Science.gov

Sample records for enzyme ace inhibitors

  1. Angiotensin Converting Enzyme (ACE) Inhibitor Extends Caenorhabditis elegans Life Span.

    PubMed

    Kumar, Sandeep; Dietrich, Nicholas; Kornfeld, Kerry

    2016-02-01

    Animal aging is characterized by progressive, degenerative changes in many organ systems. Because age-related degeneration is a major contributor to disability and death in humans, treatments that delay age-related degeneration are desirable. However, no drugs that delay normal human aging are currently available. To identify drugs that delay age-related degeneration, we used the powerful Caenorhabditis elegans model system to screen for FDA-approved drugs that can extend the adult lifespan of worms. Here we show that captopril extended mean lifespan. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat high blood pressure in humans. To explore the mechanism of captopril, we analyzed the acn-1 gene that encodes the C. elegans homolog of ACE. Reducing the activity of acn-1 extended the mean life span. Furthermore, reducing the activity of acn-1 delayed age-related degenerative changes and increased stress resistance, indicating that acn-1 influences aging. Captopril could not further extend the lifespan of animals with reduced acn-1, suggesting they function in the same pathway; we propose that captopril inhibits acn-1 to extend lifespan. To define the relationship with previously characterized longevity pathways, we analyzed mutant animals. The lifespan extension caused by reducing the activity of acn-1 was additive with caloric restriction and mitochondrial insufficiency, and did not require sir-2.1, hsf-1 or rict-1, suggesting that acn-1 functions by a distinct mechanism. The interactions with the insulin/IGF-1 pathway were complex, since the lifespan extensions caused by captopril and reducing acn-1 activity were additive with daf-2 and age-1 but required daf-16. Captopril treatment and reducing acn-1 activity caused similar effects in a wide range of genetic backgrounds, consistent with the model that they act by the same mechanism. These results identify a new drug and a new gene that can extend the lifespan of worms and suggest new

  2. Angiotensin Converting Enzyme (ACE) Inhibitor Extends Caenorhabditis elegans Life Span

    PubMed Central

    Kumar, Sandeep; Dietrich, Nicholas; Kornfeld, Kerry

    2016-01-01

    Animal aging is characterized by progressive, degenerative changes in many organ systems. Because age-related degeneration is a major contributor to disability and death in humans, treatments that delay age-related degeneration are desirable. However, no drugs that delay normal human aging are currently available. To identify drugs that delay age-related degeneration, we used the powerful Caenorhabdtitis elegans model system to screen for FDA-approved drugs that can extend the adult lifespan of worms. Here we show that captopril extended mean lifespan. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat high blood pressure in humans. To explore the mechanism of captopril, we analyzed the acn-1 gene that encodes the C. elegans homolog of ACE. Reducing the activity of acn-1 extended the mean life span. Furthermore, reducing the activity of acn-1 delayed age-related degenerative changes and increased stress resistance, indicating that acn-1 influences aging. Captopril could not further extend the lifespan of animals with reduced acn-1, suggesting they function in the same pathway; we propose that captopril inhibits acn-1 to extend lifespan. To define the relationship with previously characterized longevity pathways, we analyzed mutant animals. The lifespan extension caused by reducing the activity of acn-1 was additive with caloric restriction and mitochondrial insufficiency, and did not require sir-2.1, hsf-1 or rict-1, suggesting that acn-1 functions by a distinct mechanism. The interactions with the insulin/IGF-1 pathway were complex, since the lifespan extensions caused by captopril and reducing acn-1 activity were additive with daf-2 and age-1 but required daf-16. Captopril treatment and reducing acn-1 activity caused similar effects in a wide range of genetic backgrounds, consistent with the model that they act by the same mechanism. These results identify a new drug and a new gene that can extend the lifespan of worms and suggest new

  3. Angiotensin-I-Converting Enzyme (ACE) Inhibitors from Marine Resources: Prospects in the Pharmaceutical Industry

    PubMed Central

    Wijesekara, Isuru; Kim, Se-Kwon

    2010-01-01

    Hypertension or high blood pressure is one of the major independent risk factors for cardiovascular diseases. Angiotensin-I-converting enzyme (EC 3.4.15.1; ACE) plays an important physiological role in regulation of blood pressure by converting angiotensin I to angiotensin II, a potent vasoconstrictor. Therefore, the inhibition of ACE activity is a major target in the prevention of hypertension. Recently, the search for natural ACE inhibitors as alternatives to synthetic drugs is of great interest to prevent several side effects and a number of novel compounds such as bioactive peptides, chitooligosaccharide derivatives (COS) and phlorotannins have been derived from marine organisms as potential ACE inhibitors. These inhibitory derivatives can be developed as nutraceuticals and pharmaceuticals with potential to prevent hypertension. Hence, the aim of this review is to discuss the marine-derived ACE inhibitors and their future prospects as novel therapeutic drug candidates for treat hypertension. PMID:20479968

  4. Characterization of angiotensin converting enzyme (ACE) in the testis and assessment of the in vivo effects of the ACE inhibitor perindopril

    SciTech Connect

    Jackson, B.; Cubela, R.B.; Sakaguchi, K.; Johnston, C.I.

    1988-07-01

    Angiotensin converting enzyme (ACE) was characterized by radioligand studies utilizing the potent ACE inhibitor 351A, a derivative of lisinopril. Ligand binding characteristics were similar for ACE derived from testis, lung, and kidney, despite known differences in structure between ACe from these sources. This observation suggests that the ACE active enzymatic site is similar in different tissues. The effect of the orally active ACE inhibitor perindopril was studied ex vivo in tissues of the rat after oral gavage. Radioligand bound to tissue ACE was reduced after perindopril treatment, in tissue homogenates of lung and kidney, but not testis. Autoradiographs of radioligand binding to tissue sections obtained ex vivo after oral perindopril showed inhibition of ACE in the aorta, lung, and kidney, but did not reveal any inhibition of ACE in the testis. ACE in small vessels of the testis was inhibited as in the aorta, while at the same time testicular ACE was unaffected. ACE in rat testis appears to have a similar enzymatic binding site to ACE from the lung and kidney. Perindopril inhibited ACE in the lung and kidney but did not affect ACE in the testis, suggesting the drug is limited in testicular penetration by the blood-testis barrier. This may explain the lack of any reports of adverse effects of ACE inhibitors on testicular function.

  5. The binding of metal ions and angiotensin converting enzyme (ACE) inhibitor by 13C NMR

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yohko; Sakamoto, Yuko; Ishii, Tomoko; Ohmoto, Taichi

    1991-06-01

    Enalaprilat (MK-422, 1- [ N- [1 (S)-carboxy-3-phenylpropyl]- L-alanyl]- L-proline (1)) and Lisinopril (MK521, N- N- [ (s)-l-carboxy-3- phenylpropyl]- L-lysyl- L-proline, (2)) exhibit the capacity to act as a chelate, unidentate or bridge towards metal ions in aqueous solution, as determined by 13C NMR. By adding metal ions, in the series of Zn 2+, Ni 2+, Pb 2+, Pd 2+ and Cd 2+, the active site of the ACE inhibitor was well defined. MK-521 was more influenced by nuclei that were distant from the active site than MK-422.

  6. Identification of a new angiotensin-converting enzyme (ACE) inhibitor from Thai edible plants.

    PubMed

    Simaratanamongkol, Arunee; Umehara, Kaoru; Noguchi, Hiroshi; Panichayupakaranant, Pharkphoom

    2014-12-15

    Eight Thai edible plants were tested for their inhibitory activity against an angiotensin-converting enzyme (ACE) using an in vitro assay. The methanol extract of Apium graveolens exhibited significant ACE inhibitory activity with an IC50 value of 1.7 mg/ml, and was then subjected to an isolation procedure that resulted in identification of a pure active constituent, junipediol A 8-O-β-d-glucoside (1-β-d-glucosyloxy-2-(3-methoxy-4-hydroxyphenyl)-propane-1,3-diol) (1), which had good ACE inhibitory activity with an IC50 value of 76 μg/ml. Another eight known compounds, isofraxidin-β-d-glucoside (2), roseoside (3), apigenin-7-O-β-d-glucoside (4), luteolin-7-O-β-d-glucoside (5), icariside D2 (6), apiin (7), chrysoeriol-7-O-β-d-apiosylglucoside (8), and 11,21-dioxo-3 β,15 α,24-trihydroxyurs-12-ene-24-O-β-d-glucopyranoside (9) were also identified. Although each of these five constituents (2-6) isolated from the same fraction as 1 showed no activity at concentrations of 500 μM, together, when each was present at 300 μg/ml, they enhanced the inhibitory activity of 500 μM of 1 from 64% to 81%. PMID:25038653

  7. Discovery of new angiotensin converting enzyme (ACE) inhibitors from medicinal plants to treat hypertension using an in vitro assay

    PubMed Central

    2013-01-01

    Background and purpose of the study Angiotensin converting enzyme (ACE) inhibitors plays a critical role in treating hypertension. The purpose of the present investigation was to evaluate ACE inhibition activity of 50 Iranian medicinal plants using an in vitro assay. Methods The ACE activity was evaluated by determining the hydrolysis rate of substrate, hippuryl-L-histidyl-L-leucine (HHL), using reverse phase high performance liquid chromatography (RP-HPLC). Total phenolic content and antioxidant activity were determined by Folin-Ciocalteu colorimetric method and DPPH radical scavenging assay respectively. Results Six extracts revealed > 50% ACE inhibition activity at 330 μg/ml concentration. They were Berberis integerrima Bunge. (Berberidaceae) (88.2 ± 1.7%), Crataegus microphylla C. Koch (Rosaceae) (80.9 ± 1.3%), Nymphaea alba L. (Nymphaeaceae) (66.3 ± 1.2%), Onopordon acanthium L. (Asteraceae) (80.2 ± 2.0%), Quercus infectoria G. Olivier. (Fagaceae) (93.9 ± 2.5%) and Rubus sp. (Rosaceae) (51.3 ± 1.0%). Q. infectoria possessed the highest total phenolic content with 7410 ± 101 mg gallic acid/100 g dry plant. Antioxidant activity of Q. infectoria (IC50 value 1.7 ± 0.03 μg/ml) was more than that of BHT (IC50 value of 10.3 ± 0.15 μg/ml) and Trolox (IC50 value of 3.2 ± 0.06 μg/ml) as the positive controls. Conclusions In this study, we introduced six medicinal plants with ACE inhibition activity. Despite the high ACE inhibition and antioxidant activity of Q. infectoria, due to its tannin content (tannins interfere in ACE activity), another plant, O. acanthium, which also had high ACE inhibition and antioxidant activity, but contained no tannin, could be utilized in further studies for isolation of active compounds. PMID:24359711

  8. Unraveling the Pivotal Role of Bradykinin in ACE Inhibitor Activity.

    PubMed

    Taddei, Stefano; Bortolotto, L

    2016-10-01

    Historically, the first described effect of an angiotensin converting enzyme (ACE) inhibitor was an increased activity of bradykinin, one of the substrates of ACE. However, in the subsequent years, molecular models describing the mechanism of action of ACE inhibitors in decreasing blood pressure and cardiovascular risk have focused mostly on the renin-angiotensin system. Nonetheless, over the last 20 years, the importance of bradykinin in regulating vasodilation, natriuresis, oxidative stress, fibrinolysis, inflammation, and apoptosis has become clearer. The affinity of ACE appears to be higher for bradykinin than for angiotensin I, thereby suggesting that ACE inhibitors may be more effective inhibitors of bradykinin degradation than of angiotensin II production. Data describing the effect of ACE inhibition on bradykinin signaling support the hypothesis that the most cardioprotective benefits attributed to ACE inhibition may be due to increased bradykinin signaling rather than to decreased angiotensin II signaling, especially when high dosages of ACE inhibitors are considered. In particular, modulation of bradykinin in the endothelium appears to be a major target of ACE inhibition. These new mechanistic concepts may lead to further development of strategies enhancing the bradykinin signaling. PMID:27260014

  9. ACE inhibitor potentiation of bradykinin-induced venoconstriction

    PubMed Central

    Hecker, Markus; Blaukat, Andree; Bara, Agnieszka T; Müller-Esterl, Werner; Busse, Rudi

    1997-01-01

    Angiotensin-converting enzyme (ACE) inhibitors exert their cardiovascular effects not only by preventing the formation of angiotensin II (AII), but also by promoting the accumulation of bradykinin in or at the vessel wall. In addition, certain ACE inhibitors have been shown to augment the vasodilator response to bradykinin, presumably by an interaction at the level of the B2 receptor. We have investigated whether this is a specific effect of the ACE inhibitor class of compounds in isolated endothelium-denuded segments of the rabbit jugular vein where bradykinin elicits a constrictor response which is exclusively mediated by activation of the B2 receptor. Moexiprilat and ramiprilat (⩽ 3 nM) enhanced the constrictor response to bradykinin three to four fold. Captopril and enalaprilat were less active by approximately one and quinaprilat by two orders of magnitude. Moexiprilat and ramiprilat, on the other hand, had no effect on the constrictor response to AII or the dilator response to acetylcholine. The bradykinin-potentiating effect of the ACE inhibitors was not mimicked by inhibitors of amino-, carboxy-, metallo- or serine peptidases or the synthetic ACE substrate, hippuryl-L-histidyl-L-leucine, at a concentration which almost abolished the residual ACE activity in the vessel wall. In contrast, angiotensin-(1–7) (10 μM), an angiotensin I metabolite, significantly enhanced the constrictor response to bradykinin. Ramiprilat did not alter the binding of [3H]-bradykinin to a membrane fraction prepared from endothelium-denuded rabbit jugular veins or to cultured fibroblasts, and there was no ACE inhibitor-sensitive, bradykinin-induced cleavage of the B2 receptor in cultured endothelial cells. These findings demonstrate that ACE inhibitors selectively potentiate the B2 receptor-mediated vascular effects of bradykinin. Their relative efficacy appears to be independent of their ACE-inhibiting properties and might be related to differences in molecule structure

  10. Effect of ace inhibitors and TMOF on growth, development, and trypsin activity of larval Spodoptera littoralis.

    PubMed

    Lemeire, Els; Borovsky, Dov; Van Camp, John; Smagghe, Guy

    2008-12-01

    Angiotensin converting enzyme (ACE) is a zinc metallopeptidase capable of cleaving dipeptide or dipeptideamide moieties at the C-terminal end of peptides. ACE is present in the hemolymph and reproductive tissues of insects. The presence of ACE in the hemolymph and its broad substrate specificity suggests an important role in processing of bioactive peptides. This study reports the effects of ACE inhibitors on larval growth in the cotton leafworm Spodoptera littoralis. Feeding ACE inhibitors ad lib decreased the growth rate, inhibited ACE activity in the larval hemolymph, and down-regulated trypsin activity in the larval gut. These results indicate that S. littoralis ACE may influence trypsin biosynthesis in the larval gut by interacting with a trypsin-modulating oostatic factor (TMOF). Injecting third instar larvae with a combination of Aea-TMOF and the ACE inhibitor captopril, down-regulated trypsin biosynthesis in the larval gut indicating that an Aea-TMOF gut receptor analogue could be present. Injecting captopril and enalapril into newly molted fifth instar larvae stopped larval feeding and decreased weight gain. Together, these results indicate that ACE inhibitors are efficacious in stunting larval growth and ACE plays an important role in larval growth and development. PMID:18949805

  11. Transdermal delivery of Angiotensin Converting Enzyme inhibitors.

    PubMed

    Helal, Fouad; Lane, Majella E

    2014-09-01

    The Angiotensin Converting Enzyme (ACE) inhibitor class of drugs has been in clinical use since the 1970s for the management of all grades of heart failure, hypertension, diabetic nephropathy and prophylaxis of cardiovascular events. Because of the advantages associated with transdermal delivery compared with oral delivery many researchers have investigated the skin as a portal for administration of ACE inhibitors. This review summarises the various studies reported in the literature describing the development and evaluation of transdermal formulations of ACE inhibitors. Captopril, enalapril maleate, lisinopril dihydrate, perindopril erbumine and trandolapril are the most studied in connection with transdermal preparations. The methodologies reported are considered critically and the limitations of the various skin models used are also highlighted. Finally, opportunities for novel transdermal preparations of ACE inhibitor drugs are discussed with an emphasis on rational formulation design. PMID:24657822

  12. Angiotensin-converting enzyme inhibitors in veterinary medicine.

    PubMed

    Lefebvre, H P; Brown, S A; Chetboul, V; King, J N; Pouchelon, J-L; Toutain, P L

    2007-01-01

    Angiotensin-converting enzyme (ACE) inhibitors represent one of the most commonly used categories of drugs in canine and feline medicine. ACE inhibitors currently approved for use in veterinary medicine are benazepril, enalapril, imidapril and ramipril. They are all pro-drugs administered by oral route. A physiologically based model taking into account the saturable binding to ACE has been developed for pharmacokinetic analysis. The bioavailability of the active compounds from their respective pro-drug is low. The active metabolites are eliminated by renal, hepatorenal or biliary excretion, according to the drug. The elimination half-life of the free fraction of the active compounds is very short (ranging from approximately 10 min to 2 h). ACE inhibitors are generally well tolerated. Benazepril, enalapril, imidapril and ramipril are approved for dogs with chronic heart failure (CHF). The efficacy of ACE inhibitors has been convincingly demonstrated in dogs with CHF, especially in those with chronic valvular disease. In such clinical settings, ACE inhibitors improve hemodynamics and clinical signs, and increase survival time. In cats with cardiovascular disease, little information is available except for reports of some benefit in cats with hypertrophic cardiomyopathy in two non-controlled investigations. ACE inhibitors have also a mild to moderate hypotensive effect. There is also evidence to recommend ACE inhibitors in dogs and cats with chronic renal failure (CRF). They decrease the glomerular capillary pressure, have antiproteinuric effects, tend to delay the progression of CRF and to limit the extent of renal lesions. PMID:17506720

  13. Essential fatty acids and their metabolites could function as endogenous HMG-CoA reductase and ACE enzyme inhibitors, anti-arrhythmic, anti-hypertensive, anti-atherosclerotic, anti-inflammatory, cytoprotective, and cardioprotective molecules.

    PubMed

    Das, Undurti N

    2008-01-01

    Lowering plasma low density lipoprotein-cholesterol (LDL-C), blood pressure, homocysteine, and preventing platelet aggregation using a combination of a statin, three blood pressure lowering drugs such as a thiazide, a beta blocker, and an angiotensin converting enzyme (ACE) inhibitor each at half standard dose; folic acid; and aspirin-called as polypill- was estimated to reduce cardiovascular events by approximately 80%. Essential fatty acids (EFAs) and their long-chain metabolites: gamma-linolenic acid (GLA), dihomo-GLA (DGLA), arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and other products such as prostaglandins E1 (PGE1), prostacyclin (PGI2), PGI3, lipoxins (LXs), resolvins, protectins including neuroprotectin D1 (NPD1) prevent platelet aggregation, lower blood pressure, have anti-arrhythmic action, reduce LDL-C, ameliorate the adverse actions of homocysteine, show anti-inflammatory actions, activate telomerase, and have cytoprotective properties. Thus, EFAs and their metabolites show all the classic actions expected of the "polypill". Unlike the proposed "polypill", EFAs are endogenous molecules present in almost all tissues, have no significant or few side effects, can be taken orally for long periods of time even by pregnant women, lactating mothers, and infants, children, and adults; and have been known to reduce the incidence cardiovascular diseases including stroke. In addition, various EFAs and their long-chain metabolites not only enhance nitric oxide generation but also react with nitric oxide to yield their respective nitroalkene derivatives that produce vascular relaxation, inhibit neutrophil degranulation and superoxide formation, inhibit platelet activation, and possess PPAR-gamma ligand activity and release NO, thus prevent platelet aggregation, thrombus formation, atherosclerosis, and cardiovascular diseases. Based on these evidences, I propose that a rational combination of omega-3 and omega-6 fatty acids and the

  14. [Trials with ACE-inhibitors in acute myocardial infarction].

    PubMed

    Dalla Volta, S

    1994-12-01

    In acute myocardial infarction, the results of the trials with ACE-inhibitors have not been always good, in contrast with what has been observed in chronic heart failure. The comparison of these compounds with the placebo has demonstrated lack of reduction of mortality in the study CONSENSUS II, favorable results on the survival as first endpoint and on the secondary endpoints, as reinfarction, heart failure and stroke in the studies SOLVD, AIRE, GISSI 3, ISIS 4, and uncertain (interim report) results in the Chinese study. Nevertheless, the analysis of the recruitment of the patients with acute infarction and the way these patients have been treated seem to be the most important cause of the conflicting results. ACE-inhibitors have proved no efficacy in acute myocardial infarction without signs of left ventricular failure (CONSENSUS II), have worsened the clinical picture and the mortality in patients in shock or with severe heart failure in the acute phase. On the reverse, in presence of mild to moderate left ventricular dysfunction and failure, the use of ACE-inhibitors has been followed by reduction of mortality in the early (AIRE, GISSI 3, ISIS 4), medium term (GISSI 3) and long-term follow-up (up to 4 years in the AIRE study). In parallel with the reduction of the primary endpoint, also secondary endpoints have been favorably influenced by the different ACE-inhibitors. No differences have been observed among the different class of compounds. ACE-inhibitors seem, therefore, to have a clear indication in acute myocardial infarction with mild or moderate signs and symptoms of heart failure. PMID:7634258

  15. Angiotensin converting enzyme inhibitors as oxygen free radical scavengers.

    PubMed

    Mira, M L; Silva, M M; Queiroz, M J; Manso, C F

    1993-01-01

    The authors have compared the ability of two non-SH-containing angiotensin converting enzyme (ACE) inhibitors (enalaprilat and lisinopril) with an -SH containing ACE inhibitor (captopril) to scavenge the hydroxyl radical (.OH). All three compounds were able to scavenge .OH radicals generated in free solution at approximately diffusion-controlled rates (10(10) M-1 s-1) as established by the deoxyribose assay in the presence of EDTA. The compounds also inhibited deoxyribose degradation in reaction mixtures which did not contain EDTA but not so effectively. This later findings also suggests that they have some degree of metal-binding capability. Chemiluminescence assays of oxidation of hypoxanthine by xanthine oxidase in the presence of luminol, confirm that the three ACE inhibitors are oxygen free radical scavengers. Our results indicate that the presence of a sulphydryl group in the chemical structure of ACE inhibitors is not relevant for their oxygen free radical scavenging ability. PMID:8244086

  16. ACE

    NASA Technical Reports Server (NTRS)

    Lumia, R.

    1999-01-01

    This document describes the progress made during the fourth year of the Center for Autonomous Control Engineering (ACE). We currently support 30 graduate students, 52 undergraduate students, 9 faculty members, and 4 staff members. Progress will be divided into two categories. The first category explores progress for ACE in general. The second describes the results of each specific project supported within ACE.

  17. Acute abdomen due to intestinal angioedema induced by ACE inhibitors: not so rare?

    PubMed

    Dobbels, P; Van Overbeke, L; Vanbeckevoort, D; Hiele, M

    2009-01-01

    During the last 5 years we identified 7 patients with a history of episodic acute abdominal pain and subobstruction due to intestinal angioedema secondary to the use of Angiotensin Converting Enzyme (ACE) inhibitors. These cases were all diagnosed in one gastroenterology department. This is thereby the largest single centre case series of ACE inhibitor-induced angioedema that has been published until now. Our findings suggest that this syndrome is far more frequent than international literature would let us believe. We also describe one of the first male cases diagnosed with this entity for which there is a significant female predominance. In the presence of an appropriate history and suggestive findings on CT scan, this diagnosis can relatively easily be made if one is sufficiently intent on it. An appropriate diagnosis can save these patients a lot of unnecessary diagnostic procedures and discomfort. PMID:20163043

  18. Binding of ACE-inhibitors to in vitro and patient-derived amyloid-β fibril models

    NASA Astrophysics Data System (ADS)

    Bhavaraju, Manikanthan; Phillips, Malachi; Bowman, Deborah; Aceves-Hernandez, Juan M.; Hansmann, Ulrich H. E.

    2016-01-01

    Currently, no drugs exist that can prevent or reverse Alzheimer's disease, a neurodegenerative disease associated with the presence, in the brain, of plaques that are composed of β-amyloid (Aβ) peptides. Recent studies suggest that angiotensin-converting enzyme (ACE) inhibitors, a set of drugs used to treat hypertension, may inhibit amyloid formation in vitro. In the present study, we investigate through computer simulations the binding of ACE inhibitors to patient-derived Aβ fibrils and contrast it with that of ACE inhibitors binding to in vitro generated fibrils. The binding affinities of the ACE inhibitors are compared with that of Congo red, a dye that is used to identify amyloid structures and that is known to be a weak inhibitor of Aβ aggregation. We find that ACE inhibitors have a lower binding affinity to the patient-derived fibrils than to in vitro generated ones. For patient-derived fibrils, their binding affinities are even lower than that of Congo red. Our observations raise doubts on the hypothesis that these drugs inhibit fibril formation in Alzheimer patients by interacting directly with the amyloids.

  19. An angiotensin-converting enzyme (ACE) polymorphism may mitigate the effects of angiotensin-pathway medications on posttraumatic stress symptoms.

