylases in the latex were revealed by two-dimensional immunoblot analysis. Salutaridine biosynthesis appears to occur only in sieve elements, whereas conversion of thebaine to morphine is predominant in adjacent laticifers, which contain morphine-rich latex. Complementary use of immunofluorescence labeling and shotgun proteomics has substantially resolved the cellular localization of morphine biosynthesis in opium poppy.

Wheat Bread with Pumpkin (Cucurbita maxima L.) Pulp
as a Functional Food Product.

PubMed

Różyło, Renata; Gawlik-Dziki, Urszula; Dziki, Dariusz; Jakubczyk, Anna; Karaś, Monika; Różyło, Krzysztof

2014-12-01

In this study, a new application of pumpkin pulp in bread production is shown. The aim of this work is to determine the influence of the addition of fresh pumpkin pulp directly into wheat flour on physical, sensorial and biological properties of bread. The bioaccessibility of active compounds was also studied. An increase in the addition of pumpkin pulp from 5 to 20% (converted to dry matter) caused a decrease of bread volume and increase of crumb hardness and cohesiveness. The sensory characteristics of the bread showed that a partial replacement of wheat flour with up to 10% of pumpkin pulp gave satisfactory results. The taste, aroma and overall acceptability of control bread and bread containing 5 or 10% of pulp had the highest degree of liking. The addition of higher levels of pumpkin pulp caused an unpleasant aroma and taste. Pumpkin pulp is a good material to complement the bread with potentially bioaccessible phenolics (including flavonoids) and, especially, with peptides. The highest antioxidant activity was observed, in most cases, of the samples with added 10 and 15% of pumpkin pulp. The addition of the pulp significantly enriched the bread with potentially bioaccessible angiotensin-converting enzyme (ACE) inhibitors. The highest activity was determined in the bread with 15 and 20% pumpkin pulp. ACE inhibitors from the tested bread were highly bioaccessible in vitro . Pumpkin pulp seems to be a valuable source of active compounds to complement the wheat bread. Adding the pulp directly to the wheat flour gives satisfactory baking results and reduces the cost of production. Additionally, pumpkin pulp is sometimes treated as waste material after the acquisition of seeds, thus using it as bread supplement also has environmental and economic benefits. Key words : pumpkin, bread, texture, antioxidants, bioaccessibility in vitro, angiotensin-converting enzyme (ACE) inhibition.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strittmatter, S.M.

(/sup 3/H)Captopril binds to angiotensin converting enzyme (ACE) in rat tissue homogenates. The pharmacology, regional distribution and copurification of (/sup 3/H)captopril binding with enzymatic activity demonstrate the selectivity of (/sup 3/H)captopril labeling of ACE. (/sup 3/H)Captopril binding to purified ACE reveals differences in cationic dependence and anionic regulation between substrate catalysis and inhibitor recognition. (/sup 3/H)Captopril association with ACE is entropically driven. The selectivity of (/sup 3/H)captopril binding permits autoradiographic localization of the ACE in the brain, male reproductive system, pituitary gland and adrenal gland. In the brain, ACE is visualized in a striatonigral neuronal pathway which develops between 1more » and 7 d after birth. In the male reproductive system, (/sup 3/H)captopril associated silver grains are found over spermatid heads and in the lumen of seminiferous tubules in stages I-VIII and XII-XIV. In the pituitary gland, ACE is localized to the posterior lobe and patches of the anterior lobe. The adrenal medulla contains moderate ACE levels while low levels are found in the adrenal cortex. Adrenal medullary ACE is increased after hypophysectomy and after reserpine treatment. The general of ligand binding techniques for the study of enzymes is demonstrated by the specific labeling of another enzyme, enkephaline convertase, in crude tissue homogenates by the inhibitor (/sup 3/H)GEMSA.« less

Nrt1 and Tna1-Independent Export of NAD+ Precursor Vitamins Promotes NAD+ Homeostasis and Allows Engineering of Vitamin Production

PubMed Central

Belenky, Peter; Stebbins, Rebecca; Bogan, Katrina L.; Evans, Charles R.; Brenner, Charles

2011-01-01

NAD+ is both a co-enzyme for hydride transfer enzymes and a substrate of sirtuins and other NAD+ consuming enzymes. NAD+ biosynthesis is required for two different regimens that extend lifespan in yeast. NAD+ is synthesized from tryptophan and the three vitamin precursors of NAD+: nicotinic acid, nicotinamide and nicotinamide riboside. Supplementation of yeast cells with NAD+ precursors increases intracellular NAD+ levels and extends replicative lifespan. Here we show that both nicotinamide riboside and nicotinic acid are not only vitamins but are also exported metabolites. We found that the deletion of the nicotinamide riboside transporter, Nrt1, leads to increased export of nicotinamide riboside. This discovery was exploited to engineer a strain to produce high levels of extracellular nicotinamide riboside, which was recovered in purified form. We further demonstrate that extracellular nicotinamide is readily converted to extracellular nicotinic acid in a manner that requires intracellular nicotinamidase activity. Like nicotinamide riboside, export of nicotinic acid is elevated by the deletion of the nicotinic acid transporter, Tna1. The data indicate that NAD+ metabolism has a critical extracellular element in the yeast system and suggest that cells regulate intracellular NAD+ metabolism by balancing import and export of NAD+ precursor vitamins. PMID:21589930

Nrt1 and Tna1-independent export of NAD+ precursor vitamins promotes NAD+ homeostasis and allows engineering of vitamin production.

PubMed

Belenky, Peter; Stebbins, Rebecca; Bogan, Katrina L; Evans, Charles R; Brenner, Charles

2011-05-11

NAD(+) is both a co-enzyme for hydride transfer enzymes and a substrate of sirtuins and other NAD(+) consuming enzymes. NAD(+) biosynthesis is required for two different regimens that extend lifespan in yeast. NAD(+) is synthesized from tryptophan and the three vitamin precursors of NAD(+): nicotinic acid, nicotinamide and nicotinamide riboside. Supplementation of yeast cells with NAD(+) precursors increases intracellular NAD(+) levels and extends replicative lifespan. Here we show that both nicotinamide riboside and nicotinic acid are not only vitamins but are also exported metabolites. We found that the deletion of the nicotinamide riboside transporter, Nrt1, leads to increased export of nicotinamide riboside. This discovery was exploited to engineer a strain to produce high levels of extracellular nicotinamide riboside, which was recovered in purified form. We further demonstrate that extracellular nicotinamide is readily converted to extracellular nicotinic acid in a manner that requires intracellular nicotinamidase activity. Like nicotinamide riboside, export of nicotinic acid is elevated by the deletion of the nicotinic acid transporter, Tna1. The data indicate that NAD(+) metabolism has a critical extracellular element in the yeast system and suggest that cells regulate intracellular NAD(+) metabolism by balancing import and export of NAD(+) precursor vitamins.

Modulated Expression of Genes Encoding Estrogen Metabolizing Enzymes by G1-Phase Cyclin-Dependent Kinases 6 and 4 in Human Breast Cancer Cells

PubMed Central

Jia, Yi; Domenico, Joanne; Swasey, Christina; Wang, Meiqin; Gelfand, Erwin W.; Lucas, Joseph J.

2014-01-01

G1-phase cell cycle defects, such as alterations in cyclin D1 or cyclin-dependent kinase (cdk) levels, are seen in most tumors. For example, increased cyclin D1 and decreased cdk6 levels are seen in many human breast tumors. Overexpression of cdk6 in breast tumor cells in culture has been shown to suppress proliferation, unlike the growth stimulating effects of its close homolog, cdk4. In addition to directly affecting proliferation, alterations in cdk6 or cdk4 levels in breast tumor cells also differentially influence levels of numerous steroid metabolic enzymes (SMEs), including those involved in estrogen metabolism. Overexpression of cdk6 in tumor cell lines having low cdk6 resulted in decreased levels of mRNAs encoding aldo-keto reductase (AKR)1C1, AKR1C2 and AKR1C3, which are hydroxysteroid dehydrogenases (HSDs) involved in steroid hormone metabolism. In contrast, increasing cdk4 dramatically increased these transcript levels, especially those encoding AKR1C3, an enzyme that converts estrone to 17β-estradiol, a change that could result in a pro-estrogenic state favoring tumor growth. Effects on other estrogen metabolizing enzymes, including cytochrome P450 (CYP) 19 aromatase, 17β-HSD2, and CYP1B1 transcripts, were also observed. Interactions of cdk6 and cdk4, but not cyclin D1, with the promoter region of a cdk-regulated gene, 17β-HSD2, were detected. The results uncover a previously unsuspected link between the cell cycle and hormone metabolism and differential roles for cdk6 and cdk4 in a novel mechanism for pre-receptor control of steroid hormone action, with important implications for the origin and treatment of steroid hormone-dependent cancers. PMID:24848372

Potent, selective, orally bioavailable inhibitors of tumor necrosis factor-alpha converting enzyme (TACE): discovery of indole, benzofuran, imidazopyridine and pyrazolopyridine P1' substituents.

PubMed

Lu, Zhonghui; Ott, Gregory R; Anand, Rajan; Liu, Rui-Qin; Covington, Maryanne B; Vaddi, Krishna; Qian, Mingxin; Newton, Robert C; Christ, David D; Trzaskos, James; Duan, James J-W

2008-03-15

Potent and selective inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with several new heterocyclic P1' groups in conjunction with cyclic beta-amino hydroxamic acid scaffolds. Among them, the pyrazolopyridine provided the best overall profile when combined with tetrahydropyran beta-amino hydroxamic acid scaffold. Specifically, inhibitor 49 showed IC(50) value of 1 nM against porcine TACE and 170 nM in the suppression of LPS-induced TNF-alpha of human whole blood. Compound 49 also displayed excellent selectivity over a wide panel of MMPs as well as excellent oral bioavailability (F%>90%) in rat n-in-1 PK studies.

Fructose 1,6-diphosphatase in striated muscle

PubMed Central

Krebs, H. A.; Woodford, Muriel

1965-01-01

1. The occurrence of fructose diphosphatase in muscle tissue was investigated with reference to the question whether lactate can be converted into glycogen in muscle, as postulated by Meyerhof (1930), fructose diphosphatase being one of the enzymes required for this conversion. 2. Fructose diphosphatase was found in skeletal muscle of man, dog, cat, rat, mouse, rabbit, guinea pig, cattle, sheep, pigeon, fowl and frog. Under the test conditions between 5 and 60 μmoles of substrate were split/g. fresh wt./hr. at 22°. 3. Like liver fructose diphosphatase, the muscle enzyme is inhibited by substrate concentrations above 0·1 mm, by AMP and by trace quantities of Zn2+, Fe2+ and Fe3+; it is `activated' by EDTA. Inhibitions by the above agents may account for the failure of previous authors to detect the enzyme. 4. Heart muscle of several vertebrate species and the smooth muscle of pigeon and fowl gizzard had no measurable activity. 5. The presence of fructose diphosphatase and the virtual absence of the enzyme systems converting pyruvate into phosphopyruvate means that lactate and pyruvate cannot be converted into glycogen in muscle, whereas the phosphorylated C3 compounds can. The reconversion into carbohydrate of lactate (which readily diffuses out of muscle) occurs in liver and kidney only. The reconversion of phosphorylated C3 intermediates (which cannot diffuse out of the tissue) can occur only within the muscle. 6. α-Glycerophosphate is probably the main intermediate requiring conversion into glycogen. The possible role of α-glycerophosphate formation in vertebrate muscle, already well established in insect muscle, is discussed. PMID:14346089

The chemical mechanism of sheep liver 6-phosphogluconate dehydrogenase. A Schiff-base intermediate is not involved.

PubMed Central

Topham, C M; Dalziel, K

1986-01-01

[2-18O]Ribulose 5-phosphate was prepared and shown to be converted enzymically by 6-phosphogluconate dehydrogenase from sheep liver into 6-phosphogluconate with complete retention of the heavy isotope. This finding unequivocally excludes the possibility of a Schiff-base mechanism for the enzyme. The involvement of metal ions has already been excluded, and other possible mechanisms are discussed. The enzyme was purified by an improved large-scale procedure, which is briefly described. PMID:3718491

The 46 kDa dimeric protein from Variovorax paradoxus shows faster methotrexate degrading activity in its nanoform compare to the native enzyme.

PubMed

Bayineni, Venkata Krishna; Venkatesh, Krishna; Sahu, Chandan Kumar; Kadeppagari, Ravi-Kumar

2016-04-01

Methotrexate degrading enzymes are required to overcome the toxicity of the methotrexate while treating the cancer. The enzyme from Variovorax paradoxus converts the methotrexate in to non toxic products. Methotrexate degrading enzyme from V. paradoxus is a dimeric protein with a molecular mass of 46 kDa and it acts on casein and gelatin. This enzyme is optimally active at pH 7.5 and 40°C and nanoparticles of this enzyme were prepared by desolvation-crosslinking method. Enzyme nanoparticles could degrade methotrexate faster than the native enzyme and they show lower Km compare to the native enzyme. Enzyme nanoparticles show better thermostability and they were stable for much longer time in the serum compare to the native enzyme. Enzyme nanoparticles show better functionality than the native enzyme while clearing the methotrexate added to the serum suggesting their advantage over the native enzyme for the therapeutic and biotechnological applications. Copyright © 2016 Elsevier Inc. All rights reserved.

Joseph Rudinger memorial lecture: Unexpected functions of angiotensin converting enzyme, beyond its enzymatic activity.

PubMed

Martinez, Jean

2017-10-01

Angiotensin converting enzyme (ACE) is a well-known enzyme, largely studied for its action on hypertension, as it produces angiotensin II from angiotensin I. This paper describes two original behaviours of ACE. We showed that ACE could hydrolyse gastrin, a neuropeptide from the gastrointestinal tract, releasing the C-terminal amidated dipeptide H-Asp-Phe-NH 2 . This dipeptide is believed to be involved in the gastrin-induced acid secretion in the stomach. This hypothetic mechanism of action of gastrin resulted in a strategy to rationally design gastrin receptor antagonists. Beyond, we showed that the brain renin angiotensin system (RAS) could be activated by a new characterized peptide named acein, resulting in stimulation of dopamine release within the striatum. This new and original 'receptor-like' activity for brain membrane-bound ACE is quite significant taking into account the role of dopamine in the brain, particularly in neurodegenerative diseases. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

A 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea.

PubMed

Berg, Ivan A; Kockelkorn, Daniel; Buckel, Wolfgang; Fuchs, Georg

2007-12-14

The assimilation of carbon dioxide (CO2) into organic material is quantitatively the most important biosynthetic process. We discovered that an autotrophic member of the archaeal order Sulfolobales, Metallosphaera sedula, fixed CO2 with acetyl-coenzyme A (acetyl-CoA)/propionyl-CoA carboxylase as the key carboxylating enzyme. In this system, one acetyl-CoA and two bicarbonate molecules were reductively converted via 3-hydroxypropionate to succinyl-CoA. This intermediate was reduced to 4-hydroxybutyrate and converted into two acetyl-CoA molecules via 4-hydroxybutyryl-CoA dehydratase. The key genes of this pathway were found not only in Metallosphaera but also in Sulfolobus, Archaeoglobus, and Cenarchaeum species. Moreover, the Global Ocean Sampling database contains half as many 4-hydroxybutyryl-CoA dehydratase sequences as compared with those found for another key photosynthetic CO2-fixing enzyme, ribulose-1,5-bisphosphate carboxylase-oxygenase. This indicates the importance of this enzyme in global carbon cycling.

Association of Urinary N-Domain Angiotensin I-Converting Enzyme with Plasma Inflammatory Markers and Endothelial Function

PubMed Central

Fernandes, Fernanda B; Plavnik, Frida L; Teixeira, Andressa MS; Christofalo, Dejaldo MJ; Ajzen, Sergio A; Higa, Elisa MS; Ronchi, Fernanda A; Sesso, Ricardo CC; Casarini, Dulce E

2008-01-01

The aim of this study was to investigate the association between urinary 90 kDa N-domain Angiotensin I-converting enzyme (ACE) form with C-reactive protein (CRP) and homocysteine plasma levels (Hcy), urinary nitric oxide (NOu), and endothelial function (EF) in normotensive subjects. Forty healthy subjects were evaluated through brachial Doppler US to test the response to reactive hyperemia and a panel of blood tests to determine CRP and Hcy levels, NOu, and urinary ACE. They were divided into groups according to the presence (ACE90+) or absence (ACE90–) of the 90 kDa ACE, the presence (FH+) or absence (FH–) of family history of hypertension, and the presence or absence of these two variables FH+/ACE90+ and FH–/ACE90–. We found an impaired endothelial dilatation in subjects who presented the 90 kDa N-domain ACE as follows: 11.4% ± 5.3% in ACE90+ compared with 17.6% ± 7.1% in ACE90– group and 12.4% ± 5.6% in FH+/ACE90+ compared with 17.7% ± 6.2% in FH–/ACE90– group, P < 0.05. Hcy and CRP levels were statistically significantly lower in FH+/ACE90+ than in FH–/ACE90– group, as follows: 10.0 ± 2.3 μM compared with 12.7 ± 1.5 μM, and 1.3 ± 1.8 mg/L compared with 3.6 ± 2.0 mg/L, respectively. A correlation between flow-mediated dilatation (FMD) and CRP, Hcy, and NOu levels was not found. Our study suggests a reduction in the basal NO production confirmed by NOu analysis in subjects with the 90 kDa N-domain ACE isoform alone or associated with a family history of hypertension. Our data suggest that the presence of the 90 kDa N-domain ACE itself may have a negative impact on flow-mediated dilatation stimulated by reactive hyperemia. PMID:18475311

Dietary sodium deprivation evokes activation of brain regional neurons and down-regulation of angiotensin II type 1 receptor and angiotensin-convertion enzyme mRNA expression.

PubMed

Lu, B; Yang, X J; Chen, K; Yang, D J; Yan, J Q

2009-12-15

Previous studies have indicated that the renin-angiotensin-aldosterone system (RAAS) is implicated in the induction of sodium appetite in rats and that different dietary sodium intakes influence the mRNA expression of central and peripheral RAAS components. To determine whether dietary sodium deprivation activates regional brain neurons related to sodium appetite, and changes their gene expression of RAAS components of rats, the present study examined the c-Fos expression after chronic exposure to low sodium diet, and determined the relationship between plasma and brain angiotensin I (ANG I), angiotensin II (ANG II) and aldosterone (ALD) levels and the sodium ingestive behavior variations, as well as the effects of prolonged dietary sodium deprivation on ANG II type 1 (AT1) and ANG II type 2 (AT2) receptors and angiotensin-convertion enzyme (ACE) mRNA levels in the involved brain regions using the method of real-time polymerase chain reaction (PCR). Results showed that the Fos immunoreactivity (Fos-ir) expression in forebrain areas such as subfornical organ (SFO), paraventricular hypothalamic nuclei (PVN), supraoptic nucleus (SON) and organum vasculosum laminae terminalis (OVLT) all increased significantly and that the levels of ANG I, ANG II and ALD also increased in plasma and forebrain in rats fed with low sodium diet. In contrast, AT1, ACE mRNA in PVN, SON and OVLT decreased significantly in dietary sodium depleted rats, while AT2 mRNA expression did not change in the examined areas. These results suggest that many brain areas are activated by increased levels of plasma and/or brain ANG II and ALD, which underlies the elevated preference for hypertonic salt solution after prolonged exposure to low sodium diet, and that the regional AT1 and ACE mRNA are down-regulated after dietary sodium deprivation, which may be mediated by increased ANG II in plasma and/or brain tissue.

Genetic and physiological characterization of the purine salvage pathway in the archaebacterium Methanobacterium thermoautotrophicum Marburg.

PubMed Central

Worrell, V E; Nagle, D P

1990-01-01

The enzymes involved in the purine interconversion pathway of wild-type and purine analog-resistant strains of Methanobacterium thermoautotrophicum Marburg were assayed by radiometric and spectrophotometric methods. Wild-type cells incorporated labeled adenine, guanine, and hypoxanthine, whereas mutant strains varied in their ability to incorporate these bases. Adenine, guanine, hypoxanthine, and xanthine were activated by phosphoribosyltransferase activities present in wild-type cell extracts. Some mutant strains simultaneously lost the ability to convert both guanine and hypoxanthine to the respective nucleotide, suggesting that the same enzyme activates both bases. Adenosine, guanosine, and inosine phosphorylase activities were detected for the conversion of base to nucleoside. Adenine deaminase activity was detected at low levels. Guanine deaminase activity was not detected. Nucleoside kinase activities for the conversion of adenosine, guanosine, and inosine to the respective nucleotides were detected by a new assay. The nucleotide-interconverting enzymes AMP deaminase, succinyl-AMP synthetase, succinyl-AMP lyase, IMP dehydrogenase, and GMP synthetase were present in extracts; GMP reductase was not detected. The results indicate that this autotrophic methanogen has a complex system for the utilization of exogenous purines. PMID:2345148

Enhancing enzymatic hydrolysis of sugarcane bagasse by ferric chloride catalyzed organosolv pretreatment and Tween 80.

PubMed

Zhang, Hongdan; Fan, Meishan; Li, Xin; Zhang, Aiping; Xie, Jun

2018-06-01

In this work, a FeCl 3 -catalyzed organosolv pretreatment was employed at 160 °C to remove hemicellulose and lignin in sugarcane bagasse leaving the cellulose-enriched residue for enzymatic hydrolysis to sugars. The solubilized hemicellulose fractions consisted more monomer xylose than oligomer xylose. The FeCl 3 -catalyzed organosolv pretreatment significantly improved the enzymatic hydrolysis, nearly 100% of cellulose components were converted to glucose after pretreatment with 0.05 M FeCl 3 . Structural analysis was employed to reveal how pretreatment affected the enzymatic hydrolysis. With the addition of Tween 80, the same level of glucose was obtained with 50% reduction of enzyme dosage after 24 h. Furthermore, the influence of Tween 80 on different pretreatment systems was investigated, indicating that the improvement was increased as the lignin content increased, decreased with high enzyme loading and extending hydrolysis time. This work suggested that the addition of Tween 80 could improve the enzymatic hydrolysis, reduce the hydrolysis time and enzyme dosage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Salicylic acid 3-hydroxylase regulates Arabidopsis leaf longevity by mediating salicylic acid catabolism

PubMed Central

Zhang, Kewei; Halitschke, Rayko; Yin, Changxi; Liu, Chang-Jun; Gan, Su-Sheng

2013-01-01

The plant hormone salicylic acid (SA) plays critical roles in plant defense, stress responses, and senescence. Although SA biosynthesis is well understood, the pathways by which SA is catabolized remain elusive. Here we report the identification and characterization of an SA 3-hydroxylase (S3H) involved in SA catabolism during leaf senescence. S3H is associated with senescence and is inducible by SA and is thus a key part of a negative feedback regulation system of SA levels during senescence. The enzyme converts SA (with a Km of 58.29 µM) to both 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-DHBA in vitro but only 2,3-DHBA in vivo. The s3h knockout mutants fail to produce 2,3-DHBA sugar conjugates, accumulate very high levels of SA and its sugar conjugates, and exhibit a precocious senescence phenotype. Conversely, the gain-of-function lines contain high levels of 2,3-DHBA sugar conjugates and extremely low levels of SA and its sugar conjugates and display a significantly extended leaf longevity. This research reveals an elegant SA catabolic mechanism by which plants regulate SA levels by converting it to 2,3-DHBA to prevent SA overaccumulation. The research also provides strong molecular genetic evidence for an important role of SA in regulating the onset and rate of leaf senescence. PMID:23959884

The use of asparaginase to reduce acrylamide levels in cooked food.

PubMed

Xu, Fei; Oruna-Concha, Maria-Jose; Elmore, J Stephen

2016-11-01

Strategies proposed for reducing the formation of the suspected carcinogen acrylamide in cooked foods often rely on a reduction in the extent of the Maillard reaction, in which acrylamide is formed from the reaction between asparagine and reducing sugars. However, the Maillard reaction also provides desirable sensory attributes of cooked foods. Mitigation procedures that modify the Maillard reaction may negatively affect flavour and colour. The use of asparaginase to convert asparagine to aspartic acid may provide a means to reduce acrylamide formation, while maintaining sensory quality. This review collates research on the use of enzymes, asparaginase in particular, to mitigate acrylamide formation. Asparaginase is a powerful tool for the food industry and it is likely that its use will increase. However, the potential adverse effects of asparaginase treatment on sensory properties of cooked foods and the need to achieve sufficient enzyme-substrate contact remain areas for future research. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phosphoramidon potentiates mammalian tachykinin-induced biting, licking and scratching behaviour in mice.

PubMed

Sakurada, T; Tan-No, K; Yamada, T; Sakurada, S; Kisara, K

1990-12-01

The effects of peptidase inhibitors were examined upon behavioural responses including scratch, bite and lick produced by intrathecal (IT) injection of substance P (SP) and neurokinin A (NK A) in mice. Phosphoramidon (0.002-2.0 nmol), an endopeptidase-24.11 inhibitor, simultaneously injected with SP or NK A, remarkably enhanced and prolonged SP- or NK A-induced behavioural response in a dose-dependent manner. The behavioural response to SP was significantly increased by 2.0 nmol of bestatin, an aminopeptidase inhibitor, but not by 1.0 nmol. Captopril, an angiotensin-converting enzyme inhibitor, was without effect on both tachykinin-induced responses. When phosphoramidon was injected together with bestatin and captopril which have no significant effect alone, SP- or NK A-induced behavioral response was significantly increased. These data suggest that endopeptidase-24.11 may be an important enzyme responsible for terminating of SP- or NK A-induced behavioral response at the spinal cord level.

Subcellular characteristics of functional intracellular renin–angiotensin systems☆

PubMed Central

Abadir, Peter M.; Walston, Jeremy D.; Carey, Robert M.

2013-01-01

The renin–angio tensin system (RAS) is now regarded as an integral component in not only the development of hypertension, but also in physiologic and pathophysiologic mechanisms in multiple tissues and chronic disease states. While many of the endocrine (circulating), paracrine (cell-to-different cell) and autacrine (cell-to-same cell) effects of the RAS are believed to be mediated through the canonical extracellular RAS, a complete, independent and differentially regulated intracellular RAS (iRAS) has also been proposed. Angiotensinogen, the enzymes renin and angiotensin-converting enzyme (ACE) and the angiotensin peptides can all be synthesized and retained intracellularly. Angiotensin receptors (types I and 2) are also abundant intracellularly mainly at the nuclear and mitochondrial levels. The aim of this review is to focus on the most recent information concerning the subcellular localization, distribution and functions of the iRAS and to discuss the potential consequences of activation of the subcellular RAS on different organ systems. PMID:23032352

Europe Report, Science and Technology.

DTIC Science & Technology

1986-06-18

amylase, heat stable alpha-amylase and glucoamylase for processing starch as a substrate for 71 glucose and its isomerization to fructose using an...continuous column process under laboratory conditions. We have demonstrated that these preparations isomerize glucose syrups up to 42 percent, converting...food industry is the leading consumer of microbial enzymes devouring about 80 percent of the world production of enzymes -- glucose isomerase, alpha

Cholecystokinin-converting enzymes in brain.

PubMed Central

Malesci, A; Straus, E; Yalow, R S

1980-01-01

Crude extracts of porcine cerebral cortical tissue convert cholecystokinin (CCK) to its COOH-terminal fragments, the dodecapeptide (CCK-12) and the octapeptide (CCK-8). The Sephadex G-75 void volume eluate of the crude extract cleaves the arginine-isoleucine bond and effects conversion only to CCK-12; the Sephadex G-50 void volume eluate of the same extract cleaves the arginine-aspartate bond as well, so that both CCK-12 and CCK-8 are end products. Thus, there are at least two enzymes; the one involved in the conversion to CCK-12 is of larger molecular radius than the other. The Km for the cleavage of CCK at the arginine-isoleucine bond by the Sephadex G-75 void volume eluate enzyme is 1.1 X 10(-6) M; the Km for trypsin cleavage of the same bond is 4.7 x 10(-6) M. The lower Vmax for the brain enzyme (1.5 x 10(-11) mol/min per g of extract) compared with trypsin (66 x 10(-11) mol/min per g of trypsin) simply reflects the lesser degree of purify of the brain extract than of the highly purified trypsin. Images PMID:6987659

Epilactose production by 2 cellobiose 2-epimerases in natural milk.

PubMed

Krewinkel, Manuel; Gosch, Maria; Rentschler, Eva; Fischer, Lutz

2014-01-01

It was reported recently that cellobiose 2-epimerases (CE) from various aerobic microorganisms convert lactose to epilactose in defined buffer systems. In this study, we showed that CE from 2 mesophilic microorganisms, Flavobacterium johnsoniae and Pedobacter heparinus, were capable of converting lactose to prebiotic epilactose not only in buffer but also in a complex milk system. First, the 2 enzymes were separately cloned, recombinantly expressed in Escherichia coli, and purified by column chromatography. The production of F. johnsoniae CE was carried out in a stirred-tank reactor, indicating that future upscaling is possible. The bioconversions of milk lactose were carried out at an industrially relevant low temperature of 8°C to avoid undesired microbial contaminations or chemical side reactions. Both enzymes were reasonably active at this low temperature, because of their origin from mesophilic organisms. The enzymes showed different operational stabilities over a 24-h time-course. A conversion yield of about 30 to 33% epilactose was achieved with both enzymes. No side products were detected other than epilactose. Therefore, CE may introduce an added value for particular dairy products by in situ production of the prebiotic sugar epilactose. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ultraviolet irradiation induces accumulation of isoflavonoids and transcription of genes of enzymes involved in the calycosin-7-O-β-d-glucoside pathway in Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao.

PubMed

Xu, Rong-Yan; Nan, Peng; Yang, Yixin; Pan, Haiyun; Zhou, Tongshui; Chen, Jiakuan

2011-07-01

Isoflavonoids are a group of phenolic secondary metabolites found almost exclusively in leguminous plants. Formononetin, calycosin and calycosin-7-O-β-d-glucoside (CG) are isoflavonoid products in the CG pathway. Accumulation of the three isoflavonoids plus daidzein and expression of six genes of enzymes involved in the CG pathway were studied in Astragalus membranaceus Bge. var. mongholicus (Bge.) Hsiao with ultraviolet (UV) irradiation. Our results showed that (1) main isoflavonoids in roots, stems and leaves were CG, daidzein and calycosin, respectively; they accumulated significantly under the induction of UV irradiation during 8 days but their content declined later; (2) expression of six genes of enzymes involved in the CG pathway was inhibited slightly at early stage but the expression was increased greatly afterward; (3) chalcone synthase, chalcone reductase and chalcone isomerase were expressed to their individual maximum level within shorter hours than were cinnamate 4-hydroxylase, isoflavone synthase (IFS) and isoflavone 3'-hydroxylase and (4) more calycosin but less daidzein accumulated in leaves. IFS was highly expressed in leaves, which might lead to high accumulation of the common precursor of daidzein and 2,7-dihydroxy-4'-O-methoxy-isoflavanone, the latter of which would be converted to formononetin, calycosin and CG via a series of reactions. Little daidzein accumulated in leaves, which suggested that rather than be converted to daidzein, the 2,7,4'-trihydroxyisoflavanone was probably more easily caught by 2-hydroxyisoflavanone 4'-O-methyltransferase and hence provided more precursors for formononetin. The findings were discussed in terms of the influence of UV irradiation in the accumulation of isoflavonoids. Copyright © Physiologia Plantarum 2011.