    PubMed

    Nylocks, K M; Michopoulos, V; Rothbaum, A O; Almli, L; Gillespie, C F; Wingo, A; Schwartz, A C; Habib, L; Gamwell, K L; Marvar, P J; Bradley, B; Ressler, K J

    2015-06-01

    Angiotensin, which regulates blood pressure may also act within the brain to mediate stress and fear responses. Common antihypertensive medication classes of angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) have been associated with lower PTSD symptoms. Here we examine the rs4311 SNP in the ACE gene, previously implicated in panic attacks, in the relationship between ACE-I/ARB medications and PTSD symptoms. Participants were recruited from outpatient wait rooms between 2006 and March 2014 (n=  803). We examined the interaction between rs4311 genotype and the presence of blood pressure medication on PTSD symptoms and diagnosis. PTSD symptoms were lower in individuals taking ACE-Is or ARBs (N = 776). The rs4311 was associated with PTSD symptoms and diagnosis (N = 3803), as the T-carriers at the rs4311 SNP had significantly greater likelihood of a PTSD diagnosis. Lastly, the rs4311 genotype modified the effect of ACE-Is or ARBs on PTSD symptoms (N = 443; F1,443 = 4.41, P < 0.05). Individuals with the CC rs4311 genotype showed lower PTSD symptoms in the presence of ACE-Is or ARBs. In contrast, T- carriers showed the opposite, such that the presence of ACE-Is or ARBs was associated with higher PTSD symptoms. These data suggest that the renin-angiotensin system may be important in PTSD, as ACE-I/ARB usage associates with lower symptoms. Furthermore, we provide genetic evidence that some individuals are comparatively more benefitted by ACE-Is/ARBs in PTSD treatment. Future research should examine the mechanisms by which ACE-Is/ARBs affect PTSD symptoms such that pharmaco-genetically informed interventions may be used to treat PTSD. PMID:25921615

  20. Angiotensin-converting enzyme levels and activity in Alzheimer's disease: differences in brain and CSF ACE and association with ACE1 genotypes

    PubMed Central

    Miners, Scott; Ashby, Emma; Baig, Shabnam; Harrison, Rachel; Tayler, Hannah; Speedy, Elizabeth; Prince, Jonathan A; Love, Seth; Kehoe, Patrick G

    2009-01-01

    Angiotensin-converting enzyme (ACE) has been implicated in Alzheimer's disease (AD): ACE1 variations influence plasma ACE and risk of AD, and ACE is increased in AD brain. We measured frontal ACE level and activity in 89 AD and 51 control brains, and post-mortem CSF from 101 cases and 19 controls. Neuron-specific enolase (NSE) level and Braak stage were used to indicate neuronal preservation and disease progression. We genotyped the common ACE insertion/deletion polymorphism, rs4343, rs1800764 and rs4921. ACE activity was elevated in AD and correlated with Braak stage. Crude ACE levels were unchanged but adjustment for NSE suggested increased neuronal ACE production with Braak stage. Exposing SH-SY-5Y neurons to oligomeric Aβ1-42 increased ACE level and activity, suggesting Aβ may upregulate ACE in AD. In CSF, ACE level but not activity was reduced in AD. ACE1 genotype did not predict ACE level or activity in brain or CSF. ACE activity and neuronal production increase in AD brain, possibly in response to Aβ. Peripheral measurements do not reflect ACE activity in the brain. PMID:19956428

  1. ACE inhibitors can induce circulating antibodies directed to antigens of the superficial epidermal cells.

    PubMed

    Cozzani, Emanuele; Rosa, Gian Marco; Drosera, Massimo; Intra, Chiara; Barsotti, Antonio; Parodi, Aurora

    2011-07-01

    Drug-induced pemphigus has been reported in patients receiving angiotensin-converting enzyme inhibitors. The aim of this work was to study a group of hypertensive patients without skin diseases treated with angiotensin-converting enzyme (ACE) Inhibitors (I), to verify the presence of serum circulating anti-antibodies. The indirect immunofluorescence showed that 33 sera (52.38%) presented autoantibodies directed to an antigen of the cytoplasm of the superficial epidermal keratinocytes. Two of the 33 positive sera had antibodies to Dsg1 and/or 3 in ELISA. Immunoblot analyses were negative. All the 48 control sera were found to have no circulating antibodies using the three assays. Our results would confirm that ACEI drugs may trigger the production of circulating autoantibodies also in patients without clinical manifestations of pemphigus. PMID:20563876

  2. Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity and ACE Inhibitory Peptides of Salmon (Salmo salar) Protein Hydrolysates Obtained by Human and Porcine Gastrointestinal Enzymes

    PubMed Central

    Darewicz, Małgorzata; Borawska, Justyna; Vegarud, Gerd E.; Minkiewicz, Piotr; Iwaniak, Anna

    2014-01-01

    The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE) inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes) and ex vivo digestion (with human gastrointestinal enzymes). Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50%) of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes. PMID:25123137

  3. Risk-benefit ratio of angiotensin antagonists versus ACE inhibitors in end-stage renal disease.

    PubMed

    Sica, D A; Gehr, T W; Fernandez, A

    2000-05-01

    The effective treatment of hypertension is an extremely important consideration in patients with end-stage renal disease (ESRD). Virtually any drug class--with the possible exception of diuretics--can be used to treat hypertension in the patient with ESRD. Despite there being such a wide range of treatment options, drugs which interrupt the renin-angiotensin axis are generally suggested as agents of choice in this population, even though the evidence in support of their preferential use is quite scanty. ACE inhibitors, and more recently angiotensin antagonists, are the 2 drug classes most commonly employed to alter renin-angiotensin axis activity and therefore produce blood pressure control. ACE inhibitor use in patients with ESRD can sometimes prove an exacting proposition. ACE inhibitors are variably dialysed, with compounds such as catopril, enalapril, lisinopril and perindopril undergoing substantial cross-dialyser clearance during a standard dialysis session. This phenomenon makes the selection of a dose and the timing of administration for an ACE inhibitor a complex issue in patients with ESRD. Furthermore, ACE inhibitors are recognised as having a range of nonpressor effects that are pertinent to patients with ESRD. Such effects include their ability to decrease thirst drive and to decrease erythropoiesis. In addition, ACE inhibitors have a unique adverse effect profile. As is the case with their use in patients without renal failure, use of ACE inhibitors in patients with ESRD can be accompanied by cough and less frequently by angioneurotic oedema. In the ESRD population, ACE inhibitor use is also accompanied by so-called anaphylactoid dialyser reactions. Angiotensin antagonists are similar to ACE inhibitors in their mechanism of blood pressure lowering. Angiotensin antagonists are not dialysable and therefore can be distinguished from a number of the ACE inhibitors. In addition, the adverse effect profile for angiotensin antagonists is remarkably bland

  4. 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.

  5. Occurrence and fate of ACE-inhibitor peptides in cheeses and in their digestates following in vitro static gastrointestinal digestion.

    PubMed

    Stuknytė, Milda; Cattaneo, Stefano; Masotti, Fabio; De Noni, Ivano

    2015-02-01

    The occurrence of the casein-derived angiotensin converting enzyme-inhibitor (ACE-I) peptides VPP, IPP, RYLGY, RYLG, AYFYPEL, AYFYPE, LHLPLP and HLPLP were investigated in 12 different cheese samples by Ultra Performance Liquid Chromatography/High-Resolution Mass Spectrometry. The total amount of ACE-I peptides was in the range 0.87-331mgkg(-1). VPP and IPP largely prevailed in almost all cheeses. Following in vitro static gastrointestinal digestion of Cheddar, Gorgonzola, Maasdam and Grana Padano cheeses, type and amount of ACE-I peptides changed, and only VPP, IPP, HLPLP and LHLPLP were detected in the intestinal digestates. The results evidenced that the degree of proteolysis itself cannot be regarded as a promoting or hindering factor for ACE-I peptide release during cheese digestion. Moreover, the data indicated that the ACE-I potential of cheeses cannot be inferred based on the type and amount of ACE-I peptides present in undigested samples. PMID:25172679

  6. Choice of ACE inhibitor combinations in hypertensive patients with type 2 diabetes: update after recent clinical trials

    PubMed Central

    Reboldi, Gianpaolo; Gentile, Giorgio; Angeli, Fabio; Verdecchia, Paolo

    2009-01-01

    The diabetes epidemic continues to grow unabated, with a staggering toll in micro- and macrovascular complications, disability, and death. Diabetes causes a two- to fourfold increase in the risk of cardiovascular disease, and represents the first cause of dialysis treatment both in the UK and the US. Concomitant hypertension doubles total mortality and stroke risk, triples the risk of coronary heart disease and significantly hastens the progression of microvascular complications, including diabetic nephropathy. Therefore, blood pressure reduction is of particular importance in preventing cardiovascular and renal outcomes. Successful antihypertensive treatment will often require a combination therapy, either with separate drugs or with fixed-dose combinations. Angiotensin converting enzyme (ACE) inhibitor plus diuretic combination therapy improves blood pressure control, counterbalances renin-angiotensin system activation due to diuretic therapy and reduces the risk of electrolyte alterations, obtaining at the same time synergistic antiproteinuric effects. ACE inhibitor plus calcium channel blocker provides a significant additive effect on blood pressure reduction, may have favorable metabolic effects and synergistically reduce proteinuria and the rate of decline in glomerular filtration rate, as evidenced by the GUARD trial. Finally, the recently published ACCOMPLISH trial showed that an ACE inhibitor/calcium channel blocker combination may be particularly useful in reducing cardiovascular outcomes in high-risk patients. The present review will focus on different ACE inhibitor combinations in the treatment of patients with type 2 diabetes mellitus and hypertension, in the light of recent clinical trials, including GUARD and ACCOMPLISH. PMID:19475778

  7. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  8. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, Joanna S.; MacGregor, Robert R.; Wolf, Alfred P.; Langstrom, Bengt

    1990-01-01

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  9. Positron emitter labeled enzyme inhibitors

    SciTech Connect

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-04-03

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  10. [A Case of Life-Threatening Angioedema Occurred During Prolonged Angiotensin-Converting Enzyme Inhibitor Treatment].

    PubMed

    Nakamura, Rintaro; Nihei, Shun-Ichi; Arai, Hideaki; Nagata, Keiji; Isa, Yasuki; Harayama, Nobuya; Aibara, Keiji; Kamochi, Msayuki

    2016-03-01

    Although angiotensin-converting enzyme (ACE) inhibitors are widely used as the first choice drug for treating hypertension, we have only a superficial understanding of their relationship to angioedema. We report a case of life-threatening angioedema. The case was a 60-year-old man who had been taking an ACE inhibitor for hypertension for 11 years. He visited his home doctor for dyspnea, and tongue and neck swelling. He was transported to our hospital because of the possibility of airway obstruction. On admission, his tongue and neck swelling became more severe. We performed an intubation using an endoscope and started airway management. We also stopped his ACE inhibitor. The severe tongue and neck swelling improved gradually and he was extubated on day 3. On the fifth day he was discharged. We diagnosed angioedema caused by an ACE inhibitor. Although the risk of airway obstruction with ACE inhibitors is acknowledged, we have only a superficial understanding of how prolonged ACE inhibitor treatment induces angioedema. So we should consider angioedema in cases of taking ACE inhibitors, especially in cases of prolonged treatment. PMID:26972946

  11. Pollen Count and Presentation of Angiotensin-Converting Enzyme Inhibitor-Associated Angioedema

    PubMed Central

    Straka, Brittany; Nian, Hui; Sloan, Chantel; Byrd, James Brian; Woodard-Grice, Alencia; Yu, Chang; Stone, Elizabeth; Steven, Gary; Hartert, Tina; Teo, Koon K.; Pare, Guillaume; McCarty, Catherine A.; Brown, Nancy J.

    2014-01-01

    BACKGROUND The incidence of angiotensin-converting enzyme (ACE) inhibitor-associated angioedema is increased in patients with seasonal allergies. OBJECTIVE We tested the hypothesis that patients with ACE inhibitor-associated angioedema present during months when pollen counts are increased. METHODS Cohort analysis examined the month of presentation of ACE inhibitor-associated angioedema and pollen counts in the ambulatory and hospital setting. Patients with ACE inhibitor-associated angioedema were ascertained through (1) an observational study of patients presenting to Vanderbilt University Medical Center, (2) patients presenting to the Marshfield Clinic and participating in the Marshfield Clinic Personalized Medicine Research Project, and (3) patients enrolled in The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET). Measurements include date of presentation of ACE inhibitor-associated angioedema, population exposure to ACE inhibitor by date, and local pollen counts by date. RESULTS At Vanderbilt, the rate of angioedema was significantly associated with tree pollen months (P = .01 from χ2 test). When separate analyses were conducted in patients with a history of seasonal allergies and patients without, the rate of ACE inhibitor-associated angioedema was increased during tree pollen months only in patients with a history of seasonal allergies (P = .002). In Marshfield, the rate of angioedema was significantly associated with ragweed pollen months (P = .025). In ONTARGET, a positive trend was observed between the ACE inhibitor-associated angioedema rate and grass season, although it was not statistically significant (P = .057). CONCLUSIONS Patients with ACE inhibitor-associated angioedema are more likely to present with this adverse drug event during months when pollen counts are increased. PMID:24565618

  12. DNA Methylation Analysis of the Angiotensin Converting Enzyme (ACE) Gene in Major Depression

    PubMed Central

    Zill, Peter; Baghai, Thomas C.; Schüle, Cornelius; Born, Christoph; Früstück, Clemens; Büttner, Andreas; Eisenmenger, Wolfgang; Varallo-Bedarida, Gabriella; Rupprecht, Rainer; Möller, Hans-Jürgen; Bondy, Brigitta

    2012-01-01

    Background The angiotensin converting enzyme (ACE) has been repeatedly discussed as susceptibility factor for major depression (MD) and the bi-directional relation between MD and cardiovascular disorders (CVD). In this context, functional polymorphisms of the ACE gene have been linked to depression, to antidepressant treatment response, to ACE serum concentrations, as well as to hypertension, myocardial infarction and CVD risk markers. The mostly investigated ACE Ins/Del polymorphism accounts for ∼40%–50% of the ACE serum concentration variance, the remaining half is probably determined by other genetic, environmental or epigenetic factors, but these are poorly understood. Materials and Methods The main aim of the present study was the analysis of the DNA methylation pattern in the regulatory region of the ACE gene in peripheral leukocytes of 81 MD patients and 81 healthy controls. Results We detected intensive DNA methylation within a recently described, functional important region of the ACE gene promoter including hypermethylation in depressed patients (p = 0.008) and a significant inverse correlation between the ACE serum concentration and ACE promoter methylation frequency in the total sample (p = 0.02). Furthermore, a significant inverse correlation between the concentrations of the inflammatory CVD risk markers ICAM-1, E-selectin and P-selectin and the degree of ACE promoter methylation in MD patients could be demonstrated (p = 0.01 - 0.04). Conclusion The results of the present study suggest that aberrations in ACE promoter DNA methylation may be an underlying cause of MD and probably a common pathogenic factor for the bi-directional relationship between MD and cardiovascular disorders. PMID:22808171

  13. Angiotensin-converting enzyme inhibitor (enalapril maleate) accelerates recovery of mouse skin from UVB-induced wrinkles

    SciTech Connect

    Matsuura-Hachiya, Yuko; Arai, Koji Y.; Ozeki, Rieko; Kikuta, Ayako; Nishiyama, Toshio

    2013-12-06

    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 recovery 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.

  14. Adipocyte-derived lipids increase angiotensin-converting enzyme (ACE) expression and modulate macrophage phenotype.

    PubMed

    Kohlstedt, Karin; Trouvain, Caroline; Namgaladze, Dmitry; Fleming, Ingrid

    2011-03-01

    Human monocytes/macrophages express the angiotensin-converting enzyme (ACE) but nothing is known about its role under physiological conditions. As adipose tissue contains resident macrophages that have been implicated in the generation of insulin resistance in expanding fat mass, we determined whether adipocytes release factors that affect ACE expression and function in monocytes. Incubation of human monocyte-derived macrophages with conditioned medium from freshly isolated human adipocytes (BMI = 25.4 ± 0.96) resulted in a 4-fold increase in ACE expression. The effect was insensitive to denaturation and different proteases but abolished after lipid extraction. mRNA levels of the major histocompatibility complex class II protein increased in parallel with ACE, whereas the expression of tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6, and cyclooxygenase-2 decreased. As a consequence of the reduction in MCP-1, monocyte recruitment was also attenuated. Moreover, adipocyte-conditioned medium prevented the interferon (IFN)-γ induced formation of TNF-α, IL-6, and MCP-1, all markers of classically-activated (M1 type) macrophages. The decrease in cytokine expression in adipocyte-conditioned medium-treated macrophages was sensitive to ACE silencing by small interfering RNA (siRNA). Accordingly, ACE overexpression in THP-1 cells mimicked the effect of adipocyte-conditioned medium. In both cell types, ACE inhibition failed to affect the changes induced by adipocyte conditioned-medium treatment and ACE overexpression. Thus, the modulation of macrophage polarization by ACE appears to be mediated independently of enzyme activity, probably via intracellular signaling. Interestingly, human macrophage ACE expression was also upregulated by IL-4 and IL-13, which promote the "alternative" activation of macrophages and decreased by LPS and IFN-γ. Mechanistically, adipocyte-conditioned medium stimulated the phosphorylation of

  15. Cardiovascular risk reduction by reversing endothelial dysfunction:ARBs, ACE inhibitors, or both? Expectations from The ONTARGET Trial Programme

    PubMed Central

    Ruilope, Luis Miguel; Redón, Josep; Schmieder, Roland

    2007-01-01

    Endothelial dysfunction is the initial pathophysiological step in a progression of vascular damage that leads to overt cardiovascular and chronic kidney disease. Angiotensin II, the primary agent of the renin–angiotensin system (RAS), has a central role in endothelial dysfunction. Therefore, RAS blockade with an angiotensin receptor blocker (ARB) and/or angiotensin-converting enzyme (ACE) inhibitor provides a rational approach to reverse endothelial dysfunction, reduce microalbuminuria, and, thus, improves cardiovascular and renal prognosis. ARBs and ACE inhibitors act at different points in the RAS pathway and recent evidence suggests that there are differences regarding their effects on endothelial dysfunction. In addition to blood pressure lowering, studies have shown that ARBs reduce target-organ damage, including improvements in endothelial dysfunction, arterial stiffness, the progression of renal dysfunction in patients with type 2 diabetes, proteinuria, and left ventricular hypertrophy. The ONgoing Telmisartan Alone in combination with Ramipril Global Endpoint Trial (ONTARGET) Programme is expected to provide the ultimate evidence of whether improved endothelial function translates into reduced cardiovascular and renal events in high-risk patients, and to assess possible differential outcomes with telmisartan, the ACE inhibitor ramipril, or a combination of both (dual RAS blockade). Completion of ONTARGET is expected in 2008. PMID:17583170

  16. [The synthesis of specific enzyme inhibitors].

    PubMed

    Iakovleva, G M

    1987-04-01

    The review deals with directed synthesis of specific enzyme inhibitors. They are classified within the framework of the mechanistic approach, namely, stable analogues of substrates, which form enzyme complexes mimicking the Michaelis complex or those which influence the chemical stages of enzyme catalysis; conformational inhibitors; substrate analogues participating in enzyme reactions and producing modified products; suicide inhibitors; stage inhibitors (inhibitors influencing certain stages of enzyme reaction); transition state analogues; multisubstrate analogues and collected substrates. Types of chemical modification used in synthesis of the specific inhibitors are discussed. Some possibilities of the quantity structure-activity relationship methods, computer modelling and molecular graphics in designing the optimal structure of inhibitors are mentioned. PMID:3300658

  17. Angioedema in the emergency department: the impact of angiotensin-converting enzyme inhibitors.

    PubMed

    Pigman, E C; Scott, J L

    1993-07-01

    Angiotensin-converting enzyme (ACE) inhibitors have been reported to cause angioedema. The purpose of this study was to establish what proportion of patients who present to the emergency department (ED) with angioedema were concomitantly taking any of the ACE inhibitors and to show how this group differed in presentation and response to treatment from the larger population of patients with non-ACE inhibitor-related angioedema. An 8-year retrospective chart review of all patients with the diagnosis of angioedema observed from January 1, 1984 to December 31, 1991 was undertaken in the ED of an urban teaching hospital. Forty-nine patients ranging from 12 to 88 years of age with symptoms and physical examination that was consistent with the diagnosis of angioedema were entered onto the study. Twelve cases of ACE inhibitor-related angioedema were identified, all occurring in the last 4 years of the review, and when compared with the non-ACE inhibitor-related group were older (mean age, 63.3 vs 43.0 years), had less of an allergic history (0% vs 49%; P = .013), but demonstrated the same severity of symptoms and response to medical therapy. No case required an artificial or surgical airway. ACE inhibitor related angioedema is becoming a common type of angioedema observed in this ED. These patients are older and free of other allergic disease and respond well to traditional therapy. PMID:8216515

  18. A role for the extracellular matrix component hyaluronan in kidney dysfunction during ACE-inhibitor fetopathy.

    PubMed

    Hansell, P; Palm, F

    2015-04-01

    Despite data showing that inhibitors of the renin-angiotensin system increase the risks of fetal morbidity and dysfunctionality later in life, their use during pregnancy has increased. The fetopathy induced by angiotensin converting enzyme (ACE) inhibitors is characterized by anuria, hypotension and growth restriction, but can also be associated with pulmonary hypoplasia. In the kidney, this fetopathy includes atrophy of the medulla, reduced number of glomeruli, developmental lesions of tubules and vessels, tubulointerstitial inflammation and extracellular matrix accumulation. Although angiotensin II (Ang II) inhibition during nephrogenesis interferes with normal growth and development, this review will focus on effects of the heavily accumulated matrix component hyaluronan (HA). An important mechanism of HA accumulation during nephrogenesis is disruption of its normal reduction as a consequence of lack of Ang II activation of hyaluronidase. Hyaluronan has very large water-attracting properties and is pro-inflammatory when fragmented. The ensuing inflammation and interstitial oedema affect kidney function. Hyaluronan is colocalized with CD44 overexpression and infiltrating immune cells. These properties make HA a plausible contributor to the observed structural and functional kidney defects associated with the fetopathy. Available data support an involvement of HA in kidney dysfunction of the foetus and during adulthood due to the physico-chemical characteristics of HA. No clinical treatment for HA accumulation exists. Treatment with the HA-degrading enzyme hyaluronidase and an HA synthesis inhibitor has been tested successfully in experimental models in the kidney, heart and pancreas. Reduced HA accumulation to reduce interstitial oedema and inflammation may improve organ function, but this concept needs to be tested in a controlled study before causal relationships can be established. PMID:25600777

  19. Ace inhibitor therapy for heart failure in patients with impaired renal function: a review of the literature.

    PubMed

    Valika, Ali A; Gheorghiade, Mihai

    2013-03-01

    Heart failure syndromes are often associated with multi-organ dysfunction, and concomitant liver, renal, and neurologic involvement is very common. Neuro-hormonal antagonism plays a key role in the management of this syndrome, and angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are one of the cornerstones of therapy. Cardiorenal physiology is becoming more recognized in these patients with advanced heart failure, and the role of neuro-hormonal blockade in this setting is vaguely defined in the literature. Often, angiotensin-converting enzyme inhibitors are decreased or even withheld in these circumstances. The purpose of this article is to review the role and pathophysiology of ace inhibition and angiotensin receptor blockade in patients with acute and chronic heart failure syndromes and concomitant cardiorenal physiology. PMID:22213014

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 21 CFR 862.1090 - Angiotensin converting enzyme (A.C.E.) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  5. Inhibition Mechanism and Model of an Angiotensin I-Converting Enzyme (ACE)-Inhibitory Hexapeptide from Yeast (Saccharomyces cerevisiae)

    PubMed Central

    Ni, He; Li, Lin; Liu, Guang; Hu, Song-Qing

    2012-01-01

    Angiotensin I-converting enzyme (ACE) has an important function in blood pressure regulation. ACE-inhibitory peptides can lower blood pressure by inhibiting ACE activity. Based on the sequence of an ACE-inhibitory hexapeptide (TPTQQS) purified from yeast, enzyme kinetics experiments, isothermal titration calorimetry (ITC), and a docking simulation were performed. The hexapeptide was found to inhibit ACE in a non-competitive manner, as supported by the structural model. The hexapeptide bound to ACE via interactions of the N-terminal Thr1, Thr3, and Gln4 residues with the residues on the lid structure of ACE, and the C-terminal Ser6 attracted the zinc ion, which is vital for ACE catalysis. The displacement of the zinc ion from the active site resulted in the inhibition of ACE activity. The structural model based on the docking simulation was supported by experiments in which the peptide was modified. This study provides a new inhibitory mechanism of ACE by a peptide which broads our knowledge for drug designing against enzyme targets. PMID:22606330

  6. ACE Inhibitor Delapril Prevents Ca(2+)-Dependent Blunting of IK1 and Ventricular Arrhythmia in Ischemic Heart Disease.