Proteomic endorsed transcriptomic profiles of venom glands from Tityus obscurus and T. serrulatus scorpions

PubMed Central

Nishiyama, Milton Yutaka; dos Santos, Maria Beatriz Viana; Santos-da-Silva, Andria de Paula; Chalkidis, Hipócrates de Menezes; Souza-Imberg, Andreia; Candido, Denise Maria; Yamanouye, Norma; Dorce, Valquíria Abrão Coronado; Junqueira-de-Azevedo, Inácio de Loiola Meirelles

2018-01-01

Background Except for the northern region, where the Amazonian black scorpion, T. obscurus, represents the predominant and most medically relevant scorpion species, Tityus serrulatus, the Brazilian yellow scorpion, is widely distributed throughout Brazil, causing most envenoming and fatalities due to scorpion sting. In order to evaluate and compare the diversity of venom components of Tityus obscurus and T. serrulatus, we performed a transcriptomic investigation of the telsons (venom glands) corroborated by a shotgun proteomic analysis of the venom from the two species. Results The putative venom components represented 11.4% and 16.7% of the total gene expression for T. obscurus and T. serrulatus, respectively. Transcriptome and proteome data revealed high abundance of metalloproteinases sequences followed by sodium and potassium channel toxins, making the toxin core of the venom. The phylogenetic analysis of metalloproteinases from T. obscurus and T. serrulatus suggested an intraspecific gene expansion, as we previously observed for T. bahiensis, indicating that this enzyme may be under evolutionary pressure for diversification. We also identified several putative venom components such as anionic peptides, antimicrobial peptides, bradykinin-potentiating peptide, cysteine rich protein, serine proteinases, cathepsins, angiotensin-converting enzyme, endothelin-converting enzyme and chymotrypsin like protein, proteinases inhibitors, phospholipases and hyaluronidases. Conclusion The present work shows that the venom composition of these two allopatric species of Tityus are considerably similar in terms of the major classes of proteins produced and secreted, although their individual toxin sequences are considerably divergent. These differences at amino acid level may reflect in different epitopes for the same protein classes in each species, explaining the basis for the poor recognition of T. obscurus venom by the antiserum raised against other species. PMID:29561852

Overexpression of catalase prevents hypertension and tubulointerstitial fibrosis and normalization of renal angiotensin-converting enzyme-2 expression in Akita mice

PubMed Central

Shi, Yixuan; Lo, Chao-Sheng; Chenier, Isabelle; Maachi, Hasna; Filep, Janos G.; Ingelfinger, Julie R.; Zhang, Shao-Ling

2013-01-01

We investigated the relationship among oxidative stress, hypertension, renal injury, and angiotensin-converting enzyme-2 (ACE2) expression in type 1 diabetic Akita mice. Blood glucose, blood pressure, and albuminuria were monitored for up to 5 mo in adult male Akita and Akita catalase (Cat) transgenic (Tg) mice specifically overexpressing Cat, a key antioxidant enzyme in their renal proximal tubular cells (RPTCs). Same-age non-Akita littermates and Cat-Tg mice served as controls. In separate studies, adult male Akita mice (14 wk) were treated with ANG 1–7 (500 μg·kg−1·day−1 sc) ± A-779, an antagonist of the Mas receptor (10 mg·kg−1·day−1 sc), and euthanized at the age of 18 wk. The left kidneys were processed for histology and apoptosis studies. Renal proximal tubules were isolated from the right kidneys to assess protein and gene expression. Urinary angiotensinogen (AGT), angiotensin II (ANG II), and ANG 1–7 were quantified by specific ELISAs. Overexpression of Cat attenuated renal oxidative stress; prevented hypertension; normalized RPTC ACE2 expression and urinary ANG 1–7 levels (both were low in Akita mice); ameliorated glomerular filtration rate, albuminuria, kidney hypertrophy, tubulointerstitial fibrosis, and tubular apoptosis; and suppressed profibrotic and proapoptotic gene expression in RPTCs of Akita Cat-Tg mice compared with Akita mice. Furthermore, daily administration of ANG 1–7 normalized systemic hypertension in Akita mice, which was reversed by A-779. These data demonstrate that Cat overexpression prevents hypertension and progression of nephropathy and highlight the importance of intrarenal oxidative stress and ACE2 expression contributing to hypertension and renal injury in diabetes. PMID:23552863

Anti-angiotensin converting enzyme (ACE) proteins from mycelia of Ganoderma lucidum (Curtis) P. Karst

PubMed Central

2013-01-01

Background Ganoderma lucidum has been purported as a potent remedy in the treatment and prevention of several ailments, including hypertension. This study aimed to explore the anti-ACE potential of protein fractions from the mycelia of G. lucidum. Methods Ganoderma lucidum mycelia were cultivated by submerged fermentation in a liquid medium containing brown sugar and spent brewer’s yeast. Intracellular proteins were fractionated from mycelia crude water extract by ammonium sulphate precipitation, and their angiotensin converting enzyme inhibitory activity was evaluated. The potential anti-ACE protein fractions were further separated by RP-HPLC and characterised using proteomics platforms. Results Preliminary result demonstrated that the mycelia crude water extract inhibited ACE at IC50 value of 1.134 ± 0.036 mg/mL. Following protein fractionation and HPLC purification, the presence of highly potential anti-ACE proteins with the IC50 values less than 200 μg/mL was detected. Characterisation of these proteins demonstrated the presence of four different antihypertensive-related proteins involved in the regulation of blood pressure through different mechanisms. Conclusions This study suggests that the mycelia of G. lucidum has high potential in lowering blood pressure level due to the presence of several antihypertensive-related proteins such as cystathionine beta synthase-like protein, DEAD/DEAH box helicase-like protein, paxillin-like protein, and alpha/beta hydrolase-like protein. PMID:24093919

Concomitant presence of endothelial nitric oxide 894T and angiotensin II-converting enzyme D alleles are associated with diabetic nephropathy in a Kurdish population from Western Iran.

PubMed

Rahimi, Zohreh; Vaisi-Raygani, Asad; Rahimi, Ziba; Parsian, Abbas

2012-02-01

The present study investigated the influence of insertion (I)/deletion (D) polymorphism of the angiotensin II-converting enzyme (ACE) gene in combination with endothelial nitric oxide (eNOS) G894T polymorphism on the predisposition to diabetic nephropathy (DN). Using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) method, the ACE and eNOS polymorphisms were genotyped in 72 microalbuminuric, 68 macroalbuminuric and 72 normoalbuinuric type 2 diabetes mellitus (T2DM) patients from Western Iran. The presence of eNOS T or ACE D allele was not associated with increased risk of macroalbuminuria (odds ratio (OR) = 1.36, P = 0.27 and OR = 1.6, P = 0.062, respectively). However, in the presence of both alleles there was a trend towards increased risk of macroalbuminuria (fivefold, P = 0.05). Our study indicates that the concomitant presence of both ACE D and eNOS T alleles tends to be associated with an elevation risk of macroalbuminuria compared with the presence of each polymorphism alone. This risk could be attributed to the increasing activity of ACE and angiotensin II level in the presence of D allele and decreasing NO production in the presence of T allele accelerating diabetic nephropathy. © 2011 The Authors. Nephrology © 2011 Asian Pacific Society of Nephrology.

Potentiation of Paclitaxel-Induced Pain Syndrome in Mice by Angiotensin I Converting Enzyme Inhibition and Involvement of Kinins.

PubMed

Brusco, Indiara; Silva, Cássia Regina; Trevisan, Gabriela; de Campos Velho Gewehr, Camila; Rigo, Flávia Karine; La Rocca Tamiozzo, Lidia; Rossato, Mateus Fortes; Tonello, Raquel; Dalmolin, Gerusa Duarte; de Almeida Cabrini, Daniela; Gomez, Marcus Vinícius; Ferreira, Juliano; Oliveira, Sara Marchesan

2017-12-01

Paclitaxel is a chemotherapeutic agent used to treat solid tumours. However, it causes an acute and neuropathic pain syndrome that limits its use. Among the mechanisms involved in neuropathic pain caused by paclitaxel is activation of kinin receptors. Angiotensin converting enzyme (ACE) inhibitors can enhance kinin receptor signalling. The goal of this study was to evaluate the role of kinins on paclitaxel-associated acute pain syndromes (P-APS) and the effect of ACE inhibition on P-APS and paclitaxel-associated chronic peripheral neuropathy (P-CPN) in mice. Herein, we show that paclitaxel caused mechanical allodynia and spontaneous nociceptive behaviour that was reduced by antagonists of kinin receptors B 1 (DALBk and SSR240612) and B 2 (Hoe140 and FR173657). Moreover, enalapril (an ACE inhibitor) enhanced the mechanical allodynia induced by a low dose of paclitaxel. Likewise, paclitaxel injection inhibited ACE activity and increased the expressions of B 1 and B 2 receptors and bradykinin-related peptides levels in peripheral tissue. Together, our data support the involvement of kinin receptors in the P-APS and suggest kinin receptor antagonists to treat this syndrome. Because hypertension is the most frequent comorbidity affecting cancer patients, treatment of hypertension with ACE inhibitors in patients undergoing paclitaxel chemotherapy should be reviewed, since this could enhance the P-APS and P-CPN.

Angiotensin-converting enzyme gene polymorphism in arrhythmogenic right ventricular dysplasia: is DD genotype helpful in predicting syncope risk?

PubMed

Ozben, Beste; Altun, Ibrahim; Sabri Hancer, Veysel; Bilge, Ahmet Kaya; Tanrikulu, Azra Meryem; Diz-Kucukkaya, Reyhan; Fak, Ali Serdar; Yilmaz, Ercument; Adalet, Kamil

2008-12-01

Arrhythmogenic right ventricular dysplasia (ARVD) is a heritable disorder characterised by fibrofatty replacement of right ventricular myocytes and increased risk of ventricular arrhythmias and sudden cardiac death. Angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism affects myocardial ACE levels. DD genotype favours myocardial fibrosis and is associated with malignant ventricular tachycardia. The aim of this study was to explore ACE gene polymorphism in ARVD patients. Twenty-nine patients with ARVD and 24 controls were included. All ARVD patients had documented sustained ventricular tachycardia. Thirteen patients had syncopal episodes. Six patients were resuscitated from sudden cardiac death. ACE gene polymorphism was identified by polymerase chain reaction technique. There was no significant difference in DD genotype frequency between ARVD patients and controls (44.8% vs. 45.8%, p=0.94). However, DD genotype frequency was significantly higher in ARVD patients with syncopal episodes compared to those without syncope (69.2% vs. 25.0%, p=0.017, odds ratio:6.750, 95% confidence interval: 1.318-34.565). DD genotype was detected in higher frequency also in patients with a family history of sudden cardiac death (66.7% vs. 39.1%,p=0.36). High prevalence of DD genotype in ARVD patients with syncope suggests that ACE I/D polymorphism might be useful in identifying high-risk patients for syncope.

Starch Biorefinery Enzymes.

PubMed

Läufer, Albrecht

2017-03-07

Nature uses enzymes to build and convert biomass; mankind uses the same enzymes and produces them on a large scale to make optimum use of biomass in biorefineries. Bacterial α-amylases and fungal glucoamylases have been the workhorses of starch biorefineries for many decades. Pullulanases were introduced in the 1980s. Proteases, cellulases, hemicellulases, and phytases have been on the market for a few years as process aids, improving yields, performance, and costs. Detailed studies of the complex chemical structures of biomass and of the physicochemical limitations of industrial biorefineries have led enzyme developers to produce novel tailor-made solutions for improving yield and profitability in the industry. This chapter reviews the development of enzyme applications in the major starch biorefining processes.

Soybean phenolic-rich extracts inhibit key-enzymes linked to type 2 diabetes (α-amylase and α-glucosidase) and hypertension (angiotensin I converting enzyme) in vitro.

PubMed

Ademiluyi, Adedayo O; Oboh, Ganiyu

2013-03-01

This study sought to assess the inhibitory activities of phenolic-rich extracts from soybean on α-amylase, α-glucosidase and angiotensin I converting enzyme (ACE) activities in vitro. The free phenolic extract of the soybean was obtained by extraction with 80% acetone, while that of the bound phenolic extract was done by extracting the alkaline and acid hydrolyzed residue with ethyl acetate. The inhibitory action of these extracts on the enzymes activity as well as their antioxidant properties was assessed. Both phenolic-rich extracts inhibited α-amylase, α-glucosidase and ACE enzyme activities in a dose dependent pattern. However, the bound phenolic extract exhibited significantly (P < 0.05) higher α-amylase and ACE inhibition while the free phenolic extract had significantly (P < 0.05) higher α-glucosidase inhibitory activity. Nevertheless, the free phenolic extract had higher α-glucosidase inhibitory activity when compared to that of α-amylase; this property confer an advantage on soybean phenolic-rich extracts over commercial antidiabetic drugs with little or no side effect. And inhibition of ACE suggests the antihypertension potential of soybean phenolic-rich extracts. Furthermore, the enzyme inhibitory activities of the phenolic-rich extracts were not associated with their phenolic content. Therefore, phenolic-rich extracts of soybean could inhibit key-enzyme linked to type 2 diabetes (α-amylase and α-glucosidase) and hypertension (ACE) and thus could explain in part the mechanism by which soybean renders these health promoting effect. Copyright © 2011 Elsevier GmbH. All rights reserved.

Enhanced synthesis of choline and glycine betaine in transgenic tobacco plants that overexpress phosphoethanolamine N-methyltransferase

PubMed Central

McNeil, Scott D.; Nuccio, Michael L.; Ziemak, Michael J.; Hanson, Andrew D.

2001-01-01

Choline (Cho) is the precursor of the osmoprotectant glycine betaine and is itself an essential nutrient for humans. Metabolic engineering of Cho biosynthesis in plants could therefore enhance both their resistance to osmotic stresses (drought and salinity) and their nutritional value. The key enzyme of the plant Cho-synthesis pathway is phosphoethanolamine N-methyltransferase, which catalyzes all three of the methylations required to convert phosphoethanolamine to phosphocholine. We show here that overexpressing this enzyme in transgenic tobacco increased the levels of phosphocholine by 5-fold and free Cho by 50-fold without affecting phosphatidylcholine content or growth. Moreover, the expanded Cho pool led to a 30-fold increase in synthesis of glycine betaine via an engineered glycine betaine pathway. Supplying the transgenics with the Cho precursor ethanolamine (EA) further enhanced Cho levels even though the supplied EA was extensively catabolized. These latter results establish that there is further scope for improving Cho synthesis by engineering an increased endogenous supply of EA and suggest that this could be achieved by enhancing EA synthesis and/or by suppressing its degradation. PMID:11481443

Androgenic correlates of genetic variation in the gene encoding 5alpha-reductase type 1.

PubMed

Ellis, Justine A; Panagiotopoulos, Sianna; Akdeniz, Aysel; Jerums, George; Harrap, Stephen B

2005-01-01

Androgens determine male secondary sexual characteristics and influence a variety of metabolic pathways. Circulating levels of androgens are highly heritable; however, the genes involved are largely unknown. The 5alpha-reductase enzymes types 1 and 2 responsible for converting testosterone to the more potent androgen dihydrotestosterone are encoded by the SRD5A1 and SRD5A2 genes, respectively. We performed indirect genetic association studies of SRD5A1 and SRD5A2 and the dihydrotestosterone/testosterone ratio that reflects the activity of 5alpha-reductase in 57 males with type 2 diabetes. We found evidence of significant association between a single nucleotide polymorphism in SRD5A1 and the dihydrotestosterone/testosterone ratio (median 0.10, interquartile range 0.08 vs. median 0.06, interquartile range 0.04, P = 0.009). The polymorphism was not associated with any diabetic phenotypes. These results suggest that functional genetic variants might exist in or around SRD5A1 that affect the activity of the 5alpha-reductase enzyme type 1 and influence androgen levels.

Marketing research on the angiotensin-converting enzyme inhibitors antihypertensive medicines.

PubMed

Boboia, Anamaria; Grigorescu, Marius Rareş; Turcu-Ştiolică, Adina

2017-01-01

The research aimed at investigating sales trends of angiotensin-converting enzyme inhibitors antihypertensive medicines, both in terms of quantity and value, in ten community pharmacies, for a period of three years. The research on the antihypertensive medicines consumption is important for highlighting the ever increasing impact of hypertension among the population. The methods used in this research were the following: marketing research, method of sampling, descriptive methods, retrospective analysis, method of comparison. The results showed that the drugs containing the active substances of the angiotensin converting enzyme inhibitors class had had significant increases in quantitative and value sales, bringing substantial revenues to pharmacies. From the quantitative perspective, the best-selling products were those containing Enalaprilum, while in terms of value, the best-selling medicines were those containing Perindoprilum. We evidenced that spectacular sales were also achieved for products that have Lisinoprilum, respectively Captoprilum, as active substances. The largest quantities were marketed for the Captopril Terapia® product and the highest earnings were recorded for the Prestarium® medicine. This paper approaches an interesting and topical issue, which can be helpful to professionals (pharmacists, doctors) and other categories, such as economists, statisticians, representatives of companies manufacturing medicines, as well as to hypertensive patients, as it could be used to warn population regarding the incidence of cardiovascular diseases, and, at the same time, trace sales trends in order to accomplish profitable business plans.

In vitro angiotensin I converting enzyme inhibition by a peptide isolated from Chiropsalmus quadrigatus Haeckel (box jellyfish) venom hydrolysate.

PubMed

So, Pamela Berilyn T; Rubio, Peter; Lirio, Stephen; Macabeo, Allan Patrick; Huang, Hsi-Ya; Corpuz, Mary Jho-Anne T; Villaflores, Oliver B

2016-09-01

The anti-angiotensin I converting enzyme activity of box jellyfish, Chiropsalmus quadrigatus Haeckel venom hydrolysate was studied. The venom extract was obtained by centrifugation and ultrasonication. Protein concentration of 12.99 μg/mL was determined using Bradford assay. The pepsin and papain hydrolysate was tested for its toxicity by Limit test following the OECD Guideline 425 using 5 female Sprague-Dawley rats. Results showed that the hydrolysate is nontoxic with an LD50 above 2000 mg/kg. In vitro angiotensin I converting enzyme (ACE) inhibitory activity was determined using ACE kit-WST. Isolation of ACE inhibitory peptides using column chromatography with SP-Sephadex G-25 yielded 8 pooled fractions with fraction 3 (86.5%) exhibiting the highest activity. This was followed by reverse phase - high performance liquid chromatography (RP-HPLC) with an octadecyl silica column (Inertsil ODS-3) using methanol:water 15:85 at a flow rate of 1.0 mL/min. Among the 13 fractions separated with the RP-HPLC, fraction 3.5 exhibited the highest ACE inhibitory activity (84.1%). The peptide sequence ACPGPNPGRP (IC50 2.03 μM) from fraction 3.5 was identified using Matrix-assisted laser desorption/ionization with time-of-flight tandem mass spectroscopy analysis (MALDI-TOF/MS). Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of Two Late-Stage Enzymes Involved in Fosfomycin Biosynthesis in Pseudomonads.

PubMed

Olivares, Philip; Ulrich, Emily C; Chekan, Jonathan R; van der Donk, Wilfred A; Nair, Satish K

2017-02-17

The broad-spectrum phosphonate antibiotic fosfomycin is currently in use for clinical treatment of infections caused by both Gram-positive and Gram-negative uropathogens. The antibiotic is biosynthesized by various streptomycetes, as well as by pseudomonads. Notably, the biosynthetic strategies used by the two genera share only two steps: the first step in which primary metabolite phosphoenolpyruvate (PEP) is converted to phosphonopyruvate (PnPy) and the terminal step in which 2-hydroxypropylphosphonate (2-HPP) is converted to fosfomycin. Otherwise, distinct enzymatic paths are employed. Here, we biochemically confirm the last two steps in the fosfomycin biosynthetic pathway of Pseudomonas syringae PB-5123, showing that Psf3 performs the reduction of 2-oxopropylphosphonate (2-OPP) to (S)-2-HPP, followed by the Psf4-catalyzed epoxidation of (S)-2-HPP to fosfomycin. Psf4 can also accept (R)-2-HPP as a substrate but instead performs an oxidation to make 2-OPP. We show that the combined activities of Psf3 and Psf4 can be used to convert racemic 2-HPP to fosfomycin in an enantioconvergent process. X-ray structures of each enzyme with bound substrates provide insights into the stereospecificity of each conversion. These studies shed light on the reaction mechanisms of the two terminal enzymes in a distinct pathway employed by pseudomonads for the production of a potent antimicrobial agent.

Injections of angiotensin-converting enzyme2 inhibitor MLN4760 into nucleus tractus solitarii reduce baroreceptor reflex sensitivity for heart rate control in rats

PubMed Central

Diz, Debra I.; Garcia-Espinosa, Maria A.; Gegick, Stephen; Tommasi, Ellen N.; Ferrario, Carlos M.; Tallant, E. Ann; Chappell, Mark C.; Gallagher, Patricia E.

2009-01-01

Injections of the angiotensin(1–7) [Ang(1–7)] antagonist [d-Ala7]-Ang(1–7) into the nucleus of the solitary tract (NTS) of Sprague–Dawley rats reduce baroreceptor reflex sensitivity (BRS) for control of heart rate by ~40%, whereas injections of the angiotensin II (Ang II) type 1 receptor antagonist candesartan increase BRS by 40% when reflex bradycardia is assessed. The enzyme angiotensin-converting enzyme 2 (ACE2) is known to convert Ang II to Ang(1–7). We report that ACE2 activity, as well as ACE and neprilysin activities, are present in plasma membrane fractions of the dorsomedial medulla of Sprague–Dawley rats. Moreover, we show that BRS for reflex bradycardia is attenuated (1.16±0.29 ms mmHg−1 before versus 0.33±0.11 ms mmHg−1 after; P < 0.05; n = 8) 30–60 min following injection of the selective ACE2 inhibitor MLN4760 (12 pmol in 120 nl) into the NTS. These findings support the concept that within the NTS, local synthesis of Ang(1–7) from Ang II is required for normal sensitivity for the baroreflex control of heart rate in response to increases in arterial pressure. PMID:18356558

Angiotensin-converting enzyme inhibitor (enalapril maleate) accelerates recovery of mouse skin from UVB-induced wrinkles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuura-Hachiya, Yuko; Arai, Koji Y.; Ozeki, Rieko

Highlights: •Angiotensin converting enzyme (ACE) increases in UVB-irradiated skin. •Administration of an ACE inhibitor improved UVB-induced skin wrinkle. •ACE inhibitor improved UVB-induced epidermal hypertrophy. •ACE inhibitor improved transepidermal water loss in the UVB-irradiated skin. -- Abstract: Angiotensin-converting enzyme (ACE) activity and angiotensin II signaling regulate cell proliferation, differentiation, and tissue remodeling, as well as blood pressure, while in skin, angiotensin II signaling is involved in wound healing, inflammation, and pathological scar formation. Therefore, we hypothesized that angiotensin II is also involved in photoaging of skin. In this study, we examined the effect of enalapril maleate, an ACE inhibitor, on recoverymore » of wrinkled skin of hairless mice exposed to long-term UVB irradiation. Immunohistochemical observation revealed that expression of ACE, angiotensin II, and angiotensin II type 1 (AT1) and type 2 (AT2) receptors in the skin was increased after UVB irradiation (3 times/week at increasing intensities for 8 weeks). Administration of enalapril maleate (5 times/week for 6 weeks, starting 1 week after 10-week irradiation) accelerated recovery from UVB-induced wrinkles, epidermal hyperplasia and epidermal barrier dysfunction, as compared with the vehicle control. Our results indicate that ACE and angiotensin II activity are involved in skin photoaging, and suggest that ACE inhibitor such as enalapril maleate may have potential for improvement of photoaged skin.« less

Effect of protease inhibitors on angiotensin-converting enzyme activity in human T-lymphocytes.

PubMed

Petrov, V; Fagard, R; Lijnen, P

2000-05-01

The purpose of these investigations was to determine whether the aminopeptidase B and leucine aminopeptidase inhibitor bestatin, the chymase inhibitor chymostatin, the calpain inhibitor E-64, and the neutral serine protease inhibitor leupeptin affect the angiotensin converting enzyme (ACE) activity in T-lymphocytes. ACE activity in homogenates of T-lymphocytes or in intact T-lymphocytes in suspension was measured by determining fluorimetrically histidyl-leucine, formed from the conversion of hippuryl-histidyl-leucine, coupled with ophtaldialdehyde. The effect of various concentrations (10(-9) to 10(-3) mol/L) of the angiotensin-converting enzyme inhibitors lisinopril and captopril and of the various protease inhibitors on ACE activity was studied. Lisinopril and captopril reduced the ACE activity in homogenates of T-lymphocytes in a concentration-dependent manner. Lisinopril exhibited a more pronounced inhibition of ACE in T-lymphocytes than did captopril. Chymostatin and E-64 had no effect on the ACE activity in T-lymphocytes, whereas leupeptin inhibited its activity in a dose-dependent fashion. Bestatin, on the contrary, increased the ACE activity in homogenates of T-lymphocytes as well as in intact T-lymphocytes in proportion to the concentration. Our data showed that the ACE activity in T-lymphocytes was stimulated by bestatin and inhibited by leupeptin, whereas chymostatin and E-64 did not affect the ACE activity in T-lymphocytes.

Predictors of heart failure in patients with stable coronary artery disease: a PEACE study.

PubMed

Lewis, Eldrin F; Solomon, Scott D; Jablonski, Kathleen A; Rice, Madeline Murguia; Clemenza, Francesco; Hsia, Judith; Maggioni, Aldo P; Zabalgoitia, Miguel; Huynh, Thao; Cuddy, Thomas E; Gersh, Bernard J; Rouleau, Jean; Braunwald, Eugene; Pfeffer, Marc A

2009-05-01

Heart failure (HF) is a disease commonly associated with coronary artery disease. Most risk models for HF development have focused on patients with acute myocardial infarction. The Prevention of Events with Angiotensin-Converting Enzyme Inhibition population enabled the development of a risk model to predict HF in patients with stable coronary artery disease and preserved ejection fraction. In the 8290, Prevention of Events with Angiotensin-Converting Enzyme Inhibition patients without preexisting HF, new-onset HF hospitalizations, and fatal HF were assessed over a median follow-up of 4.8 years. Covariates were evaluated and maintained in the Cox regression multivariable model using backward selection if P<0.05. A risk score was developed and converted to an integer-based scoring system. Among the Prevention of Events with Angiotensin-Converting Enzyme Inhibition population (age, 64+/-8; female, 18%; prior myocardial infarction, 55%), there were 268 cases of fatal and nonfatal HF. Twelve characteristics were associated with increased risk of HF along with several baseline medications, including older age, history of hypertension, and diabetes. Randomization to trandolapril independently reduced the risk of HF. There was no interaction between trandolapril treatment and other risk factors for HF. The risk score (range, 0 to 21) demonstrated excellent discriminatory power (c-statistic 0.80). Risk of HF ranged from 1.75% in patients with a risk score of 0% to 33% in patients with risk score >or=16. Among patients with stable coronary artery disease and preserved ejection fraction, traditional and newer factors were independently associated with increased risk of HF. Trandolopril decreased the risk of HF in these patients with preserved ejection fraction.

Heterologous Expression of a Bioactive β-Hexosyltransferase, an Enzyme Producer of Prebiotics, from Sporobolomyces singularis

PubMed Central

Dagher, Suzanne F.; Azcarate-Peril, M. Andrea

2013-01-01

Galacto-oligosaccharides (GOS) are indigestible dietary fibers that are able to reach the lower gastrointestinal tract to be selectively fermented by health-promoting bacteria. In this report, we describe the heterologous expression of an optimized synthetically produced version of the β-hexosyltransferase gene (Bht) from Sporobolomyces singularis. The Bht gene encodes a glycosyl hydrolase (EC 3.2.1.21) that acts as galactosyltransferase, able to catalyze a one-step conversion of lactose to GOS. Expression of the enzyme in Escherichia coli yielded an inactive insoluble protein, while the methylotrophic yeast Pichia pastoris GS115 produced a bioactive β-hexosyltransferase (rBHT). The enzyme exhibited faster kinetics at pHs between 3.5 and 6 and at temperatures between 40 and 50°C. Enzyme stability improved at temperatures lower than 40°C, and glucose was found to be a competitive inhibitor of enzymatic activity. P. pastoris secreted a fraction of the bioactive rBHT into the fermentation broth, while the majority of the enzyme remained associated with the outer membrane. Both the secreted and the membrane-associated forms were able to efficiently convert lactose to GOS. Additionally, resting cells with membrane-bound enzyme converted 90% of the initial lactose into GOS at 68% yield (g/g) (the maximum theoretical is 75%) with no secondary residual (glucose or galactose) products. This is the first report of a bioactive BHT from S. singularis that has been heterologously expressed. PMID:23241974

Functional Characterization of Proanthocyanidin Pathway Enzymes from Tea and Their Application for Metabolic Engineering1[W][OA

PubMed Central

Pang, Yongzhen; Abeysinghe, I. Sarath B.; He, Ji; He, Xianzhi; Huhman, David; Mewan, K. Mudith; Sumner, Lloyd W.; Yun, Jianfei; Dixon, Richard A.

2013-01-01

Tea (Camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (PAs) and their precursors. To better understand the PA pathway in tea, we generated a complementary DNA library from leaf tissue of the blister blight-resistant tea cultivar TRI2043 and functionally characterized key enzymes responsible for the biosynthesis of PA precursors. Structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the PA-specific branch pathway were well represented in the library. Recombinant tea leucoanthocyanidin reductase (CsLAR) expressed in Escherichia coli was active with leucocyanidin as substrate to produce the 2R,3S-trans-flavan-ol (+)-catechin in vitro. Two genes encoding anthocyanidin reductase, CsANR1 and CsANR2, were also expressed in E. coli, and the recombinant proteins exhibited similar kinetic properties. Both converted cyanidin to a mixture of (+)-epicatechin and (−)-catechin, although in different proportions, indicating that both enzymes possess epimerase activity. These epimers were unexpected based on the belief that tea PAs are made from (−)-epicatechin and (+)-catechin. Ectopic expression of CsANR2 or CsLAR led to the accumulation of low levels of PA precursors and their conjugates in Medicago truncatula hairy roots and anthocyanin-overproducing tobacco (Nicotiana tabacum), but levels of oligomeric PAs were very low. Surprisingly, the expression of CsLAR in tobacco overproducing anthocyanin led to the accumulation of higher levels of epicatechin and its glucoside than of catechin, again highlighting the potential importance of epimerization in flavan-3-ol biosynthesis. These data provide a resource for understanding tea PA biosynthesis and tools for the bioengineering of flavanols. PMID:23288883

Multi-species comparative analysis of the equine ACE gene identifies a highly conserved potential transcription factor binding site in intron 16.

PubMed

Hamilton, Natasha A; Tammen, Imke; Raadsma, Herman W

2013-01-01

Angiotensin converting enzyme (ACE) is essential for control of blood pressure. The human ACE gene contains an intronic Alu indel (I/D) polymorphism that has been associated with variation in serum enzyme levels, although the functional mechanism has not been identified. The polymorphism has also been associated with cardiovascular disease, type II diabetes, renal disease and elite athleticism. We have characterized the ACE gene in horses of breeds selected for differing physical abilities. The equine gene has a similar structure to that of all known mammalian ACE genes. Nine common single nucleotide polymorphisms (SNPs) discovered in pooled DNA were found to be inherited in nine haplotypes. Three of these SNPs were located in intron 16, homologous to that containing the Alu polymorphism in the human. A highly conserved 18 bp sequence, also within that intron, was identified as being a potential binding site for the transcription factors Oct-1, HFH-1 and HNF-3β, and lies within a larger area of higher than normal homology. This putative regulatory element may contribute to regulation of the documented inter-individual variation in human circulating enzyme levels, for which a functional mechanism is yet to be defined. Two equine SNPs occurred within the conserved area in intron 16, although neither of them disrupted the putative binding site. We propose a possible regulatory mechanism of the ACE gene in mammalian species which was previously unknown. This advance will allow further analysis leading to a better understanding of the mechanisms underpinning the associations seen between the human Alu polymorphism and enzyme levels, cardiovascular disease states and elite athleticism.

Multi-Species Comparative Analysis of the Equine ACE Gene Identifies a Highly Conserved Potential Transcription Factor Binding Site in Intron 16

PubMed Central

Hamilton, Natasha A.; Tammen, Imke; Raadsma, Herman W.

2013-01-01

Angiotensin converting enzyme (ACE) is essential for control of blood pressure. The human ACE gene contains an intronic Alu indel (I/D) polymorphism that has been associated with variation in serum enzyme levels, although the functional mechanism has not been identified. The polymorphism has also been associated with cardiovascular disease, type II diabetes, renal disease and elite athleticism. We have characterized the ACE gene in horses of breeds selected for differing physical abilities. The equine gene has a similar structure to that of all known mammalian ACE genes. Nine common single nucleotide polymorphisms (SNPs) discovered in pooled DNA were found to be inherited in nine haplotypes. Three of these SNPs were located in intron 16, homologous to that containing the Alu polymorphism in the human. A highly conserved 18 bp sequence, also within that intron, was identified as being a potential binding site for the transcription factors Oct-1, HFH-1 and HNF-3β, and lies within a larger area of higher than normal homology. This putative regulatory element may contribute to regulation of the documented inter-individual variation in human circulating enzyme levels, for which a functional mechanism is yet to be defined. Two equine SNPs occurred within the conserved area in intron 16, although neither of them disrupted the putative binding site. We propose a possible regulatory mechanism of the ACE gene in mammalian species which was previously unknown. This advance will allow further analysis leading to a better understanding of the mechanisms underpinning the associations seen between the human Alu polymorphism and enzyme levels, cardiovascular disease states and elite athleticism. PMID:23408978

The effect of alpha amylase enzyme on quality of sweet sorghum juice for chrystal sugar

NASA Astrophysics Data System (ADS)

Marwati, T.; Cahyaningrum, N.; Widodo, S.; Astiati, U. T.; Budiyanto, A.; Wahyudiono; Arif, A. B.; Richana, N.