    PubMed

    Thireau, J; Zalvidea, S; Meschin, P; Pasquie, J-L; Aimond, F; Richard, S

    2015-01-01

    Angiotensin-converting enzyme inhibitors (ACE-I) improve clinical outcome in patients with myocardial infarction (MI) and chronic heart failure. We investigated potential anti-arrhythmic (AA) benefits in a mouse model of ischemic HF. We hypothesized that normalization of diastolic calcium (Ca(2+)) by ACE-I may prevent Ca(2+)-dependent reduction of inward rectifying K(+) current (IK1) and occurrence of arrhythmias after MI. Mice were randomly assigned to three groups: Sham, MI, and MI-D (6 weeks of treatment with ACE-I delapril started 24h after MI). Electrophysiological analyses showed that delapril attenuates MI-induced prolongations of electrocardiogram parameters (QRS complex, QT, QTc intervals) and conduction time from His bundle to ventricular activation. Delapril improved the sympatho-vagal balance (LF/HF) and reduced atrio-ventricular blocks and ventricular arrhythmia. Investigations in cardiomyocytes showed that delapril prevented the decrease of IK1 measured by patch-clamp technique. IK1 reduction was related to intracellular Ca(2+) overload. This reduction was not observed when intracellular free-Ca(2+) was maintained low. Conversely, increasing intracellular free-Ca(2+) in Sham following application of SERCA2a inhibitor thapsigargin reduced IK1. Thapsigargin had no effect in MI animals and abolished the benefits of delapril on IK1 in MI-D mice. Delapril prevented both the prolongation of action potential late repolarization and the depolarization of resting membrane potential, two phenomena known to trigger abnormal electrical activities, promoted by MI. In conclusion, early chronic therapy with delapril after MI prevented Ca(2+)-dependent reduction of IK1. This mechanism may significantly contribute to the antiarrhythmic benefits of ACE-I in patients at risk for sudden cardiac death. PMID:26321755

  7. Exercise-induced ventricular arrhythmias in congestive heart failure and role of ACE inhibitors.

    PubMed

    Hasija, P K; Karloopia, S D; Shahi, B N; Chauhan, S S

    1998-02-01

    Ventricular arrhythmias are considered to be related to left ventricular (LV) dysfunction. ACE inhibitors though improve LV function their beneficial role on exercise-induced ventricular arrhythmias is not established. To study the effects of ACE inhibitors on exercise capacity vis-a-vis their role on exercise-induced ventricular arrhythmias, 25 patients of congestive heart failure (CHF) of various etiologies in NYHA Class II and III were subjected to a prospective randomised controlled trial. The control group comprising of 12 patients received conventional treatment (digitalis and diuretics) and the test group was given enalapril/captopril in addition as tolerated. They were followed up for 3 months. Exercise testing on treadmill and monitoring of clinical and biochemical parameters were done at the beginning and end of study in all cases. Ventricular arrhythmias observed during exercise and post-exercise for 10 minutes was analysed using Lown's grading for frequency and severity of ventricular arrhythmia. The mean exercise duration showed significant improvement on ACE inhibitor as compared to the control group (p < 0.05) however there was no significant change in the grades of arrhythmia. Serum electrolytes and other bio-chemical parameter were within normal range. It is concluded that effect of ACE inhibitor on improving functional capacity in CHF is independent of it's any effect on exercise-induced ventricular arrhythmias. PMID:11273109

  8. Angiotensin-converting enzyme (ACE-I/D) polymorphism frequency in Brazilian soccer players.

    PubMed

    Coelho, Daniel Barbosa; Pimenta, Eduardo; Rosse, Izinara Cruz; Veneroso, Christiano; Pussieldi, Guilherme; Becker, Lenice Kapes; Carvalho, Maria-Raquel; Silami-Garcia, Emerson

    2016-06-01

    This study aimed to analyze the angiotensin-converting enzyme (ACE-I/D) allelic and genotypic frequencies in Brazilian soccer players of different ages. The study group comprised 353 players from first-division clubs in the under (U)-14, U-15, U-17, U-20, and professional categories. The allelic and genotypic frequencies did not differ significantly in any of the categories between the group of players and the control group. This was the first study of ACE-I/D polymorphism in Brazilian soccer players. PMID:27232187

  9. Angiotensin-Converting Enzyme Inhibitor Use and Major Cardiovascular Outcomes in Type 2 Diabetes Mellitus Treated With the Dipeptidyl Peptidase 4 Inhibitor Alogliptin.

    PubMed

    White, William B; Wilson, Craig A; Bakris, George L; Bergenstal, Richard M; Cannon, Christopher P; Cushman, William C; Heller, Simon K; Mehta, Cyrus R; Nissen, Steven E; Zannad, Faiez; Kupfer, Stuart

    2016-09-01

    Activation of the sympathetic nervous system when there is dipeptidyl peptidase 4 inhibition in the presence of high-dose angiotensin-converting enzyme (ACE) inhibition has led to concerns of potential increases in cardiovascular events when the 2 classes of drugs are coadministered. We evaluated cardiovascular outcomes from the EXAMINE (Examination of Cardiovascular Outcomes With Alogliptin versus Standard of Care) trial according to ACE inhibitor use. Patients with type 2 diabetes mellitus and a recent acute coronary syndrome were randomly assigned to receive the dipeptidyl peptidase 4 inhibitor alogliptin or placebo added to existing antihyperglycemic and cardiovascular prophylactic therapies. Risks of adjudicated cardiovascular death, nonfatal myocardial infarction and stroke, and hospitalized heart failure were analyzed using a Cox proportional hazards model in patients according to ACE inhibitor use and dose. There were 3323 (62%) EXAMINE patients treated with an ACE inhibitor (1681 on alogliptin and 1642 on placebo). The composite rates of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke were comparable for alogliptin and placebo with ACE inhibitor (11.4% versus 11.8%; hazard ratio, 0.97; 95% confidence interval, 0.79-1.19; P=0.76) and without ACE inhibitor use (11.2% versus 11.9%; hazard ratio, 0.94; 95% confidence interval, 0.73-1.21; P=0.62). Composite rates for cardiovascular death and heart failure in patients on ACE inhibitor occurred in 6.8% of patients on alogliptin versus 7.2% on placebo (hazard ratio, 0.93; 95% confidence interval, 0.72-1.2; P=0.57). There were no differences for these end points nor for blood pressure or heart rate in patients on higher doses of ACE inhibitor. Cardiovascular outcomes were similar for alogliptin and placebo in patients with type 2 diabetes mellitus and coronary disease treated with ACE inhibitors. PMID:27480840

  10. Acute Kidney Injury in Elderly Patients With Chronic Kidney Disease: Do Angiotensin-Converting Enzyme Inhibitors Carry a Risk?

    PubMed

    Chaumont, Martin; Pourcelet, Aline; van Nuffelen, Marc; Racapé, Judith; Leeman, Marc; Hougardy, Jean-Michel

    2016-06-01

    In contrast to angiotensin receptor blockers (ARBs), mainly excreted by the liver, the dosage of angiotensin-converting enzyme (ACE) inhibitors, cleared by the kidney, must be adapted to account for renal clearance in patients with chronic kidney disease (CKD) to avoid acute kidney injury (AKI). Community-acquired AKI and the use of ACE inhibitors or ARBs in the emergency department were retrospectively assessed in 324 patients with baseline stage 3 or higher CKD. After stepwise regression analysis, the use of ACE inhibitors (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.1; P=.02) and the presence of dehydration (OR, 30.8; 95% CI, 3.9-239.1) were associated with AKI. A total of 45% of patients using ACE inhibitors experienced overdosing, which causes most of the excess risk of AKI. These results suggest that dosage adjustment of ACE inhibitors to renal function or substitution of ACE inhibitors with ARBs could reduce the incidence of AKI. Moreover, ACE inhibitors and ARBs should be stopped in cases of dehydration. PMID:27080620

  11. Preoperative angiotensin converting enzyme inhibitor usage in patients with chronic subdural hematoma: Associations with initial presentation and clinical outcome.

    PubMed

    Neidert, Marian C; Schmidt, Tobias; Mitova, Tatyana; Fierstra, Jorn; Bellut, David; Regli, Luca; Burkhardt, Jan-Karl; Bozinov, Oliver

    2016-06-01

    The aim of this study is to analyze the association of preoperative usage of angiotensin converting enzyme (ACE) inhibitors with the initial presentation and clinical outcome of patients with chronic subdural hematoma (cSDH). Patients treated for cSDH between 2009 and 2013 at our institution were included in this retrospective case-control study. Medical charts were reviewed retrospectively and data were analyzed using descriptive and inferential statistics. Out of 203 patients (58 females, mean age 73.2years), 53 (26%) patients were on ACE inhibitors before their presentation with cSDH. Median initial hematoma volume in individuals with ACE inhibitors (179.2±standard error of the mean [SEM] 13.0ml) was significantly higher compared to patients without ACE inhibitors (140.4±SEM 6.2ml; p=0.007). There was an increased probability of surgical reintervention in the ACE inhibitor group (12/53, 23% versus 19/153, 12%; p=0.079), especially in patients older than 80years (6/23, 26% versus 3/45, 7%; p=0.026). ACE inhibitors are associated with higher hematoma volume in patients with cSDH and with a higher frequency of recurrences requiring surgery (especially in the very old). We hypothesize that these effects are due to ACE inhibitor induced bradykinin elevation causing increased vascular permeability of the highly vascularized neomembranes in cSDH. PMID:26898577

  12. Inhibitors of angiotensin-converting enzyme modulate mitosis and gene expression in pancreatic cancer cells

    SciTech Connect

    Reddy, M.K.; Baskaran, K.; Molteni, A.

    1995-12-01

    The angiotensin-converting enzyme (ACE) inhibitor captopril inhibits mitosis in several cell types that contain ACE and renin activity. In the present study, we evaluated the effect of the ACE inhibitors captopril and CGS 13945 (10{sup {minus}8} to 10{sup {minus}2}M) on proliferation and gene expression in hamster pancreatic duct carcinoma cells in culture. These cells lack renin and ACE activity. Both ACE inhibitors produced a dose-dependent reduction in tumor cell proliferation within 24 hr. Captopril at a concentration of 0.36 mM and CGS 13945 at 150 {mu}M decreased cellular growth rate to approximately half that of the control. Neither drug influenced the viability or the cell cycle distribution of the tumor cells. Slot blot analysis of mRNA for four genes, proliferation associated cell nuclear antigen (PCNA), K-ras, protein kinase C-{Beta} (PKC-{Beta}) and carbonic anhydrase II (CA II) was performed. Both ACE inhibitors increased K-ras expression by a factor of 2, and had no effect on CA II mRNA levels. Captopril also lowered PCNA by 40% and CGS 13945 lowered PKC-{Beta} gene expression to 30% of the control level. The data demonstrate that ACE inhibitors exhibit antimitotic activity and differential gene modulation in hamster pancreatic duct carcinoma cells. The absence of renin and ACE activity in these cells suggests that the antimitotic action of captopril and CGS 13945 is independent of renin-angiotensin regulation. The growth inhibition may occur through downregulation of growth-related gene expression. 27 refs., 5 figs.

  13. Refill Adherence in Relation to Substitution and the Use of Multiple Medications: A Nationwide Population Based Study on New ACE-Inhibitor Users

    PubMed Central

    Jönsson, Anna K.; Lesén, Eva; Mårdby, Ann-Charlotte; Sundell, Karolina Andersson

    2016-01-01

    Objective Generic substitution has contributed to economic savings but switching products may affect patient adherence, particularly among those using multiple medications. The aim was to analyse if use of multiple medications influenced the association between switching products and refill adherence to angiotensin-converting-enzyme (ACE) inhibitors in Sweden. Study Design and Setting New users of ACE-inhibitors, starting between 1 July 2006 and 30 June 2007, were identified in the Swedish Prescribed Drug Register. Refill adherence was assessed using the continuous measure of medication acquisition (CMA) and analysed with linear regression and analysis of covariance. Results The study population included 42735 individuals whereof 51.2% were exposed to switching ACE-inhibitor and 39.6% used multiple medications. Refill adherence was higher among those exposed to switching products than those not, but did not vary depending on the use of multiple medications or among those not. Refill adherence varied with age, educational level, household income, country of birth, previous hospitalisation and previous cardiovascular diagnosis. Conclusion The results indicate a positive association between refill adherence and switching products, mainly due to generic substitution, among new users of ACE-inhibitors in Sweden. This association was independent of use of multiple medications. PMID:27192203

  14. Postanesthetic Severe Oral Angioedema in Patient's Taking Angiotensin-Converting Enzyme Inhibitor

    PubMed Central

    Marques, Acílio; Retroz-Marques, Carla; Mota, Sara; Cabral, Raquel; Campos, Matos

    2014-01-01

    Angiotensin-converting enzyme (ACE) inhibitors are the leading cause of a drug-induced angioedema. This occurrence is frequently underdiagnosed, but its relapse can be life-threatening. The authors' intention in reporting this clinical case is to sound a warning about reviewing attitudes and surveillance to try to improve patient perioperative safety. PMID:25431681

  15. Comparison of the Efficacy and Safety of Different ACE Inhibitors in Patients With Chronic Heart Failure

    PubMed Central

    Sun, WeiPing; Zhang, HaiBin; Guo, JinCheng; Zhang, XueKun; Zhang, LiXin; Li, ChunLei; Zhang, Ling

    2016-01-01

    Abstract Heart failure is a public health problem and a great economic burden for patients and healthcare systems. Suppression of the renin–angiotensin system (RAS) by angiotensin-converting enzyme (ACE)-inhibitors remains the mainstay of treatment for heart failure. However, the abundance of ACE inhibitors makes it difficult for doctors to choose. We performed this network meta-analysis of ACEIs in patients with heart failure in order to address this area of uncertainty. We searched PubMed, Embase, CENTRAL, and Medline. Any randomized controlled trial evaluating the efficacy and safety of captopril, enalapril, lisinopril, ramipril, or trandolapril or combined interventions of 2 or more of these drugs. Two reviewers extracted the data and made the quality assessment. At first, we used Stata software (version 12.0, StataCorp, College Station, TX) to make traditional pairwise meta-analyses for studies that directly compared different interventions. Then, network meta-analysis was performed using WinBUGS (version 1.4.3, MRC Biostatistics Unit, Cambridge, UK). A total of 29 studies were included. Lisinopril was associated with a higher rate of all-cause mortality compared with placebo (odds ratio 65.9, 95% credible interval 1.91 to 239.6) or ramipril (14.65, 1.23 to 49.5). Enalapril significantly reduced systolic blood pressure when compared with placebo (standardized mean differences −0.6, 95% credible interval −1.03 to −0.18). Both captopril (odds ratio 76.2, 95% credible interval 1.56 to 149.3) and enalapril (274.4, 2.4 to 512.9) were associated with a higher incidence of cough compared to placebo. Some important outcomes such as rehospitalization and cardiac death were not included. The sample size and the number of studies were limited, especially for ramipril. Our results suggest that enalapril might be the best option when considering factors such as increased ejection fraction, stroke volume, and decreased mean arterial pressure. However, enalapril was

  16. The ACE inhibitor ( sup 3 H)SQ29,852 identifies a high affinity recognition site located in the human temporal cortex

    SciTech Connect

    Barnes, N.M.; Costall, B.; Egli, P.; Horovitz, Z.P.; Ironside, J.W.; Naylor, R.J.; Williams, T.J. )

    1990-07-01

    The angiotensin converting enzyme (ACE) inhibitor ({sup 3}H)SQ29,852 identified a single high affinity recognition site (defined by 10.0 microM captopril) in the human temporal cortex (pKD 8.62 +/- 0.03; Bmax 248 +/- 24 fmol mg-1 protein, mean +/- S.E.M., n = 4). ACE inhibitors and thiorphan competed to a similar level for the ({sup 3}H)SQ29,852 binding site in the human temporal cortex with a rank order of affinity (pKi values mean +/- S.E.M., n = 3), lisinopril (9.49 +/- 0.02), captopril (9.16 +/- 0.08), SQ29,852 (8.58 +/- 0.04), epicaptopril (7.09 +/- 0.08), fosinopril (7.08 +/- 0.05) and thiorphan (6.40 +/- 0.04). Since this rank order of affinity is similar to the affinity of these compounds to inhibit brain ACE activity it is concluded that ({sup 3}H)SQ29,852 selectively labels the inhibitor recognition site of ACE in the human temporal cortex.

  17. Investigation of interaction studies of cefpirome with ACE-inhibitors in various buffers

    NASA Astrophysics Data System (ADS)

    Nawaz, Muhammad; Arayne, Muhammad Saeed; Sultana, Najma; Abbas, Hira Fatima

    2015-02-01

    This work describes a RP-HPLC method for the determination and interaction studies of cefpirome with ACE-inhibitors (captopril, enalapril and lisinopril) in various buffers. The separation and interaction of cefpirome with ACE-inhibitors was achieved on a Purospher Star, C18 (5 μm, 250 × 4.6 mm) column. Mobile phase consisted of methanol: water (80:20, v/v, pH 3.3); however, for the separation of lisinopril, it was modified to methanol-water (40:60, v/v, pH 3.3) and pumped at a flow rate of 1 mL min-1. In all cases, UV detection was performed at 225 nm. Interactions were carried out in physiological pH i.e., pH 1 (simulated gastric juice), 4 (simulated full stomach), 7.4 (blood pH) and 9 (simulated GI), drug contents were analyzed by reverse phase high performance liquid chromatography. Method was found linear in the concentration range of 1.0-50.0 μg mL-1 with correlation coefficient (r2) of 0.999. Precision (RSD%) was less than 2.0%, indicating good precision of the method and accuracy was 98.0-100.0%. Furthermore, cefpirome-ACE-inhibitors' complexes were also synthesized and results were elucidated on the basis of FT-IR, and 1H NMR. The interaction results show that these interactions are pH dependent and for the co-administration of cefpirome and ACE-inhibitors, a proper interval should be given.

  18. Application of quantitative NMR for purity determination of standard ACE inhibitors.

    PubMed

    Shen, Shi; Yang, Xing; Shi, Yaqin

    2015-10-10

    This study investigated the accuracy of the quantitative NMR method for purity determination of ACE inhibitors reference standards and the discovery of two pairs of new diastereoisomers. Six types of ACE inhibitors, imidapril hydrochloride, benazepril hydrochloride, lisinopril, enalapril maleate, quinapril hydrochloride, and captopril were quantificated and validated for the qNMR method by discussing factors that affect parameters of the qNMR experiment, internal standards, integration, pH-effect, and uncertainty. The results were compared with data obtained by the mass balance method. The study found that maleic acid influenced the quantification of captopril in deuteroxide because of a chemical reaction. The mixtures of the reaction products were isolated by HPLC and structurally elucidated by NMR as two pairs of new diastereoisomers, 1-[(2S,4R)-thio-2-methylpropionyl-5-d-ethanedicarboxylicacid]-L-proline and 1-[(2S,4S)-thio-2-methylpropionyl-5-d-ethanedicarboxylicacid]-L-proline. The results showed that the accuracy and precision of quantitative (1)H NMR spectroscopy satisfied the requirements for quantitative analysis of chemical reference standards and provided a simple, rapid, and reliable method for purity determination of ACE inhibitors systematically. PMID:26070161

  19. Fine-Mapping Angiotensin-Converting Enzyme Gene: Separate QTLs Identified for Hypertension and for ACE Activity

    PubMed Central

    Chung, Chia-Min; Wang, Ruey-Yun; Fann, Cathy S. J.; Chen, Jaw-Wen; Jong, Yuh-Shiun; Jou, Yuh-Shan; Yang, Hsin-Chou; Kang, Chih-Sen; Chen, Chien-Chung; Chang, Huan-Cheng; Pan, Wen-Harn

    2013-01-01

    Angiotensin-converting enzyme (ACE) has been implicated in multiple biological system, particularly cardiovascular diseases. However, findings associating ACE insertion/deletion polymorphism with hypertension or other related traits are inconsistent. Therefore, in a two-stage approach, we aimed to fine-map ACE in order to narrow-down the function-specific locations. We genotyped 31 single nucleotide polymorphisms (SNPs) of ACE from 1168 individuals from 305 young-onset (age ≤40) hypertension pedigrees, and found four linkage disequilibrium (LD) blocks. A tag-SNP, rs1800764 on LD block 2, upstream of and near the ACE promoter, was significantly associated with young-onset hypertension (p = 0.04). Tag-SNPs on all LD blocks were significantly associated with ACE activity (p-value: 10–16 to <10–33). The two regions most associated with ACE activity were found between exon13 and intron18 and between intron 20 and 3′UTR, as revealed by measured haplotype analysis. These two major QTLs of ACE activity and the moderate effect variant upstream of ACE promoter for young-onset hypertension were replicated by another independent association study with 842 subjects. PMID:23469169

  20. Automated multi-step purification protocol for Angiotensin-I-Converting-Enzyme (ACE).

    PubMed

    Eisele, Thomas; Stressler, Timo; Kranz, Bertolt; Fischer, Lutz

    2012-12-12

    Highly purified proteins are essential for the investigation of the functional and biochemical properties of proteins. The purification of a protein requires several steps, which are often time-consuming. In our study, the Angiotensin-I-Converting-Enzyme (ACE; EC 3.4.15.1) was solubilised from pig lung without additional detergents, which are commonly used, under mild alkaline conditions in a Tris-HCl buffer (50mM, pH 9.0) for 48h. An automation of the ACE purification was performed using a multi-step protocol in less than 8h, resulting in a purified protein with a specific activity of 37Umg(-1) (purification factor 308) and a yield of 23.6%. The automated ACE purification used an ordinary fast-protein-liquid-chromatography (FPLC) system equipped with two additional switching valves. These switching valves were needed for the buffer stream inversion and for the connection of the Superloop™ used for the protein parking. Automated ACE purification was performed using four combined chromatography steps, including two desalting procedures. The purification methods contained two hydrophobic interaction chromatography steps, a Cibacron 3FG-A chromatography step and a strong anion exchange chromatography step. The purified ACE was characterised by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and native-PAGE. The estimated monomer size of the purified glycosylated ACE was determined to be ∼175kDa by SDS-PAGE, with the dimeric form at ∼330kDa as characterised by a native PAGE using a novel activity staining protocol. For the activity staining, the tripeptide l-Phe-Gly-Gly was used as the substrate. The ACE cleaved the dipeptide Gly-Gly, releasing the l-Phe to be oxidised with l-amino acid oxidase. Combined with peroxidase and o-dianisidine, the generated H(2)O(2) stained a brown coloured band. This automated purification protocol can be easily adapted to be used with other protein purification tasks. PMID:23217308

  1. ACE inhibition reduces infarction in normotensive but not hypertensive rats: correlation with cortical ACE activity

    PubMed Central

    Porritt, Michelle J; Chen, Michelle; Rewell, Sarah S J; Dean, Rachael G; Burrell, Louise M; Howells, David W

    2010-01-01

    Angiotensin-converting enzyme (ACE) inhibition can reduce stroke risk by up to 43% in humans and reduce the associated disability, and hence understanding the mechanism of improvement is important. In animals and humans, these effects may be independent of the blood pressure-lowering effects of ACE inhibition. Normotensive (Wistar–Kyoto (WKY)) and hypertensive (spontaneously hypertensive rat (SHR)) animals were treated with the ACE inhibitors ramipril or lisinopril for 7 or 42 days before 2 hours of transient middle cerebral artery occlusion (MCAo). Blood pressure, serum ACE, and blood glucose levels were measured and stroke infarct volume was recorded 24 hours after stroke. Despite greater reductions in blood pressure, infarct size was not improved by ACE inhibition in hypertensive animals. Short-term ACE inhibition produced only a modest reduction in blood pressure, but WKY rats showed marked reductions in infarct volume. Long-term ACE inhibition had additional reductions in blood pressure; however, infarct volumes in WKY rats did not improve further but worsened. WKY rats differed from SHR in having marked cortical ACE activity that was highly sensitive to ACE inhibition. The beneficial effects of ACE inhibition on infarct volume in normotensive rats do not correlate with changes in blood pressure. However, WKY rats have ACE inhibitor-sensitive cortical ACE activity that is lacking in the SHR. PMID:20407464

  2. Activation of angiotensin-converting enzyme 2 (ACE2) attenuates allergic airway inflammation in rat asthma model.

    PubMed

    Dhawale, Vaibhav Shrirang; Amara, Venkateswara Rao; Karpe, Pinakin Arun; Malek, Vajir; Patel, Deep; Tikoo, Kulbhushan

    2016-09-01

    Angiotensin-I converting enzyme (ACE) is positively correlated to asthma, chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS) and is highly expressed in lungs. ACE2, the counteracting enzyme of ACE, was proven to be protective in pulmonary, cardiovascular diseases. In the present study we checked the effect of ACE2 activation in animal model of asthma. Asthma was induced in male wistar rats by sensitization and challenge with ovalbumin and then treated with ACE2 activator, diminazene aceturate (DIZE) for 2weeks. 48h after last allergen challenge, animals were anesthetized, blood, BALF, femoral bone marrow lavage were collected for leucocyte count; trachea for measuring airway responsiveness to carbachol; lungs and heart were isolated for histological studies and western blotting. In our animal model, the characteristic features of asthma such as altered airway responsiveness to carbachol, eosinophilia and neutrophilia were observed. Western blotting revealed the increased pulmonary expression of ACE1, IL-1β, IL-4, NF-κB, BCL2, p-AKT, p-p38 and decreased expression of ACE2 and IκB. DIZE treatment prevented these alterations. Intraalveolar interstitial thickening, inflammatory cell infiltration, interstitial fibrosis, oxidative stress and right ventricular hypertrophy in asthma control animals were also reversed by DIZE treatment. Activation of ACE2 by DIZE conferred protection against asthma as evident from biochemical, functional, histological and molecular parameters. To the best of our knowledge, we report for the first time that activation of ACE2 by DIZE prevents asthma progression by altering AKT, p38, NF-κB and other inflammatory markers. PMID:27343405

  3. ACE inhibitors

    MedlinePlus

    ... Clinical Cardiology; American Heart Association Council on Nutrition, Physical Activity, and Metabolism; American Heart Association Interdisciplinary Council on Quality of Care and Outcomes Research. State of the science: promoting self-care in persons with heart failure: ...

  4. ACE inhibitors

    MedlinePlus

    ... your dose helps. But sometimes your doctor will switch you to a different medication. Do not lower ... American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation . 2013 Oct 15; ...