2018-01-01

Sweet sorghum juice (Sorghum bicolor L. Moench) has characteristics similar to sugar cane juice and potentially used for sugar substitutes that can support food security. Nevertheless the sweet sorghum juicecontain starch which impede sorghum sugar crystallization. Therefore, research on the enzymatic process is needed to convert starch into reducing sugar. The experimental design used was the Factorial Randomized Design with the first factor was alpha amylase enzyme concentration (0, 20, 40, 60, 80, 100, 120 μL/100 mL) and second factor was incubation time (0, 30, 60, 90 minute) at temperature 100°C. The experiment was conducted on fresh sweet sorghum. The results showed that the addition of the alpha amylase enzyme increased the content of reducing sugar and decreased levels of starch. Elevating concentration of alpha amylase enzyme will increase the reducing sugar content in sweet sorghum juice. The optimum alpha amylase enzyme concentration to produce the highest total sugar was 80 μL/100 mL of sweet sorghum juice with the optimum incubation time was 90 minutes. The results of this study are expected to create a new sweetener for sugar substitution. From the economic prospective aspect, sorghum is a potential crop and can be relied upon to support the success of the food diversification program which further leads to the world food security

Identification of new polymorphisms of the angiotensin I-converting enzyme (ACE) gene, and study of their relationship to plasma ACE levels by two-QTL segregation-linkage analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villard, E.; Soubrier, F.; Tiret, L.

1996-06-01

Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disequilibrium (LD) with the ACE insertion/deletion (I/D) polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D polymorphism. These polymorphisms couldmore » be divided into two groups: five polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, polymorphisms were in nearly complete association, whereas polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D polymorphism, all polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D polymorphism itself or the newly characterized 4656(CT){sub 2/3} polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.« less

Interaction of angiotensin-converting enzyme (ACE) with membrane-bound carboxypeptidase M (CPM) - a new function of ACE.

PubMed

Sun, Xiaoou; Wiesner, Burkhard; Lorenz, Dorothea; Papsdorf, Gisela; Pankow, Kristin; Wang, Po; Dietrich, Nils; Siems, Wolf-Eberhard; Maul, Björn

2008-12-01

Angiotensin-converting enzyme (ACE) demonstrates, besides its typical dipeptidyl-carboxypeptidase activity, several unusual functions. Here, we demonstrate with molecular, biochemical, and cellular techniques that the somatic wild-type murine ACE (mACE), stably transfected in Chinese Hamster Ovary (CHO) or Madin-Darby Canine Kidney (MDCK) cells, interacts with endogenous membranal co-localized carboxypeptidase M (CPM). CPM belongs to the group of glycosylphosphatidylinositol (GPI)-anchored proteins. Here we report that ACE, completely independent of its known dipeptidase activities, has GPI-targeted properties. Our results indicate that the spatial proximity between mACE and the endogenous CPM enables an ACE-evoked release of CPM. These results are discussed with respect to the recently proposed GPI-ase activity and function of sperm-bound ACE.

Angiotensin converting enzyme inhibition and the kidney

NASA Technical Reports Server (NTRS)

Hollenberg, N. K.

1988-01-01

Angiotensin II (Ang II) induces a marked reduction in renal blood flow at doses well below those required to induce a pressor response, and as blood flow falls there is a decline in glomerular filtration rate and sodium excretion. This striking sensitivity of the renal blood supply led many workers to consider the possibility that angiotensin functions as a local renal hormone. As angiotensin converting enzyme (ACE) was found in particular abundance in the lung, it seemed reasonable to suspect that most of the conversion occurred there, and that the function of Ang II would be primarily systemic, rather than intrarenal. In this review, I will explore the evidence that has accumulated on these two possibilities, since they have important implications for our current understanding of normal kidney function and derangements of kidney function in disease.

Angiotensin converting enzyme insertion/deletion polymorphism: association with ethnic origin.

PubMed

Barley, J; Blackwood, A; Carter, N D; Crews, D E; Cruickshank, J K; Jeffery, S; Ogunlesi, A O; Sagnella, G A

1994-08-01

To determine the distribution of the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene in several ethnic groups: Caucasian Europeans, Black Nigerians, Samoan Polynesians and Yanomami Indians. The ratio of the frequencies of the II, ID and DD genotypes were 1:2:1 in the Europeans, but there was a tendency towards a higher frequency of the D allele in the Nigerians. In contrast, the Samoans and the Yanomami Indians displayed a much higher frequency of the I allele than of the D allele. The relationship between ACE genotype and disease in these latter groups is still not known, but the present results clearly suggest that ethnic origin should be carefully considered in the increasing number of studies on the association between I/D ACE genotype and disease aetiology.

Synthesis and evaluation of novel triazoles and mannich bases functionalized 1,4-dihydropyridine as angiotensin converting enzyme (ACE) inhibitors.

PubMed

Kumbhare, Ravindra M; Kosurkar, Umesh B; Bagul, Pankaj K; Kanwal, Abhinav; Appalanaidu, K; Dadmal, Tulshiram L; Banerjee, Sanjay Kumar

2014-11-01

A series of novel diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate embedded triazole and mannich bases were synthesized, and evaluated for their angiotensin converting enzyme (ACE) inhibitory activity. Screening of above synthesized compounds for ACE inhibition showed that triazoles functionalized compounds have better ACE inhibitory activity compared to that of mannich bases analogues. Among all triazoles we found 6 h, 6 i and 6 j to have good ACE inhibition activity with IC50 values 0.713 μM, 0.409 μM and 0.653 μM, respectively. Among mannich bases series compounds, only 7c resulted as most active ACE inhibitor with IC50 value of 0.928 μM. Copyright © 2014. Published by Elsevier Ltd.

Purification of angiotensin I-converting enzyme (ACE) inhibitory peptides from casein hydrolysate by IMAC-Ni2.

PubMed

Wu, Shanguang; Feng, Xuezhen; Lu, Yuan; Lu, Yuting; Liu, Saisai; Tian, Yuhong

2017-10-01

Casein proteins were hydrolyzed by papain to identify inhibitory peptides of angiotensin I-converting enzyme (ACE). The hydrolysate was fractionized by immobilized metal affinity chromatography (IMAC-Ni 2+ ). The fraction with high ACE inhibitory activity was enriched and further chromatographed on a reverse-phase column to yield four fractions. Among the fractions, the L4 fraction exhibited the highest ACE inhibitory activity and was identified by sequence analysis as Trp-Tyr-Leu-His-Tyr-Ala (WYLHYA), with IC 50 value of 16.22 ± 0.83 µM in vitro. This peptide was expected to be applied as an ingredient for preventing hypertension and IMAC-Ni 2+ may provide a simple method for purification of ACE inhibitory peptides.

Analysis of nucleotide diphosphate sugar dehydrogenases reveals family and group-specific relationships.

PubMed

Freas, Nicholas; Newton, Peter; Perozich, John

2016-01-01

UDP-glucose dehydrogenase (UDPGDH), UDP-N-acetyl-mannosamine dehydrogenase (UDPNAMDH) and GDP-mannose dehydrogenase (GDPMDH) belong to a family of NAD (+)-linked 4-electron-transfering oxidoreductases called nucleotide diphosphate sugar dehydrogenases (NDP-SDHs). UDPGDH is an enzyme responsible for converting UDP-d-glucose to UDP-d-glucuronic acid, a product that has different roles depending on the organism in which it is found. UDPNAMDH and GDPMDH convert UDP-N-acetyl-mannosamine to UDP-N-acetyl-mannosaminuronic acid and GDP-mannose to GDP-mannuronic acid, respectively, by a similar mechanism to UDPGDH. Their products are used as essential building blocks for the exopolysaccharides found in organisms like Pseudomonas aeruginosa and Staphylococcus aureus. Few studies have investigated the relationships between these enzymes. This study reveals the relationships between the three enzymes by analysing 229 amino acid sequences. Eighteen invariant and several other highly conserved residues were identified, each serving critical roles in maintaining enzyme structure, coenzyme binding or catalytic function. Also, 10 conserved motifs that included most of the conserved residues were identified and their roles proposed. A phylogenetic tree demonstrated relationships between each group and verified group assignment. Finally, group entropy analysis identified novel conservations unique to each NDP-SDH group, including residue positions critical to NDP-sugar substrate interaction, enzyme structure and intersubunit contact. These positions may serve as targets for future research. UDP-glucose dehydrogenase (UDPGDH, EC 1.1.1.22).

Integrated Optic Chemical-Biological Sensors

DTIC Science & Technology

1999-02-26

response. In this process, an enzyme ( urease ) acts as a catalyst, converting a specific substrate (urea) to a specific product (ammonia). Implementing...a sandwich assay, a urease labeled antibody is introduced to a surface bound antigen. This complex is exposed to urea, generating ammonia. Using a...containing suspected agents. After agent binding to the antibody-coated beads, an appropriate enzyme labeled antibody (an antibody with a urease label

Differential processing of substance P and neurokinin A by plasma dipeptidyl(amino)peptidase IV, aminopeptidase M and angiotensin converting enzyme.

PubMed

Wang, L H; Ahmad, S; Benter, I F; Chow, A; Mizutani, S; Ward, P E

1991-01-01

In addition to plasma metabolism of substance P (SP) by angiotensin converting enzyme (ACE; EC 3.4.15.1) (less than 1.0 nmol/min/ml), the majority of SP hydrolysis by rat and human plasma was due to dipeptidyl(amino)peptidase IV (DAP IV; EC 3.4.14.5) (3.15-5.91 nmol/min/ml), which sequentially converted SP to SP(3-11) and SP(5-11). In turn, the SP(5-11) metabolite was rapidly hydrolyzed by rat and human plasma aminopeptidase M (AmM; EC 3.4.11.2) (24.2-25.5 nmol/min/ml). The Km values of SP for DAP IV and of SP(5-11) for AmM ranged from 32.7 to 123 microM. In contrast, neurokinin A (NKA) was resistant to both ACE and DAP IV but was subject to N-terminal hydrolysis by AmM (3.76-10.8 nmol/min/ml; Km = 90.7 microM). These data demonstrate differential processing of SP and NKA by specific peptidases in rat and human plasma.

Hydrolysis by somatic angiotensin-I converting enzyme of basic dipeptides from a cholecystokinin/gastrin and a LH-RH peptide extended at the C-terminus with gly-Arg/Lys-arg, but not from diarginyl insulin.

PubMed

Isaac, R E; Michaud, A; Keen, J N; Williams, T A; Coates, D; Wetsel, W C; Corvol, P

1999-06-01

Endoproteolytic cleavage of protein prohormones often generates intermediates extended at the C-terminus by Arg-Arg or Lys-Arg, the removal of which by a carboxypeptidase (CPE) is normally an important step in the maturation of many peptide hormones. Recent studies in mice that lack CP activity indicate the existence of alternative tissue or plasma enzymes capable of removing C-terminal basic residues from prohormone intermediates. Using inhibitors of angiotensin I-converting enzyme (ACE) and CP, we show that both these enzymes in mouse serum can remove the basic amino acids from the C-terminus of CCK5-GRR and LH-RH-GKR, but only CP is responsible for converting diarginyl insulin to insulin. ACE activity removes C-terminal dipeptides to generate the Gly-extended peptides, whereas CP hydrolysis gives rise to CCK5-GR and LH-RH-GK, both of which are susceptible to the dipeptidyl carboxypeptidase activity of ACE. Somatic ACE has two similar protein domains (the N-domain and the C-domain), each with an active site that can display different substrate specificities. CCK5-GRR is a high-affinity substrate for both the N-domain and C-domain active sites of human sACE (Km of 9.4 microm and 9.0 microm, respectively) with the N-domain showing greater efficiency (kcat : Km ratio of 2.6 in favour of the N-domain). We conclude that somatic forms of ACE should be considered as alternatives to CPs for the removal of basic residues from some Arg/Lys-extended peptides.

Novel biological properties of Oenothera paradoxa defatted seed extracts: effects on metallopeptidase activity.

PubMed

Kiss, Anna K; Derwińska, Małgorzata; Dawidowska, Anna; Naruszewicz, Marek

2008-09-10

In this study, for the first time, we used the in vitro metallopeptidase model for the identification of a potential novel activity of defatted evening primrose seed extracts. Prepared extracts of different polarity (aqueous, 60% ethanolic, isopropanolic, and 30% isopropanolic) at concentrations of 1.5-100 microg/mL exhibited a significant and dose dependent inhibition of three tested enzymes. The 50% inhibition of enzymes activity showed that aminopeptidase N (APN) was the enzyme affected to the greatest extent with IC50 at the level of 2.8 microg/mL and 2.9 microg/mL for aqueous and 30% isopropanolic extracts, respectively. The activity of neutral endopeptidase (NEP) was quite strongly inhibited by the extracts as well. The HPLC-DAD analysis and bioguided fractionation led to the identification of four active compounds: (-)-epicatechin gallate, proanthocyanidin B3, oenothein B, and penta-O-galloyl-beta-D-glucose (PGG). Oenothein B has been shown previously to inhibit metallopeptidases. The three other compounds are known to inhibit angiotensin-converting enzyme (ACE), but they have not been previously reported to inhibit the NEP and APN activity. PGG and procyanidins with different degrees of polymerization, as the dominating compounds in O. paradoxa seeds, seemed to play a role in the crude extract activity.

Streptomyces clavuligerus HlmI is an intramolecular disulfide-forming dithiol oxidase in holomycin biosynthesis

PubMed Central

Li, Bo; Walsh, Christopher T.

2011-01-01

Holomycin and related dithiolopyrrolone antibiotics display broad-spectrum antimicrobial activities and contain a unique 5, 5-bicyclic ring structure with an N-acylated aminopyrrolone fused to a cyclic ene-disulfide. Here we show that the intramolecular disulfide bridge is constructed from the acyclic ene-dithiol at a late stage in the pathway by a thioredoxin oxidoreductase-like enzyme HlmI from the holomycin producer Streptomyces clavuligerus. Recombinant HlmI was purified from E. coli with bound flavin adenine dinucleotide (FAD), and converts reduced holomycin to holomycin utilizing O2 as cosubstrate. As a dithiol oxidase, HlmI is functionally homologous to GliT and DepH, which perform a similar dithiol to disulfide oxidation in the biosynthesis of fungal natural product gliotoxin and epigenetic regulator compound FK228 respectively. Deletion of the hlmI gene in the wild type S. clavuligerus and in a holomycin-overproducing mutant resulted in decreased level of holomycin production and increased sensitivity toward holomycin, suggesting a self-protection role of HlmI in the holomycin biosynthetic pathway. HlmI belongs to a new clade of uncharacterized thioredoxin oxidoreductase-like enzymes, distinctive from the GliT-like enzymes and the DepH-like enzymes, and represents a third example of oxidoreductases that catalyzes disulfide formation in the biosynthesis of small molecules. PMID:21504228

Epigenetic regulation of somatic angiotensin-converting enzyme by DNA methylation and histone acetylation.

PubMed

Rivière, Guillaume; Lienhard, Daniel; Andrieu, Thomas; Vieau, Didier; Frey, Brigitte M; Frey, Felix J

2011-04-01

Somatic angiotensin-converting enzyme (sACE) is crucial in cardiovascular homeostasis and displays a tissue-specific profile. Epigenetic patterns modulate genes expression and their alterations were implied in pathologies including hypertension. However, the influence of DNA methylation and chromatin condensation state on the expression of sACE is unknown. We examined whether such epigenetic mechanisms could participate in the control of sACE expression in vitro and in vivo. We identified two CpG islands in the human ace-1 gene 3 kb proximal promoter region. Their methylation abolished the luciferase activity of ace-1 promoter/reporter constructs transfected into human liver (HepG2), colon (HT29), microvascular endothelial (HMEC-1) and lung (SUT) cell lines (p < 0.001). Bisulphite sequencing revealed a cell-type specific basal methylation pattern of the ace-1 gene -1,466/+25 region. As assessed by RT-qPCR, inhibition of DNA methylation by 5-aza-2'-deoxycytidine and/or of histone deacetylation by trichostatin A highly stimulated sACE mRNA expression cell-type specifically (p < 0.001 vs. vehicle treated cells). In the rat, in vivo 5-aza-cytidine injections demethylated the ace-1 promoter and increased sACE mRNA expression in the lungs and liver (p = 0.05), but not in the kidney. In conclusion, the expression level of somatic ACE is modulated by CpG-methylation and histone deacetylases inhibition. The basal methylation pattern of the promoter of the ace-1 gene is cell-type specific and correlates to sACE transcription. DNMT inhibition is associated with altered methylation of the ace-1 promoter and a cell-type and tissue-specific increase of sACE mRNA levels. This study indicates a strong influence of epigenetic mechanisms on sACE expression.

Apolipoprotein B and angiotensin-converting enzyme polymorphisms and aerobic interval training: randomized controlled trial in coronary artery disease patients.

PubMed

Tamburus, N Y; Verlengia, R; Kunz, V C; César, M C; Silva, E

2018-01-01

Physical training has been strongly recommended as a non-pharmacological treatment for coronary artery disease (CAD). Genetic polymorphisms have been studied to understand the biological variability in response to exercise among individuals. This study aimed to verify the possible influence of apolipoprotein B (ApoB: rs1042031 and rs693) and angiotensin-converting enzyme (ACE-ID: rs1799752) genotypes on the lipid profile and functional aerobic capacity, respectively, after an aerobic interval training (AIT) program in patients with CAD and/or cardiovascular risk factors. Sixty-six men were randomized and assigned to trained group (n=32) or control group (n=34). Cardiopulmonary exercise test was performed to determine the ventilatory anaerobic threshold (VAT) from cardiorespiratory variables. The AIT program, at an intensity equivalent to %VAT (70-110%), was conducted three times a week for 16 weeks. ApoB gene polymorphisms (-12669C>T (rs1042031) and -7673G>A (rs693)) were identified by real-time polymerase chain reaction (PCR). I/D polymorphism in the ACE gene (rs1799752) was identified through PCR and fragment size analysis. After 16 weeks, low-density lipoprotein (LDL) levels increased in the trained and control groups with the GA+AA genotype (-7673G>A) of the ApoB gene. Trained groups with ACE-II and ACE-ID genotypes presented an increase in oxygen consumption (VO2VAT) and power output after the AIT program. The presence of the ACE I-allele was associated with increased aerobic functional capacity after the AIT program. Increased LDL levels were observed over time in patients with the -7673G>A polymorphism of the ApoB gene. Trial Registration Information: ClinicalTrials.gov: NCT02313831.

Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: possible involvement of angiotensin-converting enzyme-2.

PubMed

Han, Su-Xia; He, Guang-Ming; Wang, Tao; Chen, Lei; Ning, Yun-Ye; Luo, Feng; An, Jin; Yang, Ting; Dong, Jia-Jia; Liao, Zeng-Lin; Xu, Dan; Wen, Fu-Qiang

2010-05-15

Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin-angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH and its possible mechanism, rats were daily exposed to cigarette smoke for 6months in the absence and in the presence of losartan. Elevated right ventricular systolic pressure (RVSP), thickened wall of pulmonary arteries with apparent medial hypertrophy along with increased angiotensin II (Ang II) and decreased ACE2 levels were observed in smoke-exposed-only rats. Losartan administration ameliorated pulmonary vascular remodeling, inhibited the smoke-induced RVSP and Ang II elevation and partially reversed the ACE2 decrease in rat lungs. In cultured primary pulmonary artery smooth muscle cells (PASMCs) from 3- and 6-month smoke-exposed rats, ACE2 levels were significantly lower than in those from the control rats. Moreover, PASMCs from 6-month exposed rats proliferated more rapidly than those from 3-month exposed or control rats, and cells grew even more rapidly in the presence of DX600, an ACE2 inhibitor. Consistent with the in vivo study, in vitro losartan pretreatment also inhibited cigarette smoke extract (CSE)-induced cell proliferation and ACE2 reduction in rat PASMCs. The results suggest that losartan may be therapeutically useful in the chronic smoking-induced pulmonary vascular remodeling and PAH and ACE2 may be involved as part of its mechanism. Our study might provide insight into the development of new therapeutic interventions for PAH smokers.

Angiotensin-converting enzyme 2 is subject to post-transcriptional regulation by miR-421.

PubMed

Lambert, Daniel W; Lambert, Louise A; Clarke, Nicola E; Hooper, Nigel M; Porter, Karen E; Turner, Anthony J

2014-08-01

ACE2 (angiotensin converting enzyme 2) plays a critical role in the local tissue RAS (renin-angiotensin system) by hydrolysing the potent hypertensive and mitogenic peptide AngII (angiotensin II). Changes in the levels of ACE2 have been observed in a number of pathologies, including cardiovascular disease, but little is known of the mechanisms regulating its expression. In the present study, therefore, the potential role of miRNAs in the regulation of ACE2 expression in primary human cardiac myofibroblasts was examined. Putative miRNA-binding sites were identified in the 3'-UTR of the ACE2 transcript using online prediction algorithms. Two of these, miR-200b and miR-421, were selected for further analysis. A reporter system using the 3'-UTR of ACE2 fused to the coding region of firefly luciferase was used to determine the functionality of the identified binding sites in vitro. This identified miR-421, but not miR-200b, as a potential regulator of ACE2. The ability of miR-421, an miRNA implicated in the development of thrombosis, to down-regulate ACE2 expression was subsequently confirmed by Western blot analysis of both primary cardiac myofibroblasts and transformed cells transfected with a synthetic miR-421 precursor. Real-time PCR analysis of miR-421 revealed widespread expression in human tissues. miR-421 levels in cardiac myofibroblasts showed significant inter-patient variability, in keeping with the variability of ACE2 expression we have observed previously. In conclusion, the present study is the first to demonstrate that ACE2 may be subject to post-transcriptional regulation and reveals a novel potential therapeutic target, miR-421, which could be exploited to modulate ACE2 expression in disease.

Assessment of the Siksika chronic disease nephropathy-prevention clinic

PubMed Central

Ward, David R.R.; Novak, Ellen; Scott-Douglas, Nairne; Brar, Sony; White, Melvin; Hemmelgarn, Brenda R.

2013-01-01

Objective To determine if a community-based multifactorial intervention clinic led by a nurse practitioner would improve management of First Nations people at risk of developing chronic kidney disease. Design Qualitative descriptive study. Setting A nephropathy-prevention clinic in Siksika Nation, Alta. Participants First Nations people with diabetes, hypertension, or dyslipidemia who were referred to the clinic. Main outcome measures Changes in blood pressure (BP), hemoglobin A1c, and low-density lipoprotein levels, as well as in use of antiplatelet therapy, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker medications, and statin therapy. Results Members of the Siksika Nation were treated according to clinical practice guidelines. A total of 78 patients had at least 2 visits to the clinic and were included in this analysis (61.5% were women; mean age 56 years). Among those initially above target, a significant reduction was achieved in mean hemoglobin A1c (0.96%; P < .01), systolic BP (15.84 mm Hg; P < .05), diastolic BP (7.16 mm Hg; P < .001), and low-density lipoprotein (0.62 mmol/L; P < .01) levels. There was a significant increase in the proportion of patients with clinical indications who were treated with acetylsalicylic acid (42.4%; P < .01), angiotensin-converting enzyme inhibitor or angiotensin receptor blocker medications (35.9%; P < .01), or statin therapy (35.9%; P < .01). Conclusion A community-based, nurse practitioner–led clinic can improve many clinically relevant factors in patients at risk of developing chronic kidney disease. Studies have shown that achieving treatment targets is associated with a reduced risk of early death and cardiovascular events; the effect in the First Nations population on these hard clinical end points remains to be determined. PMID:23341675

Mineralocorticoid receptor blockade in addition to angiotensin converting enzyme inhibitor or angiotensin II receptor blocker treatment: an emerging paradigm in diabetic nephropathy: a systematic review.

PubMed

Mavrakanas, Thomas A; Gariani, Karim; Martin, Pierre-Yves

2014-02-01

Blockade of the renin-angiotensin-aldosterone system (RAAS) is a standard therapeutic intervention in diabetic patients with chronic kidney disease (CKD). Concomitant mineralocorticoid receptor blockade has been studied as a novel approach to further slow down CKD progression. We used PubMed and EMBASE databases to search for relevant literature. We included in our review eight studies in patients of at least 18 years of age, with a diagnosis of type 1 or type 2 diabetes mellitus and diabetic nephropathy, under an angiotensin converting enzyme inhibitor (ACEI) and/or an angiotensin II receptor blocker (ARB) as standard treatment. A subset of patients in each study also received a mineralocorticoid receptor blocker (MRB) (either spironolactone or eplerenone) in addition to standard treatment. Combined treatment with a mineralocorticoid receptor blocker further reduced albuminuria by 23 to 61% compared with standard treatment. Estimated glomerular filtration rate values upon study completion slightly decreased under combined treatment. Blood pressure levels upon study completion were significantly lower with combined treatment in three studies. Hyperkalemia prevalence increased in patients under combined treatment raising dropout rate up to 17%. Therefore, combined treatment by an ACEI/ARB and a MRB may further decrease albuminuria in diabetic nephropathy. This effect may be due to the specific properties of the MRB treatment. Clinicians should regularly check potassium levels because of the increased risk of hyperkalemia. Available evidence should be confirmed by an adequately powered comparative trial of the standard treatment (ACEI or ARB) versus combined treatment by an ACEI/ARB and a MRB. Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Association of Angiotensin-Converting Enzyme (ACE) Gene Polymorphism with Inflammation and Cellular Cytotoxicity in Vitiligo Patients.

PubMed

Rashed, Laila; Abdel Hay, Rania; Mahmoud, Rania; Hasan, Nermeen; Zahra, Amr; Fayez, Salwa

2015-01-01

Vitiligo is a disorder with profound heterogeneity in its aetio-pathophysiology. Angiotensin converting enzyme (ACE) plays an important role in the physiology of the vasculature, blood pressure and inflammation. An insertion/deletion (I/D) polymorphism of the ACE gene was reported be associated with the development of vitiligo. Our aim was to evaluate the ACE I/D polymorphism in vitiligo patients and controls. Our second aim was to find a possible association between ACE gene polymorphism and inflammatory mediators (as interleukin (IL)-6) and/or cellular cytotoxicity induced by serum nitrite (as a breakdown product of the cytotoxic nitric oxide) in vitiligo patients. This case-control study included 74 vitiligo patients and 75 apparently healthy controls. The distribution of ACE gene I/D genotype was investigated using PCR. Serum ACE, IL-6 and nitrite were measured by colorimetric method, ELISA and Griess assay respectively. The ACE allele frequency was significantly different between vitiligo patients and healthy controls (P = 0.026). However there was no significant difference between the ACE genotyping frequency in both groups (P = 0.115). There were statistically significant higher VIDA score (P = 0.007), and serum IL-6 (P < 0.001) in patients with the DD genotype when compared to other genotypes. Serum nitrite in patients with the DD genotype was significantly higher (P = 0.007) when compared to patients with II genotype. Serum levels of ACE, IL-6 and nitrite in vitiligo patients were statistically significantly higher than those in controls. As a conclusion, ACE gene polymorphism might grant susceptibility to develop vitiligo. Serum IL-6 and nitrite levels might have an important role in the pathogenesis of vitiligo. Targeting these two factors might have an implication in the treatment of some resistant cases.

Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: Possible involvement of angiotensin-converting enzyme-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han Suxia; He Guangming; Wang Tao

Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin-angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH and its possible mechanism, rats were daily exposed to cigarette smoke for 6 months in the absence and in the presence of losartan. Elevated right ventricular systolic pressure (RVSP), thickened wall of pulmonary arteries with apparent medial hypertrophy along withmore » increased angiotensin II (Ang II) and decreased ACE2 levels were observed in smoke-exposed-only rats. Losartan administration ameliorated pulmonary vascular remodeling, inhibited the smoke-induced RVSP and Ang II elevation and partially reversed the ACE2 decrease in rat lungs. In cultured primary pulmonary artery smooth muscle cells (PASMCs) from 3- and 6-month smoke-exposed rats, ACE2 levels were significantly lower than in those from the control rats. Moreover, PASMCs from 6-month exposed rats proliferated more rapidly than those from 3-month exposed or control rats, and cells grew even more rapidly in the presence of DX600, an ACE2 inhibitor. Consistent with the in vivo study, in vitro losartan pretreatment also inhibited cigarette smoke extract (CSE)-induced cell proliferation and ACE2 reduction in rat PASMCs. The results suggest that losartan may be therapeutically useful in the chronic smoking-induced pulmonary vascular remodeling and PAH and ACE2 may be involved as part of its mechanism. Our study might provide insight into the development of new therapeutic interventions for PAH smokers.« less

Preoperative angiotensin-converting enzyme inhibitors and angiotensin receptor blocker use and acute kidney injury in patients undergoing cardiac surgery

PubMed Central

Coca, Steven G.; Garg, Amit X.; Swaminathan, Madhav; Garwood, Susan; Hong, Kwangik; Thiessen-Philbrook, Heather; Passik, Cary; Koyner, Jay L.; Parikh, Chirag R.; Jai, Raman; Jeevanandam, Valluvan; Akhter, Shahab; Devarajan, Prasad; Bennett, Michael; Edelsteinm, Charles; Patel, Uptal; Chu, Michael; Goldbach, Martin; Guo, Lin Ruo; McKenzie, Neil; Myers, Mary Lee; Novick, Richard; Quantz, Mac; Zappitelli, Michael; Dewar, Michael; Darr, Umer; Hashim, Sabet; Elefteriades, John; Geirsson, Arnar

2013-01-01

Background Using either an angiotensin-converting enzyme inhibitor (ACEi) or an angiotensin receptor blocker (ARB) the morning of surgery may lead to ‘functional’ postoperative acute kidney injury (AKI), measured by an abrupt increase in serum creatinine. Whether the same is true for ‘structural’ AKI, measured with new urinary biomarkers, is unknown. Methods The TRIBE-AKI study was a prospective cohort study of 1594 adults undergoing cardiac surgery at six hospitals between July 2007 and December 2010. We classified the degree of exposure to ACEi/ARB into three categories: ‘none’ (no exposure prior to surgery), ‘held’ (on chronic ACEi/ARB but held on the morning of surgery) or ‘continued’ (on chronic ACEi/ARB and taken the morning of surgery). The co-primary outcomes were ‘functional’ AKI based upon changes in pre- to postoperative serum creatinine, and ‘structural AKI’, based upon peak postoperative levels of four urinary biomarkers of kidney injury. Results Across the three levels (none, held and continued) of ACEi/ARB exposure there was a graded increase in functional AKI, as defined by AKI stage 1 or worse; (31, 34 and 42%, P for trend 0.03) and by percentage change in serum creatinine from pre- to postoperative (25, 26 and 30%, P for trend 0.03). In contrast, there were no differences in structural AKI across the strata of ACEi/ARB exposure, as assessed by four structural AKI biomarkers (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18 or liver-fatty acid-binding protein). Conclusions Preoperative ACEi/ARB usage was associated with functional but not structural acute kidney injury. As AKI from ACEi/ARB in this setting is unclear, interventional studies testing different strategies of perioperative ACEi/ARB use are warranted. PMID:24081864

Prognostic significance of ventricular late potentials in patients with pulmonary sarcoidosis.

PubMed

Yodogawa, Kenji; Seino, Yoshihiko; Ohara, Toshihiko; Iwasaki, Yu-Ki; Hayashi, Meiso; Miyauchi, Yasushi; Azuma, Arata; Shimizu, Wataru

2018-06-01

Early detection of cardiac involvement in sarcoidosis is difficult but essential to achieve optimal treatment. Signal-averaged electrocardiography (SAECG) can detect subtle cardiac electrical abnormalities termed late potentials (LPs) and would be useful for the early diagnosis of cardiac involvement. This study aims to investigate the prognostic significance of LP in patients with pulmonary sarcoidosis. We prospectively studied 74 patients with pulmonary sarcoidosis without overt electrocardiographic abnormalities. All participants underwent SAECG, cardiac echocardiography, and 24-hour ambulatory Holter monitoring. Serum angiotensin-converting enzyme and B-type natriuretic peptide levels were also evaluated. We followed these patients for the evaluation of incidence of cardiac events including cardiac death, arrhythmias, and heart failure requiring hospital admission. Of the studied population, 29 patients (39.2%) had detectable LP. During a mean follow-up period of 9.8 years, 8 patients with LPs had cardiovascular events, including development of complete atrioventricular block (n = 4), ventricular tachycardia (n = 2), and heart failure (n = 2). Meanwhile, only 1 of 45 patients without LP developed cardiac event (heart failure). Multivariate analyses revealed that LPs were associated with an increased risk of developing cardiac events (hazard ratio 9.66; 95% confidence interval 1.20-78.01; P = .033) whereas age, sex, serum angiotensin-converting enzyme and B-type natriuretic peptide levels, number of premature ventricular contractions on 24-hour Holter monitoring, and echocardiographic parameters were not associated with subsequent cardiac events. SAECG might possibly be useful for the early detection of cardiac sarcoidosis and, if independently validated, could eventually be considered as a screening test for further risk stratification. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Quantitative metabolome analysis profiles activation of glutaminolysis in glioma with IDH1 mutation.