  5. Inhibitors of alanine racemase enzyme: a review.

    PubMed

    Azam, Mohammed Afzal; Jayaram, Unni

    2016-08-01

    Alanine racemase is a fold type III PLP-dependent amino acid racemase enzyme catalysing the conversion of l-alanine to d-alanine utilised by bacterial cell wall for peptidoglycan synthesis. As there are no known homologs in humans, it is considered as an excellent antibacterial drug target. The standard inhibitors of this enzyme include O-carbamyl-d-serine, d-cycloserine, chlorovinyl glycine, alaphosphin, etc. d-Cycloserine is indicated for pulmonary and extra pulmonary tuberculosis but therapeutic use of drug is limited due to its severe toxic effects. Toxic effects due to off-target affinities of cycloserine and other substrate analogs have prompted new research efforts to identify alanine racemase inhibitors that are not substrate analogs. In this review, an updated status of known inhibitors of alanine racemase enzyme has been provided which will serve as a rich source of structural information and will be helpful in generating selective and potent inhibitor of alanine racemase. PMID:26024289

  6. Biological abatement of enzyme inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulose pretreatments release phenolic compounds that cause enzyme inhibition and deactivation. Bio-abatement, the biological removal of furfurals, acetic acid and phenolics, may utilize fungal fermentation to metabolize these compounds to CO2, water, cell mass, and heat. Our work with Coni...

  7. No association of angiotensin-converting enzyme 2 gene (ACE2) polymorphisms with essential hypertension.

    PubMed

    Benjafield, Adam V; Wang, William Y S; Morris, Brian J

    2004-07-01

    Recent intriguing findings from genetic linkage, knockout, and physiologic studies in mice and rats led us to conduct the first investigation of the novel angiotensin-converting enzyme 2 gene (ACE2) in human hypertension (HT). We genotyped four single nucleotide polymorphisms (SNP) (A-->G at nucleotide 1075 in intron 1, G-->A at nucleotide 8790 in intron 3, C-->G at nucleotide 28330 in intron 11, and G-->C at nucleotide 36787 in intron 16) in HT (n = 152) and normotensive (NT, n = 193) groups having inherently high biological power (>80%) due to our inclusion only of subjects whose parents had the same BP status as themselves. The SNPs were in linkage disequilibrium (D' = 54% to 100%, P =.05 to 0.0001). Because ACE2 is on the X chromosome, data for each sex were analyzed separately. Minor allele frequencies in HT versus NT were as follows: for the intron 1 variant 0.21 versus 0.17 in female subjects (P =.31) and 0.25 versus 0.29 in male subjects (P =.60); intron 3 variant 0.22 versus 0.18 in female subjects (P =.35) and 0.15 versus 0.20 in male subjects (P =.47); intron 11 variant 0.39 versus 0.46 in male subjects (P = 0.17) and 0.31 versus 0.30 in male subjects (P =.96); intron 16 variant 0.20 versus 0.19 in female subjects (P =.72) and 0.17 versus 0.17 in male subjects (P =.95). Haplotype analysis was also negative. These data provide little support for ACE2 in genetic predisposition to HT. PMID:15233982

  8. Impact of disease states on the pharmacokinetics and pharmacodynamics of angiotensin-converting enzyme inhibitors.

    PubMed

    LeBlanc, Jaclyn M; Dasta, Joseph F; Pruchnicki, Maria C; Schentag, Jerome J

    2006-09-01

    The pharmacokinetics and pharmacodynamics of angiotensin-converting enzyme inhibitors (ACE) in elderly patients and patients with renal and hepatic impairment were examined, and a role for an AUC/EC50 ratio to guide dosing was evaluated. A Medline and International Pharmaceutical Abstracts search was used to identify human studies and abstracts. Relevant data were evaluated and summarized. Dosing regimens were compared using an AUC/EC50 ratio. Most studies evaluating ACE inhibitors in renal impairment report a strong linear correlation between creatine clearance and drug elimination. AUC and EC50 values for these drugs in elderly subjects appear similar to younger and hypertensive patients. There is increased AUC in some patients with hepatic impairment. Pharmacodynamic data are conflicting. Prolonged ACE inhibition is evident in renal impairment but not necessarily other disease states. ACE inhibitor dosing for hypertension is reasonable based on pharmacokinetics and EC50 values. Further individualization of therapy may improve outcomes, and using the threshold AUC/EC50 ratio may help guide appropriate dosing. PMID:16920891

  9. Effect of angiotensin-converting enzyme inhibitors on myocardial ischemia/reperfusion injury: an overview.

    PubMed

    Zughaib, M E; Sun, J Z; Bolli, R

    1993-01-01

    the case of non-thiol-containing molecules). What is clear is that the enhanced recovery of function effected by these drugs is not due to hemodynamic effects, inhibition of the converting enzyme per se, or an "antischemic" action (since the drugs were effective when given at the time of reperfusion). The effects of ACE inhibitors on myocardial infarct size remain controversial. Further studies will be necessary to conclusively establish whether ACE inhibitors can protect against the detrimental effects of myocardial ischemia and reperfusion. Nevertheless, the evidence provided thus far is encouraging and warrants an in-depth assessment of the role of these drugs in attenuating myocardial ischemia/reperfusion injury. PMID:8357331

  10. [The new drug is much more effective than ACE inhibitors in chronic heart failure].

    PubMed

    Sr, Jiří Widimský

    2015-02-01

    PARADIGM-HF study observed clinical outcomes after treatment by new drug LCZ696 or enalapril in patients with systolic chronic heart failure. It was randomized double-blind trial with LCZ696 (200 mg twice a day) and enalapril (10 mg twice a day). 8442 patients were enrolled with NYHA class II or III and left ventricular ejection fiction of 40% or less. Study drugs were added to other recommended medication. The trial was prematurely terminated after median follow-up of 27 months. The primary endpoint of the study was a combination of cardiovascular mortality and the first hospitalization for heart failure. LCZ696 drug, an inhibitor of angiotensin receptor and neprilysin (Arnie), has led to a reduction in the primary composite target by 20% (p <0.001). The treatment has decreased cardiovascular mortality by 20%, p <0.001 and hospitalization for worsening heart failure by 21%, p <0.001. LCZ696 has also decreased total mortality by 16%, p <0.001. The use of LCZ696 has been accompanied by frequent symptomatic hypotension and hypotension with a decrease in systolic blood pressure below 90 mm Hg, however, LCZ696 was less often associated with an increase in serum creatinine and serum potassium than enalapril. In addition, cough has occurred less frequently after LCZ696 than after enalapril. Discontinuation of therapy occurred in 746 patients (17.8%) treated with LCZ696 and in 833 patients (19.8%) treated with enalapril (19.8%) (p = 0.02). PARADIGM-HF study has also shown superiority of LCZ696 compared to ACE inhibitors in stable outpatients with chronic systolic heart failure NYHA stages II and III. Therefore, LCZ696 is more effective than ACE inhibitors (and angiotensin receptor blockers). Moreover, it is well tolerated. LCZ696 seems to replace the ACE inhibitors in mentioned patients. The authors also discuss the results of the first randomized study PARAMOUNT investigating LCZ696 efficacy in patients with chronic heart failure and good left ventricular ejection

  11. Angiotensin-converting enzyme 2 (ACE2) from raccoon dog can serve as an efficient receptor for the spike protein of severe acute respiratory syndrome coronavirus.

    PubMed

    Xu, Lili; Zhang, Yanfang; Liu, Yun; Chen, Zhiwei; Deng, Hongkui; Ma, Zhongbin; Wang, Hualin; Hu, Zhihong; Deng, Fei

    2009-11-01

    Raccoon dog is one of the suspected intermediate hosts of severe acute respiratory syndrome coronavirus (SARS-CoV). In this study, the angiotensin-converting enzyme 2 (ACE2) gene of raccoon dog (rdACE2) was cloned and sequenced. The amino acid sequence of rdACE2 has identities of 99.3, 89.2, 83.9 and 80.4 % to ACE2 proteins from dog, masked palm civet (pcACE2), human (huACE2) and bat, respectively. There are six amino acid changes in rdACE2 compared with huACE2, and four changes compared with pcACE2, within the 18 residues of ACE2 known to make direct contact with the SARS-CoV S protein. A HeLa cell line stably expressing rdACE2 was established; Western blot analyses and an enzyme-activity assay indicated that the cell line expressed ACE2 at a similar level to two previously established cell lines that express ACE2 from human and masked palm civet, respectively. Human immunodeficiency virus-backboned pseudoviruses expressing spike proteins derived from human SARS-CoV or SARS-CoV-like viruses of masked palm civets and raccoon dogs were tested for their entry efficiency into these cell lines. The results showed that rdACE2 is a more efficient receptor for human SARS-CoV, but not for SARS-CoV-like viruses of masked palm civets and raccoon dogs, than huACE2 or pcACE2. This study provides useful data to elucidate the role of raccoon dog in SARS outbreaks. PMID:19625462

  12. Enzyme-Inhibitor Association Thermodynamics

    PubMed Central

    Resat, Haluk; Marrone, Tami J.; McCammon, J. Andrew

    1997-01-01

    Studying the thermodynamics of biochemical association reactions at the microscopic level requires efficient sampling of the configurations of the reactants and solvent as a function of the reaction pathways. In most cases, the associating ligand and receptor have complementary interlocking shapes. Upon association, loosely connected or disconnected solvent cavities at and around the binding site are formed. Disconnected solvent regions lead to severe statistical sampling problems when simulations are performed with explicit solvent. It was recently proposed that, when such limitations are encountered, they might be overcome by the use of the grand canonical ensemble. Here we investigate one such case and report the association free energy profile (potential of mean force) between trypsin and benzamidine along a chosen reaction coordinate as calculated using the grand canonical Monte Carlo method. The free energy profile is also calculated for a continuum solvent model using the Poisson equation, and the results are compared to the explicit water simulations. The comparison shows that the continuum solvent approach is surprisingly successful in reproducing the explicit solvent simulation results. The Monte Carlo results are analyzed in detail with respect to solvation structure. In the binding site channel there are waters bridging the carbonyl oxygen groups of Asp189 with the NH2 groups of benzamidine, which are displaced upon inhibitor binding. A similar solvent-bridging configuration has been seen in the crystal structure of trypsin complexed with bovine pancreatic trypsin inhibitor. The predicted locations of other internal waters are in very good agreement with the positions found in the crystal structures, which supports the accuracy of the simulations. ImagesFIGURE 5 PMID:9017183

  13. Recovery of casein-derived peptides with in vitro inhibitory activity of angiotensin converting enzyme (ACE) using aqueous two-phase systems.

    PubMed

    de Souza, Evaldo Cardozo; Coimbra, Jane Sélia Dos Reis; de Oliveira, Eduardo Basílio; Bonomo, Renata Cristina Ferreira

    2014-10-22

    Peptides inhibiting the activity of angiotensin converting enzyme (ACE) were obtained by trypsin-catalyzed hydrolysis of bovine milk casein, performed at 37°C, during 1, 2, 5, 8 and 24h. Results of in vitro inhibitory activity ranged between 13.4% and 78.5%. The highest ACE inhibitory activity was evidenced for hydrolysates obtained after 2h of reaction. Aqueous two-phase systems (ATPS) formed by polyethylene glycol of 1500gmol(-1) (PEG 1500)+sodium phosphate or potassium phosphates were produced and evaluated, in terms of partition coefficients (K) and extraction yields (y), to recovery the casein hydrolysates at room temperature. In ATPS containing sodium phosphate, the peptides showed a slightly greater affinity toward the bottom salt-rich phase (0.1≤K≤0.9; 5.7%≤y≤47%). In the case of ATPS containing potassium phosphates, these molecules showed substantially greater affinity toward the top polymer-rich phase (137≤K≤266; y≥99%). These results point out extraction using PEG 1500/potassium phosphate ATPS is an efficient technique to recover casein hydrolysates containing ACE inhibitors peptides. Outlined data will be helpful in integrating such unit operation to larger scale processes. PMID:25464099

  14. Angiotensin I–Converting Enzyme Type 2 (ACE2) Gene Therapy Improves Glycemic Control in Diabetic Mice

    PubMed Central

    Bindom, Sharell M.; Hans, Chetan P.; Xia, Huijing; Boulares, A. Hamid; Lazartigues, Eric

    2010-01-01

    OBJECTIVE Several clinical studies have shown the benefits of renin-angiotensin system (RAS) blockade in the development of diabetes, and a local RAS has been identified in pancreatic islets. Angiotensin I–converting enzyme (ACE)2, a new component of the RAS, has been identified in the pancreas, but its role in β-cell function remains unknown. Using 8- and 16-week-old obese db/db mice, we examined the ability of ACE2 to alter pancreatic β-cell function and thereby modulate hyperglycemia. RESEARCH DESIGN AND METHODS Both db/db and nondiabetic lean control (db/m) mice were infected with an adenovirus expressing human ACE2 (Ad-hACE2-eGFP) or the control virus (Ad-eGFP) via injection into the pancreas. Glycemia and β-cell function were assessed 1 week later at the peak of viral expression. RESULTS In 8-week-old db/db mice, Ad-hACE2-eGFP significantly improved fasting glycemia, enhanced intraperitoneal glucose tolerance, increased islet insulin content and β-cell proliferation, and reduced β-cell apoptosis compared with Ad-eGFP. ACE2 overexpression had no effect on insulin sensitivity in comparison with Ad-eGFP treatment in diabetic mice. Angiotensin-(1–7) receptor blockade by d-Ala7–Ang-(1-7) prevented the ACE2-mediated improvements in intraperitoneal glucose tolerance, glycemia, and islet function and also impaired insulin sensitivity in both Ad-hACE2-eGFP– and Ad-eGFP–treated db/db mice. d-Ala7–Ang-(1-7) had no effect on db/m mice. In 16-week-old diabetic mice, Ad-hACE2-eGFP treatment improved fasting blood glucose but had no effect on any of the other parameters. CONCLUSIONS These findings identify ACE2 as a novel target for the prevention of β-cell dysfunction and apoptosis occurring in type 2 diabetes. PMID:20660625

  15. Angiotensin I-Converting Enzyme Inhibitor Activity on Egg Albumen Fermentation

    PubMed Central

    Nahariah, N.; Legowo, A. M.; Abustam, E.; Hintono, A.

    2015-01-01

    Lactobacillus plantarum is used for fermentation of fish products, meat and milk. However, the utilization of these bacteria in egg processing has not been done. This study was designed to evaluate the potential of fermented egg albumen as a functional food that is rich in angiotensin I-converting enzyme inhibitors activity (ACE-inhibitor activity) and is antihypertensive. A completely randomized design was used in this study with six durations of fermentation (6, 12, 18, 24, 30, and 36 h) as treatments. Six hundred eggs obtained from the same chicken farm were used in the experiment as sources of egg albumen. Bacteria L. plantarum FNCC 0027 used in the fermentation was isolated from cow’s milk. The parameters measured were the total bacteria, dissolved protein, pH, total acid and the activity of ACE-inhibitors. The results showed that there were significant effects of fermentation time on the parameters tested. Total bacteria increased significantly during fermentation for 6, 12, 18, and 24 h and then decreased with the increasing time of fermentation to 30 and 36 h. Soluble protein increased significantly during fermentation to 18 h and then subsequently decreased during of fermentation to 24, 30, and 36 h. The pH value decreased markedly during fermentation. The activities of ACE-inhibitor in fermented egg albumen increased during fermentation to 18 h and then decreased with the increasing of the duration of fermentation to 24, 30, and 36 h. The egg albumen which was fermented for 18 h resulted in a functional food that was rich in ACE-inhibitor activity. PMID:25715689

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

    PubMed

    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

  17. 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

  18. Structural determinants for binding to angiotensin converting enzyme 2 (ACE2) and angiotensin receptors 1 and 2

    PubMed Central

    Clayton, Daniel; Hanchapola, Iresha; Thomas, Walter G.; Widdop, Robert E.; Smith, Alexander I.; Perlmutter, Patrick; Aguilar, Marie-Isabel

    2015-01-01

    Angiotensin converting enzyme 2 (ACE2) is a zinc carboxypeptidase involved in the renin–angiotensin system (RAS) and inactivates the potent vasopressive peptide angiotensin II (Ang II) by removing the C-terminal phenylalanine residue to yield Ang1–7. This conversion inactivates the vasoconstrictive action of Ang II and yields a peptide that acts as a vasodilatory molecule at the Mas receptor and potentially other receptors. Given the growing complexity of RAS and level of cross-talk between ligands and their corresponding enzymes and receptors, the design of molecules with selectivity for the major RAS binding partners to control cardiovascular tone is an on-going challenge. In previous studies we used single β-amino acid substitutions to modulate the structure of Ang II and its selectivity for ACE2, AT1R, and angiotensin type 2 (AT2R) receptor. We showed that modification at the C-terminus of Ang II generally resulted in more pronounced changes to secondary structure and ligand binding, and here, we further explore this region for the potential to modulate ligand specificity. In this study, (1) a library of 47 peptides derived from the C-terminal tetrapeptide sequence (-IHPF) of Ang II was synthesized and assessed for ACE2 binding, (2) the terminal group requirements for high affinity ACE2 binding were explored by and N- and C-terminal modification, (3) high affinity ACE2 binding chimeric AngII analogs were then synthesized and assessed, (4) the structure of the full-length Ang II analogs were assessed by circular dichroism, and (5) the Ang II analogs were assessed for AT1R/AT2R selectivity by cell-based assays. Studies on the C-terminus of Ang II demonstrated varied specificity at different residue positions for ACE2 binding and four Ang II chimeric peptides were identified as selective ligands for the AT2 receptor. Overall, these results provide insight into the residue and structural requirements for ACE2 binding and angiotensin receptor selectivity. PMID

  19. Preclinical development and characterization of an intravenous dosage form for the ACE inhibitor RS-10029.

    PubMed

    Visor, G C; Lin, L H; Henry, P; Singer, L

    1989-01-01

    Preclinical development of an intravenous dosage form for the ACE inhibitor RS-10029 involved the formulation and characterization of the drug's chemical/physical stability in two prototype formulations (injectable solution and lyophilized powder). Included in these studies were quantitative evaluations of various processing and administration parameters (membrane qualification, terminal sterilization, compatibility/delivery of the drug with typical infusion fluids and administration sets) on finished product integrity and quality. Analytical methodology used in these studies consisted primarily of a stability specific HPLC assay and a light obscuration based sensor (HIAC) for particulate matter analysis. Results of these studies indicate that the drug is relatively stable at ambient temperature and under accelerated storage conditions (predicted T90 at 25 degrees C greater than 2 yr, and T90 at 50 degrees C greater than 2 mo). However, the ability of the product to withstand a full terminal sterilization cycle is limited, and therefore other approaches toward sterile processing were examined. With regard to the stability and compatibility of the drug in a variety of fluids and devices there appears to be no overt limitations in its use for either bolus or infusion delivery. PMID:2600732

  20. Early genes induction in spontaneously hypertensive rats left ventricle with angiotensin-converting enzyme inhibitors but not hydralazine

    SciTech Connect

    Susic, D.; Aristizabal, D.J.; Prakash, O.; Nunez, E.; Frohlich, E.D.

    1995-12-01

    Spontaneously hypertensive rats were given an angiotensin-converting enzyme (ACE) inhibitor (benazepril or quinapril) or hydralazine and were left for up to 6 hr. To examine whether administration of antihypertensive agents affects expression of immediate early genes in left ventricular myocardium, groups of rats were sacrificed at 1, 3, and 6 hr after dosing; total RNA was extracted from left ventricular tissue and analyzed by blot hybridization technique using labeled probes for c-myc, c-fos, and GAPDH mRNA. All three antihypertensive agents reduced pressure similarly, and treatment with the two ACE inhibitors increased c-fos and c-myc mRNA expression in left ventriculum. By contrast, hydralazine did not increase steady-state mRNA expression of either proto-oncogene. Thus, in parallel with the pressure fall, acute administration of the ACE inhibitors induced expression of c-fos and c-myc mRNAs in the left ventricle. Since the equidepressor dose of hyralazine did not affect expression of these proto-oncogenes, this effect of ACE inhibitors is independent of their hemodynamic action. 27 refs., 1 fig., 2 tabs.

  1. The influence of a polymorphism in the gene encoding angiotensin converting enzyme (ACE) on treatment outcomes in late-onset Pompe patients receiving alglucosidase alfa.

    PubMed

    Baek, Rena C; Palmer, Rachel; Pomponio, Robert J; Lu, Yuefeng; Ma, Xiwen; McVie-Wylie, Alison J

    2016-09-01

    Correlations between angiotensin-converting enzyme (ACE) genotype (I/I, I/D, D/D), disease severity at baseline and response to enzyme replacement therapy (ERT) were assessed in the Pompe disease Late-Onset Treatment Study (LOTS). No correlations were observed between ACE genotype and disease severity at baseline. However, D/D patients appeared to have a reduced response to alglucosidase alfa treatment than I/I or I/D patients, suggesting that ACE polymorphisms may influence the response to alglucosidase alfa treatment and warrants further investigation. PMID:27489778

  2. Isolation of angiotensin converting enzyme (ACE) inhibiting triterpenes from Schinus molle.

    PubMed

    Olafsson, K; Jaroszewski, J W; Smitt, U W; Nyman, U

    1997-08-01

    Bioactivity-guided fractionation of extracts of Schinus molle leaves, using an in vitro assay, led to the isolation of ACE-inhibitory steroidal triterpenes of the euphane type, identified by means of NMR spectroscopic methods. One of the triterpenes was isolated as an equilibrium mixture of epimeric aldehydes. The triterpenes showed moderate ACE-inhibitory activity (IC(50) about 250 microM). PMID:17252394

  3. Inequity of access to ACE inhibitors in Swedish heart failure patients: a register-based study

    PubMed Central

    Lindahl, Bertil; Hanning, Marianne; Westerling, Ragnar

    2016-01-01

    Background Several international studies suggest inequity in access to evidence-based heart failure (HF) care. Specifically, studies of ACE inhibitors (ACEIs) point to reduced ACEI access related to female sex, old age and socioeconomic position. Thus far, most studies have either been rather small, lacking diagnostic data, or lacking the possibility to account for several individual-based sociodemographic factors. Our aim was to investigate differences, which could reflect inequity in access to ACEIs based on sex, age, socioeconomic status or immigration status in Swedish patients with HF. Methods Individually linked register data for all Swedish adults hospitalised for HF in 2005–2010 (n=93 258) were analysed by multivariate regression models to assess the independent risk of female sex, high age, low employment status, low income level, low educational level or foreign country of birth, associated with lack of an ACEI dispensation within 1 year of hospitalisation. Adjustment for possible confounding was made for age, comorbidity, Angiotensin receptor blocker therapy, period and follow-up time. Results Analysis revealed an adjusted OR for no ACEI dispensation for women of 1.31 (95% CI 1.27 to 1.35); for the oldest patients of 2.71 (95% CI 2.53 to 2.91); and for unemployed patients of 1.59 (95% CI 1.46 to 1.73). Conclusions Access to ACEI treatment was reduced in women, older patients and unemployed patients. We conclude that access to ACEIs is inequitable among Swedish patients with HF. Future studies should include clinical data, as well as mortality outcomes in different groups. PMID:26261264

  4. ACE Inhibitor and Angiotensin Receptor-II Antagonist Prescribing and Hospital Admissions with Acute Kidney Injury: A Longitudinal Ecological Study

    PubMed Central

    Tomlinson, Laurie A.; Abel, Gary A.; Chaudhry, Afzal N.; Tomson, Charles R.; Wilkinson, Ian B.; Roland, Martin O.; Payne, Rupert A.

    2013-01-01

    Background ACE Inhibitors (ACE-I) and Angiotensin-Receptor Antagonists (ARAs) are commonly prescribed but can cause acute kidney injury (AKI) during intercurrent illness. Rates of hospitalization with AKI are increasing. We aimed to determine whether hospital AKI admission rates are associated with increased ACE-I/ARA prescribing. Methods and Findings English NHS prescribing data for ACE-I/ARA prescriptions were matched at the level of the general practice to numbers of hospital admissions with a primary diagnosis of AKI. Numbers of prescriptions were weighted for the demographic characteristics of general practices by expressing prescribing as rates where the denominator is Age, Sex, and Temporary Resident Originated Prescribing Units (ASTRO-PUs). We performed a mixed-effect Poisson regression to model the number of admissions for AKI occurring in each practice for each of 4 years from 1/4/2007. From 2007/8-2010/11, crude AKI admission rates increased from 0.38 to 0.57 per 1000 patients (51.6% increase), and national annual ACE-I/ARA prescribing rates increased by 0.032 from 0.202 to 0.234 (15.8% increase). There was strong evidence (p<0.001) that increases in practice-level prescribing of ACE-I/ARA over the study period were associated with an increase in AKI admission rates. The increase in prescribing seen in a typical practice corresponded to an increase in admissions of approximately 5.1% (rate ratio = 1.051 for a 0.03 per ASTRO-PU increase in annual prescribing rate, 95%CI 1.047-1.055). Using the regression model we predict that 1,636 (95%CI 1,540-1,780) AKI admissions would have been avoided if prescribing rates were at the 2007/8 level, equivalent to 14.8% of the total increase in AKI admissions. Conclusion In this ecological analysis, up to 15% of the increase in AKI admissions in England over a 4-year time period is potentially attributable to increased prescribing of ACE-I and ARAs. However, these findings are limited by the lack of patient level

  5. Patients With Newly Diagnosed Hypertension Treated With the Renin Angiotensin Receptor Blocker Azilsartan Medoxomil vs Angiotensin-Converting Enzyme Inhibitors: The Prospective EARLY Registry.

    PubMed

    Schmieder, Roland E; Potthoff, Sebastian A; Bramlage, Peter; Baumgart, Peter; Mahfoud, Felix; Buhck, Hartmut; Ouarrak, Taoufik; Ehmen, Martina; Senges, Jochen; Gitt, Anselm K

    2015-12-01

    For patients with newly diagnosed hypertension, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are usually the first-line therapies. There is, however, no real-life data regarding the relative clinical effectiveness and tolerability of either drug class. The prospective registry, Treatment With Azilsartan Compared to ACE Inhibitors in Antihypertensive Therapy (EARLY), was conducted to evaluate the effectiveness of the ARB azilsartan medoxomil (AZL-M) vs ACE inhibitors in real-world patients. Of the 1153 patients with newly diagnosed hypertension who were included in the registry, 789 were prescribed AZL-M and 364 were prescribed an ACE inhibitor. After multivariate adjustment, AZL-M was found to provide superior blood pressure reduction and better target blood pressure (<140/90 mm Hg) achievement. The proportion of patients with adverse events was not statistically different between groups. The authors conclude that in newly diagnosed hypertensive patients, AZL-M provides superior blood pressure control with a similar safety profile compared with ACE inhibitors. PMID:26105590

  6. Effects of Small Molecule Calcium-Activated Chloride Channel Inhibitors on Structure and Function of Accessory Cholera Enterotoxin (Ace) of Vibrio cholerae

    PubMed Central

    Chatterjee, Tanaya; Sheikh, Irshad Ali; Chakravarty, Devlina; Chakrabarti, Pinak; Sarkar, Paramita; Saha, Tultul; Chakrabarti, Manoj K.; Hoque, Kazi Mirajul

    2015-01-01

    Cholera pathogenesis occurs due to synergistic pro-secretory effects of several toxins, such as cholera toxin (CTX) and Accessory cholera enterotoxin (Ace) secreted by Vibrio cholerae strains. Ace activates chloride channels stimulating chloride/bicarbonate transport that augments fluid secretion resulting in diarrhea. These channels have been targeted for drug development. However, lesser attention has been paid to the interaction of chloride channel modulators with bacterial toxins. Here we report the modulation of the structure/function of recombinant Ace by small molecule calcium-activated chloride channel (CaCC) inhibitors, namely CaCCinh-A01, digallic acid (DGA) and tannic acid. Biophysical studies indicate that the unfolding (induced by urea) free energy increases upon binding CaCCinh-A01 and DGA, compared to native Ace, whereas binding of tannic acid destabilizes the protein. Far-UV CD experiments revealed that the α-helical content of Ace-CaCCinh-A01 and Ace-DGA complexes increased relative to Ace. In contrast, binding to tannic acid had the opposite effect, indicating the loss of protein secondary structure. The modulation of Ace structure induced by CaCC inhibitors was also analyzed using docking and molecular dynamics (MD) simulation. Functional studies, performed using mouse ileal loops and Ussing chamber experiments, corroborate biophysical data, all pointing to the fact that tannic acid destabilizes Ace, inhibiting its function, whereas DGA stabilizes the toxin with enhanced fluid accumulation in mouse ileal loop. The efficacy of tannic acid in mouse model suggests that the targeted modulation of Ace structure may be of therapeutic benefit for gastrointestinal disorders. PMID:26540279

  7. Hypotensive, Angiotensin Converting Enzyme (ACE) Inhibitory and Diuretic Activities of the Aqueous-methanol Extract of Ipomoea reniformis

    PubMed Central

    Jabeen, Qaiser; Aslam, Naveed

    2013-01-01

    Ipomoea reniformis Roxb. (Convolvulaceae) is a small, weedy herb used for the management of cardiac problems in traditional systems of medicine in India and Pakistan. Objective of the present study was to investigate the hypotensive, diuretic and angiotensin converting enzyme (ACE) inhibitory activities of the aqueous-methanol (30:70) crude extract of the dried aerial parts of I. reniformis (Ir.Cr.) in rats. To record blood pressure lowering effects of the Ir.Cr, different doses of the extract were administered through jugular vein to the ketamine-diazepam anesthetized normotensive rats and blood pressure was recorded via carotid artery. ACE inhibitory activity of the extract was studied in-vitro; using hippuryl-l-histidyl-l-leucine as substrate, the product hippurate was quantified spectrophotometrically after reacting with cyanuric chloride/dioxane reagent. Effects of intraperitoneal administration of the extract on urine and urinary electrolyte excretion were also investigated in rats. The extract (Ir.Cr.) produced 21.51 ± 3.41, 28.99 ± 2.30, 53.34 ± 0.88 and 61.71 ± 3.37% fall in mean arterial blood pressure of the anesthetized rats at the doses of 0.1, 0.3, 1.0 and 3.0 mg/Kg, respectively. Ir.Cr. was found to have serum ACE inhibitory activity, with IC50 value of 422 ± 21.16 μg/mL. The extract also increased urine volume and urinary Na+ excretion significantly at the doses of 30 and 50 mg/Kg in rats. The study concludes that the crude extract of Ipomoea reniformis (Ir.Cr.) has hypotensive, ACE inhibitory and diuretic activities, which provide the scientific justification for the traditional uses of the plant as cardioprotective, antihypertensive and diuretic remedy. PMID:24523757

  8. An International, Web-Based, Prospective Cohort Study to Determine Whether the Use of ACE Inhibitors prior to the Onset of Scleroderma Renal Crisis Is Associated with Worse Outcomes—Methodology and Preliminary Results

    PubMed Central

    Hudson, Marie; Baron, Murray; Lo, Ernest; Weinfeld, Joanna; Furst, Daniel E.; Khanna, Dinesh

    2010-01-01

    Background. To describe the methodology of a study designed to determine whether systemic sclerosis (SSc) patients with incident scleroderma renal crisis (SRC) on angiotensin converting enzyme (ACE) inhibitors prior to the onset of SRC have worse outcomes. Methods. Prospective, international cohort study of SRC subjects identified through an ongoing web-based survey. Every second Friday afternoon, an e-mail was sent to 589 participating physicians to identify new cases of SRC. Death or dialysis at one year after the onset of SRC will be compared in patients exposed or not to ACE inhibitors prior to the onset of SRC. Results. Fifteen months after the start of the survey, we had identified 76 incident cases of SRC. Of these, 66 (87%) had a hypertensive SRC and 10 (13%) a normotensive SRC. Twenty-two percent (22%) of the patients were on an ACE inhibitor immediately prior to the onset of the SRC. To date, we have collected one-year follow-up data on approximately 1/3 of the cohort. Of these, over 50% have died or remain on dialysis at one year. Conclusion. An international, web-based cohort study design is a feasible method of recruiting a substantial number of patients to study an infrequent vascular manifestation of SSc. PMID:20936135

  9. [Liver damage in a patient treated with a vitamin K antagonist, a statin and an ACE inhibitor].

    PubMed

    Bruggisser, M; Terraciano, L; Rätz Bravo, A; Haschke, M

    2010-10-20

    We report the case of a 71-year-old male patient who presented at the emergency room with episodes of epistaxis and jaundice. The patient was on therapy with phenprocoumon, atorvastatin and perindopril. Findings on admission included prominent elevation of transaminases and bilirubin and a high INR due to impaired liver function and oral anticoagulation. After exclusion of other causes like viral or autoimmune hepatitis and after having obtained a liver biopsy, a diagnosis of drug induced liver damage (DILI) was made. Epidemiology, pathophysiology and clinical signs of DILI are discussed with a special focus on coumarines, statins and ACE-inhibitors. PMID:20960395

  10. EARLY Treatment with azilsartan compared to ACE-inhibitors in anti-hypertensive therapy – rationale and design of the EARLY hypertension registry

    PubMed Central

    2013-01-01

    Background Arterial hypertension is highly prevalent but poorly controlled. Blood pressure (BP) reduction substantially reduces cardiovascular morbidity and mortality. Recent randomized, double-blind clinical trials demonstrated that azilsartan medoxomil (AZM) is more effective in reducing BP than the ubiquitary ACE inhibitor ramipril. Therefore, we aimed to test whether these can be verified under clinical practice conditions. Methods/Design The “Treatment with Azilsartan Compared to ACE-Inhibitors in Anti-Hypertensive Therapy” (EARLY) registry is a prospective, observational, national, multicenter registry with a follow-up of up to 12 months. It will include up to 5000 patients on AZM or ACE-inhibitor monotherapy in a ratio of 7 to 3. A subgroup of patients will undergo 24-hour BP monitoring. EARLY has two co-primary objectives: 1) Description of the safety profile of azilsartan and 2) achievement of BP targets based on recent national and international guidelines for patients treated with azilsartan in comparison to those treated with ACE-inhibitors. The most important secondary endpoints are the determination of persistence with treatment and the documentation of cardiovascular and renal events. Recruitment commenced in January 2012 and will be completed by February 2013. Conclusions The data obtained will supplement previous results from randomized controlled trials to document the potential value of utilizing azilsartan medoxomil in comparison to ACE-inhibitor treatment for target BP achievement in clinical practice. PMID:23819631

  11. Role of angiotensin converting enzyme in the vascular effects of an endopeptidase 24.15 inhibitor.

    PubMed Central

    Telford, S E; Smith, A I; Lew, R A; Perich, R B; Madden, A C; Evans, R G

    1995-01-01

    1. We investigated the role of angiotensin converting enzyme (ACE) in the cardiovascular effects of N-[1-(R,S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-aminobenzoate (cFP), a peptidase inhibitor selective for metalloendopeptidase (EP) E.C. 3.4.24.15. 2. In conscious rabbits, cFP (5 mg kg-1, i.v.) markedly slowed the degradation of [3H]-bradykinin, potentiated the depressor response to right atrial administration of bradykinin (10-1000 ng kg-1), and inhibited the pressor response to right atrial angiotensin I (10-100 ng kg-1). In each of these respects, the effects of cFP were indistinguishable from those of the ACE inhibitor, captopril (0.5 mg plus 10 mg kg-1h-1 i.v.). Furthermore, the effects of combined administration of cFP and captopril were indistinguishable from those of captopril alone. 3. In experimentally naive anaesthetized rats, cFP administration (9.3 mg kg-1, i.v.) was followed by a moderate but sustained fall in arterial pressure of 13 mmHg. However, in rats pretreated with bradykinin (50 micrograms kg-1) a more pronounced fall of 30 mmHg was observed. Captopril (5 mg kg-1) had similar hypotensive effects to those of cFP, and cFP had no effect when it was administered after captopril. 4. CFP displaced the binding of [125I]-351A (the p-hydroxybenzamidine derivative of lisinopril) from preparations of rat plasma ACE and solubilized lung membrane ACE (KD = 1.2 and 0.14 microM respectively), and inhibited rat plasma ACE activity (KI = 2.4 microM). Addition of phosphoramidon (10 microM), an inhibitor of a range of metalloendopeptidases, including neutral endopeptidase (E.C.3.4.24.11), markedly reduced the potency of cFP in these systems.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7620708

  12. Non-disulfide-bridged peptides from Tityus serrulatus venom: Evidence for proline-free ACE-inhibitors.

    PubMed

    Pucca, Manuela Berto; Cerni, Felipe Augusto; Pinheiro-Junior, Ernesto Lopes; Zoccal, Karina Furlani; Bordon, Karla de Castro Figueiredo; Amorim, Fernanda Gobbi; Peigneur, Steve; Vriens, Kim; Thevissen, Karin; Cammue, Bruno Philippe Angelo; Júnior, Ronaldo Bragança Martins; Arruda, Eurico; Faccioli, Lúcia Helena; Tytgat, Jan; Arantes, Eliane Candiani

    2016-08-01

    The present study purifies two T. serrulatus non-disulfide-bridged peptides (NDBPs), named venom peptides 7.2 (RLRSKG) and 8 (KIWRS) and details their synthesis and biological activity, comparing to the synthetic venom peptide 7.1 (RLRSKGKK), previously identified. The synthetic replicate peptides were subjected to a range of biological assays: hemolytic, antifungal, antiviral, electrophysiological, immunological and angiotensin-converting enzyme (ACE) inhibition activities. All venom peptides neither showed to be cytolytic nor demonstrated significant antifungal or antiviral activities. Interestingly, peptides were able to modulate macrophages' responses, increasing IL-6 production. The three venom peptides also demonstrated potential to inhibit ACE in the following order: 7.2>7.1>8. The ACE inhibition activity was unexpected, since peptides that display this function are usually proline-rich peptides. In attempt to understand the origin of such small peptides, we discovered that the isolated peptides 7.2 and 8 are fragments of the same molecule, named Pape peptide precursor. Furthermore, the study discusses that Pape fragments could be originated from a post-splitting mechanism resulting from metalloserrulases and other proteinases cleavage, which can be seen as a clever mechanism used by the scorpion to enlarge its repertoire of venom components. Scorpion venom remains as an interesting source of bioactive proteins and this study advances our knowledge about three NDBPs and their biological activities. PMID:27221550

  13. ACE blood test

    MedlinePlus

    Serum angiotensin-converting enzyme; SACE ... Chernecky CC, Berger BJ. Angiotensin-converting enzyme (ACE) - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:138-139.

  14. In silico analysis and molecular docking studies of potential angiotensin-converting enzyme inhibitor using quercetin glycosides

    PubMed Central

    Muhammad, Syed Aun; Fatima, Nighat

    2015-01-01

    The purpose of this study was to analyze the inhibitory action of quercetin glycosides by computational docking studies. For this, natural metabolite quercetin glycosides isolated from buckwheat and onions were used as ligand for molecular interaction. The crystallographic structure of molecular target angiotensin-converting enzyme (ACE) (peptidyl-dipeptidase A) was obtained from PDB database (PDB ID: 1O86). Enalapril, a well-known brand of ACE inhibitor was taken as the standard for comparative analysis. Computational docking analysis was performed using PyRx, AutoDock Vina option based on scoring functions. The quercetin showed optimum binding affinity with a molecular target (angiotensin-converting-enzyme) with the binding energy of −8.5 kcal/mol as compared to the standard (−7.0 kcal/mol). These results indicated that quercetin glycosides could be one of the potential ligands to treat hypertension, myocardial infarction, and congestive heart failure. PMID:26109757

  15. Ventricular dilatation in the absence of ACE inhibitors: influence of haemodynamic and neurohormonal variables following myocardial infarction

    PubMed Central

    Walsh, J; Batin, P; Hawkins, M; McEntegart, D; Cowley, A

    1999-01-01

    Objective—To examine the relation between patterns of ventricular remodelling and haemodynamic and neurohormonal variables, at rest and during symptom limited exercise, in the year following acute myocardial infarction in patients not receiving angiotensin converting enzyme (ACE) inhibitors.
Design—A prospective observational study.
Patients—65 patients recruited following hospital admission with a transmural anterior myocardial infarction.
Methods—Central haemodynamics and neurohormonal activation at rest and during symptom limited treadmill exercise were measured at baseline before hospital discharge, one month later, and at three monthly intervals thereafter. Patients were classified according to individual patterns of change in left ventricular end diastolic volumes at rest, assessed at each visit using transthoracic echocardiography.
Results—In most patients (n = 43, 66%) ventricular volumes were unchanged or reduced. Mean (SEM) treadmill exercise capacity and peak exercise cardiac index increased at month 12 by 200 (24) seconds (p < 0.001 v baseline) and by 0.8 (0.4) l/min/m2 (p<0.05 v baseline), respectively, in this group. In patients with limited ventricular dilatation (n = 11, 17%) exercise capacity increased by 259 (52) seconds (p < 0.001 v baseline) and peak exercise cardiac index improved by 0.8 (0.7) l/min/m2 (NS). In the remaining 11 patients with progressive left ventricular dilatation, exercise capacity increased by 308 (53) seconds (p< 0.001 v baseline) and peak exercise cardiac index similarly improved by 1.3 (0.7) l/min/m2 (NS). There were trends towards increased atrial natriuretic factor (ANF) secretion at rest and at peak exercise in this group.
Conclusions—Ventricular dilatation after acute myocardial infarction is a heterogeneous process that is progressive in only a minority of patients. Compensatory mechanisms, including ANF release, appear capable of maintaining and improving exercise capacity in

  16. Decreased Risk of Radiation Pneumonitis With Incidental Concurrent Use of Angiotensin-Converting Enzyme Inhibitors and Thoracic Radiation Therapy

    SciTech Connect

    Kharofa, Jordan; Cohen, Eric P.; Tomic, Rade; Xiang Qun; Gore, Elizabeth

    2012-09-01

    Purpose: Angiotensin-converting enzyme (ACE) inhibitors have been shown to mitigate radiation-induced lung injury in preclinical models. The aim of this study was to evaluate whether ACE inhibitors decrease the risk of radiation pneumonitis in lung cancer patients receiving thoracic irradiation. Methods and Materials: Patients with Stage I through III small-cell and non-small-cell lung cancer treated definitively with radiation from 2004-2009 at the Clement J. Zablocki Veterans Affairs Medical Center were retrospectively reviewed. Acute pulmonary toxicity was quantified within 6 months of completion of treatment according to the Common Terminology Criteria for Adverse Events version 4. The use of ACE inhibitors, nonsteroidal anti-inflammatory drugs, inhaled glucocorticosteroids, statins, and angiotensin receptor blockers; dose-volume histogram parameters; and patient factors were assessed for association with Grade 2 or higher pneumonitis. Results: A total of 162 patients met the criteria for inclusion. The majority of patients had Stage III disease (64%) and received concurrent chemotherapy (61%). Sixty-two patients were identified as ACE inhibitor users (38%). All patients had acceptable radiation plans based on dose-volume histogram constraints (V20 [volume of lung receiving at least 20 Gy] {<=}37% and mean lung dose {<=}20 Gy) with the exception of 2 patients who did not meet both criteria. Grade 2 or higher pulmonary toxicity occurred in 12 patients (7.4%). The rate of Grade 2 or higher pneumonitis was lower in ACE inhibitor users vs. nonusers (2% vs. 11%, p = 0.032). Rates of Grade 2 or higher pneumonitis were significantly increased in patients aged greater than 70 years (16% vs. 2%, p = 0.005) or in whom V5 (volume of lung receiving at least 5 Gy) was 50% or greater (13% vs. 4%, p = 0.04). V10 (volume of lung receiving at least 10 Gy), V20, V30 (volume of lung receiving at least 30 Gy), and mean lung dose were not independently associated with Grade 2 or

  17. Assessing the teratogenic potential of angiotensin-converting enzyme inhibitors in pregnancy.

    PubMed

    Burrows, R F; Burrows, E A

    1998-08-01

    To assess the teratogenic potential of angiotensin-converting enzyme (ACE) inhibitors, we report on 20 prospective pregnancies and 85 identified from articles in the literature. The anomaly rate was 20.6% in small series <10 entrants (95% CI 8.7-37.9%) and 1.4% in larger series > or =10 entrants (95% CI 0.03-7.3%) p=0.0016. The most consistent anomaly seen, skull hypoplasia, along with renal dysfunction appear to be more related to prolonged or late pregnancy exposure than to first trimester exposure. There is little supportive evidence that ACE inhibitors (captopril or enalapril) are teratogenic. There seems to be no absolute reason to discontinue these 2 medications prior to pregnancy, nor to create anxiety when a patient is identified with the combination of early pregnancy and treatment with these medications. There appears to be reason to discontinue the medication in pregnancy but the adverse event rate cannot be assessed because of inadequate prospective information. PMID:9761159

  18. Treatment of Hypertension in Black Patients With Angiotensin-Converting Enzyme Inhibitors

    PubMed Central

    Shulman, Neil B.

    1988-01-01

    The prevalence of hypertension and the incidence of complications from uncontrolled elevated blood pressure in blacks is much greater than in the white population. In general, blacks have underlying differences in the factors relating to blood pressure level, including low plasma renin, and, in certain instances, a decreased ability to excrete sodium. The stepped-care approach in the management of the black hypertensive patient is similar to that taken with white patients, but racial differences in response to antihypertensive drugs exist that require careful consideration when choosing a treatment regimen. Thiazide diuretics are effective in blacks and are often used as initial therapy. Blacks tend to respond less well to β-blockers, but when combined with a diuretic, they are also effective. Encouraging data are available on the use of calcium channel blockers in blacks. When combined with a diuretic, the angiotensin-converting enzyme (ACE) inhibitors also provide an alternative to therapy for black patients. The use of low doses of ACE inhibitors has reduced the high incidence of adverse effects associated with this group of drugs in earlier studies. PMID:3280812

  19. Fragment-based design for the development of N-domain-selective angiotensin-1-converting enzyme inhibitors.

    PubMed

    Douglas, Ross G; Sharma, Rajni K; Masuyer, Geoffrey; Lubbe, Lizelle; Zamora, Ismael; Acharya, K Ravi; Chibale, Kelly; Sturrock, Edward D

    2014-02-01

    ACE (angiotensin-1-converting enzyme) is a zinc metallopeptidase that plays a prominent role in blood pressure regulation and electrolyte homeostasis. ACE consists of two homologous domains that despite similarities of sequence and topology display differences in substrate processing and inhibitor binding. The design of inhibitors that selectively inhibit the N-domain (N-selective) could be useful in treating conditions of tissue injury and fibrosis due to build-up of N-domain-specific substrate Ac-SDKP (N-acetyl-Ser-Asp-Lys-Pro). Using a receptor-based SHOP (scaffold hopping) approach with N-selective inhibitor RXP407, a shortlist of scaffolds that consisted of modified RXP407 backbones with novel chemotypes was generated. These scaffolds were selected on the basis of enhanced predicted interaction energies with N-domain residues that differed from their C-domain counterparts. One scaffold was synthesized and inhibitory binding tested using a fluorogenic ACE assay. A molecule incorporating a tetrazole moiety in the P2 position (compound 33RE) displayed potent inhibition (K(i)=11.21±0.74 nM) and was 927-fold more selective for the N-domain than the C-domain. A crystal structure of compound 33RE in complex with the N-domain revealed its mode of binding through aromatic stacking with His388 and a direct hydrogen bond with the hydroxy group of the N-domain specific Tyr369. This work further elucidates the molecular basis for N-domain-selective inhibition and assists in the design of novel N-selective ACE inhibitors that could be employed in treatment of fibrosis disorders. PMID:24015848

  20. Two-photon uncageable enzyme inhibitors bearing targeting vectors.

    PubMed

    Anstaett, Philipp; Pierroz, Vanessa; Ferrari, Stefano; Gasser, Gilles

    2015-10-01

    The activity of two cyclooxygenase-2 enzyme inhibitors, Celecoxib and Lumiracoxib, could be suppressed by coupling to photo-labile protecting groups, so-called photocages. These groups could be further functionalized with a peptide targeting vector for specific cellular delivery. The enzyme inhibition potential of the cyclooxygenase-2 inhibitors could be regained upon two-photon excitation with tissue-transparent near-IR light at 800 nm. PMID:26314377

  1. Inhibition of angiotensin converting enzyme (ACE) by flavonoids isolated from Ailanthus excelsa (Roxb) (Simaroubaceae).