PubMed

Ohka, Fumiharu; Ito, Maki; Ranjit, Melissa; Senga, Takeshi; Motomura, Ayako; Motomura, Kazuya; Saito, Kaori; Kato, Keiko; Kato, Yukinari; Wakabayashi, Toshihiko; Soga, Tomoyoshi; Natsume, Atsushi

2014-06-01

Isocitrate dehydrogenase 1 (IDH1), which localizes to the cytosol and peroxisomes, catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG) and in parallel converts NADP(+) to NADPH. IDH1 mutations are frequently detected in grades 2-4 gliomas and in acute myeloid leukemias (AML). Mutations of IDH1 have been identified at codon 132, with arginine being replaced with histidine in most cases. Mutant IDH1 gains novel enzyme activity converting α-KG to D-2-hydroxyglutarate (2-HG) which acts as a competitive inhibitor of α-KG. As a result, the activity of α-KG-dependent enzyme is reduced. Based on these findings, 2-HG has been proposed to be an oncometabolite. In this study, we established HEK293 and U87 cells that stably expressed IDH1-WT and IDH1-R132H and investigated the effect of glutaminase inhibition on cell proliferation with 6-diazo-5-oxo-L-norleucine (DON). We found that cell proliferation was suppressed in IDH1-R132H cells. The addition of α-KG restored cell proliferation. The metabolic features of 33 gliomas with wild type IDH1 (IDH1-WT) and with IDH1-R132H mutation were examined by global metabolome analysis using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS). We showed that the 2-HG levels were highly elevated in gliomas with IDH1-R132H mutation. Intriguingly, in gliomas with IDH1-R132H, glutamine and glutamate levels were significantly reduced which implies replenishment of α-KG by glutaminolysis. Based on these results, we concluded that glutaminolysis is activated in gliomas with IDH1-R132H mutation and that development of novel therapeutic approaches targeting activated glutaminolysis is warranted.

Acyclic phosph(on)ate inhibitors of Plasmodium falciparum hypoxanthine-guanine-xanthine phosphoribosyltransferase

PubMed Central

Clinch, Keith; Crump, Douglas R.; Evans, Gary B.; Hazleton, Keith Z.; Mason, Jennifer M.; Schramm, Vern L.

2013-01-01

The pathogenic protozoa responsible for malaria lack enzymes for the de novo synthesis of purines and rely on purine salvage from the host. In Plasmodium falciparum (Pf), hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) converts hypoxanthine to inosine monophosphate and is essential for purine salvage making the enzyme an anti-malarial drug target. We have synthesized a number of simple acyclic aza-C- nucleosides and shown that some are potent inhibitors of Pf HGXPRT while showing excellent selectivity for the Pf versus the human enzyme. PMID:23810424

Non-enzymic beta-decarboxylation of aspartic acid.

NASA Technical Reports Server (NTRS)

Doctor, V. M.; Oro, J.

1972-01-01

Study of the mechanism of nonenzymic beta-decarboxylation of aspartic acid in the presence of metal ions and pyridoxal. The results suggest that aspartic acid is first converted to oxalacetic acid by transamination with pyridoxal which in turn is converted to pyridoxamine. This is followed by decarboxylation of oxalacetic acid to form pyruvic acid which transaminates with pyridoxamine to form alanine. The possible significance of these results to prebiotic molecular evolution is briefly discussed.

Simultaneous conversion of free fatty acids and triglycerides to biodiesel by immobilized Aspergillus oryzae expressing Fusarium heterosporum lipase.

PubMed

Amoah, Jerome; Quayson, Emmanuel; Hama, Shinji; Yoshida, Ayumi; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

2017-03-01

The presence of high levels of free fatty acids (FFA) in oil is a barrier to one-step biodiesel production. Undesirable soaps are formed during conventional chemical methods, and enzyme deactivation occurs when enzymatic methods are used. This work investigates an efficient technique to simultaneously convert a mixture of free fatty acids and triglycerides (TAG). A partial soybean hydrolysate containing 73.04% free fatty acids and 24.81% triglycerides was used as a substrate for the enzymatic production of fatty acid methyl ester (FAME). Whole-cell Candida antarctica lipase B-expressing Aspergillus oryzae, and Novozym 435 produced only 75.2 and 73.5% FAME, respectively. Fusarium heterosporum lipase-expressing A. oryzae produced more than 93% FAME in 72 h using three molar equivalents of methanol. FFA and TAG were converted simultaneously in the presence of increasing water content that resulted from esterification. Therefore, F. heterosporum lipase with a noted high level of tolerance of water could be useful in the industrial production of biodiesel from feedstock that has high proportion of free fatty acids. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of activity in Sarcoidosis. Sensitivity and specificity of 67Gallium scintigraphy, serum ACE levels, chest roentgenography, and blood lymphocyte subpopulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klech, H.; Kohn, H.; Kummer, F.

1982-12-01

The value of different factors are examined to assess activity in 60 patients with biopsy-proven sarcoidosis. In patients with active sarcoidosis (n . 35), /sup 67/Ga scans proved to be the most sensitive method (94 percent sensitivity), followed by serum angiotensin I converting enzyme (S-ACE) levels, chest x-ray films, and lymphocyte assays. In patients with peripheral pulmonary lesions, chest x-ray films failed in 32 percent of cases to document activity (68 percent sensitivity) whereas /sup 67/Ga scans and S-ACE levels remained to give reliable results. Despite poor specificity, negative /sup 67/Ga scans together with normal ACE levels have a highmore » predictive value for exclusion of active sarcoidosis. In patients with peripheral pulmonary lesions, chest roentgenography is of doubtful value for staging lung involvement and assessment of activity including monitoring and control of therapy.« less

[The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor].

PubMed

Ceker, Zahit; Takmaz, Suna Akın; Baltaci, Bülent; Başar, Hülya

2015-01-01

The importance of minimizing the exaggerated sympatho-adrenergic responses and QT interval and QT interval dispersion changes that may develop due to laryngoscopy and tracheal intubation during anesthesia induction in the hypertensive patients is clear. Esmolol decreases the hemodynamic response to laryngoscopy and intubation. However, the effect of esmolol in decreasing the prolonged QT interval and QT interval dispersion as induced by laryngoscopy and intubation is controversial. We investigated the effect of esmolol on the hemodynamic, and corrected-QT interval and corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients using angiotensin converting enzyme inhibitors. 60 ASA I-II patients, with essential hypertension using angiotensin converting enzyme inhibitors were included in the study. The esmolol group received esmolol at a bolus dose of 500mcg/kg followed by a 100mcg/kg/min infusion which continued until the 4th min after intubation. The control group received 0.9% saline similar to the esmolol group. The mean blood pressure, heart rate values and the electrocardiogram records were obtained as baseline values before the anesthesia, 5min after esmolol and saline administration, 3min after the induction and 30s, 2min and 4min after intubation. The corrected-QT interval was shorter in the esmolol group (p=0.012), the corrected-QT interval dispersion interval was longer in the control group (p=0.034) and the mean heart rate was higher in the control group (p=0.022) 30s after intubation. The risk of arrhythmia frequency was higher in the control group in the 4-min period following intubation (p=0.038). Endotracheal intubation was found to prolong corrected-QT interval and corrected-QT interval dispersion, and increase the heart rate during anesthesia induction with propofol in hypertensive patients using angiotensin converting enzyme inhibitors. These effects were prevented with esmolol (500mcg/kg bolus, followed by 100mcg/kg/min infusion). During induction, the blood pressure tends to decrease with esmolol where care is needed. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Converting baker's waste into alcohol. Revised final progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halsey, R.; Wilson, P.B.

All types of baker's waste (including waste from candy manufacturers) can be converted into alcohol to be used as a fuel. All types of waste at any stage in process can be converted, such as: basic ingredients (including floor sweepings); dry mixes (including floor sweepings); dough at any stage; partially or fully cooked products; and day old returned products. The basic steps are the same, only the initial preparation will vary slightly. The variation will be: amount of water to be added and amount and type of nutrients (if any) to be added. The basic steps are: slurrying, liquefying tomore » put starch into liquid state, saccharifying to convert starch into fermentable sugars, fermentation to convert sugars into alcohol, and distillation to separate the alcohol from the mash. Each step is discussed in detail along with problems that may arise. Directions are given and materials (enzymes, yeast, etc.) and equipment are descibed briefly.« less

Genetics Home Reference: fundus albipunctatus

MedlinePlus

... integral operation of the visual cycle is the recycling of a molecule called 11-cis retinal, which ... dehydrogenase 5, which performs one step in this recycling process. This enzyme converts a molecule called 11- ...

Utility of Adenosine Monophosphate Detection System for Monitoring the Activities of Diverse Enzyme Reactions.

PubMed

Mondal, Subhanjan; Hsiao, Kevin; Goueli, Said A

Adenosine monophosphate (AMP) is a key cellular metabolite regulating energy homeostasis and signal transduction. AMP is also a product of various enzymatic reactions, many of which are dysregulated during disease conditions. Thus, monitoring the activities of these enzymes is a primary goal for developing modulators for these enzymes. In this study, we demonstrate the versatility of an enzyme-coupled assay that quantifies the amount of AMP produced by any enzymatic reaction regardless of its substrates. We successfully implemented it to enzyme reactions that use adenosine triphosphate (ATP) as a substrate (aminoacyl tRNA synthetase and DNA ligase) by an elaborate strategy of removing residual ATP and converting AMP produced into ATP; so it can be detected using luciferase/luciferin and generating light. We also tested this assay to measure the activities of AMP-generating enzymes that do not require ATP as substrate, including phosphodiesterases (cyclic adenosine monophosphate) and Escherichia coli DNA ligases (nicotinamide adenine dinucleotide [NAD + ]). In a further elaboration of the AMP-Glo platform, we coupled it to E. coli DNA ligase, enabling measurement of NAD + and enzymes that use NAD + like monoadenosine and polyadenosine diphosphate-ribosyltransferases. Sulfotransferases use 3'-phosphoadenosine-5'-phosphosulfate as the universal sulfo-group donor and phosphoadenosine-5'-phosphate (PAP) is the universal product. PAP can be quantified by converting PAP to AMP by a Golgi-resident PAP-specific phosphatase, IMPAD1. By coupling IMPAD1 to the AMP-Glo system, we can measure the activities of sulfotransferases. Thus, by utilizing the combinations of biochemical enzymatic conversion of various cellular metabolites to AMP, we were able to demonstrate the versatility of the AMP-Glo assay.

Plant tropane alkaloid biosynthesis evolved independently in the Solanaceae and Erythroxylaceae

PubMed Central

Jirschitzka, Jan; Schmidt, Gregor W.; Reichelt, Michael; Schneider, Bernd; Gershenzon, Jonathan; D’Auria, John Charles

2012-01-01

The pharmacologically important tropane alkaloids have a scattered distribution among angiosperm families, like many other groups of secondary metabolites. To determine whether tropane alkaloids have evolved repeatedly in different lineages or arise from an ancestral pathway that has been lost in most lines, we investigated the tropinone-reduction step of their biosynthesis. In species of the Solanaceae, which produce compounds such as atropine and scopolamine, this reaction is known to be catalyzed by enzymes of the short-chain dehydrogenase/reductase family. However, in Erythroxylum coca (Erythroxylaceae), which accumulates cocaine and other tropane alkaloids, no proteins of the short-chain dehydrogenase/reductase family were found that could catalyze this reaction. Instead, purification of E. coca tropinone-reduction activity and cloning of the corresponding gene revealed that a protein of the aldo-keto reductase family carries out this reaction in E. coca. This protein, designated methylecgonone reductase, converts methylecgonone to methylecgonine, the penultimate step in cocaine biosynthesis. The protein has highest sequence similarity to other aldo-keto reductases, such as chalcone reductase, an enzyme of flavonoid biosynthesis, and codeinone reductase, an enzyme of morphine alkaloid biosynthesis. Methylecgonone reductase reduces methylecgonone (2-carbomethoxy-3-tropinone) stereospecifically to 2-carbomethoxy-3β-tropine (methylecgonine), and has its highest activity, protein level, and gene transcript level in young, expanding leaves of E. coca. This enzyme is not found at all in root tissues, which are the site of tropane alkaloid biosynthesis in the Solanaceae. This evidence supports the theory that the ability to produce tropane alkaloids has arisen more than once during the evolution of the angiosperms. PMID:22665766

Glycogen Synthase in Sertoli Cells: More Than Glycogenesis?

PubMed

Maldonado, Rodrigo; Mancilla, Héctor; Villarroel-Espíndola, Franz; Slebe, Felipe; Slebe, Juan Carlos; Méndez, Raúl; Guinovart, Joan J; Concha, Ilona I

2016-11-01

Sertoli cell metabolism actively maintains the nutritional needs of germ cells. It has been described that after glucose incorporation in Sertoli cells, less than 1% is converted to glycogen suggesting low levels of glycogen synthase activity. Phosphorylation of muscle glycogen synthase (MGS) at serine 640 (pS640MGS) decreases its activity, and this form of the enzyme was discovered as a non-ribosomal protein that modulates the translation of a subset of transcripts in HeLa cells. The aim of our study was to functionally characterize MGS in cultured Sertoli cells, as well as to explore this new feature related to RNA molecules. We detected MGS in the cytoplasm of Sertoli cells as well as in the nuclei. The activity rates of the enzyme were extremely low indicating that MGS is expressed but almost inactive. Protein targeting to glycogen (PTG) overexpression was performed to activate MGS by dephosphorylation. PTG induced glycogen synthesis massively, confirming that this enzyme is present but inactive. This finding correlates with high levels of pS640MGS, which were assayed by phosphatase treatment. To explore a putative new function for MGS in Sertoli cells, we performed RNA immunoprecipitation coupled to microarray studies. The results revealed that MGS co-immunoprecipitated with the several mRNAs and also rRNAs. These findings indicate that MGS is expressed Sertoli cells but in an inactive form, and also support a possibly novel feature of this metabolic enzyme associated with RNA-related molecules. J. Cell. Biochem. 117: 2597-2607, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Molecular diversity of tuliposide A-converting enzyme in the tulip.

PubMed

Nomura, Taiji; Tsuchigami, Aya; Ogita, Shinjiro; Kato, Yasuo

2013-01-01

Tuliposide A-converting enzyme (TCEA) catalyzes the conversion of 6-tuliposide A to its lactonized aglycon, tulipalin A, in the tulip (Tulipa gesneriana). The TgTCEA gene, isolated previously from petals, was transcribed in all tulip tissues but not in the bulbs despite the presence of TCEA activity, which allowed prediction of the presence of a TgTCEA isozyme gene preferentially expressed in the bulbs. Here, the TgTCEA-b gene, the TgTCEA homolog, was identified in bulbs. TgTCEA-b polypeptides showed approximately 77% identity to the petal TgTCEA. Functional characterization of the recombinant enzyme verified that TgTCEA-b encoded the TCEA. Moreover, the TgTCEA-b was found to be localized to plastids, as found for the petal TgTCEA. Transcript analysis revealed that TgTCEA-b was functionally transcribed in the bulb scales, unlike the TgTCEA gene, whose transcripts were absent there. In contrast, TgTCEA-b transcripts were in the minority in other tissues where TgTCEA transcripts were dominant, indicating a tissue preference for the transcription of those isozyme genes.

Role of tumour necrosis factor alpha converting enzyme (TACE/ADAM17) and associated proteins in coronary artery disease and cardiac events.

PubMed

Chemaly, Melody; McGilligan, Victoria; Gibson, Mark; Clauss, Matthias; Watterson, Steven; Alexander, H Denis; Bjourson, Anthony John; Peace, Aaron

2017-12-01

Tumour necrosis factor alpha converting enzyme (TACE/ADAM17) is a member of the A disintegrin and metalloproteinase (ADAM) family of ectodomain shedding proteinases. It regulates many inflammatory processes by cleaving several transmembrane proteins, including tumour necrosis factor alpha (TNFα) and its receptors tumour necrosis factor alpha receptor 1 and tumour necrosis factor alpha receptor 2. There is evidence that TACE is involved in several inflammatory diseases, such as ischaemia, heart failure, arthritis, atherosclerosis, diabetes and cancer as well as neurological and immune diseases. This review summarizes the latest discoveries regarding the mechanism of action and regulation of TACE. It also focuses on the role of TACE in atherosclerosis and coronary artery disease (CAD), highlighting clinical studies that have investigated its expression and protein activity. The multitude of substrates cleaved by TACE make this enzyme an attractive target for therapy and a candidate for biomarker research and development in CAD. Crown Copyright © 2017. Published by Elsevier Masson SAS. All rights reserved.

Abalone Protein Hydrolysates: Preparation, Angiotensin I Converting Enzyme Inhibition and Cellular Antioxidant Activity.

PubMed

Park, Soo Yeon; Je, Jae-Young; Hwang, Joung-Youl; Ahn, Chang-Bum

2015-09-01

Abalone protein was hydrolyzed by enzymatic hydrolysis and the optimal enzyme/substrate (E/S) ratios were determined. Abalone protein hydrolysates (APH) produced by Protamex at E/S ratio of 1:100 showed angiotensin I converting enzyme inhibitory activity with IC50 of 0.46 mg/mL, and APH obtained by Flavourzyme at E/S ratio of 1:100 possessed the oxygen radical absorbance capacity value of 457.6 μM trolox equivalent/mg sample. Flavourzyme abalone protein hydrolysates (FAPH) also exhibited H2O2 scavenging activity with IC50 of 0.48 mg/mL and Fe(2+) chelating activity with IC50 of 2.26 mg/mL as well as high reducing power. FAPH significantly (P<0.05) protected H2O2-induced hepatic cell damage in cultured hepatocytes, and the cell viability was restored to 90.27% in the presence of FAPH. FAPH exhibited 46.20% intracellular ROS scavenging activity and 57.89% lipid peroxidation inhibition activity in cultured hepatocytes. Overall, APH may be useful as an ingredient for functional foods.

Abalone Protein Hydrolysates: Preparation, Angiotensin I Converting Enzyme Inhibition and Cellular Antioxidant Activity

PubMed Central

Park, Soo Yeon; Je, Jae-Young; Hwang, Joung-Youl; Ahn, Chang-Bum

2015-01-01

Abalone protein was hydrolyzed by enzymatic hydrolysis and the optimal enzyme/substrate (E/S) ratios were determined. Abalone protein hydrolysates (APH) produced by Protamex at E/S ratio of 1:100 showed angiotensin I converting enzyme inhibitory activity with IC50 of 0.46 mg/mL, and APH obtained by Flavourzyme at E/S ratio of 1:100 possessed the oxygen radical absorbance capacity value of 457.6 μM trolox equivalent/mg sample. Flavourzyme abalone protein hydrolysates (FAPH) also exhibited H2O2 scavenging activity with IC50 of 0.48 mg/mL and Fe2+ chelating activity with IC50 of 2.26 mg/mL as well as high reducing power. FAPH significantly (P<0.05) protected H2O2-induced hepatic cell damage in cultured hepatocytes, and the cell viability was restored to 90.27% in the presence of FAPH. FAPH exhibited 46.20% intracellular ROS scavenging activity and 57.89% lipid peroxidation inhibition activity in cultured hepatocytes. Overall, APH may be useful as an ingredient for functional foods. PMID:26451354

Implications of the angiotensin converting enzyme gene insertion/deletion polymorphism in health and disease: a snapshot review

PubMed Central

Gard, Paul R

2010-01-01

This review considers the 250+ papers concerning the association of the angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism (rs1799752) and various disease conditions published in 2009. The deletion allele occurs in approximately 55% of the population and is associated with increased activity of the ACE enzyme. It might be predicted that the D allele, therefore, might be associated with pathologies involving increased activity of the renin-angiotensin system. The D allele was seen to be associated with an increased risk of hypertension, pre-eclampsia, heart failure, cerebral infarct, diabetic nephropathy, encephalopathy, asthma, severe hypoglycaemia in diabetes, gastric cancer (in Caucasians) and poor prognosis following kidney transplant. On the positive side, the D allele appears to offer protection against schizophrenia and chronic periodontitis and confers greater up-per-body strength in old age. The I allele, meanwhile, offers improved endurance/athletic performance and aerobic capacity as determined by lung function tests, although it does increase the risk of oral squamous cell carcinoma and obstructive sleep apnoea in hypertensives. PMID:21537387

NT5E Mutations and Arterial Calcifications

PubMed Central

St. Hilaire, Cynthia; Ziegler, Shira G.; Markello, Thomas C.; Brusco, Alfredo; Groden, Catherine; Gill, Fred; Carlson-Donohoe, Hannah; Lederman, Robert J.; Chen, Marcus Y.; Yang, Dan; Siegenthaler, Michael P.; Arduino, Carlo; Mancini, Cecilia; Freudenthal, Bernard; Stanescu, Horia C.; Zdebik, Anselm A.; Chaganti, R. Krishna; Nussbaum, Robert L.; Kleta, Robert; Gahl, William A.; Boehm, Manfred

2011-01-01

BACKGROUND Arterial calcifications are associated with increased cardiovascular risk, but the genetic basis of this association is unclear. METHODS We performed clinical, radiographic, and genetic studies in three families with symptomatic arterial calcifications. Single-nucleotide-polymorphism analysis, targeted gene sequencing, quantitative polymerase-chain-reaction assays, Western blotting, enzyme measurements, transduction rescue experiments, and in vitro calcification assays were performed. RESULTS We identified nine persons with calcifications of the lower-extremity arteries and hand and foot joint capsules: all five siblings in one family, three siblings in another, and one patient in a third family. Serum calcium, phosphate, and vitamin D levels were normal. Affected members of Family 1 shared a single 22.4-Mb region of homozygosity on chromosome 6 and had a homozygous nonsense mutation (c.662C→A, p.S221X) in NT5E, encoding CD73, which converts AMP to adenosine. Affected members of Family 2 had a homozygous missense mutation (c.1073G→A, p.C358Y) in NT5E. The proband of Family 3 was a compound heterozygote for c.662C→A and c.1609dupA (p.V537fsX7). All mutations found in the three families result in nonfunctional CD73. Cultured fibroblasts from affected members of Family 1 showed markedly reduced expression of NT5E messenger RNA, CD73 protein, and enzyme activity, as well as increased alkaline phosphatase levels and accumulated calcium phosphate crystals. Genetic rescue experiments normalized the CD73 and alkaline phosphatase activity in patients’ cells, and adenosine treatment reduced the levels of alkaline phosphatase and calcification. CONCLUSIONS We identified mutations in NT5E in members of three families with symptomatic arterial and joint calcifications. This gene encodes CD73, which converts AMP to adenosine, supporting a role for this metabolic pathway in inhibiting ectopic tissue calcification. (Funded by the National Human Genome Research Institute and the National Heart, Lung, and Blood Institute of the National Institutes of Health.) PMID:21288095

Tryptophan decarboxylase plays an important role in ajmalicine biosynthesis in Rauvolfia verticillata.

PubMed

Liu, Wanhong; Chen, Rong; Chen, Min; Zhang, Haoxing; Peng, Meifang; Yang, Chunxian; Ming, Xingjia; Lan, Xiaozhong; Liao, Zhihua

2012-07-01

Tryptophan decarboxylase (TDC) converts tryptophan into tryptamine that is the indole moiety of ajmalicine. The full-length cDNA of Rauvolfia verticillata (RvTDC) was 1,772 bps that contained a 1,500-bp ORF encoding a 499-amino-acid polypeptide. Recombinant 55.5 kDa RvTDC converted tryptophan into tryptamine. The K (m) of RvTDC for tryptophan was 2.89 mM, higher than those reported in other TIAs-producing plants. It demonstrated that RvTDC had lower affinity to tryptophan than other plant TDCs. The K (m) of RvTDC was also much higher than that of strictosidine synthase and strictosidine glucosidase in Rauvolfia. This suggested that TDC might be the committed-step enzyme involved in ajmalicine biosynthesis in R. verticillata. The expression of RvTDC was slightly upregulated by MeJA; the five MEP pathway genes and SGD showed no positive response to MeJA; and STR was sharply downregulated by MeJA. MeJA-treated hairy roots produced higher level of ajmalicine (0.270 mg g(-1) DW) than the EtOH control (0.183 mg g(-1) DW). Highest RvTDC expression level was detected in hairy root, about respectively 11, 19, 65, and 109-fold higher than in bark, young leaf, old leaf, and root. Highest ajmalicine content was also found in hairy root (0.249 mg g(-1) DW) followed by in bark (0.161 mg g(-1) DW) and young leaf (0.130 mg g(-1) DW), and least in root (0.014 mg g(-1) DW). Generally, the expression level of RvTDC was positively consistent with the accumulation of ajmalicine. Therefore, it could be deduced that TDC might be the key enzyme involved in ajmalicine biosynthesis in Rauvolfia.

DNA methylation and genetic variation of the angiotensin converting enzyme (ACE) in depression.

PubMed

Lam, Dilys; Ancelin, Marie-Laure; Ritchie, Karen; Saffery, Richard; Ryan, Joanne

2018-02-01

Depression is one of the most prevalent psychiatric disorders, and in older persons is associated with high levels of comorbidity and under-treatment. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) stress axis is consistently observed in the older population as well as depressed patients, with the angiotensin converting enzyme (ACE) a key regulator of the stress response. Epigenetic regulation of ACE may play an important role in HPA axis (dys)regulation. To investigate ACE promoter methylation as a biomarker of late-life depression, and its association with genetic variation and cortisol secretion. The longitudinal general population ESPRIT study is aimed at investigating psychiatric disorders in older persons (n=1863, average age=73). Depression was assessed using the Mini International Neuropsychiatric Interview according to DSM-IV criteria and the Centre for Epidemiologic Studies Depression Scale (CES-D). Genotype information for seven polymorphisms across the ACE gene was also available. Blood and saliva samples collected at baseline and used to extract DNA and measure cortisol, respectively. Sequenom MassARRAY was used to measure promoter DNA methylation of the ACE gene (n=552). There was no evidence of an association between ACE promoter methylation and depression. However, there was evidence that ACE genetic variants influenced methylation, and modified the association between depression and methylation (Δ at various sites; -2.05% to 1.74%; p=0.019 to 0.039). Multivariate analyses were adjusted for participants' lifestyle, health and medical history. Independent of depression status, ACE methylation was inversely correlated with cortisol levels (r=-0.336, p=0.042). This study provides evidence that associations between ACE methylation and depression are genotype-dependent, suggesting that the development of reliable depression biomarkers may need to consider methylation levels in combination with underlying genetic variation. ACE methylation may also be a suitable biomarker of cortisol and/or HPA axis activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of renal sympathetic denervation and angiotensin-converting enzyme inhibitor on left ventricular hypertrophy. Comparison in spontaneously hypertensive rats.

PubMed

Ding, X; Xu, X; Yan, Y; Song, X; Liu, S; Wang, G; Su, D; Jing, Q; Qin, Y

2015-06-01

The aim of this study was to investigate whether renal sympathetic denervation (RSD) is more effective on myocardial hypertrophy than the angiotensin-converting enzyme inhibitor (ACEI) perindopril in spontaneously hypertensive rats (SHRs). After bilateral renal denervation blood pressure (BP) was measured every 10 days. On day 50 the heart was (histo)pathologically examined. The ventricular weight to body weight ratios (VW/BW), myocardial diameter and collagen volume fraction (CVF) were calculated, and cardiac hypertrophy marker genes were analyzed by RT-PCR. At the baseline evaluation all groups had comparable BP. After treatment the BP of the RSD group was significantly reduced (p < 0.05). The BP of the RSD group was lower than that of the perindopril group on days 10, 20 and 30th (p < 0.05) but on day 50 systolic BP of the RSD group was significantly higher (p < 0.05) whereas there were no significant differences in diastolic BP. The VW/BW decreased in the RSD group, whereas the value did not change significantly in the perindopril group. The myocardial diameter of the left ventricular cardiomyocytes was also significantly lower in the RSD group and stayed the same in the perindopril group. Collagen volume fraction (CVF) in the RSD group was significantly lower than in the perindopril group (p < 0.05). Significant changes in the expression levels of NPPA, MYH7, and MYH6 (P < 0.05) were observed in the RD-SHR groups (p < 0.05). There was a significant difference in the expression level of MYH6 (p < 0.05) between the RSD group and the perindopril group but the expression levels of NPPA and MYH7 were not significantly different. In this study, RSD had a significant antihypertensive effect and inhibited hypertensive-induced cardiac hypertrophy in SHRs and showed advantages compared with ACEI in decreasing BP in the early stage and in inhibiting myocardial fibrosis.

Angiotensin converting enzyme genotype and chronic allograft nephropathy in protocol biopsies.

PubMed

Hueso, Miguel; Alía, Pedro; Moreso, Francesc; Beltrán-Sastre, Violeta; Riera, Luis; González, Carlota; Navarro, Miguel Angel; Grinyó, Josep Maria; Navarro, Estanis; Serón, Daniel

2004-08-01

Genotype DD of the angiotensin-converting enzyme (ACE) is not associated with an increased incidence of native renal diseases, although it could modulate progression to renal failure in patients who already display chronic lesions. Because its role in renal allograft degeneration is not well characterized, whether ACE genotype was associated with the prevalence of chronic allograft nephropathy (CAN) was studied, in a group of protocol biopsies from 180 patients, or with the incidence of CAN in 152 patients with at least two sequential biopsies. As a control group, ACE genotype was also studied in 41 donors and 72 healthy subjects. For analyzing the influence of ACE genotype in graft survival, patients were grouped into six categories (II-normal biopsy, ID-normal, DD-normal, II-CAN, ID-CAN and DD-CAN). Finally, relative renal ACE mRNA levels were measured in 67 cases by real-time PCR using the delta threshold cycle method. ACE-DD genotype was more frequent in patients who received a transplant than in control subjects (43.3% versus 30.1%, P = 0.026), but prevalence (DD = 42.7% versus non-DD = 42.2%) or incidence (DD = 24.6% versus non-DD = 29.9%) of CAN was not different regarding recipient ACE genotype. Furthermore, patients with the ACE-DD genotype and CAN had the poorest graft survival (II-normal = 100%, ID-normal = 91%, DD-normal = 84%, II-CAN = 100%, ID-CAN = 66%, and DD-CAN = 36%; P = 0.034) and higher ACE mRNA levels than non-DD and CAN (DD = -3.36 +/- 2.35 versus non-DD = -5.65 +/- 1.72-fold in ACE copies; P = 0.012). It is concluded that ACE-DD genotype is not associated with an increased prevalence or incidence of CAN but is actually associated with higher ACE mRNA levels and poorer graft survival in patients who already display CAN.

Flavor Enhancer From Catfish (Clarias batrachus) Bekasam Powder and Angiotensin-I-Converting Enzyme (ACE) Inhibitory Activity in Various Dishes

NASA Astrophysics Data System (ADS)

Lestari, Yanesti N.; Murwani, Retno; Agustini, Tri W.

2018-02-01

Flavor enhancer is characterized by high glutamic acid content and it can be obtained from fermented food such as Bekasam. Fermented food had inhibitory effect on Angiotensin-I-Converting Enzyme (ACE) activity which is advantageous for hypertension. However, such activity was not known to sustain in food system. The aim of this research was to study addition of flavour enhancer from Catfish Bekasam Powder (CBP) in various food systems and to determine the ACE inhibitory (ACEI) activity in the food system. Four food system consisted of carrot, champignon, and chicken meat dishes were boiled in water and added with CBP or MSG. Each food system was added with graded level of CBP (0%; 0.5%; 0.8%; 1.1%; and 1,4%) and for control monosodium glutamate (MSG) was used. ACEI activity in each food system and organoleptic test using multiple comparison differentiation on 15 semi-trained panellists were determined. The results showed that there were fluctuation of ACEI activity in the carrot, champignon, and chicken meat dishes (p=0.017; 0.043; and 0.032). The MSG containing dishes showed the lowest ACEI activity. Addition of graded level of CBP on carrot, champignon, and chicken meat dishes were directly proportional to glutamic acid content but inversely proportional to ACEI activity (p<0.05). The addition of commercial MSG on all dishes increased glutamic acid content but reduced ACE-inhibitory activity significantly (p<0.05). Comparing CBP to MSG addition in champignon dish revealed that increasing level of CBP increased the flavour preference of the panellists. On the contrary the higher the addition CBP in noodle and chicken meat dishes the worse were the flavour score (p<0.05). It can be concluded that the addition of CBP as flavour enhancer on various dishes can deliver better flavour and ACE-inhibitory activity than the addition of commercial MSG.

Characteristic Variations and Similarities in Biochemical, Molecular, and Functional Properties of Glyoxalases across Prokaryotes and Eukaryotes.

PubMed

Kaur, Charanpreet; Sharma, Shweta; Hasan, Mohammad Rokebul; Pareek, Ashwani; Singla-Pareek, Sneh L; Sopory, Sudhir K

2017-03-30

The glyoxalase system is the ubiquitous pathway for the detoxification of methylglyoxal (MG) in the biological systems. It comprises two enzymes, glyoxalase I (GLYI) and glyoxalase II (GLYII), which act sequentially to convert MG into d-lactate, thereby helping living systems get rid of this otherwise cytotoxic byproduct of metabolism. In addition, a glutathione-independent GLYIII enzyme activity also exists in the biological systems that can directly convert MG to d-lactate. Humans and Escherichia coli possess a single copy of GLYI (encoding either the Ni- or Zn-dependent form) and GLYII genes, which through MG detoxification provide protection against various pathological and disease conditions. By contrast, the plant genome possesses multiple GLYI and GLYII genes with a role in abiotic stress tolerance. Plants possess both Ni 2+ - and Zn 2+ -dependent forms of GLYI, and studies on plant glyoxalases reveal the various unique features of these enzymes distinguishing them from prokaryotic and other eukaryotic glyoxalases. Through this review, we provide an overview of the plant glyoxalase family along with a comparative analysis of glyoxalases across various species, highlighting similarities as well as differences in the biochemical, molecular, and physiological properties of these enzymes. We believe that the evolution of multiple glyoxalases isoforms in plants is an important component of their robust defense strategies.

Antiproteinuric therapy and fabry nephropathy: sustained reduction of proteinuria in patients receiving enzyme replacement therapy with agalsidase-beta.

PubMed

Tahir, Hindia; Jackson, Leslie L; Warnock, David G

2007-09-01

This report describes an open-label, nonrandomized, prospective evaluation of the effects of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker therapy on patients who have Fabry disease and also received enzyme replacement therapy with agalsidase-beta, given at 1 mg/kg body wt every 2 wk. Previous placebo-controlled phase III and phase IV trials with agalsidase-beta demonstrated clearing of globotriaosylceramide from vascular endothelia but little effect on proteinuria or progressive loss of kidney function in patients with Fabry disease and severe chronic kidney disease marked by overt proteinuria and/or estimated GFR <60 ml/min per 1.73 m2. Angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker therapy is the standard of care for patients with proteinuric kidney diseases, but their use is challenging in patients with Fabry disease and low or low-normal baseline systemic BP. A group of patients with Fabry disease were treated with antiproteinuric therapy, in conjunction with agalsidase-beta; sustained reductions in proteinuria with stabilization of kidney function were achieved in a group of six patients who had severe Fabry nephropathy; the progression rate was -0.23 +/- 1.12 ml/min per 1.73 m2 per yr with 30 mo of follow-up.

Adenine formation from adenosine by mycoplasmas: adenosine phosphorylase activity.

PubMed Central

Hatanaka, M; Del Giudice, R; Long, C

1975-01-01

Mammalian cells have enzymes to convert adenosine to inosine by deamination and inosine to hypoxanthine by phosphorolysis, but they do not possess the enzymes necessary to form the free base, adenine, from adenosine. Mycoplasmas grown in broth or in cell cultures can produce adenine from adenosine. This activity was detected in a variety of mycoplasmatales, and the enzyme was shown to be adenosine phosphorylase. Adenosine formation from adenine and ribose 1-phosphate, the reverse reaction of adenine formation from adenosine, was also observed with the mycoplasma enzyme. Adenosine phosphorylase is apparently common to the mycoplasmatales but it is not universal, and the organisms can be divided into three groups on the basis of their use of adenosine as substrate. Thirteen of 16 Mycoplasma, Acholeplasma, and Siroplasma species tested exhibit adenosine phosphorylase activity. M. lipophilium differed from the other mycoplasmas and shared with mammalian cells the ability to convert adenosine to inosine by deamination. M. pneumoniae and the unclassified M. sp. 70-159 showed no reaction with adenosine. Adenosine phosphorylase activity offers an additional method for the detection of mycoplasma contamination of cells. The patterns of nucleoside metabolism will provide additional characteristics for identification of mycoplasmas and also may provide new insight into the classification of mycoplasmas. PMID:236559

Heterologous Acidothermus cellulolyticus 1,4-β-Endoglucanase E1 Produced Within the Corn Biomass Converts Corn Stover Into Glucose

NASA Astrophysics Data System (ADS)

Ransom, Callista; Balan, Venkatesh; Biswas, Gadab; Dale, Bruce; Crockett, Elaine; Sticklen, Mariam

Commercial conversion of lignocellulosic biomass to fermentable sugars requires inexpensive bulk production of biologically active cellulase enzymes, which might be achieved through direct production of these enzymes within the biomass crops. Transgenic corn plants containing the catalytic domain of Acidothermus cellulolyticus E1 endo-1,4-β glucanase and the bar bialaphos resistance coding sequences were generated after Biolistic® (BioRad Hercules, CA) bombardment of immature embryo-derived cells. E1 sequences were regulated under the control of the cauliflower mosaic virus 35S promoter and tobacco mosaic virus translational enhancer, and E1 protein was targeted to the apoplast using the signal peptide of tobacco pathogenesis-related protein to achieve accumulation of this enzyme. The integration, expression, and segregation of E1 and bar transgenes were demonstrated, respectively, through Southern and Western blotting, and progeny analyses. Accumulation of up to 1.13% of transgenic plant total soluble proteins was detected as biologically active E1 by enzymatic activity assay. The corn-produced, heterologous E1 could successfully convert ammonia fiber explosion-pretreated corn stover polysaccharides into glucose as a fermentable sugar for ethanol production, confirming that the E1 enzyme is produced in its active from.

Scaffoldless engineered enzyme assembly for enhanced methanol utilization

DOE PAGES

Price, J. Vincent; Chen, Long; Whitaker, W. Brian; ...

2016-10-24

Methanol is an important feedstock derived from natural gas and can be chemically converted into commodity and specialty chemicals at high pressure and temperature. Although biological conversion of methanol can proceed at ambient conditions, there is a dearth of engineered microorganisms that use methanol to produce metabolites. In nature, methanol dehydrogenase (Mdh), which converts methanol to formaldehyde, highly favors the reverse reaction. Thus, efficient coupling with the irreversible sequestration of formaldehyde by 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloseisomerase (Phi) serves as the key driving force to pull the pathway equilibrium toward central metabolism. An emerging strategy to promote efficient substrate channelingmore » is to spatially organize pathway enzymes in an engineered assembly to provide kinetic driving forces that promote carbon flux in a desirable direction. Here, we report a scaffoldless, self-assembly strategy to organize Mdh, Hps, and Phi into an engineered supramolecular enzyme complex using an SH3–ligand interaction pair, which enhances methanol conversion to fructose-6-phosphate (F6P). To increase methanol consumption, an “NADH Sink” was created using Escherichia coli lactate dehydrogenase as an NADH scavenger, thereby preventing reversible formaldehyde reduction. Combination of the two strategies improved in vitro F6P production by 97-fold compared with unassembled enzymes. The beneficial effect of supramolecular enzyme assembly was also realized in vivo as the engineered enzyme assembly improved whole-cell methanol consumption rate by ninefold. This approach will ultimately allow direct coupling of enhanced F6P synthesis with other metabolic engineering strategies for the production of many desired metabolites from methanol.« less

Scaffoldless engineered enzyme assembly for enhanced methanol utilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, J. Vincent; Chen, Long; Whitaker, W. Brian

Methanol is an important feedstock derived from natural gas and can be chemically converted into commodity and specialty chemicals at high pressure and temperature. Although biological conversion of methanol can proceed at ambient conditions, there is a dearth of engineered microorganisms that use methanol to produce metabolites. In nature, methanol dehydrogenase (Mdh), which converts methanol to formaldehyde, highly favors the reverse reaction. Thus, efficient coupling with the irreversible sequestration of formaldehyde by 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloseisomerase (Phi) serves as the key driving force to pull the pathway equilibrium toward central metabolism. An emerging strategy to promote efficient substrate channelingmore » is to spatially organize pathway enzymes in an engineered assembly to provide kinetic driving forces that promote carbon flux in a desirable direction. Here, we report a scaffoldless, self-assembly strategy to organize Mdh, Hps, and Phi into an engineered supramolecular enzyme complex using an SH3–ligand interaction pair, which enhances methanol conversion to fructose-6-phosphate (F6P). To increase methanol consumption, an “NADH Sink” was created using Escherichia coli lactate dehydrogenase as an NADH scavenger, thereby preventing reversible formaldehyde reduction. Combination of the two strategies improved in vitro F6P production by 97-fold compared with unassembled enzymes. The beneficial effect of supramolecular enzyme assembly was also realized in vivo as the engineered enzyme assembly improved whole-cell methanol consumption rate by ninefold. This approach will ultimately allow direct coupling of enhanced F6P synthesis with other metabolic engineering strategies for the production of many desired metabolites from methanol.« less

Scaffoldless engineered enzyme assembly for enhanced methanol utilization

PubMed Central

Price, J. Vincent; Chen, Long; Whitaker, W. Brian; Papoutsakis, Eleftherios; Chen, Wilfred

2016-01-01

Methanol is an important feedstock derived from natural gas and can be chemically converted into commodity and specialty chemicals at high pressure and temperature. Although biological conversion of methanol can proceed at ambient conditions, there is a dearth of engineered microorganisms that use methanol to produce metabolites. In nature, methanol dehydrogenase (Mdh), which converts methanol to formaldehyde, highly favors the reverse reaction. Thus, efficient coupling with the irreversible sequestration of formaldehyde by 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloseisomerase (Phi) serves as the key driving force to pull the pathway equilibrium toward central metabolism. An emerging strategy to promote efficient substrate channeling is to spatially organize pathway enzymes in an engineered assembly to provide kinetic driving forces that promote carbon flux in a desirable direction. Here, we report a scaffoldless, self-assembly strategy to organize Mdh, Hps, and Phi into an engineered supramolecular enzyme complex using an SH3–ligand interaction pair, which enhances methanol conversion to fructose-6-phosphate (F6P). To increase methanol consumption, an “NADH Sink” was created using Escherichia coli lactate dehydrogenase as an NADH scavenger, thereby preventing reversible formaldehyde reduction. Combination of the two strategies improved in vitro F6P production by 97-fold compared with unassembled enzymes. The beneficial effect of supramolecular enzyme assembly was also realized in vivo as the engineered enzyme assembly improved whole-cell methanol consumption rate by ninefold. This approach will ultimately allow direct coupling of enhanced F6P synthesis with other metabolic engineering strategies for the production of many desired metabolites from methanol. PMID:27791059

Purification and properties of nitroalkane-oxidizing enzyme from Hansenula mrakii.

PubMed Central

Kido, T; Yamamoto, T; Soda, K

1976-01-01

A nitroalkane-oxidizing enzyme was purified about 1,300-fold from a cell extract of Hansenula mrakii grown in a medium containing nitroethane as the sole nitrogen source by ammonium sulfate fractionation, diethylaminoethyl-cellulose column chromatography, hydroxyapatite column chromatography, and Bio-Gel P-150 column chromatography. The enzyme was shown to be homogeneous upon acrylamide gel electrophoresis and ultracentrifugation. The enzyme exhibits absorption maxima at 274, 370, 415, and 440 nm and a shoulder at 470 nm. Balance studies showed that 2 mol of 2-nitropropane is converted into an equimolar amount of acetone and nitrite with the consumption of 1 mol of oxygen. Hydrogen peroxide is not formed in the enzyme reaction. In addition to 2-nitropropane, 1-nitropropane and nitroethane are oxidatively dentrified by the enzyme, but nitromethane is inert to the enzyme. The nitroalkanes are not oxidized under anaerobic conditions. Images PMID:947888

Purification and characterization of angiotensin I converting enzyme inhibition peptides from sandworm Sipunculus nudus

NASA Astrophysics Data System (ADS)

Sun, Xueping; Wang, Man; Liu, Buming; Sun, Zhenliang

2017-10-01

Three angiotensin I converting enzyme (ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography (RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC50 values of the purified peptides for ACE inhibition activity were 34.72 μmol L-1, 20.55 μmol L-1 and 22.77 μmol L-1, respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.

The carboxypeptidase angiotensin converting enzyme (ACE) shapes the MHC class I peptide repertoire

PubMed Central

Shen, Xiao Z.; Billet, Sandrine; Lin, Chentao; Okwan-Duodu, Derick; Chen, Xu; Lukacher, Aron E.; Bernstein, Kenneth E.

2011-01-01

The surface presentation of peptides by major histocompatibility complex (MHC) class I molecules is critical to CD8+ T cell mediated adaptive immune responses. Aminopeptidases are implicated in the editing of peptides for MHC class I loading, but C-terminal editing is thought due to proteasome cleavage. By comparing genetically deficient, wild-type and over-expressing mice, we now identify the dipeptidase angiotensin-converting enzyme (ACE) as playing a physiologic role in peptide processing for MHC class I. ACE edits the C-termini of proteasome-produced class I peptides. The lack of ACE exposes novel antigens but also abrogates some self-antigens. ACE has major effects on surface MHC class I expression in a haplotype-dependent manner. We propose a revised model of MHC class I peptide processing by introducing carboxypeptidase activity. PMID:21964607

Synthesis and biological studies of highly concentrated lisinopril-capped gold nanoparticles for CT tracking of angiotensin converting enzyme (ACE)

NASA Astrophysics Data System (ADS)

Ghann, William E.; Aras, Omer; Fleiter, Thorsten; Daniel, Marie-Christine

2011-05-01

For patients with a history of heart attack or stroke, the prevention of another cardiovascular or cerebrovascular event is crucial. The development of cardiac and pulmonary fibrosis has been associated with overexpression of tissue angiotensin-converting enzyme (ACE). Recently, gold nanoparticles (GNPs) have shown great potential as X-ray computed tomography (CT) contrast agents. Since lisinopril is an ACE inhibitor, it has been used as coating on GNPs for targeted imaging of tissue ACE in prevention of fibrosis. Herein, lisinopril-capped gold nanoparticles (LIS-GNPs) were synthesized up to a concentration of 55 mgAu/mL. Their contrast was measured using CT and the results were compared to Omnipaque, a commonly used iodine-based contrast agent. The targeting ability of these LIS-GNPs was also assessed.

Novel angiotensin I-converting enzyme inhibitory peptides isolated from Alcalase hydrolysate of mung bean protein.

PubMed

Li, Guan-Hong; Wan, Ju-Zhen; Le, Guo-Wei; Shi, Yong-Hui

2006-08-01

Mung bean protein isolates were hydrolyzed for 2 h by Alcalase. The generated hydrolysate showed angiotensin I-converting enzyme (ACE) inhibitory activity with the IC(50) value of 0.64 mg protein/ml. Three kinds of novel ACE inhibitory peptides were isolated from the hydrolysate by Sephadex G-15 and reverse-phase high performance liquid chromatography (RP-HPLC). These peptides were identified by amino acid composition analysis and matrix assisted-laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), as Lys-Asp-Tyr-Arg-Leu, Val-Thr-Pro-Ala-Leu-Arg and Lys-Leu-Pro-Ala-Gly-Thr-Leu-Phe with the IC(50) values of 26.5 microM, 82.4 microM and 13.4 microM, respectively. Copyright (c) 2006 European Peptide Society and John Wiley & Sons, Ltd.

Media effects in modulating the conformational equilibrium of a model compound for tumor necrosis factor converting enzyme inhibition

NASA Astrophysics Data System (ADS)

Banchelli, Martina; Guardiani, Carlo; Sandberg, Robert B.; Menichetti, Stefano; Procacci, Piero; Caminati, Gabriella

2015-07-01

Small-molecule inhibitors of Tumor Necrosis Factor α Converting Enzyme (TACE) are a promising therapeutic tool for Rheumatoid Arthritis, Multiple Sclerosis and other autoimmune diseases. Here we report on an extensive chemical-physical analysis of the media effects in modulating the conformational landscape of MBET306, the common scaffold and a synthetic precursor of a family of recently discovered tartrate-based TACE inhibitors. The structural features of this molecule with potential pharmaceutical applications have been disclosed by interpreting extensive photophysical measurements in various solvents with the aid of enhanced sampling molecular dynamics simulations and time dependent density functional calculations. Using a combination of experimental and computational techniques, the paper provides a general protocol for studying the structure in solution of molecular systems characterized by the existence of conformational metastable states.

Isolation and structural analysis of antihypertensive peptides that exist naturally in Gouda cheese.

PubMed

Saito, T; Nakamura, T; Kitazawa, H; Kawai, Y; Itoh, T

2000-07-01

Seven kinds of ripened cheeses (8-mo-aged and 24-mo-aged Gouda, Emmental, Blue, Camembert, Edam, and Havarti) were homogenized with distilled water, and water-soluble peptides were prepared by C-18 hydrophobic chromatography. The inhibitory activity to angiotensin I-converting enzyme and decrease in the systolic blood pressure in spontaneously hypertensive rats were measured before and after oral administration of each peptide sample. The strongest depressive effect in the systolic blood pressure (-24.7 mm Hg) and intensive inhibitory activity to angiotensin I-converting enzyme (75.7%) were detected in the peptides from 8-mo-aged Gouda cheese. Four peptides were isolated by HPLC with reverse-phase and gel filtration modes. Their chemical structures and origins, clarified by combination analyses of protein sequencing, amino acid composition, and mass spectrometry, were as follows: peptide A, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln [alpha(s1)-casein (CN), B-8P; f 1-9]; peptide B, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln-Gly-Leu-Pro-Gln (alpha(s1)-CN, B-8P; f 1-13); peptide F, Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-Asn (beta-CN, A2-5P; f 60-68); and peptide G, Met-Pro-Phe-Pro-Lys-Tyr-Pro-Val-Gln-Pro-Phe (beta-CN, A2-5P; f 109-119). Peptides A and F, which were chemically synthesized, showed potent angiotensin I-converting enzyme inhibitory activity with little antihypertensive effects.

Inhibition of angiotensin-converting enzyme increases oestradiol production in ewes submitted to oestrous synchronization protocol.

PubMed

Costa, A s; Junior, A S; Viana, G E N; Muratori, M C S; Reis, A M; Costa, A P R

2014-10-01

This study aimed at evaluating the effects of angiotensin-converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre-experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre-experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p < 0.05), but not in other groups, without changing the concentration of progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin-converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep. © 2014 Blackwell Verlag GmbH.

Characterization of Paenibacillus sp. MBT213 Isolated from Raw Milk and Its Ability to Convert Ginsenoside Rb1 into Ginsenoside Rd from Panax ginseng

PubMed Central

Cho, Soo Hyun; Park, Young W; Song, Gyu Yong

2017-01-01

This study was conducted to isolate and characterize Paenibacillus sp. MBT213 possessing β-glucosidase activity from raw milk, and examine the enzymatic capacity on the hydrolysis of a major ginsenoside (Rb1). Strain MBT213 was found to have a high hydrolytic ability on ginsenoside Rb1 by Esculin Iron Agar test. 16S rDNA analysis revealed that MBT213 was Paenibacillu sp. Crude enzyme of MBT213 strain exhibited high conversion capacity on ginsenoside Rb1 into ginsenoside Rd proven by TLC and HPLC analyses. The API ZYM kit confirmed that Paenibacillu sp. MBT213 exerted higher β-glucosidase and β-galactosidase activity than other strains. Optimum pH and temperature for crude enzyme were found at 7.0 and 35°C in hydrolysis of ginsenoside Rb1. After 10 d of optimal reaction conditions for the crude enzyme, ginsenoside Rb1 fully converted to ginsenoside Rd. Ginseng roots (20%) were fermented for 14 d, and analyzed by HPLC showed that amount of ginsenoside Rb1 significantly decreased, while that of ginsenoside Rd was significantly increased. The study confirmed that the β-glucosidase produced by Paenibacillus sp. MBT213 can hydrolyze the major ginsenoside Rb1 and convert to Rd during fermentation of the ginseng. The β-glucosidase activity of this novel Paenibacillus sp. MBT213 strain may be utilized in development of variety of health foods, dairy foods and pharmaceutical products. PMID:29147097

Marketing research on the angiotensin-converting enzyme inhibitors antihypertensive medicines

PubMed Central

BOBOIA, ANAMARIA; GRIGORESCU, MARIUS RAREŞ; TURCU - ŞTIOLICĂ, ADINA

2017-01-01

Background and aims The research aimed at investigating sales trends of angiotensin-converting enzyme inhibitors antihypertensive medicines, both in terms of quantity and value, in ten community pharmacies, for a period of three years. The research on the antihypertensive medicines consumption is important for highlighting the ever increasing impact of hypertension among the population. Methods The methods used in this research were the following: marketing research, method of sampling, descriptive methods, retrospective analysis, method of comparison. Results The results showed that the drugs containing the active substances of the angiotensin converting enzyme inhibitors class had had significant increases in quantitative and value sales, bringing substantial revenues to pharmacies. From the quantitative perspective, the best-selling products were those containing Enalaprilum, while in terms of value, the best-selling medicines were those containing Perindoprilum. We evidenced that spectacular sales were also achieved for products that have Lisinoprilum, respectively Captoprilum, as active substances. The largest quantities were marketed for the Captopril Terapia® product and the highest earnings were recorded for the Prestarium® medicine. Conclusion This paper approaches an interesting and topical issue, which can be helpful to professionals (pharmacists, doctors) and other categories, such as economists, statisticians, representatives of companies manufacturing medicines, as well as to hypertensive patients, as it could be used to warn population regarding the incidence of cardiovascular diseases, and, at the same time, trace sales trends in order to accomplish profitable business plans. PMID:28246502

The role of aldosterone antagonism agents in diabetic kidney disease.

PubMed

Wombwell, Eric; Naglich, Andrew

2015-03-01

Diabetic kidney disease is a common consequence of the development of diabetes. In the United Kingdom 18-30% of chronic kidney disease cases and 44% of end-stage renal disease cases in the United States have been attributed to complications of diabetic kidney disease. Angiotensin blockade using angiotensin converting enzyme inhibitors or angiotensin receptor blockers is the standard for slowing the progression of diabetic kidney disease. Evidence suggests that aldosterone antagonism added to standard therapy may be beneficial. This paper aims to explore the pathophysiological contribution of aldosterone in diabetic kidney disease and review available literature for aldosterone antagonism through mineralocorticoid receptor blockade. A comprehensive literature search was conducted. Results were analysed and summarised. Nine trials evaluating a total of 535 patients with diabetic kidney disease were identified that evaluated the use of aldosterone antagonists for reducing the signs of diabetic kidney disease. All trials demonstrated a marked decrease in urinary protein excretion when compared to, or added to angiotensin converting enzyme inhibition or angiotensin receptor blockade. The most commonly reported side effect in all of the trials was hyperkalaemia, which occurred in 6.1% of all patients evaluated. Aldosterone antagonists were generally well tolerated in the evaluated patient populations. Aldosterone antagonism may represent a safe and effective complimentary therapy to the use of angiotensin converting enzyme inhibition, or angiotensin receptor blockade, for slowing the progression of diabetic kidney disease. © 2014 European Dialysis and Transplant Nurses Association/European Renal Care Association.

Isolation and characterization of styrene metabolism genes from styrene-assimilating soil bacteria Rhodococcus sp. ST-5 and ST-10.

PubMed

Toda, Hiroshi; Itoh, Nobuya

2012-01-01

Styrene metabolism genes were isolated from styrene-assimilating bacteria Rhodococcus sp. ST-5 and ST-10. Strain ST-5 had a gene cluster containing four open reading frames which encoded styrene degradation enzymes. The genes showed high similarity to styABCD of Pseudomonas sp. Y2. On the other hand, strain ST-10 had only two genes which encoded styrene monooxygenase and flavin oxidoreductase (styAB). Escherichia coli transformants possessing the sty genes of strains ST-5 and ST-10 produced (S)-styrene oxide from styrene, indicating that these genes function as styrene degradation enzymes. Metabolite analysis by resting-cell reaction with gas chromatography-mass spectrometry revealed that strain ST-5 converts styrene to phenylacetaldehyde via styrene oxide by styrene oxide isomerase (styC) reaction. On the other hand, strain ST-10 lacked this enzyme, and thus accumulated styrene oxide as an intermediate. HPLC analysis showed that styrene oxide was spontaneously isomerized to phenylacetaldehyde by chemical reaction. The produced phenylacetaldehyde was converted to phenylacetic acid (PAA) in strain ST-10 as well as in strain ST-5. Furthermore, phenylacetic acid was converted to phenylacetyl-CoA by the catalysis of phenylacetate-CoA ligase in strains ST-5 and ST-10. This study proposes possible styrene metabolism pathways in Rhodococcus sp. strains ST-5 and ST-10. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Impact of angiotensin and endothelin converting enzymes and related bradykinin on renal functions in L-NAME hypertensive rats

NASA Astrophysics Data System (ADS)

Omar, Ali Zainal; Maulood, Ismail M.

2017-09-01

The renin-angiotensin system (RAS), one of the most important hormonal systems, controls the kidney functions by regulating fluid volume, and electrolyte balance. The current study included the effects of kinin-kallikrein system (KKS) and its interaction with both angiotensin converting enzyme (ACE) and endothelin converting enzyme (ECE) on some of kidney function test parameters. In the present experiment, rats were divided into six groups, the first group was infused with normal saline, the second group was L-NG-Nitroarginine methyl ester (L-NAME) treated rats, third group was bradykinin (BK), forth group was captopril (ACEi), fifth group was phosphoramidon (ECEi), sixth group was a combination of BK with phosphoramidon. L-NAME was intravenously infused for one hour to develop systematic hypertension in male rats. After one hour of infusion, the results showed that L-NAME significantly increased serum creatinine. While, it decreased glomerular filtration rate (GFR), and K+ excretion rate. Moreover, BK increased packed cell volume PCV%, serum creatinine and K+ ion concentration. While, it reduced GFR, serum Ca+2 ion concentration, K+ and Na+ excretion rates. On the other hand, captopril infusion showed its effect by reduction in GFR, serum Ca+2 ion and electrolyte excretion rates. Phosphoramidon an ECEi dramatically reduced serum Ca+2 ion, but it increased pH, GFR and Ca+2 excretion rate. The results suggested that BK and Captopril each alone severely reduces GFR value. Interestingly, inhibition of ET-1 production via phosphoramidon could markedly elevate GFR values.

Evaluation of subacute change in RAAS activity (as indicated by urinary aldosterone:creatinine, after pharmacologic provocation) and the response to ACE inhibition.

PubMed

Ames, Marisa K; Atkins, Clarke E; Lantis, Andrea C; zum Brunnen, James

2016-01-01

The objective of this study was to evaluate subacute changes in renin-angiotensin-aldosterone system (RAAS) activity during angiotensin-converting enzyme inhibitor (ACEI) therapy in dogs with experimental RAAS activation. Analysis of data (urine aldosterone:creatinine ratio (UAldo:C) and serum angiotensin-converting enzyme activity), in 31 healthy dogs with furosemide or amlodipine-activated RAAS that received an ACEI. When furosemide or amlodipine activation of RAAS preceded ACEI administration, incomplete RAAS blockade (IRB) was defined as a UAldo:C greater than (a) the dog's 'activated' baseline value or (b) a population-derived cut-off value (mean + 2 SD (>1.0 μg/g) of pretreatment UAldo:C from our population of research dogs). In studies where RAAS activation occurred concurrently with ACEIs, IRB was defined as (a) a UAldo:C greater than either twofold the dog's prestimulation baseline value or (b) 1.0 µg/g. Dogs were followed for 7-17 days. Serum angiotensin-converting enzyme activity was measured in 19 dogs and was significantly reduced (P<0.0001) after ACEI administration. The overall incidence of IRB, when RAAS activation preceded ACEI administration, was 33% and 8% for definitions (a) and (b), respectively. The overall incidence of IRB, when ACEIs were concurrent with RAAS activation, was 65% and 61% for definitions (a) and (b), respectively. Increases in UAldo:C, despite ACEI administration, is evidence of IRB in this subacute model of experimental RAAS activation and suppression. © The Author(s) 2016.

Approaching chronic cough

PubMed Central

Poulose, Vijo; Tiew, Pei Yee; How, Choon How

2016-01-01

Chronic cough is one of the most common reasons for referral to a respiratory physician. Although fatal complications are rare, it may cause considerable distress in the patient’s daily life. Western and local data shows that in patients with a normal chest radiograph, the most common causes are postnasal drip syndrome, postinfectious cough, gastro-oesophageal reflux disease and cough variant asthma. Less common causes are the use of angiotensin-converting enzyme inhibitors, smoker’s cough and nonasthmatic eosinophilic bronchitis. A detailed history-taking and physical examination will provide a diagnosis in most patients, even at the primary care level. Some cases may need further investigations or specialist referral for diagnosis. PMID:26892615

Single Molecule and Collective Dynamics of Motor Protein Coupled with Mechano-Sensitive Chemical Reaction

NASA Astrophysics Data System (ADS)

Iwaki, Mitsuhiro; Marcucci, Lorenzo; Togashi, Yuichi; Yanagida, Toshio

2013-12-01

Motor proteins such as myosin and kinesin hydrolyze ATP into ADP and Pi to convert chemical energy into mechanical work. This resultsin various motile processes like muscle contraction, vesicle transport and cell division. Recent single molecule experiments have revealed that external load applied to these motor proteins perturb not only the mechanical motion, but the ATP hydrolysis cycle as well, making these molecules mechano-enzymes. Here, we describe our single molecule detection techniques to reveal the mechano-enzymatic properties of myosin and introduce recent progress from both experimental and theoretical approaches at the single- and multiple-molecule level.

Biochemical Characterization of the Lactobacillus reuteri Glycoside Hydrolase Family 70 GTFB Type of 4,6-α-Glucanotransferase Enzymes That Synthesize Soluble Dietary Starch Fibers.

PubMed

Bai, Yuxiang; van der Kaaij, Rachel Maria; Leemhuis, Hans; Pijning, Tjaard; van Leeuwen, Sander Sebastiaan; Jin, Zhengyu; Dijkhuizen, Lubbert

2015-10-01

4,6-α-Glucanotransferase (4,6-α-GTase) enzymes, such as GTFB and GTFW of Lactobacillus reuteri strains, constitute a new reaction specificity in glycoside hydrolase family 70 (GH70) and are novel enzymes that convert starch or starch hydrolysates into isomalto/maltopolysaccharides (IMMPs). These IMMPs still have linear chains with some α1→4 linkages but mostly (relatively long) linear chains with α1→6 linkages and are soluble dietary starch fibers. 4,6-α-GTase enzymes and their products have significant potential for industrial applications. Here we report that an N-terminal truncation (amino acids 1 to 733) strongly enhances the soluble expression level of fully active GTFB-ΔN (approximately 75-fold compared to full-length wild type GTFB) in Escherichia coli. In addition, quantitative assays based on amylose V as the substrate are described; these assays allow accurate determination of both hydrolysis (minor) activity (glucose release, reducing power) and total activity (iodine staining) and calculation of the transferase (major) activity of these 4,6-α-GTase enzymes. The data show that GTFB-ΔN is clearly less hydrolytic than GTFW, which is also supported by nuclear magnetic resonance (NMR) analysis of their final products. From these assays, the biochemical properties of GTFB-ΔN were characterized in detail, including determination of kinetic parameters and acceptor substrate specificity. The GTFB enzyme displayed high conversion yields at relatively high substrate concentrations, a promising feature for industrial application. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

ACE2 alterations in kidney disease.

PubMed

Soler, María José; Wysocki, Jan; Batlle, Daniel

2013-11-01

Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that degrades angiotensin (Ang) II to Ang-(1-7). ACE2 is highly expressed within the kidneys, it is largely localized in tubular epithelial cells and less prominently in glomerular epithelial cells and in the renal vasculature. ACE2 activity has been shown to be altered in diabetic kidney disease, hypertensive renal disease and in different models of kidney injury. There is often a dissociation between tubular and glomerular ACE2 expression, particularly in diabetic kidney disease where ACE2 expression is increased at the tubular level but decreased at the glomerular level. In this review, we will discuss alterations in circulating and renal ACE2 recently described in different renal pathologies and disease models as well as their possible significance.

ACE2 alterations in kidney disease

PubMed Central

Soler, María José; Wysocki, Jan; Batlle, Daniel

2013-01-01

Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that degrades angiotensin (Ang) II to Ang-(1–7). ACE2 is highly expressed within the kidneys, it is largely localized in tubular epithelial cells and less prominently in glomerular epithelial cells and in the renal vasculature. ACE2 activity has been shown to be altered in diabetic kidney disease, hypertensive renal disease and in different models of kidney injury. There is often a dissociation between tubular and glomerular ACE2 expression, particularly in diabetic kidney disease where ACE2 expression is increased at the tubular level but decreased at the glomerular level. In this review, we will discuss alterations in circulating and renal ACE2 recently described in different renal pathologies and disease models as well as their possible significance. PMID:23956234

Renal function in urinary schistosomiasis in the Natal Province of South Africa.

PubMed

Coopan, R M; Naidoo, K; Jialal, I

1987-11-01

Renal function was assessed in 101 schoolchildren with active urinary schistosomiasis by measuring serum creatinine, urate, urea, and B2-microglobulin, urinary B2 microglobulin, and the glomerular filtration rate. Glomerular function in all subjects was normal as were serum creatinine, urate, and urea levels. Serum B2-microglobulin was elevated in only 8% of subjects while urinary B2-microglobulin only was raised in 7% of subjects, indicating proximal tubular dysfunction, a previously unreported feature in urinary schistosomiasis. Urinary tract abnormalities were found in 43% of subjects consenting to an excretory urogram but no correlation with biochemical parameters of renal function was noted. Serum angiotensin converting enzyme level measured in 70 subjects was elevated in 11% of subjects and was regarded as a possible measure of increased granulomatous activity.

Novel functions of the α-ketoglutarate dehydrogenase complex may mediate diverse oxidant-induced changes in mitochondrial enzymes associated with Alzheimer’s disease

PubMed Central

Shi, Qingli; Xu, Hui; Kleinman, Wayne A.; Gibson, Gary E.