    PubMed

    Loizzo, Monica Rosa; Said, Ataa; Tundis, Rosa; Rashed, Khaled; Statti, Giancarlo Antonio; Hufner, Antje; Menichini, Francesco

    2007-01-01

    In our screening program for antihypertensive properties of plants, the leaves of Ailanthus excelsa (Roxb), a plant used in Egyptian traditional medicine, were analysed. Chromatographic separation of A. excelsa MeOH extract yielded six flavonoids for the first time from this species, namely apigenin, luteolin, kaempferol-3-O-alpha-arabinopyranoside, kaempferol-3-O-beta-galactopyranoside, quercetin-3-O-alpha-arabinopyranoside and luteolin-7-O-beta-glucopyranoside. The in vitro hypotensive activities of the MeOH extract and the isolated compounds were elucidated. All the flavonoids tested exhibited ACE inhibitory activity, in particular the most active compound was kaempferol-3-O-beta-galactopyranoside with an IC(50) value of 260 microm. PMID:17072829

  2. ACE Inhibitor and Angiotensin Receptor Blocker Use and Mortality in Patients with Chronic Kidney Disease

    PubMed Central

    Molnar, Miklos Z; Kalantar-Zadeh, Kamyar; Lott, Evan H; Lu, Jun Ling; Malakauskas, Sandra M; Ma, Jennie Z; Quarles, Darryl L; Kovesdy, Csaba P

    2014-01-01

    Objective To assess the association between ACEI/ARB use and mortality in CKD patients. Background There is insufficient evidence about the association of angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARBs) with mortality in chronic kidney disease (CKD) patients. Methods A logistic regression analysis was used to calculate the propensity of ACEI/ARB initiation in 141,413 US veterans with non-dialysis CKD previously unexposed to ACEI/ARB treatment. We examined the association of ACEI/ARB administration with all-cause mortality in patients matched by propensity scores, using the Kaplan-Meier method and Cox models in “intention-to-treat” analyses, and in generalized linear models with binary outcomes and inverse probability treatment weighing (IPTW) in “as-treated” analyses. Results The mean±SD age of the patients at baseline was 75±10 years, 8% of patients were black, and 22% were diabetic. ACEI/ARB administration was associated with significantly lower risk of mortality both in the intention-to-treat analysis (HR=0.81; 95%CI: 0.78-0.84, p<0.001) and in the as-treated analysis with IPTW (OR=0.37; 95%CI: 0.34-0.41, p<0.001). The association of ACEI/ARB treatment with lower risk of mortality was present in all examined subgroups. Conclusions In this large contemporary cohort of non-dialysis dependent CKD patients, ACEI/ARB administration was associated with greater survival. PMID:24269363

  3. Can ACE inhibitors and angiotensin receptor blockers be detrimental in CKD patients?

    PubMed

    Onuigbo, Macaulay A C

    2011-01-01

    Current epidemiological data from the USA, Europe, Asia and the Indian subcontinent, Africa, the Far East, South America, the Middle East and Eastern Europe all point to the increasing incidence of renal failure encompassing acute kidney injury (AKI), chronic kidney disease (CKD) and end-stage renal disease (ESRD). While the explanations for these worldwide epidemics remain speculative, it must be acknowledged that these increases in AKI, CKD and ESRD, happening worldwide, have occurred despite the universal application of strategies of renoprotection over the last 2 decades, more especially the widespread use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). We note that many of the published large renin-angiotensin-aldosterone system (RAAS) blockade randomized controlled trials, upon which current evidence-based practice for the increasing use of ACEIs and ARBs for renoprotection derived from, have strong deficiencies that have been highlighted over the years. From reports in the literature, there is an increasing association of exacerbations of renal failure with ACEIs and ARBs, more so in the older hypertensive patient, >65 years old. The biological plausibility for ACEI and ARB to protect the kidneys against a background of potential multiple pathogenetic pathways to account for CKD progression appears to be not very defensible. We reviewed the literature along these lines and submit that ACEIs and ARBs often cause unrecognized significant worsening renal failure in CKD patients, sometimes irreversible, and that more caution is required regarding their use, especially in the older hypertensive patients, with likely ischemic hypertensive nephropathy. Given the increasing association of concomitant RAAS blockade with worsening renal failure following exposure to iodinated contrast, during acute illness, in the perioperative period and following lower bowel preparations prior to colonoscopy, we submit that, preferably

  4. The effects of drug market regulation on pharmaceutical prices in Europe: overview and evidence from the market of ACE inhibitors

    PubMed Central

    2011-01-01

    This study provides an overview of policy measures targeting pharmaceutical expenditure in Europe and analyses their impact on originator pharmaceutical prices. Panel data methods are used to examine the market of ACE Inhibitors in six European countries (Denmark, France, Germany, Netherlands, Sweden, United Kingdom) over period 1991-2006. We find that although some measures are effective in reducing originator prices, others appear to have an insignificant effect. Results suggest that supply side measures such as mandatory generic substitution, regressive pharmacy mark-ups and claw-backs are effective in reducing pharmaceuticals prices. Results are not as strong for demand side measures. Profit controls and the use of cost-effectiveness analysis appear to have a negative effect on prices, while results on reference pricing are inconclusive. Findings also indicate that, although originator prices are not immediately affected by generic entry, they may be influenced by changes in generic prices post patent expiry. PMID:22828053

  5. Angiotensin II regulates ACE and ACE2 in neurons through p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2 signaling

    PubMed Central

    Xiao, Liang; Haack, Karla K. V.

    2013-01-01

    Brain ANG II plays an important role in modulating sympathetic function and homeostasis. The generation and degradation of ANG II are carried out, to a large extent, through the angiotensin-converting enzyme (ACE) and ACE2, respectively. In disease states, such as hypertension and chronic heart failure, central expression of ACE is upregulated and ACE2 is decreased in central sympathoregulatory neurons. In this study, we determined the expression of ACE and ACE2 in response to ANG II in a neuronal cell culture and the subsequent signaling mechanism(s) involved. A mouse catecholaminergic neuronal cell line (CATH.a) was treated with ANG II (30, 100, and 300 nM) for 24 h, and protein expression was determined by Western blot analysis. ANG II induced a significant dose-dependent increase in ACE and decrease in ACE2 mRNA and protein expression in CATH.a neurons. This effect was abolished by pretreatment of the cells with the p38 MAPK inhibitor SB-203580 (10 μM) 30 min before administration of ANG II or the ERK1/2 inhibitor U-0126 (10 μM). These data suggest that ANG II increases ACE and attenuates ACE2 expression in neurons via the ANG II type 1 receptor, p38 MAPK, and ERK1/2 signaling pathways. PMID:23535237

  6. Angiotensin I-converting enzyme (ACE) inhibitory activities of sardinelle (Sardinella aurita) by-products protein hydrolysates obtained by treatment with microbial and visceral fish serine proteases.

    PubMed

    Bougatef, Ali; Nedjar-Arroume, Naima; Ravallec-Plé, Rozenn; Leroy, Yves; Guillochon, Didier; Barkia, Ahmed; Nasri, Moncef

    2008-11-15

    The angiotensin I-converting enzyme (ACE) inhibitory activities of protein hydrolysates prepared from heads and viscera of sardinelle (Sardinella aurita) by treatment with various proteases were investigated. Protein hydrolysates were obtained by treatment with Alcalase(®), chymotrypsin, crude enzyme preparations from Bacillus licheniformis NH1 and Aspergillus clavatus ES1, and crude enzyme extract from sardine (Sardina pilchardus) viscera. All hydrolysates exhibited inhibitory activity towards ACE. The alkaline protease extract from the viscera of sardine produced hydrolysate with the highest ACE inhibitory activity (63.2±1.5% at 2mg/ml). Further, the degrees of hydrolysis and the inhibitory activities of ACE increased with increasing proteolysis time. The protein hydrolysate generated with alkaline proteases from the viscera of sardine was then fractionated by size exclusion chromatography on a Sephadex G-25 into eight major fractions (P1-P8). Biological functions of all fractions were assayed, and P4 was found to display a high ACE inhibitory activity. The IC50 values for ACE inhibitory activities of sardinelle by-products protein hydrolysates and fraction P4 were 1.2±0.09 and 0.81±0.013mg/ml, respectively. Further, P4 showed resistance to in vitro digestion by gastrointestinal proteases. The amino acid analysis by GC/MS showed that P4 was rich in phenylalanine, arginine, glycine, leucine, methionine, histidine and tyrosine. The added-value of sardinelle by-products may be improved by enzymatic treatment with visceral serine proteases from sardine. PMID:26047434

  7. A novel angiotensin-І converting enzyme (ACE) inhibitory peptide from gastrointestinal protease hydrolysate of silkworm pupa (Bombyx mori) protein: Biochemical characterization and molecular docking study.

    PubMed

    Wu, Qiongying; Jia, Junqiang; Yan, Hui; Du, Jinjuan; Gui, Zhongzheng

    2015-06-01

    Silkworm pupa (Bombyx mori) protein was hydrolyzed using gastrointestinal endopeptidases (pepsin, trypsin and α-chymotrypsin). Then, the hydrolysate was purified sequentially by ultrafiltration, gel filtration chromatography and RP-HPLC. A novel ACE inhibitory peptide, Ala-Ser-Leu, with the IC50 value of 102.15μM, was identified by IT-MS/MS. This is the first report of Ala-Ser-Leu from natural protein. Lineweaver-Burk plots suggest that the peptide is a competitive inhibitor against ACE. The molecular docking studies revealed that the ACE inhibition of Ala-Ser-Leu is mainly attributed to forming very strong hydrogen bonds with the S1 pocket (Ala354) and the S2 pocket (Gln281 and His353). The results indicate that silkworm pupa (B. mori) protein or its gastrointestinal protease hydrolysate could be used as a functional ingredient in auxiliary therapeutic foods against hypertension. PMID:25111373

  8. Angioedema of the lips and tongue induced by angiotensin-converting enzyme inhibitor. A report of two cases.

    PubMed

    Stevenson, Helen A; Steele, John C; Field, E Anne; Darroch, Campbell J

    2004-01-01

    The following case reports describe the clinical presentation, diagnosis and management of two patients who attended Liverpool University Dental Hospital with rapidly increasing swelling of the lips and tongue. Both patients were suffering from angioedema and were taking an angiotension-converting enzyme (ACE) inhibitor (ACEI). A provisional diagnosis of ACEI-induced angioedema was made. An intramuscular injection of chlorpheniramine maleate was given to both patients and they were immediately transferred to the local accident and emergency department. These cases illustrate the potential role of the general dental practitioner in the early recognition and management of this potentially life-threatening condition. PMID:14768205

  9. Inhibition of tissue angiotensin converting enzyme. Quantitation by autoradiography

    SciTech Connect

    Sakaguchi, K.; Chai, S.Y.; Jackson, B.; Johnston, C.I.; Mendelsohn, F.A.

    1988-03-01

    Inhibition of angiotensin converting enzyme (ACE) in serum and tissues of rats was studied after administration of lisinopril, an ACE inhibitor. Tissue ACE was assessed by quantitative in vitro autoradiography using the ACE inhibitor (/sup 125/I)351A, as a ligand, and serum ACE was measured by a fluorimetric method. Following oral administration of lisinopril (10 mg/kg), serum ACE activity was acutely reduced but recovered gradually over 24 hours. Four hours after lisinopril administration, ACE activity was markedly inhibited in kidney (11% of control level), adrenal (8%), duodenum (8%), and lung (33%; p less than 0.05). In contrast, ACE in testis was little altered by lisinopril (96%). In brain, ACE activity was markedly reduced 4 hours after lisinopril administration in the circumventricular organs, including the subfornical organ (16-22%) and organum vasculosum of the lamina terminalis (7%; p less than 0.05). In other areas of the brain, including the choroid plexus and caudate putamen, ACE activity was unchanged. Twenty-four hours after administration, ACE activity in peripheral tissues and the circumventricular organs of the brain had only partially recovered toward control levels, as it was still below 50% of control activity levels. These results establish that lisinopril has differential effects on inhibiting ACE in different tissues and suggest that the prolonged tissue ACE inhibition after a single oral dose of lisinopril may reflect targets involved in the hypotensive action of ACE inhibitors.

  10. Sperm-specific expression of angiotensin-converting enzyme (ACE) is mediated by a 91-base-pair promoter containing a CRE-like element.

    PubMed Central

    Howard, T; Balogh, R; Overbeek, P; Bernstein, K E

    1993-01-01

    The gene encoding the testis isozyme of angiotensin-converting enzyme (testis ACE) is one example of the many genes expressed uniquely during spermatogenesis. This protein is expressed by developing germ cells late in their development and results from the activation of a sperm-specific promoter that is located within intron 12 of the gene encoding the somatic isozyme of ACE. In vitro transcription, DNase footprinting, gel shift assays, and transgenic mouse studies have been used to define the minimal testes ACE promoter and to characterize DNA-protein interactions mediating germ cell-specific expression. These studies show that proper cell- and stage-specific expression of testis ACE requires only a small portion of the immediate upstream sequence extending to -91. A critical motif within this core promoter is a cyclic AMP-responsive element sequence that interacts with a testis-specific transactivating factor. Since this putative cyclic AMP-responsive element has been conserved within the testis ACE promoters of different species and is found at the same site in other genes that are expressed specifically in the testis, it may provide a common mechanism for the recognition of sperm-specific promoters. Images PMID:8380220

  11. Comparison of the Efficacy and Safety of Different ACE Inhibitors in Patients With Chronic Heart Failure: A PRISMA-Compliant Network Meta-Analysis.

    PubMed

    Sun, WeiPing; Zhang, HaiBin; Guo, JinCheng; Zhang, XueKun; Zhang, LiXin; Li, ChunLei; Zhang, Ling

    2016-02-01

    Heart failure is a public health problem and a great economic burden for patients and healthcare systems. Suppression of the renin-angiotensin system (RAS) by angiotensin-converting enzyme (ACE)-inhibitors remains the mainstay of treatment for heart failure. However, the abundance of ACE inhibitors makes it difficult for doctors to choose.We performed this network meta-analysis of ACEIs in patients with heart failure in order to address this area of uncertainty.We searched PubMed, Embase, CENTRAL, and Medline.Any randomized controlled trial evaluating the efficacy and safety of captopril, enalapril, lisinopril, ramipril, or trandolapril or combined interventions of 2 or more of these drugs.Two reviewers extracted the data and made the quality assessment. At first, we used Stata software (version 12.0, StataCorp, College Station, TX) to make traditional pairwise meta-analyses for studies that directly compared different interventions. Then, network meta-analysis was performed using WinBUGS (version 1.4.3, MRC Biostatistics Unit, Cambridge, UK).A total of 29 studies were included. Lisinopril was associated with a higher rate of all-cause mortality compared with placebo (odds ratio 65.9, 95% credible interval 1.91 to 239.6) or ramipril (14.65, 1.23 to 49.5). Enalapril significantly reduced systolic blood pressure when compared with placebo (standardized mean differences -0.6, 95% credible interval -1.03 to -0.18). Both captopril (odds ratio 76.2, 95% credible interval 1.56 to 149.3) and enalapril (274.4, 2.4 to 512.9) were associated with a higher incidence of cough compared to placebo.Some important outcomes such as rehospitalization and cardiac death were not included. The sample size and the number of studies were limited, especially for ramipril.Our results suggest that enalapril might be the best option when considering factors such as increased ejection fraction, stroke volume, and decreased mean arterial pressure. However, enalapril was associated with the

  12. Association of plasminogen activator inhibitor-1 and angiotensin converting enzyme polymorphisms with recurrent pregnancy loss in Iranian women

    PubMed Central

    Shakarami, Fatemeh; Akbari, Mohammad Taghi; Zare Karizi, Shohreh

    2015-01-01

    Background: Recurrent pregnancy loss (RPL) defined by two or more failed pregnancies before 20 weeks of gestation. Several factors play a role in RPL including thrombophilic conditions which can be influenced by gene polymorphisms. Plasminogen activator inhibitor-1 (PAI-1) and angiotensin converting enzyme (ACE) genes are closely related to fibrinolytic process, embryonic development and pregnancy success. Objective: The aim of this study was to investigate the relationship between RPL and common polymorphisms in ACE and PAI-1 genes. Materials and Methods: In this case control study, 100 women with recurrent abortions (at least two) were selected as cases and 100 healthy women with two or more normal term deliveries without a history of abortion as controls. Total genomic DNA was isolated from blood leukocytes. The status of the PAI-1 4G/5G and ACE (D/I) polymorphism was determined by PCR-RFLP. Results: Homozygosity for PAI-1 4G polymorphism was seen in 17 cases (17%), and 5 controls (5%) (p=0.006) so patients with homozygote 4G mutation were significantly more prone to RPL in contrast to control group (OR: 4.63, % 95 CI: 1.55-13.84). In addition, 7 patients (7 %), and no one from the control group, were homozygote (I/I) for ACE polymorphism (p=0.034), suggesting no significant associations between ACE D allele or DD genotype and RPL. Conclusion: Considering these results, because 4G/4G polymorphism for PAI-1 gene could be a thrombophilic variant leading to abortion, analysis of this mutation and other susceptibility factors are recommended in patients with RPL. PMID:26644791

  13. Angiotensin-converting Enzyme Inhibitor and Statin Medication Use and Incident Mobility Limitation in Community Older Adults. The Health, Aging and Body Composition Study

    PubMed Central

    Gray, Shelly L.; Boudreau, Robert M.; Newman, Anne B.; Studenski, Stephanie A.; Shorr, Ronald I; Bauer, Douglas C.; Simonsick, Eleanor M.; Hanlon, Joseph T

    2012-01-01

    Objective Angiotensin-converting enzyme (ACE) inhibitors and statin medications have been proposed as potential agents to prevent or delay physical disability; yet limited research has evaluated whether such use in older community dwelling adults is associated with a lower risk of incident mobility limitation. Design Longitudinal cohort study Setting Health, Aging and Body Composition (Health ABC) Participants 3055 participants who were well functioning at baseline (e.g., no mobility limitations). Measurements Summated standardized daily doses (low, medium and high) and duration of ACE inhibitor and statin use was computed. Mobility limitation (two consecutive self-reports of having any difficulty walking 1/4 mile or climbing 10 steps without resting) was assessed every 6 months after baseline. Multivariable Cox proportional hazard analyses were conducted adjusting for demographics, health status, and health behaviors. Results At baseline, ACE inhibitors and statins were used by 15.2% and 12.9%, respectively and both increased to over 25% by year 6. Over 6.5 years of follow-up, 49.8% had developed mobility limitation. In separate multivariable models, neither ACE inhibitor (multivariate hazard ratio [HR] 0.95; 95% confidence interval [CI] 0.82–1.09) nor statin use (multivariate HR 1.02; 95% CI 0.87–1.17) was associated with a lower risk for mobility limitation. Similar findings were seen in analyses examining dose- and duration-response relationships and sensitivity analyses restricted to those with hypertension. Conclusions These findings indicate that ACE inhibitors and statins widely prescribed to treat hypertension and hypercholesterolemia, respectively do not lower risk of mobility limitation, an important life quality indicator. PMID:22092102

  14. [Angiotensin-converting enzyme inhibitors as neutralizers of hydroxyl radical].

    PubMed

    Mira, M L; Silva, M M; Queirós, M J; Manso, C

    1992-05-01

    Angiotensin converting enzyme inhibitors are utilized in the treatment of essential hypertension and of chronic cardiac failure. They are also employed in the treatment of the myocardial lesion of ischemia-reperfusion, which involves oxygen free radicals. In the present study we investigated the possibility of three angiotensin converting enzyme inhibitors (captopril, enalapril, lisinopril) to act as hydroxyl radical scavengers. The rate constants for reactions of those compounds with .OH were determined using the deoxyribose method. All there compounds proved to be good scavengers of .OH with rate constants of about 10(10)M-1s-1 and are iron chelators specially enalapril. The fact that captopril possesses a thiol group does not confer an higher antioxidative capacity. These results suggest that scavenging of oxygen free radicals may be a possible mechanism contributing to the therapeutic effect of angiotensin converting enzyme inhibitors. PMID:1325814

  15. Long-range safety and protective benefits of angiotensin-converting enzyme inhibitors for hypertension. Do we need more clinical trials?

    PubMed Central

    Sambhi, M P; Gavras, H; Robertson, J I; Smith, W M

    1993-01-01

    Inhibition of the renin-angiotensin system is being applied with considerable success to the treatment of hypertension and heart failure. Angiotensin-converting enzyme (ACE) inhibitors are the only currently available agents that can achieve this objective. In general, the major therapeutic effects of these agents in the treatment of mild to moderate hypertension or of heart failure are exerted on the vascular tissue through inhibition of the renin-angiotensin system and, secondarily, of the sympathetic nervous system. When cardiovascular functional reserve is diminished and autoregulation of regional and systemic blood flow is strained, however, ACE inhibitors may affect other organ functions (heart, kidneys, and possibly brain), hormones other than the renin system, and local tissue humoral systems. The interrelations between the renin-angiotensin system and several other vasoactive systems--including circulating and locally generated tissue hormones and centrally acting neurohormonal factors--are complex and unclear. A better understanding of these mechanisms and interrelations would allow for a more rational therapeutic use of these agents. Unknown also are the clinical effects of prolonged ACE inhibition. Whether the use of ACE inhibitors can provide primary cardiorenal protection requires proof through definitive clinical trials. Images PMID:8460511

  16. 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. PMID:25364320

  17. T-lymphocyte induction of human monocyte angiotensin converting enzyme (ACE) is not dependent upon T-lymphocyte proliferation

    SciTech Connect

    Vuk-Pavlovic, Z.; Rohrbach, M.S.

    1986-03-05

    Human peripheral blood monocytes cultured in serum free media for seven days show a basal activity of the ectoenzyme ACE which is augmented 2-3 times by the presence of autologous peripheral blood T-lymphocytes. Since these two cell types are also involved in autologous mixed lymphocyte reaction if serum is present, the authors compared the ability of T-cells to stimulate ACE activity in the presence or absence of proliferation (measured by /sup 3/H-thymidine incorporation). By the seventh day, cultures with 5% AB/sup +/ serum showed significant increase in proliferation but no increase in ACE activity compared to the serum free cultures. Even higher proliferation rate achieved by co-culturing T-lymphocytes with allogeneic monocytes did not increase ACE production; on the contrary, ACE activity remained at the basal level. Monocyte-T-cell co-cultures stimulated with increasing concentrations of ConA or PHA showed dose dependent increases in proliferation but parallel decreases in ACE activity. Addition of soluble antigen (Candida albicans) also enhanced proliferation but not ACE synthesis. They conclude that T-lymphocyte induction of monocyte ACE is a result of cooperation between autologous cells which is not dependent upon T-cell proliferation.

  18. Cardiorespiratory effects of continuous i.v. administration of the ACE inhibitor enalaprilat in the critically ill.

    PubMed Central

    Boldt, J; Müller, M; Heesen, M; Härter, K; Hempelmann, G

    1995-01-01

    1. Cardiorespiratory effects of long-term, continuous i.v. administration of the ACE inhibitor enalaprilat were studied. 2. Forty-five consecutive critically patients suffering from trauma or postoperative complications were randomly separated into three groups (15 patients in each group) receiving either 0.25 mg h-1 or 0.50 mg h-1 enalaprilat, respectively, or saline solution as placebo (= control group). The infusion was continued for 5 days. 3. Haemodynamic and respiratory parameters were intensively monitored on admission to the intensive care unit (= 'baseline' values) and daily during the next 5 days. 4. Mean arterial blood pressure (MAP) decreased significantly only in the enalaprilat-treated patients, whereas heart rate (HR) remained unchanged in these patients. 5. Pulmonary capillary wedge pressure (PCWP) and pulmonary artery pressure (PAP) were decreased by enalaprilat (0.50 mg h-1: PAP (mean +/- s.d.) decreased from 28.0 +/- 4.1 to 24.0 +/- 3.0 mm Hg) and remained significantly lower than in the control group. In the untreated control group, cardiac index (CI), oxygen consumption (VO2I) and oxygen delivery (DO2I) significantly decreased, which was blunted by enalaprilat infusion. Oxygen extraction (O2-extr) increased in both enalaprilat groups (0.25 mg h-1: from 26.1 +/- 5.5 to 30.4 +/- 4.0%; 0.50 mg h-1: 25.2 +/- 5.6 to 30.9 +/- 4.4%) and decreased in the control patients. 6. Right ventricular haemodynamics improved by enalaprilat infusion (0.50 mg h-1: RVEF increased from 40.0 +/- 3.5 to 45.5 +/- 4.0%). Lactate plasma concentrations decreased in the group with 0.50 mg h-1 enalaprilat (from 1.9 +/- 1.0 to 1.3 +/- 0.3 mg dl-1) and increased in the control patients. 7. Continuous infusion of the ACE inhibitor enalaprilat exerted beneficial cardiorespiratory effects in the critically ill. The widespread common risk of altered perfusion with decreased CI, DO2, VO2, O2-extr and increased lactate concentration was blunted by enalaprilat infusion. 8. Although

  19. Endopeptidase 3.4.24.11 converts N-1-(R,S)carboxy-3-phenylpropyl-Ala-Ala-Phe-p-carboxyanilide into a potent inhibitor of angiotensin-converting enzyme.

    PubMed Central

    Williams, C H; Yamamoto, T; Walsh, D M; Allsop, D

    1993-01-01

    It was reported recently that N-1-(R,S)carboxy-3-phenylpropyl-Ala-Ala-Phe-p-carboxyanilide (CPP-A-A-F-pAB), an inhibitor of endopeptidase 3.4.24.15 (E-24.15), also inhibits angiotensin-converting enzyme (ACE) from rabbit lung. We have found that this compound is without effect on ACE purified from pig kidney, at a concentration some 1000-fold greater than the Ki reported for inhibition of the enzyme from lung. However, preincubation of CPP-A-A-F-pAB with neutral endopeptidase 3.4.24.11 (E-24.11) does result in potent inhibitory effects on ACE. We have shown this to be due to formation of a fragment, CPP-A-A, the structure of which is closely related to ACE inhibitors such as enalaprilat. CPP-A-A was found to be a potent inhibitor of pig ACE. Under the conditions used it had an IC50 value of 1.6 x 10(-8) M, compared with the value obtained for captopril of 7.5 x 10(-10) M. These results have important implications for studies of E-24.15 when using CPP-A-A-F-pAB in vivo or in crude tissue extracts where E-24.11 might also be present. PMID:8379924

  20. Risk of Hospitalized Gastrointestinal Bleeding in Persons Randomized to Diuretic, ACE-Inhibitor, or Calcium-Channel Blocker in ALLHAT

    PubMed Central

    Phillips, William; Piller, Linda B.; Williamson, Jeff D.; Whittle, Jeffrey; Jafri, Syed Z.A.; Ford, Charles E.; Einhorn, Paula T.; Oparil, Suzanne; Furberg, Curt D.; Grimm, Richard H.; Alderman, Michael H.; Davis, Barry R.; Probstfield, Jeffrey L.