2011-01-01

Measures in autopsied brains from Alzheimer’s Disease (AD) patients reveal a decrease in the activity of α-ketoglutarate dehydrogenase complex (KGDHC) and an increase in malate dehydrogenase (MDH) activity. The present experiments tested whether both changes could be caused by the common oxidant H2O2 and to probe the mechanism underlying these changes. Since the response to H2O2 is modified by the level of the E2k subunit of KGDHC, the interaction of MDH and KGDHC was studied in cells with varying levels of E2k. In cells with only 23% of normal E2k protein levels, one hour treatment with H2O2 decreased KGDHC and increased MDH activity as well as the mRNA level for both cytosolic and mitochondrial MDH. The increase in MDH did not occur in cells with 100% or 46% of normal E2k. Longer treatments with H2O2 inhibited the activity of both enzymes. Glutathione is a major regulator of cellular redox state and can modify enzyme activities. H2O2 converts reduced glutathione (GSH) to oxidized glutathione (GSSG), which reacts with protein thiols. Treatment of purified KGDHC with GSSG leads to glutathionylation of all three KGDHC subunits. Thus, cellular glutathione level was manipulated by two means to determine the effect on KGDHC and MDH activities. Both buthionine sulfoximine (BSO), which inhibits glutathione synthesis without altering redox state, and H2O2 diminished glutathione to a similar level after 24 hrs. However, H2O2, but not BSO, reduced KGDHC and MDH activities, and the reduction was greater in the E2k-23 line. These findings suggest that the E2k may mediate diverse responses of KGDHC and MDH to oxidants. In addition, the differential response of activities to BSO and H2O2 together with the in vitro interaction of KGDHC with GSSG suggests that glutathionylation is one possible mechanism underlying oxidative stress-induced inhibition of the TCA cycle enzymes. PMID:18206986

Genetic Variants of Angiotensin-Converting Enzyme Are Linked to Autism: A Case-Control Study.

PubMed

Firouzabadi, Negar; Ghazanfari, Nima; Alavi Shoushtari, Ali; Erfani, Nasrallah; Fathi, Farshid; Bazrafkan, Mozhdeh; Bahramali, Ehsan

2016-01-01

Autism is a disease of complex nature with a significant genetic component. The importance of renin-angiotensin system (RAS) elements in cognition and behavior besides the interaction of angiotensin II (Ang II), the main product of angiotensin-converting enzyme (ACE), with neurotransmitters in CNS, especially dopamine, proposes the involvement of RAS in autism. Since the genetic architecture of autism has remained elusive, here we postulated that genetic variations in RAS are associated with autism. Considering the relation between the three polymorphisms of ACE (I/D, rs4343 and rs4291) with the level of ACE activity, we have investigated this association with autism, in a case-control study. Genotype and allele frequencies of polymorphisms were determined in DNAs extracted from venous blood of 120 autistic patients and their age and sex-matched healthy controls, using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) methods. There were strong associations between both DD genotype of ACE I/D and the D allele, with autism (P = 0.006, OR = 2.9, 95% CI = 1.64-5.13 and P = 0.006, OR = 2.18, 95% CI = 1.37-3.48 respectively). Furthermore, a significant association between the G allele of rs4343 and autism was observed (P = 0.006, OR = 1.84, 95%CI = 1.26-2.67). Moreover, haplotype analysis revealed an association between DTG haplotype and autism (P = 0.008). Our data suggests the involvement of RAS genetic diversity in increasing the risk of autism.

Utility of angiotensin-converting enzyme activity in aqueous humor in the diagnosis of ocular sarcoidosis.

PubMed

Mihailovic-Vucinic, Violeta; Popevic, Ljubica; Popevic, Spasoje; Stjepanovic, Mihailo; Aleksic, Andjelka; Stanojevic-Paovic, Anka

2017-10-01

Many studies include elevated activity of angiotensin-converting enzyme (ACE) in serum in sarcoidosis and in ocular sarcoidosis as well, but there are only a few analyzing ACE activities in aqueous humor. The aim of this study is to illuminate the diagnostic value of ACE in aqueous humor in patients with ocular sarcoidosis. We analyzed twenty patients with ocular sarcoidosis and 18 patients with nonocular involvement. All patients have biopsy-positive sarcoidosis of the lungs and/or mediastinal lymph nodes. Blood samples for ACE serum levels were obtained from all patients. Aqueous humor samples were taken by paracentesis with a 25-gauge needle in local anesthesia. With appropriate statistical tests, we compared ACE activity in serum and aqueous humor in patients with and without ocular sarcoidosis. The majority of our patients with ocular sarcoidosis were female (12/20), also in the group with systemic sarcoidosis and without ocular involvement (12/6). Mean age of the whole analyzed group of sarcoidosis patients was 45 ± 6 years. There is no statistically significant difference in ACE activity in serum between two groups of patients (with and without ocular sarcoidosis). There is statistically significant difference in ACE activity in aqueous humor among patients with ocular and nonocular sarcoidosis. ACE activity in aqueous humor is significantly higher in patients with ocular sarcoidosis. Increased ACE activity in aqueous humor can point to a diagnosis of ocular sarcoidosis, without the need for ocular biopsy.

Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver.

PubMed

Reza, Hasan Mahmud; Tabassum, Nabila; Sagor, Md Abu Taher; Chowdhury, Mohammed Riaz Hasan; Rahman, Mahbubur; Jain, Preeti; Alam, Md Ashraful

2016-01-01

Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats.

Genetics Home Reference: hereditary paraganglioma-pheochromocytoma

MedlinePlus

... two important cellular pathways called the citric acid cycle (or Krebs cycle) and oxidative phosphorylation. These pathways are critical in ... can use. As part of the citric acid cycle, the SDH enzyme converts a compound called succinate ...

Estrogen: The necessary evil for human health, and ways to tame it.

PubMed

Patel, Seema; Homaei, Ahmad; Raju, Akondi Butchi; Meher, Biswa Ranjan

2018-06-01

Estrogen is a pivotal enzyme for survival and health in both genders, though their quantum, tropism, tissue-specific distribution, and receptor affinity varies with different phases of life. Converted from androgen via aromatase enzyme, this hormone is indispensable to glucose homeostasis, immune robustness, bone health, cardiovascular health, fertility, and neural functions. However, estrogen is at the center of almost all human pathologies as well-infectious, autoimmune, metabolic to degenerative. Both hypo and hyper level of estrogen has been linked to chronic and acute diseases. While normal aging is supposed to lower its level, leading to tissue degeneration (bone, muscle, neural etc.), and metabolite imbalance (glucose, lipid etc.), the increment in inflammatory agents in day-to-day life are enhancing the estrogen (or estrogen mimic) level, fueling 'estrogen dominance'. The resultant excess estrogen is inducing an overexpression of estrogen receptors (ERα and ERβ), harming tissues, leading to autoimmune diseases, and neoplasms. The unprecedented escalation in the polycystic ovary syndrome, infertility, breast cancer, ovary cancer, and gynecomastia cases are indicating that this sensitive hormone is getting exacerbated. This critical review is an effort to analyze the dual, and opposing facets of estrogen, via understanding its crosstalk with other hormones, enzymes, metabolites, and drugs. Why estrogen level correction is no trivial task, and how it can be restored to normalcy by a disciplined lifestyle with wise dietary and selective chemical usage choices has been discussed. Overall, our current state of knowledge does not disclose the full picture of estrogen's pleiotropic importance. Hence, this review should be a resource for general public as well as researchers to work in that direction. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Epoxy Fatty Acids and Inhibition of the Soluble Epoxide Hydrolase Selectively Modulate GABA Mediated Neurotransmission to Delay Onset of Seizures

PubMed Central

Inceoglu, Bora; Zolkowska, Dorota; Yoo, Hyun Ju; Wagner, Karen M.; Yang, Jun; Hackett, Edward; Hwang, Sung Hee; Lee, Kin Sing Stephen; Rogawski, Michael A.; Morisseau, Christophe; Hammock, Bruce D.

2013-01-01

In the brain, seizures lead to release of large amounts of polyunsaturated fatty acids including arachidonic acid (ARA). ARA is a substrate for three major enzymatic routes of metabolism by cyclooxygenase, lipoxygenase and cytochrome P450 enzymes. These enzymes convert ARA to potent lipid mediators including prostanoids, leukotrienes and epoxyeicosatrienoic acids (EETs). The prostanoids and leukotrienes are largely pro-inflammatory molecules that sensitize neurons whereas EETs are anti-inflammatory and reduce the excitability of neurons. Recent evidence suggests a GABA-related mode of action potentially mediated by neurosteroids. Here we tested this hypothesis using models of chemically induced seizures. The level of EETs in the brain was modulated by inhibiting the soluble epoxide hydrolase (sEH), the major enzyme that metabolizes EETs to inactive molecules, by genetic deletion of sEH and by direct administration of EETs into the brain. All three approaches delayed onset of seizures instigated by GABA antagonists but not seizures through other mechanisms. Inhibition of neurosteroid synthesis by finasteride partially blocked the anticonvulsant effects of sEH inhibitors while the efficacy of an inactive dose of neurosteroid allopregnanolone was enhanced by sEH inhibition. Consistent with earlier findings, levels of prostanoids in the brain were elevated. In contrast, levels of bioactive EpFAs were decreased following seizures. Overall these results demonstrate that EETs are natural molecules which suppress the tonic component of seizure related excitability through modulating the GABA activity and that exploration of the EET mediated signaling in the brain could yield alternative approaches to treat convulsive disorders. PMID:24349022

Comparative performance of precommercial cellulases hydrolyzing pretreated corn stover

PubMed Central

2011-01-01

Background Cellulases and related hydrolytic enzymes represent a key cost factor for biochemical conversion of cellulosic biomass feedstocks to sugars for biofuels and chemicals production. The US Department of Energy (DOE) is cost sharing projects to decrease the cost of enzymes for biomass saccharification. The performance of benchmark cellulase preparations produced by Danisco, DSM, Novozymes and Verenium to convert pretreated corn stover (PCS) cellulose to glucose was evaluated under common experimental conditions and is reported here in a non-attributed manner. Results Two hydrolysis modes were examined, enzymatic hydrolysis (EH) of PCS whole slurry or washed PCS solids at pH 5 and 50°C, and simultaneous saccharification and fermentation (SSF) of washed PCS solids at pH 5 and 38°C. Enzymes were dosed on a total protein mass basis, with protein quantified using both the bicinchoninic acid (BCA) assay and the Bradford assay. Substantial differences were observed in absolute cellulose to glucose conversion performance levels under the conditions tested. Higher cellulose conversion yields were obtained using washed solids compared to whole slurry, and estimated enzyme protein dosages required to achieve a particular cellulose conversion to glucose yield were extremely dependent on the protein assay used. All four enzyme systems achieved glucose yields of 90% of theoretical or higher in SSF mode. Glucose yields were reduced in EH mode, with all enzymes achieving glucose yields of at least 85% of theoretical on washed PCS solids and 75% in PCS whole slurry. One of the enzyme systems ('enzyme B') exhibited the best overall performance. However in attaining high conversion yields at lower total enzyme protein loadings, the relative and rank ordered performance of the enzyme systems varied significantly depending upon which hydrolysis mode and protein assay were used as the basis for comparison. Conclusions This study provides extensive information about the performance of four precommercial cellulase preparations. Though test conditions were not necessarily optimal for some of the enzymes, all were able to effectively saccharify PCS cellulose. Large differences in the estimated enzyme dosage requirements depending on the assay used to measure protein concentration highlight the need for better consensus methods to quantify enzyme protein. PMID:21899748

Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC.

PubMed

Oosterkamp, Margreet J; Boeren, Sjef; Atashgahi, Siavash; Plugge, Caroline M; Schaap, Peter J; Stams, Alfons J M

2015-06-01

Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In the proposed acetone degradation pathway, an acetone carboxylase converts acetone to acetoacetate, an AMP-dependent synthetase/ligase converts acetoacetate to acetoacetyl-CoA, and an acetyl-CoA acetyltransferase cleaves acetoacetyl-CoA to two acetyl-CoA. We also found a putative aldehyde dehydrogenase associated with acetone degradation. This enzyme functioned as a β-hydroxybutyrate dehydrogenase catalyzing the conversion of surplus acetoacetate to β-hydroxybutyrate that may be converted to the energy and carbon storage compound, poly-β-hydroxybutyrate. Accordingly, we confirmed the formation of poly-β-hydroxybutyrate in acetone-grown cells of strain BC. Our findings provide insight in nitrate-dependent acetone degradation that is activated by carboxylation of acetone. This will aid studies of similar pathways found in other microorganisms degrading acetone with nitrate or sulfate as electron acceptor. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Omapatrilat, a dual angiotensin-converting enzyme and neutral endopeptidase inhibitor, prevents fatty streak deposit in apolipoprotein E-deficient mice.

PubMed

Arnal, J F; Castano, C; Maupas, E; Mugniot, A; Darblade, B; Gourdy, P; Michel, J B; Bayard, F

2001-04-01

Angiotensin-converting enzyme (ACE) is mainly responsible for converting angiotensin I (AI) to angiotensin II (AII), and ACE inhibitors prevent atherosclerosis in animal models. Neutral endopeptidase 24.11 (NEP) degrades substance P, kinins and atrial natriuretic peptide (ANP), and aortic wall NEP activity was found to be increased in atherosclerosis. In the present study, we have evaluated the effect of candoxatril, a NEP inhibitor, and of omapatrilat, a dual ACE and NEP inhibitor, on the development of fatty streak in apolipoprotein E (apoE)-deficient mice. Groups of ten male apoE-deficient mice were given either placebo, candoxatril 50 mg/kg per day, or omapatrilat 10, or 100 mg/kg per day for 4 months. None of the treatments influenced body weight, serum total or HDL-cholesterol. Compared with the placebo, candoxatril did not protect the mice from fatty streak deposit. In contrast, omapatrilat dose dependently inhibited the constitution of fatty streak in apoE-deficient mice. The precise advantages of the dual ACE and NEP inhibition versus the inhibition of only ACE should now be considered in the prevention of atherosclerosis as well as in the occurrence of its complications.

Structural requirements of choline derivatives for 'conversion' of pneumococcal amidase. A new single-step procedure for purification of this autolysin.

PubMed

Sanz, J M; Lopez, R; Garcia, J L

1988-05-23

Tertiary amines appear to be the minimal structure needed to convert in vitro the inactive form (E-form) of pneumococcal amidase to the catalytic active form (C-form). Diethylethanolamine was one of the compounds that converted the E-form, a finding that has been used successfully to develop an affinity chromatography system in DEAE-cellulose for the rapid and efficient purification of lytic enzymes of pneumococcus and its bacteriophages.

A natural inhibitor of kidney-type glutaminase: a withanolide from Physalis pubescens with potent anti-tumor activity

PubMed Central

Wu, Canrong; Zheng, Mengzhu; Gao, Suyu; Luan, Shanshan; Cheng, Li; Wang, Liqing; Li, Jiachen; Chen, Lixia; Li, Hua

2017-01-01

Kidney-type glutaminase (KGA), a mitochondrial enzyme converting glutamine to glutamate for energy supply, was over-expressed in many cancers and had been regarded as a promising therapeutic target in recent years. Structure-based virtual ligand screening predicted physapubescin K, a new withanolide from Physalis pubescens, to be potential KGA inhibitor. Enzyme activity inhibition assays and microscale thermophoresis experiments had demonstrated the efficiency and specificity of physapubescin K targeting KGA. Additionally, physapubescin K exhibited potent proliferation inhibitory effects on a panel of human cancer cell lines, such as SW1990 and HCC827-ER. It blocked glutamine metabolism in SW1990 with increasing intracellular level of glutamine and decreasing glutamate and its downstream metabolites. Physapubescin K also significantly inhibited the tumor growth in a SW1990 xenograft mouse model. Interestingly, physapubescin K could reverse the resistance of HCC827-ER cells to erlotinib and synergize with the hexokinase 2 inhibitor to markedly enhance the inhibition of SW1990 cell proliferation. PMID:29371926

Wheat Bread with Pumpkin (Cucurbita maxima L.) Pulp
as a Functional Food Product

PubMed Central

Gawlik-Dziki, Urszula; Dziki, Dariusz; Jakubczyk, Anna; Karaś, Monika; Różyło, Krzysztof

2014-01-01

Summary In this study, a new application of pumpkin pulp in bread production is shown. The aim of this work is to determine the influence of the addition of fresh pumpkin pulp directly into wheat flour on physical, sensorial and biological properties of bread. The bioaccessibility of active compounds was also studied. An increase in the addition of pumpkin pulp from 5 to 20% (converted to dry matter) caused a decrease of bread volume and increase of crumb hardness and cohesiveness. The sensory characteristics of the bread showed that a partial replacement of wheat flour with up to 10% of pumpkin pulp gave satisfactory results. The taste, aroma and overall acceptability of control bread and bread containing 5 or 10% of pulp had the highest degree of liking. The addition of higher levels of pumpkin pulp caused an unpleasant aroma and taste. Pumpkin pulp is a good material to complement the bread with potentially bioaccessible phenolics (including flavonoids) and, especially, with peptides. The highest antioxidant activity was observed, in most cases, of the samples with added 10 and 15% of pumpkin pulp. The addition of the pulp significantly enriched the bread with potentially bioaccessible angiotensin-converting enzyme (ACE) inhibitors. The highest activity was determined in the bread with 15 and 20% pumpkin pulp. ACE inhibitors from the tested bread were highly bioaccessible in vitro. Pumpkin pulp seems to be a valuable source of active compounds to complement the wheat bread. Adding the pulp directly to the wheat flour gives satisfactory baking results and reduces the cost of production. Additionally, pumpkin pulp is sometimes treated as waste material after the acquisition of seeds, thus using it as bread supplement also has environmental and economic benefits. Key words: pumpkin, bread, texture, antioxidants, bioaccessibility in vitro, angiotensin-converting enzyme (ACE) inhibition PMID:27904316

The Role and Regulation of the 11 Beta-Hydroxysteroid Dehydrogenase Enzyme System in Patients with Inflammatory Bowel Disease.

PubMed

Hussey, M; Holleran, G; Smith, S; Sherlock, Mark; McNamara, D

2017-12-01

Glucocorticoids are known to modulate a number of immunological responses including counteracting inflammation. Within tissues expressing the glucocorticoid and mineralocorticoid receptors including the colon, glucocorticoid metabolism is regulated by the isoenzymes of 11ß-hydroxysteroid dehydrogenase (11β-HSD). 11β-HSD1 acts as an oxidoreductase converting inactive cortisone into active cortisol, while 11β-HSD2 acts as a dehydrogenase converting active cortisol to inactive cortisone. Hexose-6 phosphate dehydrogenase (H6PDH) is a key regulator of 11β-HSD1 activity via its generation of NADPH. Variations in the 11β-HSD enzyme system in relation to levels of expression and regulation may have a role in IBD. The aim of this study was to investigate possible abnormalities of 11β-HSD enzyme system in the colon of patients with IBD. By using quantitative real-time PCR, we investigated the transcription levels of 11β-HSD1 and 2 in colonic tissue from IBD patients and healthy controls undergoing a colonoscopy for disease assessment. Disease activity was recorded using clinical (Mayo Score/Harvey-Bradshaw Index), Biochemical (C-reactive protein), histological, and endoscopic parameters. In addition, transcription levels of H6PDH and the glucocorticoid receptor alpha (GR-α) as well as key pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, Rela (subunit for NF Kappa B)) were later examined among this group, and results were correlated with 11β-HSD2 gene expression. Results and patient demographics were expressed as a mean (and SD), and differences between IBD patients and control groups were analyzed using a Student's t test or Mann-Whitney U test as appropriate, with a p value of ≤0.05 considered significant. Results were controlled for disease activity as outlined above. Results have demonstrated a significant downregulation in 11β-HSD2 expression in IBD patients compared with controls (13.8 ± 17.1 au vs. 318.4 ± 521.1 au, p = 0.01), whereas levels of 11β-HSD1 did not appear to vary across the two groups. Among IBD patients, there was a trend toward higher 11β-HSD1 expression in inflamed tissue compared with matched non-inflamed tissue (422.1 ± 944 au vs. 102.2 ± 103.9, P = 0.09). Levels of H6PDH and the GR-α expression did not appear to vary among active inflamed IBD tissue and controls. As a result, we examined the association between pro-inflammatory cytokines and levels of 11β-HSD2 expression. Results showed an upregulation of key pro-inflammatory cytokine mRNA expression (TNF-α, IL-1β, IL-6) during inflammation with an associated downregulation of 11β-HSD2 mRNA expression when compared to controls. Dysregulation in this pathway could have a potential role in IBD pathogenesis and may account for exogenous glucocorticoid resistance in IBD. Further work assessing the role of the 11β-HSD enzyme system in steroid-resistant subjects is warranted.

The enzyme lecithin-cholesterol acyltransferase esterifies cerebrosterol and limits the toxic effect of this oxysterol on SH-SY5Y cells.

PubMed

La Marca, Valeria; Spagnuolo, Maria Stefania; Cigliano, Luisa; Marasco, Daniela; Abrescia, Paolo

2014-07-01

Cholesterol is mostly removed from the CNS by its conversion to cerebrosterol (24(S)-hydroxycholesterol, 24(S)OH-C), which is transported to the circulation for bile formation in liver. A neurotoxic role of this oxysterol was previously demonstrated in cell culture. Here, we provide evidence that the enzyme lecithin-cholesterol acyltransferase, long known to esterify cholesterol, also produces monoesters of 24(S)OH-C. Proteoliposomes containing apolipoprotein A-I or apolipoprotein E were used to stimulate the enzyme activity and entrap the formed esters. Proteoliposomes with apolipoprotein A-I were found to be more active than those with apolipoprotein E in stimulating the production of oxysteryl esters. Cholesterol and 24(S)OH-C were found to compete for enzyme activity. High levels of haptoglobin, as those circulating during the acute inflammatory phase, inhibited 24(S)OH-C esterification. When highly neurotoxic 24(S)OH-C was treated with enzyme and proteoliposomes before incubation with differentiated SH-SY5Y cells, the neuron survival improved. The esters of 24(S)OH-C, embedded into proteoliposomes by the enzyme and isolated from unesterified 24(S)OH-C by gel filtration chromatography, did not enter the neurons in culture. These results suggest that the enzyme, in the presence of the apolipoproteins, converts 24(S)OH-C into esters restricted to the extracellular environment, thus preventing or limiting oxysterol-induced neurotoxic injuries to neurons in culture. 24-hydroxycholesterol (24(S)OH-C) is neurotoxic. The enzyme lecithin-cholesterol acyltransferase (LCAT) synthesizes monoesters of 24(S)OH-C in reaction mixtures with proteoliposomes containing phospholipids and apolipoprotein A-I or apolipoprotein E. The esters, also produced by incubation of cerebrospinal fluid only with tritiated 24(S)OH-C, are embedded into lipoproteins that do not enter neurons in culture. The enzyme activity limits the toxicity of 24-hydroxycholesterol in neuron culture. © 2014 International Society for Neurochemistry.

Application of α-N-acetylgalactosaminidase and α-galactosidase in AB to O red blood cells conversion.

PubMed

Gao, Hongwei; Li, Subo; Tan, Yingxia; Ji, Shouping; Wang, Yingli; Bao, Guoqiang; Xu, Lijuan; Gong, Feng

2013-02-01

Enzymatical conversion of A or B RBCs into group O RBCs (ECORBCs) was achieved by using α-N-acetylgalactosaminidase and α-galactosidase, respectively. Now, we initiated AB to O-RBC conversion by using these two enzymes together. But α-N-acetylgalactosaminidase and α-galactosidase's preserving and their reaction buffer were quite different. The aim of this study is to confirm an available system for converting AB to O RBCs, especially to study the maximal permission amount of PCS which was brought to the system-accompanied enzyme addition. Enzyme activity was detected by using GalNAc-pNp or Gal-pNp as substrates. The efficiency of the conversion of A or B antigen was evaluated by routine method and measured by fluorescence-activated cell sorting analysis. The optimal buffer component and the doses of α-N-acetylgalactosaminidase and α-galactosidase were confirmed according to A and B antigen epitope removal efficiency. The activity of α-N-acetylgalactosaminidase and α-galactosidase was not decreased drastically when they were kept in PCS Buffer in 4°C. The optimal reaction buffer composed of glycine 250 mM and NaCl 3 mM, pH 6.8 and PCS less than 10%(v/v). For converting A(1)B to O RBCs completely, the doses of α-N-acetylgalactosaminidase and α-galactosidase were confirmed as 0.015 mg/ml packed RBCs(pRBCs) for A(1) antigen epitopes and 0.005 mg/ml pRBCs for B epitopes. Approximately 0.004 mg α-N-acetylgalactosaminidase and 0.005 mg α-galactosidase were required to convert 1 ml pRBCs. Our studies indicated that α-N-acetylgalactosaminidase and α-galactosidase were stable in PCS buffer and a modified protocol which was propitious to converting AB to O RBCs was provided.

Forkhead Box Transcription Factors of the FOXA Class Are Required for Basal Transcription of Angiotensin-Converting Enzyme 2

PubMed Central

Pedersen, Kim Brint; Chodavarapu, Harshita

2017-01-01

Angiotensin-converting enzyme 2 (ACE2) has protective effects on a wide range of morbidities associated with elevated angiotensin-II signaling. Most tissues, including pancreatic islets, express ACE2 mainly from the proximal promoter region. We previously found that hepatocyte nuclear factors 1α and 1β stimulate ACE2 expression from three highly conserved hepatocyte nuclear factor 1 binding motifs in the proximal promoter region. We hypothesized that other highly conserved motifs would also affect ACE2 expression. By systematic mutation of conserved elements, we identified five regions affecting ACE2 expression, of which two regions bound transcriptional activators. One of these is a functional FOXA binding motif. We further identified the main protein binding the FOXA motif in 832/13 insulinoma cells as well as in mouse pancreatic islets as FOXA2. PMID:29082356

Enzymology of the Wood–Ljungdahl Pathway of Acetogenesis

PubMed Central

Ragsdale, Stephen W.

2011-01-01

The biochemistry of acetogenesis is reviewed. The microbes that catalyze the reactions that are central to acetogenesis are described and the focus is on the enzymology of the process. These microbes play a key role in the global carbon cycle, producing over 10 trillion kilograms of acetic acid annually. Acetogens have the ability to anaerobically convert carbon dioxide and CO into acetyl-CoA by the Wood–Ljungdahl pathway, which is linked to energy conservation. They also can convert the six carbons of glucose stoichiometrically into 3 mol of acetate using this pathway. Acetogens and other anaerobic microbes (e.g., sulfate reducers and methanogens) use the Wood–Ljungdahl pathway for cell carbon synthesis. Important enzymes in this pathway that are covered in this review are pyruvate ferredoxin oxidoreductase, CO dehydrogenase/acetyl-CoA synthase, a corrinoid iron-sulfur protein, a methyltransferase, and the enzymes involved in the conversion of carbon dioxide to methyl-tetrahydrofolate. PMID:18378591

Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated?

PubMed

Paitz, Ryan T; Duffield, Kristin R; Bowden, Rachel M

2017-12-15

All vertebrate embryos are exposed to maternally derived steroids during development. In placental vertebrates, metabolism of maternal steroids by the placenta modulates embryonic exposure, but how exposure is regulated in oviparous vertebrates is less clear. Recent work in oviparous vertebrates has demonstrated that steroids are not static molecules, as they can be converted to more polar steroid sulfates by sulfotransferase enzymes. Importantly, these steroid sulfates can be converted back to the parent compound by the enzyme steroid sulfatase (STS). We investigated when and where STS was present during embryonic development in the red-eared slider turtle, Trachemys scripta We report that STS is present during all stages of development and in all tissues we examined. We conclude that STS activity may be particularly important for regulating maternal steroid exposure in oviparous vertebrates. © 2017. Published by The Company of Biologists Ltd.

Bacterial species involved in the conversion of dietary flavonoids in the human gut.

PubMed

Braune, Annett; Blaut, Michael

2016-05-03

The gut microbiota plays a crucial role in the conversion of dietary flavonoids and thereby affects their health-promoting effects in the human host. The identification of the bacteria involved in intestinal flavonoid conversion has gained increasing interest. This review summarizes available information on the so far identified human intestinal flavonoid-converting bacterial species and strains as well as their enzymes catalyzing the underlying reactions. The majority of described species involved in flavonoid transformation are capable of carrying out the O-deglycosylation of flavonoids. Other bacteria cleave the less common flavonoid-C-glucosides and/or further degrade the aglycones of flavonols, flavanonols, flavones, flavanones, dihydrochalcones, isoflavones and monomeric flavan-3-ols. To increase the currently limited knowledge in this field, identification of flavonoid-converting bacteria should be continued using culture-dependent screening or isolation procedures and molecular approaches based on sequence information of the involved enzymes.

Angiotensin-converting enzyme (ACE) alleles in the Quechua, a high altitude South American native population.

PubMed

Rupert, J L; Devine, D V; Monsalve, M V; Hochachka, P W

1999-01-01

Recently it was reported that an allelic variant of the gene encoding angiotensin-converting enzyme (ACE) was significantly over-represented in a cohort of elite British mountaineers. It was proposed that this may be evidence for a specific genetic factor influencing the human capacity for physical performance. The implication that this allele could enhance performance at high altitude prompted us to determine its frequency in Quechua speaking natives living at altitudes greater than 3000m on the Andean Altiplano in South America. We found that the frequency of the putative performance allele in the Quechuas, although significantly higher than in Caucasians, was not different from lowland Native American populations. This observation suggests that, although the higher frequency of the 'performance allele' may have facilitated the migration of the ancestral Quechua to the highlands, the ACE insertion allele has not been subsequently selected for in this high altitude population.

An Iterative, Bimodular Nonribosomal Peptide Synthetase that Converts Anthranilate and Tryptophan into Tetracyclic Asperlicins

PubMed Central

Gao, Xue; Jiang, Wei; Jiménez-Osés, Gonzalo; Choi, Moon Seok; Houk, Kendall N.; Tang, Yi; Walsh, Christopher T.

2013-01-01

The bimodular 276 kDa nonribosomal peptide synthetase AspA from Aspergillus alliaceus, heterologously expressed in Saccharomyces cerevisiae, converts tryptophan and two molecules of the aromatic β-amino acid anthranilate (Ant) into a pair of tetracyclic peptidyl alkaloids asperlicin C and D in a ratio of 10:1. The first module of AspA activates and processes two molecules of Ant iteratively to generate a tethered Ant-Ant-Trp-S-enzyme intermediate on module two. Release is postulated to involve tandem cyclizations, in which the first step is the macrocyclization of the linear tripeptidyl-S-enzyme, by the terminal condensation (CT) domain to generate the regioisomeric tetracyclic asperlicin scaffolds. Computational analysis of the transannular cyclization of the 11-membered macrocyclic intermediate shows that asperlicin C is the kinetically favored product due to the high stability of a conformation resembling the transition state for cyclization, while asperlicin D is thermodynamically more stable. PMID:23890005

Angiotensin-I-Converting Enzyme (ACE)-Inhibitory Peptides from Plants

PubMed Central

Daskaya-Dikmen, Ceren; Yucetepe, Aysun; Karbancioglu-Guler, Funda; Daskaya, Hayrettin; Ozcelik, Beraat

2017-01-01

Hypertension is an important factor in cardiovascular diseases. Angiotensin-I-converting enzyme (ACE) inhibitors like synthetic drugs are widely used to control hypertension. ACE-inhibitory peptides from food origins could be a good alternative to synthetic drugs. A number of plant-based peptides have been investigated for their potential ACE inhibitor activities by using in vitro and in vivo assays. These plant-based peptides can be obtained by solvent extraction, enzymatic hydrolysis with or without novel food processing methods, and fermentation. ACE-inhibitory activities of peptides can be affected by their structural characteristics such as chain length, composition and sequence. ACE-inhibitory peptides should have gastrointestinal stability and reach the cardiovascular system to show their bioactivity. This paper reviews the current literature on plant-derived ACE-inhibitory peptides including their sources, production and structure, as well as their activity by in vitro and in vivo studies and their bioavailability. PMID:28333109

Characterization of a Flavoprotein Oxidase from Opium Poppy Catalyzing the Final Steps in Sanguinarine and Papaverine Biosynthesis*

PubMed Central

Hagel, Jillian M.; Beaudoin, Guillaume A. W.; Fossati, Elena; Ekins, Andrew; Martin, Vincent J. J.; Facchini, Peter J.

2012-01-01

Benzylisoquinoline alkaloids are a diverse class of plant specialized metabolites that includes the analgesic morphine, the antimicrobials sanguinarine and berberine, and the vasodilator papaverine. The two-electron oxidation of dihydrosanguinarine catalyzed by dihydrobenzophenanthridine oxidase (DBOX) is the final step in sanguinarine biosynthesis. The formation of the fully conjugated ring system in sanguinarine is similar to the four-electron oxidations of (S)-canadine to berberine and (S)-tetrahydropapaverine to papaverine. We report the isolation and functional characterization of an opium poppy (Papaver somniferum) cDNA encoding DBOX, a flavoprotein oxidase with homology to (S)-tetrahydroprotoberberine oxidase and the berberine bridge enzyme. A query of translated opium poppy stem transcriptome databases using berberine bridge enzyme yielded several candidate genes, including an (S)-tetrahydroprotoberberine oxidase-like sequence selected for heterologous expression in Pichia pastoris. The recombinant enzyme preferentially catalyzed the oxidation of dihydrosanguinarine to sanguinarine but also converted (RS)-tetrahydropapaverine to papaverine and several protoberberine alkaloids to oxidized forms, including (RS)-canadine to berberine. The Km values of 201 and 146 μm for dihydrosanguinarine and the protoberberine alkaloid (S)-scoulerine, respectively, suggested high concentrations of these substrates in the plant. Virus-induced gene silencing to reduce DBOX transcript levels resulted in a corresponding reduction in sanguinarine, dihydrosanguinarine, and papaverine accumulation in opium poppy roots in support of DBOX as a multifunctional oxidative enzyme in BIA metabolism. PMID:23118227

Regulation of NlE74A on vitellogenin might be mediated by angiotensin converting enzyme through a fecundity-related SNP in the brown planthopper, Nilaparvata lugens.

PubMed

Sun, Zhongxiang; Shi, Qi; Xu, Cuicui; Wang, Rumeng; Wang, Huanhuan; Song, Yuanyuan; Zeng, Rensen

2018-06-19

The major yolk protein precursors (YPP) gene, vitellogenin (Vg), usually considered as a reproductive indicator and molecular marker for evaluating insect fecundity, is controlled by insect hormone (mainly ecdysteroids and juvenile hormone), transcription factors and many other fecundity-related genes. To better understand the underlying molecular regulation mechanisms of the NlVg in the brown planthopper Nilaparvata lugens (N. lugens), the correlation between one early ecdysone response gene E74 and one important fecundity-related gene angiotensin converting enzyme (ACE) on the regulation of Vg gene expression, was investigated. We first showed that the mRNA expression level of NlACE were significantly higher in a high-fecundity population (HFP) than a low-fecundity population (LFP) at different development stages, and knockdown of NlACE expression by RNA interference (RNAi) results in a reduced level of NlVg expression and N. lugens fecundity. Subsequently, we analyzed the promoter of NlACE and found an E74A binding site, which was also differentially expressed in HFP and LFP. Then a gene putatively encoding E74A, namely NlE74A, predominant in the ovary and fat body was cloned and characterized. Furthermore, the developmental profile during female adult and the tissue-specific expression pattern of NlACE and NlE74A were similar to the expression pattern of NlVg gene, implying that both NlACE and NlE74A may be involved in regulating the expression of NlVg. Finally, after injecting the dsRNA of NlE74A, the NlACE expression levels were significantly reduced simultaneously at 24 h and 48 h post-injection, and the NlVg expression level was significant reduced at 24 h post-injection and the downswing was more significant at 48 h post-injection. These results imply that regulation of NlE74A on NlVg transcription might be mediated by NlACE through the E74 binding site at the NlACE promoter region in N. lugens. Copyright © 2018. Published by Elsevier Inc.

Physiological and biochemical effect of neem and other Meliaceae plants secondary metabolites against Lepidopteran insects

PubMed Central

Senthil-Nathan, Sengottayan

2013-01-01

This review described the physiological and biochemical effects of various secondary metabolites from Meliaceae against major Lepidopteran insect pest including, Noctuidae and Pyralidae. The biochemical effect of major Meliaceae secondary metabolites were discussed more in this review. Several enzymes based on food materials have critical roles in nutritional indices (food utilization) of the insect pest population. Several research work has been referred and the effect of Meliaceae secondary metabolites on feeding parameters of insects by demonstrating food consumption, approximate digestibility of consumed food, efficiency of converting the ingested food to body substance, efficiency of converting digested food to body substance and consumption index was reviewed in detail. Further how the digestive enzymes including a-Amylases, α and β-glucosidases (EC 3.2.1.1), lipases (EC 3.1.1) Proteases, serine, cysteine, and aspartic proteinases affected by the Meliaceae secondary metabolites was reviewed. Further effect of Meliaceae secondary metabolites on detoxifying enzymes have been found to react against botanical insecticides including general esterases (EST), glutathione S-transferase (GST) and phosphatases was reviewed. Alkaline phosphatase (ALP, E.C.3.1.3.1) and acid phosphatase (ACP, E.C.3.1.3.2) are hydrolytic enzymes, which hydrolyze phosphomonoesters under alkaline or acid conditions, respectively. These enzymes were affected by the secondary metabolites treatment. The detailed mechanism of action was further explained in this review. Acethylcholine esterase (AChE) is a key enzyme that terminates nerve impulses by catalyzing the hydrolysis of neurotransmitter, acetylcholine, in the nervous system of various organisms. How the AChE activity was altered by the Meliaceae secondary metabolites reviewed in detail. PMID:24391591

Metabolism of β-valine via a CoA-dependent ammonia lyase pathway.

PubMed

Otzen, Marleen; Crismaru, Ciprian G; Postema, Christiaan P; Wijma, Hein J; Heberling, Matthew M; Szymanski, Wiktor; de Wildeman, Stefaan; Janssen, Dick B

2015-11-01

Pseudomonas species strain SBV1 can rapidly grow on medium containing β-valine as a sole nitrogen source. The tertiary amine feature of β-valine prevents direct deamination reactions catalyzed by aminotransferases, amino acid dehydrogenases, and amino acid oxidases. However, lyase- or aminomutase-mediated conversions would be possible. To identify enzymes involved in the degradation of β-valine, a PsSBV1 gene library was prepared and used to complement the β-valine growth deficiency of a closely related Pseudomonas strain. This resulted in the identification of a gene encoding β-valinyl-coenzyme A ligase (BvaA) and two genes encoding β-valinyl-CoA ammonia lyases (BvaB1 and BvaB2). The BvaA protein demonstrated high sequence identity to several known phenylacetate CoA ligases. Purified BvaA enzyme did not convert phenyl acetic acid but was able to activate β-valine in an adenosine triphosphate (ATP)- and CoA-dependent manner. The substrate range of the enzyme appears to be narrow, converting only β-valine and to a lesser extent, 3-aminobutyrate and β-alanine. Characterization of BvaB1 and BvaB2 revealed that both enzymes were able to deaminate β-valinyl-CoA to produce 3-methylcrotonyl-CoA, a common intermediate in the leucine degradation pathway. Interestingly, BvaB1 and BvaB2 demonstrated no significant sequence identity to known CoA-dependent ammonia lyases, suggesting they belong to a new family of enzymes. BLAST searches revealed that BvaB1 and BvaB2 show high sequence identity to each other and to several enoyl-CoA hydratases, a class of enzymes that catalyze a similar reaction with water instead of amine as the leaving group.

Astaxanthin modulates osteopontin and transforming growth factor β1 expression levels in a rat model of nephrolithiasis: a comparison with citrate administration.

PubMed

Alex, Manju; Sauganth Paul, M V; Abhilash, M; Mathews, Varghese V; Anilkumar, T V; Nair, R Harikumaran

2014-09-01

To evaluate the effect of astaxanthin on renal angiotensin-I converting enzyme (ACE) levels, osteopontin (OPN) and transforming growth factor β1 (TGF-β1) expressions and the extent of crystal deposition in experimentally induced calcium oxalate kidney stone disease in a male Wistar rat model. To compare the efficacy of astaxanthin treatment with a currently used treatment strategy (citrate administration) for kidney stones. The expression of OPN was assessed by immunohistochemistry. One step reverse transcriptase polymerase chain reaction followed by densitometry was used to assess renal OPN and TGF-β1 levels. Renal ACE levels were quantified by an enzyme-linked immunosorbent assay method. Crystal deposition in kidney was analysed by scanning electron microscopic (SEM)-energy-dispersive X-ray (EDX). The renal ACE levels and the expression of OPN and TGF-β1 were upregulated in the nephrolithiasis-induced rats. Astaxanthin treatment reduced renal ACE levels and the expression OPN and TGF-β1. SEM-EDX analysis showed that crystal deposition was reduced in the astaxanthin-treated nephrolithiatic group. Astaxanthin treatment was more effective than citrate administration in the regulation of renal ACE levels, OPN and TGF-β1 expressions. Astaxanthin administration reduced renal calcium oxalate crystal deposition possibly by modulating the renal renin-angiotensin system (RAS), which reduced the expression of OPN and TGF-β1 levels. Astaxanthin administration was more effective than citrate treatment in reducing crystal deposition and down-regulating the expression of OPN and TGF-β1. © 2013 The Authors. BJU International © 2013 BJU International.

Characteristic Variations and Similarities in Biochemical, Molecular, and Functional Properties of Glyoxalases across Prokaryotes and Eukaryotes

PubMed Central

Kaur, Charanpreet; Sharma, Shweta; Hasan, Mohammad Rokebul; Pareek, Ashwani; Singla-Pareek, Sneh L.; Sopory, Sudhir K.

2017-01-01

The glyoxalase system is the ubiquitous pathway for the detoxification of methylglyoxal (MG) in the biological systems. It comprises two enzymes, glyoxalase I (GLYI) and glyoxalase II (GLYII), which act sequentially to convert MG into d-lactate, thereby helping living systems get rid of this otherwise cytotoxic byproduct of metabolism. In addition, a glutathione-independent GLYIII enzyme activity also exists in the biological systems that can directly convert MG to d-lactate. Humans and Escherichia coli possess a single copy of GLYI (encoding either the Ni- or Zn-dependent form) and GLYII genes, which through MG detoxification provide protection against various pathological and disease conditions. By contrast, the plant genome possesses multiple GLYI and GLYII genes with a role in abiotic stress tolerance. Plants possess both Ni2+- and Zn2+-dependent forms of GLYI, and studies on plant glyoxalases reveal the various unique features of these enzymes distinguishing them from prokaryotic and other eukaryotic glyoxalases. Through this review, we provide an overview of the plant glyoxalase family along with a comparative analysis of glyoxalases across various species, highlighting similarities as well as differences in the biochemical, molecular, and physiological properties of these enzymes. We believe that the evolution of multiple glyoxalases isoforms in plants is an important component of their robust defense strategies. PMID:28358304

Short communication: Effect of casein haplotype on angiotensin-converting enzyme inhibitory and antioxidant capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes.

PubMed

Perna, Annamaria; Simonetti, Amalia; Gambacorta, Emilio

2016-09-01

The aim of this work was to investigate the effect of casein haplotype (αS1, β, and κ) on antioxidative and angiotensin-converting enzyme (ACE) inhibitory capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes. The antioxidant capacity was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power assays, whereas ACE inhibition was determined by ACE-inhibitory assay. The ACE-inhibitory and antioxidant capacities of milk casein increased during in vitro gastrointestinal digestion. Casein haplotype significantly influenced the antioxidative and ACE-inhibitory capacities of digested casein. In particular, BB-A(2)A(1)-AA casein and BB-A(1)A(1)-AA casein showed the highest ACE-inhibitory capacity, BB-A(2)A(2)-AA casein showed the highest antioxidant capacity, whereas BB-A(2)A(2)-BB casein showed the lowest biological capacity. To date, few studies have been done on the effect of casein haplotype on biological capacity of milk casein, thus the present study sets the basis for a new knowledge that could lead to the production of milk with better nutraceutical properties. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Enzymes processing somatostatin precursors: an Arg-Lys esteropeptidase from the rat brain cortex converting somatostatin-28 into somatostatin-14.

PubMed Central

Gluschankof, P; Morel, A; Gomez, S; Nicolas, P; Fahy, C; Cohen, P

1984-01-01

The post-translational proteolytic conversion of somatostatin-14 precursors was studied to characterize the enzyme system responsible for the production of the tetradecapeptide either from its 15-kDa precursor protein or from its COOH-terminal fragment, somatostatin-28. A synthetic undecapeptide Pro-Arg-Glu-Arg-Lys-Ala-Gly-Ala-Lys-Asn-Tyr(NH2), homologous to the amino acid sequence of the octacosapeptide at the putative Arg-Lys cleavage locus, was used as substrate, after 125I labeling on the COOH-terminal tyrosine residue. A 90-kDa proteolytic activity was detected in rat brain cortex extracts after molecular sieve fractionation followed by ion exchange chromatography. The protease released the peptide 125I-Ala-Gly-Ala-Lys-Asn-Tyr(NH2) from the synthetic undecapeptide substrate and converted somatostatin-28 into somatostatin-14 under similar conditions (pH 7.0). Under these experimental conditions, the product tetradecapeptide was not further degraded by the enzyme. In contrast, the purified 15-kDa hypothalamic precursor remained unaffected when exposed to the proteolytic enzyme under identical conditions. It is concluded that this Arg-Lys esteropeptidase from the brain cortex may be involved in the in vivo processing of the somatostatin-28 fragment of prosomatostatin into somatostatin-14, the former species being an obligatory intermediate in a two-step proteolytic mechanism leading to somatostatin-14. PMID:6149550

Effects of curcumin on angiotensin-converting enzyme gene expression, oxidative stress and anti-oxidant status in thioacetamide-induced hepatotoxicity.

PubMed

Fazal, Yumna; Fatima, Syeda Nuzhat; Shahid, Syed Muhammad; Mahboob, Tabassum

2015-12-01

This study aimed to evaluate the protective effects of curcumin on angiotensin-converting enzyme (ACE) gene expression, oxidative stress and anti-oxidant status in thioacetamide (TAA)-induced hepatotoxicity in rats. Total 32 albino Wistar rats (male, 200-250 g) were divided into six groups (n=8). Group 1: untreated controls; Group 2: received TAA (200 mg/kg body weight (b.w.); i.p.) for 12 weeks; Group 3: received curcumin (75 mg/kg b.w.) for 24 weeks; Group 4: received TAA (200 mg/kg b.w.; i.p.) for 12 weeks+curcumin (75 mg/kg b.w.) for 12 weeks. A significantly higher ACE gene expression was observed in TAA-induced groups as compared with control, indicating more synthesis of ACE proteins. Treatment with curcumin suppressed ACE expression in TAA liver and reversed the toxicity produced. TAA treatment results in higher lipid peroxidation and lower GSH, SOD and CAT than the normal, and this produces oxidative stress in the liver. Cirrhotic conditions were confirmed by serum enzymes (ALT, AST and ALP) as well as histopathological observations. Curcumin treatment reduced oxidative stress in animals by scavenging reactive oxygen species, protecting the anti-oxidant enzymes from being denatured and reducing the oxidative stress marker lipid peroxidation. Curcumin treatment restores hepatocytes, damaged by TAA, and protects liver tissue approaching cirrhosis. © The Author(s) 2014.

STRUCTURAL CHARACTERISTICS AND ANTIHYPERTENSIVE EFFECTS OF ANGIOTENSIN-I-CONVERTING ENZYME INHIBITORY PEPTIDES IN THE RENIN-ANGIOTENSIN AND KALLIKREIN KININ SYSTEMS

PubMed Central

Manoharan, Sivananthan; Shuib, Adawiyah Suriza; Abdullah, Noorlidah

2017-01-01

Background: The commercially available synthetic angiotensin-I-converting enzyme (ACE) inhibitors are known to exert negative side effects which have driven many research groups globally to discover the novel ACE inhibitors. Method: Literature search was performed within the PubMed, ScienceDirect.com and Google Scholar. Results: The presence of proline at the C-terminal tripeptide of ACE inhibitor can competitively inhibit the ACE activity. The effects of other amino acids are less studied leading to difficulties in predicting potent peptide sequences. The broad specificity of the enzyme may be due to the dual active sites observed on the somatic ACE. The inhibitors may not necessarily competitively inhibit the enzyme which explains why some reported inhibitors do not have the common ACE inhibitor characteristics. Finally, the in vivo assay has to be carried out before the peptides as the antihypertensive agents can be claimed. The peptides must be absorbed into circulation without being degraded, which will affect their bioavailability and potency. Thus, peptides with strong in vitro IC50 values do not necessarily have the same effect in vivo and vice versa. Conclusion: The relationship between peptide amino acid sequence and inhibitory activity, in vivo studies of the active peptides and bioavailability must be studied before the peptides as antihypertensive agents can be claimed. PMID:28573254

3D-quantitative structure-activity relationship studies on benzothiadiazepine hydroxamates as inhibitors of tumor necrosis factor-alpha converting enzyme.

PubMed

Murumkar, Prashant R; Giridhar, Rajani; Yadav, Mange Ram

2008-04-01

A set of 29 benzothiadiazepine hydroxamates having selective tumor necrosis factor-alpha converting enzyme inhibitory activity were used to compare the quality and predictive power of 3D-quantitative structure-activity relationship, comparative molecular field analysis, and comparative molecular similarity indices models for the atom-based, centroid/atom-based, data-based, and docked conformer-based alignment. Removal of two outliers from the initial training set of molecules improved the predictivity of models. Among the 3D-quantitative structure-activity relationship models developed using the above four alignments, the database alignment provided the optimal predictive comparative molecular field analysis model for the training set with cross-validated r(2) (q(2)) = 0.510, non-cross-validated r(2) = 0.972, standard error of estimates (s) = 0.098, and F = 215.44 and the optimal comparative molecular similarity indices model with cross-validated r(2) (q(2)) = 0.556, non-cross-validated r(2) = 0.946, standard error of estimates (s) = 0.163, and F = 99.785. These models also showed the best test set prediction for six compounds with predictive r(2) values of 0.460 and 0.535, respectively. The contour maps obtained from 3D-quantitative structure-activity relationship studies were appraised for activity trends for the molecules analyzed. The comparative molecular similarity indices models exhibited good external predictivity as compared with that of comparative molecular field analysis models. The data generated from the present study helped us to further design and report some novel and potent tumor necrosis factor-alpha converting enzyme inhibitors.

Evaluation of subacute change in RAAS activity (as indicated by urinary aldosterone:creatinine, after pharmacologic provocation) and the response to ACE inhibition

PubMed Central

Ames, Marisa K; Atkins, Clarke E; Lantis, Andrea C; zum Brunnen, James

2016-01-01

Objective: The objective of this study was to evaluate subacute changes in renin–angiotensin–aldosterone system (RAAS) activity during angiotensin-converting enzyme inhibitor (ACEI) therapy in dogs with experimental RAAS activation. Methods: Analysis of data (urine aldosterone:creatinine ratio (UAldo:C) and serum angiotensin-converting enzyme activity), in 31 healthy dogs with furosemide or amlodipine-activated RAAS that received an ACEI. When furosemide or amlodipine activation of RAAS preceded ACEI administration, incomplete RAAS blockade (IRB) was defined as a UAldo:C greater than (a) the dog’s ‘activated’ baseline value or (b) a population-derived cut-off value (mean + 2 SD (>1.0 μg/g) of pretreatment UAldo:C from our population of research dogs). In studies where RAAS activation occurred concurrently with ACEIs, IRB was defined as (a) a UAldo:C greater than either twofold the dog’s prestimulation baseline value or (b) 1.0 µg/g. Dogs were followed for 7–17 days. Results: Serum angiotensin-converting enzyme activity was measured in 19 dogs and was significantly reduced (P<0.0001) after ACEI administration. The overall incidence of IRB, when RAAS activation preceded ACEI administration, was 33% and 8% for definitions (a) and (b), respectively. The overall incidence of IRB, when ACEIs were concurrent with RAAS activation, was 65% and 61% for definitions (a) and (b), respectively. Conclusion: Increases in UAldo:C, despite ACEI administration, is evidence of IRB in this subacute model of experimental RAAS activation and suppression. PMID:27009288

In vitro autoradiographic localization of angiotensin-converting enzyme in sarcoid lymph nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, R.K.; Chai, S.Y.; Dunbar, M.S.

1986-09-01

Angiotensin-converting enzyme (ACE) was localized in sarcoid lymph nodes by an in vitro autoradiographic technique using a synthetic ACE inhibitor of high affinity, /sup 125/I-labelled 351A. The lymph nodes were from seven patients with active sarcoidosis who underwent mediastinoscopy and from six control subjects who had nodes resected at either mediastinoscopy or laparotomy. Angiotensin-converting enzyme was localized in the epithelioid cells of sarcoid granulomata in markedly increased amounts compared with control nodes, where it was restricted to vessels and some histiocytes. In sarcoid lymph nodes, there was little ACE present in lymphocytes or fibrous tissue. Sarcoid nodes with considerable fibrosismore » had much less intense ACE activity than the nonfibrotic nodes. The specific activity of ACE measured by an enzymatic assay in both the control and sarcoid lymph nodes closely reflected the ACE activity demonstrated by autoradiography. Sarcoid lymph nodes with fibrosis had an ACE specific activity of half that of nonfibrotic nodes (p less than 0.05). There was a 15-fold increase in specific ACE activity in sarcoid nodes (p less than 0.05) compared to normal. Serum ACE was significantly higher in those sarcoid patients whose lymph nodes were not fibrosed compared with those with fibrosis (p less than 0.01). This technique offers many advantages over the use of polyclonal antibodies. The 351A is a highly specific ACE inhibitor, chemically defined and in limitless supply. This method enables the quantitation of results, and autoradiographs may be stored indefinitely for later comparison.« less

Limonoate dehydrogenase from Arthrobacter globiformis: the native enzyme and its N-terminal sequence.

PubMed

Suhayda, C G; Omura, M; Hasegawa, S

1995-09-01

Bitter limonoids in citrus juice lower the quality and value of commercial juices. Limonoate dehydrogenase converts the precursor of bitter limonin, limonoate A-ring lactone, to nonbitter 17-dehydrolimonoate A-ring lactone. This enzyme was isolated from Arthrobacter globiformis cells by a combination of ammonium sulfate fractionation, Cibacron Blue affinity chromatography and DEAE ion exchange HPLC. Using this protocol a 428-fold purification of the enzyme was obtained. Gel filtration HPLC indicated a M(r) of 118,000 for the native enzyme. SDS-PAGE indicated an individual subunit M(r) of 31,000. N-Terminal sequencing of the protein provided a sequence of the first 16 amino acid residues. Since LDH activity in citrus is very low, cloning the gene for this bacterial enzyme into citrus trees should enhance the natural debittering mechanism in citrus fruit.

Antihypertensive effects of continuous oral administration of nattokinase and its fragments in spontaneously hypertensive rats.

PubMed

Fujita, Mitsugu; Ohnishi, Katsunori; Takaoka, Shinsaku; Ogasawara, Kazuya; Fukuyama, Ryo; Nakamuta, Hiromichi

2011-01-01

To determine whether the antihypertensive effect of nattokinase is associated with the protease activity of this enzyme, we compared nattokinase with the fragments derived from nattokinase, which possessed no protease activity, in terms of the effect on hypertension in spontaneously hypertensive rats (SHR). In the continuous oral administration test, the groups were given a basic diet alone (control), the basic diet containing nattokinase (0.2, 2.6 mg/g diet) or the basic diet containing the fragments derived from nattokinase (0.2, 0.6 mg/g diet). The group fed the basic diet containing high-dosage nattokinase (2.6 mg/g diet) showed significant reductions in systolic blood pressure (SBP), diastolic blood pressure (DBP) and plasma fibrinogen level, compared with control group and no influence on activities of renin and angiotensin-converting enzyme (ACE, EC 3.4.15.1), and plasma angiotensin II level in the renin-angiotensin system. The treatment of the basic diet containing high-dosage fragments (0.6 mg/g diet) significantly decreased SBP, DBP and plasma angiotensin II level in plasma but the treatment did not influence on plasma fibrinogen level. These results suggest that nattokinase and its fragments are different from each other in the mechanism to reduce hypertension. Nattokinase, retained its protease activity after absorbance across the intestines, may decrease blood pressure through cleavage of fibrinogen in plasma. The fragments, which absorbed as nattokinase-degradation products, prevents the elevation of plasma angiotensin II level to suppress hypertension.

Ornithine Decarboxylase, Polyamines, and Pyrrolizidine Alkaloids in Senecio and Crotalaria

PubMed Central

Birecka, Helena; Birecki, Mieczyslaw; Cohen, Eric J.; Bitonti, Alan J.; McCann, Peter P.

1988-01-01

When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high relative to that of ornithine decarboxylase. Unlike Heliotropium angiospermum and Heliotropium indicum, in which endogenous arginine was the only detectable precursor of putrescine channeled into pyrrolizidines, in the species studied here—using difluoromethylornithine and difluoromethylarginine as the enzyme inhibitors—endogenous ornithine was the main if not the only precursor of putrescine converted into the alkaloid aminoalcohol moiety. In S. riddellii and C. retusa at flowering, ornithine decarboxylase activity was present mainly in leaves, especially the young ones. However, other very young organs such as inflorescence and growing roots exhibited much lower or very low activities; the enzyme activity in stems was negligible. There was no correlation between the enzyme activity and polyamine or alkaloid content in either species. In both species only free polyamines were detected except for C. retusa roots and inflorescence—with relatively very high levels of these compounds—in which conjugated putrescine, spermidine, and spermine were also found; agmatine was not identified by HPLC in any plant organ except for C. retusa roots with rhizobial nodules. Organ- or age-dependent differences in the polyamine levels were small or insignificant. The highest alkaloid contents were found in young leaves and inflorescence. PMID:16665870

Ornithine decarboxylase, polyamines, and pyrrolizidine alkaloids in senecio and crotalaria.

PubMed

Birecka, H; Birecki, M; Cohen, E J; Bitonti, A J; McCann, P P

1988-01-01

When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high relative to that of ornithine decarboxylase. Unlike Heliotropium angiospermum and Heliotropium indicum, in which endogenous arginine was the only detectable precursor of putrescine channeled into pyrrolizidines, in the species studied here-using difluoromethylornithine and difluoromethylarginine as the enzyme inhibitors-endogenous ornithine was the main if not the only precursor of putrescine converted into the alkaloid aminoalcohol moiety. In S. riddellii and C. retusa at flowering, ornithine decarboxylase activity was present mainly in leaves, especially the young ones. However, other very young organs such as inflorescence and growing roots exhibited much lower or very low activities; the enzyme activity in stems was negligible. There was no correlation between the enzyme activity and polyamine or alkaloid content in either species. In both species only free polyamines were detected except for C. retusa roots and inflorescence-with relatively very high levels of these compounds-in which conjugated putrescine, spermidine, and spermine were also found; agmatine was not identified by HPLC in any plant organ except for C. retusa roots with rhizobial nodules. Organ- or age-dependent differences in the polyamine levels were small or insignificant. The highest alkaloid contents were found in young leaves and inflorescence.

The endothelin system has a significant role in the pathogenesis and progression of Mycobacterium tuberculosis infection.

PubMed

Correa, Andre F; Bailão, Alexandre M; Bastos, Izabela M D; Orme, Ian M; Soares, Célia M A; Kipnis, Andre; Santana, Jaime M; Junqueira-Kipnis, Ana Paula

2014-12-01

Tuberculosis (TB) remains a major global health problem, and although multiple studies have addressed the relationship between Mycobacterium tuberculosis and the host on an immunological level, few studies have addressed the impact of host physiological responses. Proteases produced by bacteria have been associated with important alterations in the host tissues, and a limited number of these enzymes have been characterized in mycobacterial species. M. tuberculosis produces a protease called Zmp1, which appears to be associated with virulence and has a putative action as an endothelin-converting enzyme. Endothelins are a family of vasoactive peptides, of which 3 distinct isoforms exist, and endothelin 1 (ET-1) is the most abundant and the best-characterized isoform. The aim of this work was to characterize the Zmp1 protease and evaluate its role in pathogenicity. Here, we have shown that M. tuberculosis produces and secretes an enzyme with ET-1 cleavage activity. These data demonstrate a possible role of Zmp1 for mycobacterium-host interactions and highlights its potential as a drug target. Moreover, the results suggest that endothelin pathways have a role in the pathogenesis of M. tuberculosis infections, and ETA or ETB receptor signaling can modulate the host response to the infection. We hypothesize that a balance between Zmp1 control of ET-1 levels and ETA/ETB signaling can allow M. tuberculosis adaptation and survival in the lung tissues. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Altered Expression of Ganglioside Metabolizing Enzymes Results in GM3 Ganglioside Accumulation in Cerebellar Cells of a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis.

PubMed

Somogyi, Aleksandra; Petcherski, Anton; Beckert, Benedikt; Huebecker, Mylene; Priestman, David A; Banning, Antje; Cotman, Susan L; Platt, Frances M; Ruonala, Mika O; Tikkanen, Ritva

2018-02-22

Juvenile neuronal ceroid lipofuscinosis (JNCL) is caused by mutations in the CLN3 gene. Most JNCL patients exhibit a 1.02 kb genomic deletion removing exons 7 and 8 of this gene, which results in a truncated CLN3 protein carrying an aberrant C-terminus. A genetically accurate mouse model ( Cln3 Δex7/8 mice) for this deletion has been generated. Using cerebellar precursor cell lines generated from wildtype and Cln3 Δex7/8 mice, we have here analyzed the consequences of the CLN3 deletion on levels of cellular gangliosides, particularly GM3, GM2, GM1a and GD1a. The levels of GM1a and GD1a were found to be significantly reduced by both biochemical and cytochemical methods. However, quantitative high-performance liquid chromatography analysis revealed a highly significant increase in GM3, suggesting a metabolic blockade in the conversion of GM3 to more complex gangliosides. Quantitative real-time PCR analysis revealed a significant reduction in the transcripts of the interconverting enzymes, especially of β-1,4- N -acetyl-galactosaminyl transferase 1 (GM2 synthase), which is the enzyme converting GM3 to GM2. Thus, our data suggest that the complex a-series gangliosides are reduced in Cln3 Δex7/8 mouse cerebellar precursor cells due to impaired transcription of the genes responsible for their synthesis.

Altered Expression of Ganglioside Metabolizing Enzymes Results in GM3 Ganglioside Accumulation in Cerebellar Cells of a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis

PubMed Central

Somogyi, Aleksandra; Petcherski, Anton; Beckert, Benedikt; Huebecker, Mylene; Priestman, David A.; Banning, Antje; Cotman, Susan L.; Platt, Frances M.; Ruonala, Mika O.

2018-01-01

Juvenile neuronal ceroid lipofuscinosis (JNCL) is caused by mutations in the CLN3 gene. Most JNCL patients exhibit a 1.02 kb genomic deletion removing exons 7 and 8 of this gene, which results in a truncated CLN3 protein carrying an aberrant C-terminus. A genetically accurate mouse model (Cln3Δex7/8 mice) for this deletion has been generated. Using cerebellar precursor cell lines generated from wildtype and Cln3Δex7/8 mice, we have here analyzed the consequences of the CLN3 deletion on levels of cellular gangliosides, particularly GM3, GM2, GM1a and GD1a. The levels of GM1a and GD1a were found to be significantly reduced by both biochemical and cytochemical methods. However, quantitative high-performance liquid chromatography analysis revealed a highly significant increase in GM3, suggesting a metabolic blockade in the conversion of GM3 to more complex gangliosides. Quantitative real-time PCR analysis revealed a significant reduction in the transcripts of the interconverting enzymes, especially of β-1,4-N-acetyl-galactosaminyl transferase 1 (GM2 synthase), which is the enzyme converting GM3 to GM2. Thus, our data suggest that the complex a-series gangliosides are reduced in Cln3Δex7/8 mouse cerebellar precursor cells due to impaired transcription of the genes responsible for their synthesis. PMID:29470438

Molecular characterization and expression study of a histidine auxotrophic mutant (his1-) of Nicotiana plumbaginifolia.

PubMed

El Malki, F; Jacobs, M

2001-01-01

The histidine auxotroph mutant his 1(-) isolated from Nicotiana plumbaginifolia haploid protoplasts was first characterized to be deficient for the enzyme histidinol phosphate aminotransferase that is responsible for one of the last steps of histidine biosynthesis. Expression of the mutated gene at the RNA level was assessed by northern analysis of various tissues. Transcriptional activity was unimpaired by the mutation and, in contrast, a higher level of expression was obtained when compared to the wild-type. The cDNA sequence encoding the mutated gene was isolated by RT-PCR and compared to the wild-type gene. A single point mutation corresponding to the substitution of a G nucleotide by A was identified at position 1212 starting from the translation site. The alignment of the deduced amino acid sequences from the mutated and wild-type gene showed that this mutation resulted in the substitution of an Arg by a His residue at position 381. This Arg residue is a conserved amino acid for histidinol phosphate aminotransferase of many species. These results indicate that the identified mutation results in an altered histidinol phosphate aminotransferase enzyme that is unable to convert the substrate imidazole acetol phosphate to histidinol phosphate and thereby leads to the blockage of histidine biosynthesis. Possible consequences of this blockage on the expression of other amino acid biosynthesis genes were evaluated by analysing the expression of the dhdps gene encoding dihydrodipicolinate synthase, the first key enzyme of the lysine pathway.

Vitamin K

USDA-ARS?s Scientific Manuscript database

Vitamin K, a fat-soluble vitamin, is an enzyme cofactor for post-translation modification of specific glutamate residues that are converted into '-carboxyglutamic acid (Gla) residues by a vitamin K-dependent (VKD) carboxylase. Seven VKD coagulation proteins are synthesized in the liver. The extra-he...