    2013-01-01

    Calcium channel-blockers (CCB) are an important class of medication useful in the treatment of hypertension. Several observational studies have suggested an association between CCB therapy and gastrointestinal hemorrhage. Using administrative databases, we re-examined in a post-hoc analysis whether the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants randomized to the calcium-channel blocker amlodipine had a greater risk of hospitalized gastrointestinal bleeding (a pre-specified outcome) compared to those randomized to the diuretic chlorthalidone or the ACE-inhibitor lisinopril. Participants randomized to chlorthalidone did not have a reduced risk for gastrointestinal bleeding hospitalizations compared to participants randomized to amlodipine (HR, 1.09, 95% CI 0.92-1.28). Those randomized to lisinopril were at increased risk of gastrointestinal bleeding compared those randomized to chlorthalidone (HR, 1.16; 95% CI, 1.00-1.36). In a post-hoc comparison, participants assigned lisinopril therapy had a higher risk of hospitalized gastrointestinal hemorrhage (HR,1.27, 95% CI 1.06-1.51) versus those assigned to amlodipine. In-study use of atenolol prior to first gastrointestinal hemorrhage was related to a lower incidence of GI bleeding (HR, 0.69; 95% CI, 0.57-0.83). In conclusion, hypertensive patients on amlodipine do not have an increased risk of GI bleeding hospitalizations compared to those on either chlorthalidone or lisinopril. PMID:24283598

  1. Life-threatening angio-oedema after the first dose of an ACE inhibitor-not an anaphylactic reaction.

    PubMed

    Krogh Nielsen, Troels; Bygum, Anette; Rye Rasmussen, Eva

    2016-01-01

    We present a case of a 60-year-old Caucasian woman, with no prior history of swellings, who was admitted to a hospital due to life-threatening angio-oedema. She had, the previous day, been prescribed an ACE inhibitor for her essential hypertension. She had taken one tablet at night-time, and awoke in the morning with a swollen face progressing to involve the tongue and throat within a few hours. On arrival at her doctor's office, her voice had altered. Corticosteroids and antihistamine were administered while awaiting an ambulance. Arriving at the emergency department, she had dyspnoea due to increasingly severe angio-oedema of the upper airways. Neither adrenaline inhalations, intravenously administrated corticosteroids, atropine nor furosemide were effective and the patient soon become bradycardic. A tracheotomy was performed and the patient was placed on a ventilator. She eventually made a full recovery. It was concluded that she had suffered from life-threatening angio-oedema due to her new medication. PMID:27229746

  2. Angiotensin I-converting enzyme (ACE) inhibitory activity and structural properties of oven- and freeze-dried protein hydrolysate from fresh water fish (Cirrhinus mrigala).

    PubMed

    Elavarasan, K; Shamasundar, B A; Badii, Faraha; Howell, Nazlin

    2016-09-01

    The angiotensin I-converting enzyme (ACE) inhibitory activity and structural properties of oven-dried (OD-FPH) and freeze-dried (FD-FPH) protein hydrolysates derived from fresh water fish (Cirrhinus mrigala) muscle, using papain, were investigated. Amino acid profiles indicated a higher proportion of hydrophobic residues in OD-FPH and hydrophilic residues in FD-FPH samples. Fourier transform infrared (FT-IR) spectra revealed random coil structure in OD-FPH and β-sheet in FD-FPH samples. The approximate molecular weight of peptides in OD-FPH and FD-FPH was in the range of 7030-339Da. The IC50 values for ACE inhibition by OD-FPH and FD-FPH samples were found to be 1.15 and 1.53mg of proteinml(-1), respectively. The ACE-inhibitory activity of OD-FPH was more stable (during sequential digestion, using pepsin and pancreatin) than that of FD-FPH sample. The study suggested that the ACE inhibitory activity of protein hydrolysate was not affected by oven-drying. PMID:27041318

  3. Characterization of angiotensin I-converting enzyme from anterior gills of the mangrove crab Ucides cordatus.

    PubMed

    Bersanetti, Patrícia A; Nogueira, Regina F; Marcondes, Marcelo F; Paiva, Paulo B; Juliano, Maria A; Juliano, Luiz; Carmona, Adriana K; Zanotto, Flavia P

    2015-03-01

    Angiotensin I-converting enzyme (ACE) is a well-known metallopeptidase that is found in vertebrates, invertebrates and bacteria. We isolated from the anterior gill of the crab Ucides cordatus an isoform of ACE, here named crab-ACE, which presented catalytic properties closely resembling to those of mammalian ACE. The enzyme was purified on Sepharose-lisinopril affinity chromatography to apparent homogeneity and a band of about 72 kDa could be visualized after silver staining and Western blotting. Assays performed with fluorescence resonance energy transfer (FRET) selective ACE substrates Abz-FRK(Dnp)P-OH, Abz-SDK(Dnp)P-OH and Abz-LFK(Dnp)-OH, allowed us to verify that crab-ACE has hydrolytic profile very similar to that of the ACE C-domain. In addition, we observed that crab-ACE can hydrolyze the ACE substrates, angiotensin I and bradykinin. The enzyme was strongly inhibited by the specific ACE inhibitor lisinopril (Ki of 1.26 nM). However, in contrast to other ACE isoforms, crab-ACE presented a very particular optimum pH, being the substrate Abz-FRK(Dnp)-P-OH hydrolyzed efficiently at pH 9.5. Other interesting characteristic of crab-ACE was that the maximum hydrolytic activity was reached at around 45°C. The description of an ACE isoform in Ucides cordatus is challenging and may contribute to a better understanding of the biochemical function of this enzyme in invertebrates. PMID:25544039

  4. The Pharmacogenetic Footprint of ACE Inhibition: A Population-Based Metabolomics Study.

    PubMed

    Altmaier, Elisabeth; Menni, Cristina; Heier, Margit; Meisinger, Christa; Thorand, Barbara; Quell, Jan; Kobl, Michael; Römisch-Margl, Werner; Valdes, Ana M; Mangino, Massimo; Waldenberger, Melanie; Strauch, Konstantin; Illig, Thomas; Adamski, Jerzy; Spector, Tim; Gieger, Christian; Suhre, Karsten; Kastenmüller, Gabi

    2016-01-01

    Angiotensin-I-converting enzyme (ACE) inhibitors are an important class of antihypertensives whose action on the human organism is still not fully understood. Although it is known that ACE especially cleaves COOH-terminal dipeptides from active polypeptides, the whole range of substrates and products is still unknown. When analyzing the action of ACE inhibitors, effects of genetic variation on metabolism need to be considered since genetic variance in the ACE gene locus was found to be associated with ACE-concentration in blood as well as with changes in the metabolic profiles of a general population. To investigate the interactions between genetic variance at the ACE-locus and the influence of ACE-therapy on the metabolic status we analyzed 517 metabolites in 1,361 participants from the KORA F4 study. We replicated our results in 1,964 individuals from TwinsUK. We observed differences in the concentration of five dipeptides and three ratios of di- and oligopeptides between ACE inhibitor users and non-users that were genotype dependent. Such changes in the concentration affected major homozygotes, and to a lesser extent heterozygotes, while minor homozygotes showed no or only small changes in the metabolite status. Two of these resulting dipeptides, namely aspartylphenylalanine and phenylalanylserine, showed significant associations with blood pressure which qualifies them-and perhaps also the other dipeptides-as readouts of ACE-activity. Since so far ACE activity measurement is substrate specific due to the usage of only one oligopeptide, taking several dipeptides as potential products of ACE into account may provide a broader picture of the ACE activity. PMID:27120469

  5. The Pharmacogenetic Footprint of ACE Inhibition: A Population-Based Metabolomics Study

    PubMed Central

    Altmaier, Elisabeth; Menni, Cristina; Heier, Margit; Meisinger, Christa; Thorand, Barbara; Quell, Jan; Kobl, Michael; Römisch-Margl, Werner; Valdes, Ana M.; Mangino, Massimo; Waldenberger, Melanie; Strauch, Konstantin; Illig, Thomas; Adamski, Jerzy; Spector, Tim; Gieger, Christian; Suhre, Karsten; Kastenmüller, Gabi

    2016-01-01

    Angiotensin-I-converting enzyme (ACE) inhibitors are an important class of antihypertensives whose action on the human organism is still not fully understood. Although it is known that ACE especially cleaves COOH-terminal dipeptides from active polypeptides, the whole range of substrates and products is still unknown. When analyzing the action of ACE inhibitors, effects of genetic variation on metabolism need to be considered since genetic variance in the ACE gene locus was found to be associated with ACE-concentration in blood as well as with changes in the metabolic profiles of a general population. To investigate the interactions between genetic variance at the ACE-locus and the influence of ACE-therapy on the metabolic status we analyzed 517 metabolites in 1,361 participants from the KORA F4 study. We replicated our results in 1,964 individuals from TwinsUK. We observed differences in the concentration of five dipeptides and three ratios of di- and oligopeptides between ACE inhibitor users and non-users that were genotype dependent. Such changes in the concentration affected major homozygotes, and to a lesser extent heterozygotes, while minor homozygotes showed no or only small changes in the metabolite status. Two of these resulting dipeptides, namely aspartylphenylalanine and phenylalanylserine, showed significant associations with blood pressure which qualifies them—and perhaps also the other dipeptides—as readouts of ACE-activity. Since so far ACE activity measurement is substrate specific due to the usage of only one oligopeptide, taking several dipeptides as potential products of ACE into account may provide a broader picture of the ACE activity. PMID:27120469

  6. Angiotensin Converting Enzyme Inhibitor-related Angioedema: A Case of an Unexpected Death.

    PubMed

    Atalay, Eray; Özdemir, Mehmet Tamer; Çiğsar, Gülşen; Omurca, Ferhat; Aslan, Nurullah; Yildiz, Mehmet; Gey, Zehra Bahar

    2015-11-01

    Angioedema is an asymmetric non-pitting oedema on face, lips, tongue and mucous membranes; any delay in diagnosis and treatment can be fatal. Treatment with lisinopril as an angiotensin converting enzyme (ACE) inhibitor, can be a reason of angioedema. Here we report a case who developed oral-facial edema four years after using lisinopril/hydrochlorothiazide. Laryngeal oedema is a main cause of death in angioedema. The treatment of choice in angioedema including fresh frozen plasma, C1 inhibitor concentrations and BRK-2 antagonists (bradykinin B2 receptor antagonists) were used. In this case; a 77 years old female patient suffering from hypertension was considered. This patient was suffering two days from swelling on her face and neck. Non- allergic angioedema was distinguished in five major forms; acquired (AAO), hereditary (HAE), renin-angiotensin-aldosterone system (RAAS) blocker-dependent, pseudoallergic angioedema (PAS) and an idiopathic angioedema (IAO). She was admitted to our clinic with the diagnosis of hereditary angioedema. Patient had skin edema and life threatening laryngeal edema. In emergency department treatment was started using intravenous methylprednisolone, diphenydramine as well as inhaled and subcutaneous epinephrine simultaneously. Despite the initial treatment, the patient died due to the insufficient respiration and cardiac arrest. The patient has no history of kidney disease. PMID:26725563

  7. Lymphocyte-suppressing action of angiotensin-converting enzyme inhibitors in coronary artery disease patients with normal blood pressure.

    PubMed

    Krysiak, Robert; Okopień, Bogusław

    2011-01-01

    The clinical effectiveness of angiotensin-converting enzyme (ACE) in the prevention and treatment of cardiovascular disorders partially results from its anti-inflammatory action. No previous study has investigated the effect of any ACE inhibitor on lymphocyte cytokine release. In this study, we compared the effects of serum- and tissue-type angiotensin-converting enzyme inhibitors on systemic inflammation and lymphocyte secretory function in normotensive patients with stable coronary artery disease. The study included 134 patients with coronary artery disease who were randomized into one of three groups and treated with enalapril (20 mg/d, n = 47), perindopril (4 mg/d, n = 45) or placebo (n = 42), respectively. The control group included 40 age-, sex- and weight-matched healthy subjects. The plasma lipid profile, glucose metabolism markers, hsCRP and lymphocyte cytokine release were examined at the beginning of the study and after 30 and 90 days of treatment. Phytohemagglutinin-stimulated T cells released significantly more interleukin-2, interferon-γ and TNFα than the lymphocytes of control subjects. Neither enalapril nor perindopril treatment was associated with any significant changes in blood pressure. Perindopril treatment inhibited lymphocyte cytokine release and systemic inflammation, while the effect of enalapril was insignificant. Perindopril, and, to a lesser extent, enalapril, strongly reduced lymphocyte cytokine release in insulin-resistant but not insulin-sensitive subjects. Our results indicate that perindopril is superior to enalapril in producing lymphocyte-suppressing and systemic anti-inflammatory effects in normotensive coronary artery disease patients. These effects may contribute to a reduction in the vascular risk of this group of patients, particularly in those subjects who are resistant to insulin, when these patients are treated with tissue-type angiotensin-converting enzyme inhibitors. PMID:22180357

  8. Renoprotective effects of combined SGLT2 and ACE inhibitor therapy in diabetic Dahl S rats

    PubMed Central

    Kojima, Naoki; Williams, Jan M; Slaughter, Tiffani N; Kato, Sota; Takahashi, Teisuke; Miyata, Noriyuki; Roman, Richard J

    2015-01-01

    This study examined whether control of hyperglycemia with a new SGLT2 inhibitor, luseogliflozin, given alone or in combination with lisinopril could prevent the development of renal injury in diabetic Dahl salt-sensitive (Dahl S) rats treated with streptozotocin (Dahl-STZ). Blood glucose levels increased from normoglycemic to hyperglycemic levels after treatment of STZ in Dahl S rats. Chronic treatment of Dahl-STZ rats with luseogliflozin (10 mg/kg/day) increased the fractional excretion of glucose and normalized blood glucose and HbA1c levels. Lisinopril (20 mg/kg/day) reduced blood pressure from 145 ± 9 to 120 ± 5 mmHg in Dahl-STZ rats, while luseogliflozin had no effect on blood pressure. Combination therapy reduced blood pressure more than that seen in the rats treated with luseogliflozin or lisinopril alone. Dahl-STZ rats exhibited hyperfiltration, mesangial matrix expansion, severe progressive proteinuria, focal glomerulosclerosis and interstitial fibrosis. Control of hyperglycemia with luseogliflozin reduced the degree of hyperfiltration and renal injury but had no effect on blood pressure or the development of proteinuria. Treatment with lisinopril reduced hyperfiltration, proteinuria and renal injury in Dahl-STZ rats. Combination therapy afforded greater renoprotection than administration of either drug alone. These results suggest that long-term control of hyperglycemia with luseogliflozin, especially in combination with lisinopril to lower blood pressure, attenuates the development of renal injury in this rat model of advanced diabetic nephropathy. PMID:26169541

  9. Purification and characterisation of a novel angiotensin-I converting enzyme (ACE)-inhibitory peptide derived from the enzymatic hydrolysate of Enteromorpha clathrata protein.

    PubMed

    Pan, Saikun; Wang, Shujun; Jing, Lingling; Yao, Dongrui

    2016-11-15

    Hydrolysates containing angiotensin-I converting enzyme (ACE)-inhibitory peptide were prepared from Enteromorpha clathrata protein using alcalase. The hydrolysates were fractionated into two molecular-weight ranges (below and above 10kDa) by ultrafiltration. The below-10kDa fraction showed higher ACE-inhibitory activity and was subsequently purified by Sephadex G-15 gel filtration chromatography. The structure of active peptide was identified as Pro-Ala-Phe-Gly by HPLC-Q-TOF-MS and its IC50 value was 35.9μM. The yield of this peptide from E. clathrata protein was 0.82%. Lineweaver-Burk plots demonstrated that the inhibitory kinetic mechanism of this peptide was non-competitive. Stability study revealed that the purified peptide showed resistance against gastrointestinal proteases. Thus, E. clathrata protein hydrolysate treated with alcalase is a beneficial ingredient of nutraceuticals and pharmaceuticals against hypertension and related diseases. PMID:27283651

  10. ACE inhibition in the treatment of children after renal transplantation.

    PubMed

    Arbeiter, Klaus; Pichler, Andrea; Stemberger, Regina; Mueller, Thomas; Ruffingshofer, Dagmar; Vargha, Regina; Balzar, Egon; Aufricht, Christoph

    2004-02-01

    Currently, there are no data available on long-term effects of angiotensin-converting enzyme inhibitors (ACE-I) on graft function in children after renal transplantation. We therefore analyzed all children who were transplanted at our institution between 1989 and 1998 and followed for at least 2 years. Those treated with ACE-I, mainly because of failure of other antihypertensive medications, were compared to those without ACE-I. The ACE-I-treated children ( n=19) showed significantly better blood pressure control during the 1st year of follow-up ( p<0.05). In children with chronic allograft dysfunction ( n=8), treatment with ACE-I stabilized graft function, with improvement in creatinine clearance in 50% ( p<0.01). Serum potassium and hemoglobin levels remained stable. One patient discontinued ACE-I because of renal artery stenosis. Taken together, ACE-I were effective and safe in the treatment of hypertension in children following renal transplantation. Children with chronic allograft dysfunction experienced a stabilizing effect on graft function. PMID:14673630

  11. Comparative effectiveness of angiotensin-converting-enzyme inhibitors and angiotensin II receptor blockers in patients with type 2 diabetes and retinopathy

    PubMed Central

    Shih, Chia-Jen; Chen, Hung-Ta; Kuo, Shu-Chen; Li, Szu-Yuan; Lai, Pi-Hsiang; Chen, Shu-Chen; Ou, Shuo-Ming; Chen, Yung-Tai

    2016-01-01

    Background: Angiotensin-converting-enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are effective treatments for diabetic retinopathy, but randomized trials and meta-analyses comparing their effects on macrovascular complications have yielded conflicting results. We compared the effectiveness of these drugs in patients with pre-existing diabetic retinopathy in a large population-based cohort. Methods: We conducted a propensity score–matched cohort study using Taiwan’s National Health Insurance Research Database. We included adult patients prescribed an ACE inhibitor or ARB within 90 days after diagnosis of diabetic retinopathy between 2000 and 2010. Primary outcomes were all-cause death and major adverse cardiovascular events (myocardial infarction, ischemic stroke or cardiovascular death). Secondary outcomes were hospital admissions with acute kidney injury or hyperkalemia. Results: We identified 11 246 patients receiving ACE inhibitors and 15 173 receiving ARBs, of whom 9769 patients in each group were matched successfully by propensity scores. In the intention-to-treat analyses, ARBs were similar to ACE inhibitors in risk of all-cause death (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.87–1.01) and major adverse cardiovascular events (HR 0.95, 95% CI 0.87–1.04), including myocardial infarction (HR 1.03, 95% CI 0.88–1.20), ischemic stroke (HR 0.94, 95% CI 0.85–1.04) and cardiovascular death (HR 1.01, 95% CI 0.88–1.16). They also did not differ from ACE inhibitors in risk of hospital admission with acute kidney injury (HR 1.01, 95% CI 0.91–1.13) and hospital admission with hyperkalemia (HR 1.01, 95% CI 0.86–1.18). Results were similar in as-treated analyses. Interpretation: Our study showed that ACE inhibitors were similar to ARBs in risk of all-cause death, major adverse cardiovascular events and adverse effects among patients with pre-existing diabetic retinopathy. PMID:27001739

  12. Xylooligomers are strong inhibitors of cellulose hydrolysis by enzymes.

    PubMed

    Qing, Qing; Yang, Bin; Wyman, Charles E

    2010-12-01

    Typically, the enzymatic hydrolysis rate of lignocellulosic biomass is fast initially but then slows down more rapidly than can be explained by just consumption of substrate. Although several factors including enzyme inhibition, enzyme deactivation, a drop in substrate reactivity, or nonproductive binding of enzyme to lignin could be responsible for this loss of effectiveness, we recently reported evidence that xylose, xylan, and xylooligomers dramatically decrease conversion rates and yields, but clarification was still needed for the magnitude of their effect. Therefore, in this study, xylan and various xylooligomers were added to Avicel hydrolysis at low enzyme loadings and found to have a greater effect than adding equal amounts of xylose derived from these materials or when added separately. Furthermore, xylooligomers were more inhibitory than xylan or xylose in terms of a decreased initial hydrolysis rate and a lower final glucose yield even for a low concentration of 1.67 mg/ml. At a higher concentration of 12.5mg/ml, xylooligomers lowered initial hydrolysis rates of Avicel by 82% and the final hydrolysis yield by 38%. Mixed DP xylooligomers showed strong inhibition on cellulase enzymes but not on beta-glucosidase enzymes. By tracking the profile change of xylooligomers, a large portion of the xylooligomers was found to be hydrolyzed by Spezyme CP enzyme preparations, indicating competitive inhibition by mixed xylooligomers. A comparison among glucose sugars and xylose sugars also showed that xylooligomers were more powerful inhibitors than well-established glucose and cellobiose. PMID:20708404

  13. A Metal-Based Inhibitor of NEDD8-Activating Enzyme

    PubMed Central

    Chan, Daniel Shiu-Hin; Leung, Chung-Hang; Wang, Hui-Min; Ma, Dik-Lung

    2012-01-01

    A cyclometallated rhodium(III) complex [Rh(ppy)2(dppz)]+ (1) (where ppy = 2-phenylpyridine and dppz = dipyrido[3,2-a:2′,3′-c]phenazine dipyridophenazine) has been prepared and identified as an inhibitor of NEDD8-activating enzyme (NAE). The complex inhibited NAE activity in cell-free and cell-based assays, and suppressed the CRL-regulated substrate degradation and NF-κB activation in human cancer cells with potency comparable to known NAE inhibitor MLN4924. Molecular modeling analysis suggested that the overall binding mode of 1 within the binding pocket of the APPBP1/UBA3 heterodimer resembled that for MLN4924. Complex 1 is the first metal complex reported to suppress the NEDDylation pathway via inhibition of the NEDD8-activating enzyme. PMID:23185368

  14. Reduction of microalbuminuria in type-2 diabetes mellitus with angiotensin-converting enzyme inhibitor alone and with cilnidipine

    PubMed Central

    Singh, V. K.; Mishra, A.; Gupta, K. K.; Misra, R.; Patel, M. L.; Shilpa

    2015-01-01

    The aim of our study was to find out the antiproteinuric effect of enalapril angiotensin-converting enzyme (ACE inhibitor) alone or in combination with cilnidipine in patients with type-2 diabetes mellitus. The study was conducted on 71 patients with type-2 diabetes mellitus patients with hypertension and microalbuminuria. They were divided into two groups randomly as follows: Group I (enalaprilalone, n = 36) and Group II (enalapril with cilnidipine, n = 35). In both the groups, baseline 24 h urinary albumin was estimated and was repeated every 3 months upto 1-year. After 1-year follow-up, reduction in microalbuminuria was found to be greater in Group II. In Group I microalbuminuria came down by 25.68 ± 21.40 while in Group II it reduced by 54.88 ± 13.84 (P < 0.001). We conclude that in diabetic population, cilnidipine has an additive effect in microalbuminuria reduction over and above the well-proven effect of ACE inhibitors. PMID:26664207

  15. Nutritional significance of lectins and enzyme inhibitors from legumes.

    PubMed

    Lajolo, Franco M; Genovese, Maria Inés

    2002-10-23

    Legumes have natural components, such as lectins, amylase, and trypsin inhibitors, that may adversely affect their nutritional properties. Much information has already been obtained on their antinutritional significance and how to inactivate them by proper processing. Chronic ingestion of residual levels is unlikely to pose risks to human health. On the other hand, the ability of these molecules to inhibit some enzymes such as trypsin, chymotrypsin, disaccharidases, and alpha-amylases, to selectively bind to glycoconjugates, and to enter the circulatory system may be a useful tool in nutrition and pharmacology. Trypsin inhibitors have also been studied as cancer risk reducing factors. These components seem to act as plant defense substances. However, increased contents may represent an impairment of the nutritional quality of legumes because these glycoproteins and the sulfur-rich protease inhibitors have been shown to be poorly digested and to participate in chemical reactions during processing reducing protein digestibility, a still unsolved question. PMID:12381157

  16. In Vitro and In Vivo Assessment of Angiotensin-Converting Enzyme (ACE) Inhibitory Activity of Fermented Soybean Milk by Lactobacillus casei Strains.

    PubMed

    Bao, Zhijie; Chi, Yujie

    2016-08-01

    Angiotensin-converting enzyme (ACE) inhibitory activity of fermented soybean milk (FSM) by Lactobacillus casei strains in vitro was investigated in this study. Effects of fermented soybean milk administration by gavage on systolic blood pressure and diastolic blood pressure was also evaluated in spontaneously hypertensive rats (SHR) rats and Wistar-Kyoto (WKY) rats. Results showed that, CICC 20280 and CICC 23184 FSM showed high ACE inhibitory activity in vitro test and ACE inhibitory activity of CICC 23184 FSM was higher than CICC 20280 FSM. The bioactive substances of FSM were peptide and γ-aminobutyric acid (GABA). Their contents in CICC 20280 FSM and CICC 23184 FSM were 3.97 ± 0.67 mg/ml (peptide), 1.71 ± 0.36 mg/ml (GABA) and 5.17 ± 0.22 mg/ml (peptide), 1.57 ± 0.21 mg/ml (GABA), respectively. Moreover, CICC 20280 and CICC 23184 FSM administration by gavage could effectively lower the blood pressure of SHR to a normal level, while there was no effect on blood pressure of WKY rats. This result indicated that the bioactive substances could play an antihypertensive role when the blood pressure was not within the normal levels (high levels). PMID:27139252

  17. Potent Inhibitors of a Shikimate Pathway Enzyme from Mycobacterium tuberculosis

    PubMed Central

    Reichau, Sebastian; Jiao, Wanting; Walker, Scott R.; Hutton, Richard D.; Baker, Edward N.; Parker, Emily J.