Purification and Properties of White Muscle Lactate Dehydrogenase from the Anoxia-Tolerant Turtle, the Red-Eared Slider, Trachemys scripta elegans

PubMed Central

Dawson, Neal J.; Bell, Ryan A. V.; Storey, Kenneth B.

2013-01-01

Lactate dehydrogenase (LDH; E.C. 1.1.1.27) is a crucial enzyme involved in energy metabolism in muscle, facilitating the production of ATP via glycolysis during oxygen deprivation by recycling NAD+. The present study investigated purified LDH from the muscle of 20 h anoxic and normoxic T. s. elegans, and LDH from anoxic muscle showed a significantly lower (47%) K m for L-lactate and a higher V max value than the normoxic form. Several lines of evidence indicated that LDH was converted to a low phosphate form under anoxia: (a) stimulation of endogenously present protein phosphatases decreased the K m of L-lactate of control LDH to anoxic levels, whereas (b) stimulation of kinases increased the K m of L-lactate of anoxic LDH to normoxic levels, and (c) dot blot analysis shows significantly less serine (78%) and threonine (58%) phosphorylation in anoxic muscle LDH as compared to normoxic LDH. The physiological consequence of anoxia-induced LDH dephosphorylation appears to be an increase in LDH activity to promote the reduction of pyruvate in muscle tissue, converting the glycolytic end product to lactate to maintain a prolonged glycolytic flux under energy-stressed anoxic conditions. PMID:23533717

Purification and Properties of White Muscle Lactate Dehydrogenase from the Anoxia-Tolerant Turtle, the Red-Eared Slider, Trachemys scripta elegans.

PubMed

Dawson, Neal J; Bell, Ryan A V; Storey, Kenneth B

2013-01-01

Lactate dehydrogenase (LDH; E.C. 1.1.1.27) is a crucial enzyme involved in energy metabolism in muscle, facilitating the production of ATP via glycolysis during oxygen deprivation by recycling NAD(+). The present study investigated purified LDH from the muscle of 20 h anoxic and normoxic T. s. elegans, and LDH from anoxic muscle showed a significantly lower (47%) K m for L-lactate and a higher V max value than the normoxic form. Several lines of evidence indicated that LDH was converted to a low phosphate form under anoxia: (a) stimulation of endogenously present protein phosphatases decreased the K m of L-lactate of control LDH to anoxic levels, whereas (b) stimulation of kinases increased the K m of L-lactate of anoxic LDH to normoxic levels, and (c) dot blot analysis shows significantly less serine (78%) and threonine (58%) phosphorylation in anoxic muscle LDH as compared to normoxic LDH. The physiological consequence of anoxia-induced LDH dephosphorylation appears to be an increase in LDH activity to promote the reduction of pyruvate in muscle tissue, converting the glycolytic end product to lactate to maintain a prolonged glycolytic flux under energy-stressed anoxic conditions.

Serum angiotensin-converting enzyme (SACE) in sarcoidosis and other granulomatous disorders.

PubMed

Studdy, P; Bird, R; James, D G

Serum angiotensin-converting enzyme (SACE) activity was significantly higher in 90 patients with sarcoidosis (55 +/- [S.D.] 23 nmol min-1 ml-1) than in 80 healthy controls (34 +/- 9 nmol min-1 ml-1). Steroid therapy modified SACE activity; 60 sarcoidosis patients who were not being treated with steroids had significantly higher enzyme activities (58 +/- 24 nmol min-1 ml-1) than 30 steroid-treated sarcoidosis patients (40 +/- 19 nmol min-1 ml-1). In 50% of the non-steroid treated sarcoidosis patients SACE activity was more than 2 S.D. above the mean value for the controls. SACE activity was measured in 22 tuberculous patients (38 +/- 14 nmol min-1 ml-1), 20 leprosy patients (34 +/- 9 nmol min-1 ml-1), 31 with primary biliary cirrhosis (44 +/- 20 nmol min-1 ml-1), 26 with inflammatory bowel disease (31 +/- 9 nmol min-1 ml-1), 8 with hepatic granulomatous disease, 5 with Hodgkin's disease, and 2 with schistosomiasis. The combined false-positive rate for these non-sarcoidosis patients was 10%. Serial SACE assays provide useful information on the course of sarcoidosis and response to steroid treatment.

Serum angiotensin--converting enzyme (SACE) in sarcoidosis and other granulomatous disorders.

PubMed

Studdy, P; Bird; James, D G; Sherlock, S

Serum angiotensin-converting enzyme (SACE) activity was significantly higher in 90 patients with sarcoidosis (55 +/- [S.D.] 23 nmol min-1 ml-1) than in 80 healthy controls (34 +/- 9 nmol min-1 ml-1). Steroid therapy modified SACE activity; 60 sarcoidosis patients who were not being treated with steroids had significantly higher enzyme activities (58 +/- 24 nmol min-1 ml-1) than 30 steroid-treated sarcoidosis patients (40 +/- 19 nmol min-1 ml-1). In 50% of the non-steroid treated sarcoidosis patients SACE activity was more than than 2 S.D. above the mean value for the controls. SACE activity was measured in 22 tuberculous patients (38 +/- 14 nmol min-1 ml-1), 20 leprosy patients (34 +/- 9 nmol min-1 ml-1), 31 with primary biliary cirrhosis (44 +/- 20 nmol min-1 ml-1), 26 with inflammatory bowel disease (31 +/- 9 nmol min-1 ml-1), eight with hepatic granulomatous disease, five with Hodgkin's disease, and two with schistosomiasis. The combined false-positive rate for these non-sarcoidosis patients was 10%. Serial SACE assays provide useful information on the course of sarcoidosis and response to steroid treatment.

Angiotensin converting enzyme (ACE) inhibitory and antihypertensive activities of protein hydrolysate from meat of Kacang goat (Capra aegagrus hircus).

PubMed

Mirdhayati, Irdha; Hermanianto, Joko; Wijaya, Christofora H; Sajuthi, Dondin; Arihara, Keizo

2016-08-01

The meat of Kacang goat has potential for production of a protein hydrolysate. Functional ingredients from protein hydrolysate of Kacang goat meat were determined by the consistency of angiotensin-converting enzyme (ACE) inhibitory activity and antihypertensive effect. This study examined the potency of Kacang goat protein hydrolysate in ACE inhibition and antihypertensive activity. Protein hydrolysates of Kacang goat meat were prepared using sequential digestion of endo-proteinase and protease complex at several concentrations and hydrolysis times. The highest ACE inhibitory activity resulted from a hydrolysate that was digested for 4 h with 5 g kg(-1) of both enzymes. An ACE inhibitory peptide was purified and a novel peptide found with a sequence of Phe-Gln-Pro-Ser (IC50 value of 27.0 µmol L(-1) ). Both protein hydrolysates and a synthesised peptide (Phe-Gln-Pro-Ser) demonstrated potent antihypertensive activities in spontaneously hypertensive rats. Protein hydrolysate of Kacang goat meat produced by sequential digestion with endo-proteinase and protease complex has great potential as a functional ingredient, particularly as an antihypertensive agent. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Soy Pulp Extract Inhibits Angiotensin I-Converting Enzyme (ACE) Activity In Vitro: Evidence for Its Potential Hypertension-Improving Action.

PubMed

Nishibori, Naoyoshi; Kishibuchi, Reina; Morita, Kyoji

2017-05-04

Soy pulp, called "okara" in Japanese, is known as a by-product of the production of bean curd (tofu), and expected to contain a variety of biologically active substances derived from soybean. However, the biological activities of okara ingredients have not yet been fully understood, and the effectiveness of okara as a functional food seems necessary to be further evaluated. Then the effect of okara extract on angiotensin I-converting enzyme (ACE) activity was examined in vitro, and the extract was shown to cause the inhibition of ACE activity in a manner depending on its concentration. Kinetic analysis indicated that this enzyme inhibition was accompanied by an increase in the Km value without any change in Vmax. Further studies suggested that putative inhibitory substances contained in the extract might be heat stable and dialyzable, and recovered mostly in the peptide fraction obtained by a spin-column separation and a high performance liquid chromatography (HPLC) fractionation. Therefore, the extract was speculated to contain small-size peptides responsible for the inhibitory effect of okara extract on ACE activity, and could be expected to improve the hypertensive conditions by reducing the production of hypertensive peptide.

The Evaluation of Dipeptidyl Peptidase (DPP)-IV, α-Glucosidase and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Whey Proteins Hydrolyzed with Serine Protease Isolated from Asian Pumpkin (Cucurbita ficifolia).

PubMed

Konrad, Babij; Anna, Dąbrowska; Marek, Szołtysik; Marta, Pokora; Aleksandra, Zambrowicz; Józefa, Chrzanowska

2014-01-01

In the present study, whey protein concentrate (WPC-80) and β-lactoglobulin were hydrolyzed with a noncommercial serine protease isolated from Asian pumpkin ( Cucurbita ficifolia ). Hydrolysates were further fractionated by ultrafiltration using membranes with cut-offs equal 3 and 10 kDa. Peptide fractions of molecular weight lower than 3 and 3-10 kDa were further subjected to the RP-HPLC. Separated preparations were investigated for their potential as the natural inhibitors of dipeptidyl peptidase (DPP-IV), α-glucosidase and angiotensin converting enzyme (ACE). WPC-80 hydrolysate showed higher inhibitory activities against the three tested enzymes than β-lactoglobulin hydrolysate. Especially high biological activities were exhibited by peptide fractions of molecular weight lower than 3 kDa, with ACE IC50 <0.64 mg/mL and DPP-IV IC50 <0.55 mg/mL. This study suggests that peptides generated from whey proteins may support postprandial glycemia regulation and blood pressure maintenance, and could be used as functional food ingredients in the diet of patients with type 2 diabetes.

The risks and benefits of patients temporarily discontinuing medications in the event of an intercurrent illness: a systematic review protocol.

PubMed

Morden, Andrew; Horwood, Jeremy; Whiting, Penny; Savovic, Jelena; Tomlinson, Laurie; Blakeman, Thomas; Tomson, Charles; Richards, Alison; Stone, Tracey; Caskey, Fergus

2015-10-24

Acute kidney injury (AKI) is common and often leads to significant morbidity and/or death. The development of AKI, or complications associated with it, may be due to use of certain medications in at-risk patients experiencing an intercurrent illness. Implicated drugs include diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), metformin and sulfonylureas. Expert consensus opinion (and clinical guidelines) recommend considering discontinuation of diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin and sulfonylureas in the event of an intercurrent illness to prevent AKI onset or reduce severity or complications. However, the evidence base for these recommendations is very limited. This systematic review aims to address the available evidence for the temporary discontinuation of diuretics, ACE inhibitors, angiotensin receptor blockers, direct renin inhibitors, non-steroidal anti-inflammatories and metformin and sulfonylureas for those at risk of AKI or with newly diagnosed AKI. Randomised controlled trials; non-randomised trials; cohort studies; case-control studies; interrupted time series studies; and before-and-after studies featuring adults aged 18 and over in any setting currently taking diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs and metformin; experiencing an intercurrent illness; or undergoing a radiological/surgical procedure (planned or unplanned) will be searched for. Relevant trial registers and systematic review databases will be searched. Systematic reviews will be assessed for methodological quality using the ROBIS tool, trials will be assessed using the Cochrane risk of bias tool, and observational studies will be assessed using the ACROBAT-NRS tool. If sufficient studies assessing similar populations, study type, settings and outcomes are found, then a formal meta-analysis will be performed to estimate summary measures of effect. If not, a narrative synthesis will be adopted. This review will synthesise evidence for the efficacy of discontinuing diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin or sulfonylureas to prevent or delay onset of AKI or associated complications. Results will provide guidance on efficacy and safety of this strategy and potentially help to develop an intervention to test the best mechanism of guiding medication discontinuation in at-risk populations. PROSPERO CRD42015023210.

Potential and utilization of thermophiles and thermostable enzymes in biorefining

PubMed Central

Turner, Pernilla; Mamo, Gashaw; Karlsson, Eva Nordberg

2007-01-01

In today's world, there is an increasing trend towards the use of renewable, cheap and readily available biomass in the production of a wide variety of fine and bulk chemicals in different biorefineries. Biorefineries utilize the activities of microbial cells and their enzymes to convert biomass into target products. Many of these processes require enzymes which are operationally stable at high temperature thus allowing e.g. easy mixing, better substrate solubility, high mass transfer rate, and lowered risk of contamination. Thermophiles have often been proposed as sources of industrially relevant thermostable enzymes. Here we discuss existing and potential applications of thermophiles and thermostable enzymes with focus on conversion of carbohydrate containing raw materials. Their importance in biorefineries is explained using examples of lignocellulose and starch conversions to desired products. Strategies that enhance thermostablity of enzymes both in vivo and in vitro are also assessed. Moreover, this review deals with efforts made on developing vectors for expressing recombinant enzymes in thermophilic hosts. PMID:17359551

Virally inactivated human platelet concentrate lysate induces regulatory T cells and immunosuppressive effect in a murine asthma model.

PubMed

Lee, Yueh-Lun; Lee, Lin-Wen; Su, Chen-Yao; Hsiao, George; Yang, Yi-Yuan; Leu, Sy-Jye; Shieh, Ying-Hua; Burnouf, Thierry

2013-09-01

Platelet concentrate lysates (PCLs) are increasingly used in regenerative medicine. We have developed a solvent/detergent (S/D)-treated PCL. The functional properties of this preparation should be unveiled. We hypothesized that, due to transforming growth factor-β1 (TGF-β1) content, PCLs may exert immunosuppressive and anti-inflammatory functions. PCL was prepared by S/D treatment, oil extraction, and hydrophobic interaction chromatography. The content of TGF-β in PCL was determined by enzyme-linked immunosorbent assay. Cultured CD4+ T cells were used to investigate the effects of PCL on expression of transcription factor forkhead box P3 (Foxp3), the inhibition of T-cell proliferation, and cytokine production. The regulatory function of PCL-converted CD4+ T cells was analyzed by suppressive assay. The BALB/c mice were given PCL-converted CD4+ T cells before ovalbumin (OVA) sensitization and challenge using an asthma model. Inflammatory parameters, such as the level of immunoglobulin E (IgE), airway hyperresponsiveness (AHR), bronchial lavage fluid eosinophils, and cytokines were assayed. Recombinant human (rHu) TGF-β1 was used as control. PCL significantly enhanced the development of CD4+Foxp3+-induced regulatory T cells (iTregs). Converted iTregs produced neither Th1 nor Th2 cytokines and inhibited normal T-cell proliferation. PCL- and rHuTGF-β-converted CD4+ T cells prevented OVA-induced asthma. PCL- and rHuTGF-β-modified T cells both significantly reduced expression levels of OVA-specific IgE and significantly inhibited the development of AHR, airway eosinophilia, and Th2 responses in mice. S/D-treated PCL promotes Foxp3+ iTregs and exerts immunosuppressive and anti-inflammatory properties. This finding may help to understand the clinical properties of platelet lysates. © 2013 American Association of Blood Banks.

Enhanced activity of an angiotensin-(1-7) neuropeptidase in glucocorticoid-induced fetal programming.

PubMed

Marshall, Allyson C; Shaltout, Hossam A; Pirro, Nancy T; Rose, James C; Diz, Debra I; Chappell, Mark C

2014-02-01

We previously identified angiotensin converting enzyme (ACE) and an endopeptidase activity that degraded angiotensin-(1-7) [Ang-(1-7)] to Ang-(1-5) and Ang-(1-4), respectively, in the cerebrospinal fluid (CSF) of 6-month old male sheep. The present study undertook a more comprehensive analysis of the CSF peptidase that converts Ang-(1-7) to Ang-(1-4) in control and in utero betamethasone-exposed sheep (BMX). Characterization of the Ang-(1-7) peptidase revealed that the thiol agents 4-aminophenylmercuric acetate (APMA) and p-chloromercuribenzoic acid (PCMB), as well as the metallo-chelators o-phenanthroline and EDTA essentially abolished the enzyme activity. Additional inhibitors for serine, aspartyl, and cysteine proteases, as well as selective inhibitors against the endopeptidases neprilysin, neurolysin, prolyl and thimet oligopeptidases did not attenuate enzymatic activity. Competition studies against the peptidase revealed similar IC50s for Ang-(1-7) (5μM) and Ang II (3μM), but lower values for Ala(1)-Ang-(1-7) and Ang-(2-7) of 1.8 and 2.0μM, respectively. In contrast, bradykinin exhibited a 6-fold higher IC50 (32μM) than Ang-(1-7) while neurotensin was a poor competitor. Mean arterial pressure (78±1 vs. 94±2mmHg, N=4-5, P<0.01) and Ang-(1-7) peptidase activity (14.2±1 vs 32±1.5fmol/min/ml CSF, N=5, P<0.01) were higher in the BMX group, and enzyme activity inversely correlated with Ang-(1-7) content in CSF. Lower Ang-(1-7) expression in brain is linked to baroreflex impairment in hypertension and aging, thus, increased activity of an Ang-(1-7) peptidase may contribute to lower CSF Ang-(1-7) levels, elevated blood pressure and impaired reflex function in this model of fetal programming. Copyright © 2013 Elsevier Inc. All rights reserved.

Mechanism of high glucose induced angiotensin II production in rat vascular smooth muscle cells.

PubMed

Lavrentyev, Eduard N; Estes, Anne M; Malik, Kafait U

2007-08-31

Angiotensin II (Ang II), a circulating hormone that can be synthesized locally in the vasculature, has been implicated in diabetes-associated vascular complications. This study was conducted to determine whether high glucose (HG) (approximately 23.1 mmol/L), a diabetic-like condition, stimulates Ang II generation and the underlying mechanism of its production in rat vascular smooth muscle cells. The contribution of various enzymes involved in Ang II generation was investigated by silencing their expression with small interfering RNA in cells exposed to normal glucose (approximately 4.1 mmol/L) and HG. Angiotensin I (Ang I) was generated from angiotensinogen by cathepsin D in the presence of normal glucose or HG. Although HG did not affect the rate of angiotensinogen conversion, it decreased expression of angiotensin-converting enzyme (ACE), downregulated ACE-dependent Ang II generation, and upregulated rat vascular chymase-dependent Ang II generation. The ACE inhibitor captopril reduced Ang II levels in the media by 90% in the presence of normal glucose and 19% in HG, whereas rat vascular chymase silencing reduced Ang II production in cells exposed to HG but not normal glucose. The glucose transporter inhibitor cytochalasin B, the aldose reductase inhibitor alrestatin, and the advanced glycation end product formation inhibitor aminoguanidine attenuated HG-induced Ang II generation. HG caused a transient increase in extracellular signal-regulated kinase (ERK)1/2 phosphorylation, and ERK1/2 inhibitors reduced Ang II accumulation by HG. These data suggest that polyol pathway metabolites and AGE can stimulate rat vascular chymase activity via ERK1/2 activation and increase Ang II production. In addition, decreased Ang II degradation, which, in part, could be attributable to a decrease in angiotensin-converting enzyme 2 expression observed in HG, contributes to increased accumulation of Ang II in vascular smooth muscle cells by HG.

[Inhibition of antisense-endothelin converting enzyme RNA on interleukin-5 released from dust mite-challenged peripheral blood mononuclear cells in patients with allergic asthma].

PubMed

Li, Li; Xu, Ju; Zhong, Nan-shan

2003-09-01

To investigate the effect of antisense endothelin converting enzyme (ECE) RNA on levels of cytokines released from CD(4)(+) lymphocytes in patients with allergic diseases responsive to house dust mites. Peripheral blood mononuclear cells (PBMCs) were separated from 21 patients who were sensitive to dust mites. PBMCs from those patients were divided into two groups. No stimulation group (A group) induded A(1) group (anti-ECE epithelial cells + PBMCs) and A(2) group (control cells + PBMCs). Stimulation group (B group) included B(1) group (anti-ECE epithelial cells + PBMCs + dust mites extract) and B(2) group (control cells + PBMCs + dust mites extract). House dust mite extract (20 microg/ml) was added to the culture of stimulation group as described above. After 72 hours, supernatants from both groups were collected and the levels of IL-5 and IFN-ggr; released into the supernatants were detected by enzyme-linked immunoabsorbent assay. IL-5 levels were increased significantly after treatment with dust mite in twelve of 21 cases. No significant differences of IL-5 were found between the groups of A(1)[(6.0 +/- 1.3) x 10(-9) g/L] and A(2) [(7.5 +/- 1.1) x 10(-9) g/L] before house dust mite stimulation in the 12 cases (P > 0.05), and no significant differences in IFN-ggr; were found between the groups of A(1) [(63 +/- 26) x 10(-9) g/L] and A(2) [(70 +/- 52) x 10(-9) g/L] before house dust mite stimulation (P > 0.05). IL-5 level was increased in both groups after stimulation but it was significantly lower in the B(1) group [(8.2 +/- 1.6) x 10(-9) g/L] than that in the B(2) [(12.0 +/- 1.8) x 10(-9) g/L] (P = 0.047). It seemed that increased IFN-ggr; level after stimulation was higher in B(2) [(153 +/- 71) x 10(-9) g/L] than that in the B(1) group (100 +/- 41) x 10(-9) g/L], but there was no statistic significance (P > 0.05). In addition, our results also showed that the release of IL-5 was significantly increased in those cases with asthma, or asthma plus allergic rhinitis after dust mites stimulation [(44 +/- 15)%] compared with that in those with urticaria [(7 +/- 4)%] (P = 0.047). Antisense-ECE downregulated the IL-5 secretion from Th2 lymphocytes in patients with allergic asthma after being challenged with dust mites. It is indicated that ET-1 is an important cytokine involved with allergic airway inflammation. Antisense-ECE RNA management in airways may be of value in treating allergic asthma.

Ring-opening polymerization of DD-lactide catalyzed by Novozyme 435.

PubMed

Hans, Marc; Keul, Helmut; Moeller, Martin

2009-03-10

In contrast to LLA, DLA is converted in toluene solution under mild reaction conditions (50-70 degrees C) using Novozyme 435 (immobilized CALB) to form the corresponding polymer. The influence of several parameters, such as enzyme concentration, temperature and monomer concentration, on the polymerization rate and the monomer conversion was studied. In contrast to the Novozyme 435 catalyzed polymerization of epsilon-caprolactone, enzyme deactivation occurs. It is attributed to the deprivation of water from the enzyme. This work points out that by careful selection of the reaction conditions, it is possible to obtain poly(D-lactide) in reasonable molecular weights and in high yields using Novozyme 435 catalysis.

Perioperative use of angiotensin-converting-enzyme inhibitors and angiotensin receptor antagonists.

PubMed

Vaquero Roncero, Luis Mario; Sánchez Poveda, David; Valdunciel García, Joaquín José; Sánchez Barrado, María Elisa; Calvo Vecino, José María

2017-08-01

Clinical repercussions of perioperative treatment with ACEIs/ARBs. Systematic review according to PRISMA statement. Perioperative period. 29 studies 11 cases/cases series, 12 observational studies and 6 randomized studies. Arterial blood pressure differences, refractory hypotension, other comorbidities. The studies show different results regarding the topics measured. They are divided in the results regarding blood pressure, long term morbidities and effects in neuraxial anesthesia. Withholding AECI/ARBs on the morning prior to surgery could be recommended as a potentially effective measure, with a low level of evidence, in order to reduce the appearance of hypotension in the perioperative period of non-cardiac surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Neural expression and post-transcriptional dosage compensation of the steroid metabolic enzyme 17β-HSD type 4

PubMed Central

2010-01-01

Background Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid estradiol (E2) is especially effective at promoting growth of the neural circuit specialized for song. In this species, only the males sing and they have a much larger and more interconnected song circuit than females. Thus, it was surprising that the gene for 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4), an enzyme that converts E2 to a less potent estrogen, had been mapped to the Z sex chromosome. As a consequence, it was likely that HSD17B4 was differentially expressed in males (ZZ) and females (ZW) because dosage compensation of Z chromosome genes is incomplete in birds. If a higher abundance of HSD17B4 mRNA in males than females was translated into functional enzyme in the brain, then contrary to expectation, males could produce less E2 in their brains than females. Results Here, we used molecular and biochemical techniques to confirm the HSD17B4 Z chromosome location in the zebra finch and to determine that HSD17B4 mRNA and activity were detectable in the early developing and adult brain. As expected, HSD17B4 mRNA expression levels were higher in males compared to females. This provides further evidence of the incomplete Z chromosome inactivation mechanisms in birds. We detected HSD17B4 mRNA in regions that suggested a role for this enzyme in the early organization and adult function of song nuclei. We did not, however, detect significant sex differences in HSD17B4 activity levels in the adult brain. Conclusions Our results demonstrate that the HSD17B4 gene is expressed and active in the zebra finch brain as an E2 metabolizing enzyme, but that dosage compensation of this Z-linked gene may occur via post-transcriptional mechanisms. PMID:20359329

Topographic effects on denitrification in drained agricultural fields

USDA-ARS?s Scientific Manuscript database

Denitrification is affected by soil moisture, while soil moisture can be affected by topography. Therefore, denitrification can be spatially correlated to topographic gradients. Three prior converted fields on the Delmarva Peninsula were sampled spatially for denitrification enzyme activity. The up...

ADVERSE PREGNANCY OUTCOMES ASSOCIATED WITH MATERNAL ENALAPRIL ANTIHYPERTENSIVE TREATMENT

EPA Science Inventory

Enalapril, one of several antihypertensive drugs that act as angiotensin-converting enzyme (ACE) inhibitors, is often used for treatment of hypertension in women of reproductive age. Adverse birth outcomes following the use of ACE inhibitors, including enalapril, during pregnanc...

Pompe Disease

MedlinePlus

... glycogen, which is converted by the GAA into glucose, a sugar that fuels muscles. In Pompe disease, mutations in the GAA gene reduce or completely eliminate this essential enzyme. Excessive amounts of lysosomal glycogen accumulate everywhere in the body, but the cells of the heart and skeletal ...

Seasonal alteration in amounts of lignans and their glucosides and gene expression of the relevant biosynthetic enzymes in the Forsythia suspense leaf.

PubMed

Morimoto, Kinuyo; Satake, Honoo

2013-01-01

Lignans of Forsythia spp. are essential components of various Chinese medicines and health diets. However, the seasonal alteration in lignan amounts and the gene expression profile of lignan-biosynthetic enzymes has yet to be investigated. In this study, we have assessed seasonal alteration in amounts of major lignans, such as pinoresinol, matairesinol, and arctigenin, and examined the gene expression profile of pinoresinol/lariciresinol reductase (PLR), pinoresinol-glucosylating enzyme (UGT71A18), and secoisolariciresinol dehydrogenase (SIRD) in the leaf of Forsythia suspense from April to November. All of the lignans in the leaf continuously increased from April to June, reached the maximal level in June, and then decreased. Ninety percent of pinoresinol and matairesinol was converted into glucosides, while approximately 50% of arctigenin was aglycone. PLR was stably expressed from April to August, whereas the PLR expression was not detected from September to November. In contrast, the UGT71A18 expression was found from August to November, but not from April to July. The SIRD expression was prominent from April to May, not detected in June to July, and then increased again from September to November. These expression profiles of the lignan-synthetic enzymes are largely compatible with the alteration in lignan contents. Furthermore, such seasonal lignan profiles are in good agreement with the fact that the Forsythia leaves for Chinese medicinal tea are harvested in June. This is the first report on seasonal alteration in lignans and the relevant biosynthetic enzyme genes in the leaf of Forsythia species.

Bioequivalence of azathioprine products.

PubMed

Baker, Daniel E

2003-01-01

All azathioprine oral tablets are considered bioequivalent by the Food and Drug Administration based on traditional testing. However, since these tests were conducted, it has been determined that some patients have a deficiency of the enzyme most responsible for the metabolism of 6-mercaptopurine-thiopurine methyltransferase (TPMT). Azathioprine is rapidly converted to 6-mercaptopurine, its active metabolite. So it is possible that differences in TPMT activity may influence the bioequivalence of azathioprine products among individuals, especially those patients deficient in TPMT enzyme activity. However, this possibility has not been evaluated.

Effects of angiotensin-converting enzyme inhibitor versus valsartan on cellular signaling events in heart transplant.

PubMed

White, Michel; Ross, Heather; Levesque, Sylvie; Whittom, Lucette; Pelletier, Guy B; Racine, Normand; Meloche, Sylvain; Voisin, Laure

2009-05-01

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) provide similar biologic effects in model systems and similar clinical impacts in humans. The changes in the cardiac angiotensin system signaling pathways in the human heart in response to ACE inhibitors versus ARBs have been incompletely studied. To investigate the effects of ACE inhibitors versus valsartan on the angiotensin II signal transduction pathways in the transplanted human heart. Twenty-seven stable cardiac transplant recipients were randomized to remain on ACE inhibitor therapy (n = 8) or to receive valsartan (n = 19). Two additional endomyocardial biopsy samples were obtained at baseline and after 9 months of therapy. The expression of cardiac angiotensin type I and II receptors and atrial natriuretic factor (ANF) was measured by quantitative polymerase chain reaction. The expression and phosphorylation levels of selected signal transduction pathways were analyzed by immunoblotting. The mean dose of valsartan was 114 +/- 41 mg/day. The use of valsartan resulted in a similar impact on blood pressure and biochemistry profile. There were no significant changes in the expression of angiotensin type I and II receptors and ANF with valsartan. Similarly, no significant changes in the expression and phosphorylation of Jun N-terminal kinase, extracellular signal-regulated kinase 1 and 2, and p38 mitogen-activated protein kinases or AKT, and mammalian target of rapamycin was observed in the valsartan-treated group. Valsartan use is associated with similar clinical and molecular cardiac effects as ACE inhibitor therapy in stable long-term cardiac transplant recipients.

Contribution of Musa paradisiaca in the inhibition of α-amylase, α-glucosidase and Angiotensin-I converting enzyme in streptozotocin induced rats.

PubMed

Shodehinde, Sidiqat A; Ademiluyi, Adedayo O; Oboh, Ganiyu; Akindahunsi, Afolabi A

2015-07-15

Unripe plantain based-diets are part of folklore remedy for the management of diabetes in tropical Africa; however, with the dearth of information on the rationale behind this practice; this study therefore, sought to investigate the antihyperglycemic effect of traditional unripe plantain products (Amala and Booli) in high fat fed/low dose streptozotocin-induced diabetic rats and to provide a possible rationale for their antidiabetic properties. Diabetes was induced experimentally by high fat fed/low dose streptozotocin-diabetic rats (25mg/kg body wt.) and the diabetic rats were fed diets supplemented with 20-40% Amala and Booli for 14 days. The effect of the diets on the blood glucose level, pancreatic α-amylase, intestinal α-glucosidase and Angiotensin-I converting enzyme (ACE) activities and plasma antioxidant status as well as amylose/amylopectin content of the unripe plantain products were determined. A marked increase in the blood glucose, α-amylase, α-glucosidase and ACE activities with a corresponding decrease in plasma antioxidant status was recorded in diabetic rats. However, these indices were significantly (P < 0.05) reversed after unripe plantain product supplemented diet treatments for 14 days. Also, the amylose/amylopectin ratio of the products is 1:3. This study revealed that unripe plantain products exert antihyperglycemic effects which could be attributed to the inhibition of α-amylase and α-glucosidase activities by their constituent phytochemicals as well as their amylose/amylopectin contents in the diabetic rats, hence, providing the possible rationale behind their antidiabetic properties. Copyright © 2015 Elsevier Inc. All rights reserved.

A study of the prevalence of significant increases in serum creatinine following angiotension-converting enzyme inhibitor administration.

PubMed

Thorp, M L; Ditmer, D G; Nash, M K; Wise, R; Jaderholm, P L; Smith, J D; Chan, W

2005-05-01

Angiontension-converting enzyme inhibitors (ACEIs) are beneficial in the treatment of diabetic and nondiabetic kidney disease, coronary artery disease and congestive heart failure. One adverse effect of ACEIs use is a rise in serum creatinine and potential renal failure. This paper attempts to quantify this risk and assess the need for pre- and post-ACEI serum creatinine measurements. A computerized search of Kaiser Permanente Northwest's electronic medical record was conducted to find patients over the age of 40 years taking lisinopril between July 1, 2000 and June 30, 2002. Patient demographic information and presence in diabetes and coronary artery disease registries was collected. A subsequent search for pre- and postlisinopril serum creatinine levels within 6 months of initial lisinopril prescription was conducted. Patients with prelisinopril creatinine < or = 1.2 mg/dl and postlisinopril creatinine > 2.5 mg/dl underwent chart review to discern adverse events associated with the rise in serum creatinine. A total of 18,977 patients were prescribed lisinopril between July 1, 2000 and June 30, 2002. In all 13 166 patients had a pre- and postlisinopril creatinine checked. In all, 31 patients had a rise in creatinine from < or = 1.2 mg/dl to > 2.5 mg/dl (0.2%). Possible contributors to rise in creatinine included congestive heart failure, dehydration and infection. No patients developed end-stage renal disease, although three died. In conclusion, end-stage renal disease is an unlikely outcome among patients prescribed lisinopril and is most likely associated with other events.