    2011-01-01

    Tuberculosis remains a serious global health threat, with the emergence of multidrug-resistant strains highlighting the urgent need for novel antituberculosis drugs. The enzyme 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS) catalyzes the first step of the shikimate pathway for the biosynthesis of aromatic compounds. This pathway has been shown to be essential in Mycobacterium tuberculosis, the pathogen responsible for tuberculosis. DAH7PS catalyzes a condensation reaction between P-enolpyruvate and erythrose 4-phosphate to give 3-deoxy-d-arabino-heptulosonate 7-phosphate. The enzyme reaction mechanism is proposed to include a tetrahedral intermediate, which is formed by attack of an active site water on the central carbon of P-enolpyruvate during the course of the reaction. Molecular modeling of this intermediate into the active site reported in this study shows a configurational preference consistent with water attack from the re face of P-enolpyruvate. Based on this model, we designed and synthesized an inhibitor of DAH7PS that mimics this reaction intermediate. Both enantiomers of this intermediate mimic were potent inhibitors of M. tuberculosis DAH7PS, with inhibitory constants in the nanomolar range. The crystal structure of the DAH7PS-inhibitor complex was solved to 2.35 Å. Both the position of the inhibitor and the conformational changes of active site residues observed in this structure correspond closely to the predictions from the intermediate modeling. This structure also identifies a water molecule that is located in the appropriate position to attack the re face of P-enolpyruvate during the course of the reaction, allowing the catalytic mechanism for this enzyme to be clearly defined. PMID:21454647

  18. Use of β-Blockers, Angiotensin-Converting Enzyme Inhibitors, Angiotensin II Receptor Blockers, and Risk of Breast Cancer Recurrence: A Danish Nationwide Prospective Cohort Study

    PubMed Central

    Sørensen, Gitte Vrelits; Ganz, Patricia A.; Cole, Steven W.; Pedersen, Lars A.; Toft Sørensen, Henrik; Cronin-Fenton, Deirdre P.; Peter Garne, Jens; Christiansen, Peer M.; Lash, Timothy L.; Ahern, Thomas P.

    2013-01-01

    Purpose To estimate associations between use of β-blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs) and breast cancer recurrence in a large Danish cohort. Patients and Methods We enrolled 18,733 women diagnosed with nonmetastatic breast cancer between 1996 and 2003. Patient, treatment, and 10-year recurrence data were ascertained from the Danish Breast Cancer Cooperative Group registry. Prescription and medical histories were ascertained by linkage to the National Prescription Registry and Registry of Patients, respectively. β-Blocker exposure was defined in aggregate and according to solubility, receptor selectivity, and individual drugs. ACE inhibitor and ARB exposures were defined in aggregate. Recurrence associations were estimated with multivariable Cox regression models in which time-varying drug exposures were lagged by 1 year. Results Compared with never users, users of any β-blocker had a lower recurrence hazard in unadjusted models (unadjusted hazard ratio [HR] = 0.91; 95% CI, 0.81 to 1.0) and a slightly higher recurrence hazard in adjusted models (adjusted HR = 1.3; 95% CI, 1.1 to 1.5). Associations were similar for exposures defined by receptor selectivity and solubility. Although most individual β-blockers showed no association with recurrence, metoprolol and sotalol were associated with increased recurrence rates (adjusted metoprolol HR = 1.5, 95% CI, 1.2 to 1.8; adjusted sotalol HR = 2.0, 95% CI, 0.99 to 4.0). ACE inhibitors were associated with a slightly increased recurrence hazard, whereas ARBs were not associated with recurrence (adjusted ACE inhibitor HR = 1.2, 95% CI, 0.97 to 1.4; adjusted ARBs HR = 1.1, 95% CI, 0.85 to 1.3). Conclusion Our data do not support the hypothesis that β-blockers attenuate breast cancer recurrence risk. PMID:23650417

  19. Diagnostic use of angiotensin converting enzyme (ACE)-inhibited renal scintigraphy in the identification of selective renal artery stenosis in the presence of multiple renal arteries: A case report

    SciTech Connect

    Morton, K.A.; Rose, S.C.; Haakenstad, A.O.; Handy, J.E.; Scuderi, A.J.; Datz, F.L. )

    1990-11-01

    In patients with renovascular hypertension, it is unknown whether the angiotensin converting enzyme-(ACE) inhibited renal scan will identify stenosis of a segmental branch of a single renal artery or of an accessory artery where multiple renal arteries are present. Since multiple renal arteries may be present in approximately 25% of all individuals, it will be important to establish whether the ACE-inhibited renal scan is useful in this population. We report a case of stenosis involving a renal artery in a patient with multiple renal arteries, successfully identified by ACE-inhibited renal scintigraphy.

  20. A New Sucrase Enzyme Inhibitor from Azadirachta indica

    PubMed Central

    Abdelhady, Mohamed I. S.; Shaheen, Usama; Bader, Ammar; Youns, Mahmoud A.

    2016-01-01

    Background: Sucrase enzyme inhibitor considered as an oral anti-diabetic therapy that delays the absorption of eaten carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycemia. Materials and Methods: Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica growing in KSA, followed by in-vitro assay of sucrase enzyme inhibition activity. Results: This investigation led to the isolation of a new remarkable sucrase enzyme inhibitor; 4’-methyl Quercetin-7-O-β-D-glucuronopyranoside (1) alongside with four known compounds; 2,3-hexahydroxydiphenoyl-(α/β)-D-4C1-glucopyranose (2), Avicularin (3), Castalagin (4) and Quercetin-3-O-glucoside (5). The structure of the new compound (1) was elucidated on the basis of its spectral data, including ESI-MS, UV, 1H NMR, 13C NMR, 1H-1H COSY, HSQC, NOESY and HMBC. Conclusion: Under the assay conditions, hydroalcoholic extract of A. indica and compounds 1-5 exhibited significant sucrase enzyme inhibitory activity. SUMMARY Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica, led to the Isolation of a new flavonoid glycoside named 4’-methyl Quercetin-7-O-β-D-glucuronopyranoside, alongside to other 4 known polyphenols. The hydroalcoholic extract as well as the isolated compounds exhibited significant sucrase enzyme inhibitory activity. Abbreviations used: ESI-MS; electrospray ionization-mass spectrometry, UV; ultraviolet, NMR; nuclear magnetic resonance, 1H-1H COSY; 1H-1H correlation spectroscopy, NOESY; nuclear overhauser effect spectroscopy, and HSQC; heteronuclear multiple bond correlation. A. indica; Azadirachta indica. PMID:27563214

  1. Scleroderma renal crisis during intravenous cyclophosphamide pulse therapy for complicated interstitial lung disease was successfully treated with angiotensin converting enzyme inhibitor and plasma exchange

    PubMed Central

    Nagamura, Norihiro; Kin, Seikon

    2016-01-01

    ABSTRACT Systemic sclerosis (SSc) is a multiorgan disorder involving the skin, heart, lungs, kidneys, and intestines. Progressive interstitial lung disease (ILD) is a serious complication in SSc patients, and cyclophosphamide (CYC) is the only recommended therapy for this condition;1) however, its clinical effectiveness is not sufficient. Scleroderma renal crisis (SRC) is a rare complication, characterized by acute renal failure and progressive hypertension. Angiotensin-converting-enzyme inhibitor (ACE-i) is a widely accepted therapy for SRC. We report an SSc patient with SRC and progressive ILD who underwent treatment with CYC and successful treatment with ACE-i and plasma exchange (PE). SRC and ILD are significant contributors to morbidity and mortality among SSc patients, and the therapy for these disorders is of great interest to rheumatologists. This study presents the possibility of favorable effects of PE for SSc-associated ILD and SRC. PMID:27578917

  2. Scleroderma renal crisis during intravenous cyclophosphamide pulse therapy for complicated interstitial lung disease was successfully treated with angiotensin converting enzyme inhibitor and plasma exchange.

    PubMed

    Nagamura, Norihiro; Kin, Seikon

    2016-08-01

    Systemic sclerosis (SSc) is a multiorgan disorder involving the skin, heart, lungs, kidneys, and intestines. Progressive interstitial lung disease (ILD) is a serious complication in SSc patients, and cyclophosphamide (CYC) is the only recommended therapy for this condition;(1)) however, its clinical effectiveness is not sufficient. Scleroderma renal crisis (SRC) is a rare complication, characterized by acute renal failure and progressive hypertension. Angiotensin-converting-enzyme inhibitor (ACE-i) is a widely accepted therapy for SRC. We report an SSc patient with SRC and progressive ILD who underwent treatment with CYC and successful treatment with ACE-i and plasma exchange (PE). SRC and ILD are significant contributors to morbidity and mortality among SSc patients, and the therapy for these disorders is of great interest to rheumatologists. This study presents the possibility of favorable effects of PE for SSc-associated ILD and SRC. PMID:27578917

  3. Multifactorial Model and Treatment Approaches of Refractory Hypotension in a Patient Who Took an ACE Inhibitor the Day of Surgery

    PubMed Central

    Srivastava, Karan; Sacher, Vikas Y.; Nelson, Craig T.; Lew, John I.

    2013-01-01

    In the field of anesthesiology, there is wide debate on discontinuing angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) therapy the day of noncardiac surgery. Although there have been many studies attributing perioperative hypotension to same-day ACEI and ARB use, there are many additional variables that play a role in perioperative hypotension. Additionally, restoring blood pressure in these patients presents a unique challenge to anesthesiologists. A case report is presented in which a patient took her ACEI the day of surgery and developed refractory hypotension during surgery. The evidence of ACEI use on the day of surgery and development of hypotension is reviewed, and additional variables that contributed to this hypotensive episode are discussed. Lastly, current challenges in restoring blood pressure are presented, and a basic model on treatment approaches for refractory hypotension in the setting of perioperative ACEI use is proposed. PMID:23662213

  4. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor.

    PubMed

    Ahmed, Khan Behlol Ayaz; Raman, Thiagarajan; Veerappan, Anbazhagan

    2016-11-01

    Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections. PMID:27524096

  5. Identification of selective enzyme inhibitors by fragment library screening.

    PubMed

    Gao, Geng; Liu, Xuying; Pavlovsky, Alexander; Viola, Ronald E

    2010-10-01

    The microbial threat to human health is growing due to the dramatic increase in the number of multidrug-resistant organisms. The decline in effective antibiotics available to treat these growing threats has provided greater urgency to the search for new antibiotics. Clearly, new approaches must be developed against novel targets to control these resistant infectious organisms. The screening of low molecular weight compounds against new protein targets provides an opportunity to identify novel inhibitors as starting points for the development of new antibiotics. Custom fragment libraries have been assembled and screened against 3 representative forms of a key enzyme in an essential microbial biosynthetic pathway. Although each of these aspartate semialdehyde dehydrogenases (ASADHs) catalyzes the same reaction and each shares identical active site functional groups, subtle differences in enzyme structures have led to different binding selectivity among the initial hits from these fragment libraries. Amino acid analogues have been identified that show selectivity for either the gram-negative or gram-positive bacterial enzyme forms. A series of benzophenone analogues selectively inhibit the gram-negative ASADH, whereas some haloacids and substituted aromatic acids have been found to inhibit only the fungal form of ASADH. Each of these low molecular weight compounds possesses high ligand binding efficiency for their target enzyme forms. These results support the goal of designing lead compounds that will selectively target ASADHs from different microbial species. PMID:20855558

  6. Human gut endogenous proteins as a potential source of angiotensin-I-converting enzyme (ACE-I)-, renin inhibitory and antioxidant peptides.

    PubMed

    Dave, Lakshmi A; Hayes, Maria; Montoya, Carlos A; Rutherfurd, Shane M; Moughan, Paul J

    2016-02-01

    It is well known that endogenous bioactive proteins and peptides play a substantial role in the body's first line of immunological defence, immune-regulation and normal body functioning. Further, the peptides derived from the luminal digestion of proteins are also important for body function. For example, within the peptide database BIOPEP (http://www.uwm.edu.pl/biochemia/index.php/en/biopep) 12 endogenous antimicrobial and 64 angiotensin-I-converting enzyme (ACE-I) inhibitory peptides derived from human milk and plasma proteins are listed. The antimicrobial peptide database (http://aps.unmc.edu/AP/main.php) lists over 111 human host-defence peptides. Several endogenous proteins are secreted in the gut and are subject to the same gastrointestinal digestion processes as food proteins derived from the diet. The human gut endogenous proteins (GEP) include mucins, serum albumin, digestive enzymes, hormones, and proteins from sloughed off epithelial cells and gut microbiota, and numerous other secreted proteins. To date, much work has been carried out regarding the health altering effects of food-derived bioactive peptides but little attention has been paid to the possibility that GEP may also be a source of bioactive peptides. In this review, we discuss the potential of GEP to constitute a gut cryptome from which bioactive peptides such as ACE-I inhibitory, renin inhibitory and antioxidant peptides may be derived. PMID:26617077

  7. On the Error of the Dixon Plot for Estimating the Inhibition Constant between Enzyme and Inhibitor

    ERIC Educational Resources Information Center

    Fukushima, Yoshihiro; Ushimaru, Makoto; Takahara, Satoshi

    2002-01-01

    In textbook treatments of enzyme inhibition kinetics, adjustment of the initial inhibitor concentration for inhibitor bound to enzyme is often neglected. For example, in graphical plots such as the Dixon plot for estimation of an inhibition constant, the initial concentration of inhibitor is usually plotted instead of the true inhibitor…

  8. High Incidence of ACE/PAI-1 in Association to a Spectrum of Other Polymorphic Cardiovascular Genes Involving PBMCs Proinflammatory Cytokines in Hypertensive Hypercholesterolemic Patients: Reversibility with a Combination of ACE Inhibitor and Statin

    PubMed Central

    Mouawad, Charbel; Haddad, Katia; Hamoui, Samar; Azar, Albert; Fajloun, Ziad; Makdissy, Nehman

    2015-01-01

    Cardiovascular diseases (CVDs) are significantly high in the Lebanese population with the two most predominant forms being atherosclerosis and venous thrombosis. The purpose of our study was to assess the association of a spectrum of CVD related genes and combined state of hypertension hypercholesterolemia (HH) in unrelated Lebanese. Twelve polymorphisms were studied by multiplex PCR and reverse hybridization of DNA from 171 healthy individuals and 144 HH subjects. Two genes were significantly associated with HH: ACE (OR: 9.20, P<0.0001) and PAI-1 (OR: 2.29, P = 0.007), respectively with the occurrence of the risky alleles “Del” and “4G”. The frequencies of the Del and 4G alleles were found to be 0.98 and 0.90 in the HH group versus 0.84 and 0.79 in the healthy group, respectively. Serum ACE activity and PAI-I increased significantly with Del/Del and 4G/5G genotypes. The co-expression of Del/4G(+/+) was detected in 113 out of 171 (66.0%) controls and 125 out of 144 (86.8%) HH subjects. Del/4G(-/-) was detected in only 6 (3.5%) controls and undetected in the HH group. Three venous thrombosis related genes [FV(Leiden), MTHFR(A1298C) and FXIII(V34L)] were significantly related to the prominence of the co-expression of Del/4G(+/+). A range of 2 to 8 combined polymorphisms co-expressed per subject where 5 mutations were the most detected. In Del/4G(+/+) subjects, peripheral blood mononuclear cells (PBMCs) produced significant elevated levels of IFN-γ and TNF-α contrary to IL-10, and no variations occurred for IL-4. ACE inhibitor (ramipril) in combination with statin (atorvastatin) and not alone reversed significantly the situation. This first report from Lebanon sheds light on an additional genetic predisposition of a complex spectrum of genes involved in CVD and suggests that the most requested gene FVL by physicians may not be sufficient to diagnose eventual future problems that can occur in the cardiovascular system. Subjects expressing the double mutations

  9. Increase of migration of cultured endothelial cells by angiotensin-converting enzyme inhibitor derived from tuna muscle.

    PubMed

    Kohama, Y; Oka, H; Murayama, N; Iida, K; Itoh, M; Itoh, M; Ying, X; Mimura, T

    1992-05-01

    The influence of angiotensin-converting enzyme (ACE) inhibitory octapeptide derived from tuna muscle (tuna AI) on the bovine aorta endothelial cell (BAEC) migration was investigated, as compared with captopril. BAEC migration was quantitated 6 d after release from contact inhibition by a teflon fence assay. The culture grown in the presence of tuna AI (1 and 10 microM) clearly exhibited an increase in migration, compared with the control. The media collected from tuna AI (1 and 10 microM)-stimulated BAECs significantly exhibited the interleukin (IL) -1 activity that was detected by the thymocyte costimulation assay with phytohemagglutinin. Although tuna AI was a weaker ACE inhibitor than captopril, the increasing effect of tuna AI on the migration and the IL-1 generation in BAECs was slightly greater than that of captopril. In quiescent BAECs, tuna AI (1 microM) apparently induced c-myc and platelet derived growth factor (PDGF) A-chain messenger ribonucleic acid (mRNA) expressions within 30 min, which persisted for 6 h. In contrast, captopril induced a very low expression of c-myc mRNA, and had no relation to PDGF A-chain mRNA expression. These results suggest that the increase of BAEC migration by tuna AI, unlike captopril, is likely related to the induction or activation of IL-1, and c-myc and PDGF mRNAs, in addition to the inhibition of the conversion of endogenous angiotensin I to angiotensin II. PMID:1527698

  10. The effect of treatment with low dose ACE inhibitor and/or diuretic on coronary microvasculature in stroke-prone spontaneously hypertensive rats.

    PubMed

    Rakusan, K; Cicutti, N; Maurin, A; Guez, D; Schiavi, P

    2000-03-01

    Angiotensin II is considered to have angiogenic properties. Nevertheless, several authors reported an increase in coronary capillary density after treatment with ACE inhibitors. The aim of the present study was to evaluate the effect of treatment with low doses of ACE inhibitor perindopril, low doses of the diuretic indapamide, or a combination of the two on microvascular structure in hearts from stroke-prone spontaneously hypertensive rats (SHR-sp). Young adult male SHR treated with indapamide (0.24 mg/kg/day), perindopril (0.76 mg/kg/day), or both were compared with untreated animals after 8 or 14 weeks of treatment. Survival of SHR-sp was significantly increased after treatment. Only perindopril alone or in combination with indapamide significantly decreased blood pressure and cardiac mass. Treatment also significantly increased capillary and myocyte densities but arteriolar density tended to decrease. External and internal diameters significantly increased in treated animals while arteriolar thickness remained the same. Thus, thickness in vessels of the same size was the greatest in untreated animals, followed by indapamide- and perindopril-treated rats with the thinnest walls in rats with combined treatment, and the treatment resulted in a significant increase in the lumen to wall ratio. Capillary and arteriolar growth responses in treated animals seem to indicate that the two are independently regulated processes. Treatment with indapamide alone at this dosage did not significantly influence most responses but in combination with perindopril it strengthened the effect of perindopril. PMID:10684730

  11. In situ assembly of enzyme inhibitors using extended tethering.

    PubMed

    Erlanson, Daniel A; Lam, Joni W; Wiesmann, Christian; Luong, Tinh N; Simmons, Robert L; DeLano, Warren L; Choong, Ingrid C; Burdett, Matthew T; Flanagan, W Michael; Lee, Dennis; Gordon, Eric M; O'Brien, Tom

    2003-03-01

    Cysteine aspartyl protease-3 (caspase-3) is a mediator of apoptosis and a therapeutic target for a wide range of diseases. Using a dynamic combinatorial technology, 'extended tethering', we identified unique nonpeptidic inhibitors for this enzyme. Extended tethering allowed the identification of ligands that bind to discrete regions of caspase-3 and also helped direct the assembly of these ligands into small-molecule inhibitors. We first designed a small-molecule 'extender' that irreversibly alkylates the cysteine residue of caspase-3 and also contains a thiol group. The modified protein was then screened against a library of disulfide-containing small-molecule fragments. Mass-spectrometry was used to identify ligands that bind noncovalently to the protein and that also form a disulfide linkage with the extender. Linking the selected fragments with binding elements from the extenders generates reversible, tight-binding molecules that are druglike and distinct from known inhibitors. One molecule derived from this approach inhibited apoptosis in cells. PMID:12563278

  12. Using Trypsin & Soybean Trypsin Inhibitor to Teach Principles of Enzyme Kinetics

    ERIC Educational Resources Information Center

    Howard, David R.; Herr, Julie; Hollister, Rhiannon

    2006-01-01

    Trypsin and soybean trypsin inhibitor (Kunitz inhibitor) can be used in a relatively simple and inexpensive student exercise to demonstrate the usefulness of enzyme kinetics. The study of enzyme kinetics is essential to biology because enzymes play such a crucial role in the biochemical pathways of all living organisms. The data from enzyme…

  13. 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

  14. Plant Protein Inhibitors of Enzymes: Their Role in Animal Nutrition and Plant Defence.

    ERIC Educational Resources Information Center

    Richardson, Michael

    1981-01-01

    Current information and research related to plant protein inhibitors of enzymes are reviewed, including potential uses of the inhibitors for medical treatment and for breeding plant varieties with greater resistance to insects. (DC)

  15. Role of homocysteinylation of ACE in endothelial dysfunction of arteries

    PubMed Central

    Huang, An; Pinto, John T.; Froogh, Ghezal; Kandhi, Sharath; Qin, Jun; Wolin, Michael S.; Hintze, Thomas H.

    2014-01-01

    The direct impact of de novo synthesis of homocysteine (Hcy) and its reactive metabolites, Hcy-S-S-Hcy and Hcy thiolactone (HCTL), on vascular function has not been fully elucidated. We hypothesized that Hcy synthesized within endothelial cells affects activity of angiotensin-converting enzyme (ACE) by direct homocysteinylation of its amino- and/or sulfhydryl moieties. This covalent modification enhances ACE reactivity toward angiotensin II (ANG II)-NADPH oxidase-superoxide-dependent endothelial dysfunction. Mesenteric and coronary arteries isolated from normal rats were incubated for 3 days with or without exogenous methionine (Met, 0.1–0.3 mM), a precursor to Hcy. Incubation of arteries in Met-free media resulted in time-dependent decreases in vascular Hcy formation. By contrast, vessels incubated with Met produced Hcy in a dose-dependent manner. There was a notably greater de novo synthesis of Hcy from endothelial than from smooth muscle cells. Enhanced levels of Hcy production significantly impaired shear stress-induced dilation and release of nitric oxide, events that are associated with elevated production of vascular superoxide. Each of these processes was attenuated by ANG II type I receptor blocker or ACE and NADPH oxidase inhibitors. In addition, in vitro exposure of purified ACE to Hcy-S-S-Hcy/HCTL resulted in formation of homocysteinylated ACE and an enhanced ACE activity. The enhanced ACE activity was confirmed in isolated coronary and mesenteric arteries that had been exposed directly to Hcy-S-S-Hcy/HCTL or after Met incubation. In conclusion, vasculature-derived Hcy initiates endothelial dysfunction that, in part, may be mediated by ANG II-dependent activation of NADPH oxidase in association with homocysteinylation of ACE. PMID:25416191

  16. Angiotensinogen (AGT) M235T, AGT T174M and Angiotensin-1-Converting Enzyme (ACE) I/D Gene Polymorphisms in Essential Hypertension: Effects on Ramipril Efficacy

    PubMed Central

    Kolovou, Vana; Lagou, Evangelia; Mihas, Constantinos; Vasiliki, Giannakopoulou; Katsiki, Niki; Kollia, Aikaterini; Triposkiadis, Filippos; Degiannis, Dimitris; Mavrogeni, Sophie; Kolovou, Genovefa

    2015-01-01

    Background: Hypertension, one of the most important risk factors for premature cardiovascular disease, is a major worldwide public health problem. Angiotensin-1-converting enzyme (ACE) and angiotensinogen (AGT) gene polymorphisms are thought to be associated with primary hypertension. In the present study, we examined the frequency of these gene polymorphisms in an adult population with and without essential hypertension. Furthermore, we evaluated the effect of ACE and AGT gene polymorphisms on ramipril treatment efficacy in the hypertensive patients. Methods: A total of 166 adults (83 hypertensives and 83 normotensives) were involved in the study and genotyped for AGTM235T (rs699), AGTT174M (rs4762) and ACEI/D (rs1799752) gene polymorphisms. Results: The genotype and allele distribution of the AGTM235T variant significantly differed between hypertensives and normotensives [odds ratio (OR) = 1.57% (T vs M allele), 95% confidence intervals (CIs): 1.01 - 2.44; p=0.045 for hypertensives]. However, none of the 3 studied Simple Nucleotide Polymorphisms were associated with the blood pressure-lowering response to ramipril. Conclusion: These results suggest that AGTM235T gene polymorphism is associated with essential hypertension. However, none of the AGTM235T, AGTT174M and ACEI/D gene polymorphisms influenced ramipril effectiveness. PMID:27006715

  17. RU28318, an Aldosterone Antagonist, in Combination with an ACE Inhibitor and Angiotensin Receptor Blocker Attenuates Cardiac Dysfunction in Diabetes

    PubMed Central

    Benter, Ibrahim F.; Babiker, Fawzi; Al-Rashdan, Ibrahim; Yousif, Mariam; Akhtar, Saghir

    2013-01-01

    Aims. We evaluated the effects of RU28318 (RU), a selective mineralocorticoid receptor (MR) antagonist, Captopril (Capt), an angiotensin converting enzyme inhibitor, and Losartan (Los), an angiotensin receptor blocker, alone or in combination with ischemia/reperfusion- (I/R-) induced cardiac dysfunction in hearts obtained from normal and diabetic rats. Methods. Isolated hearts were perfused for 30 min and then subjected to 30 min of global ischemia (I) followed by a period of 30 min of reperfusion (R). Drugs were administered for 30 min either before or after ischemia. Drug regimens tested were RU, Capt, Los, RU + Capt, RU + Los, Capt + Los, and RU + Capt + Los (Triple). Recovery of cardiac hemodynamics was evaluated. Results. Recovery of cardiac function was up to 5-fold worse in hearts obtained from diabetic animals compared to controls. Treatment with RU was generally better in preventing or reversing ischemia-induced cardiac dysfunction in normal hearts compared to treatment with Capt or Los alone. In diabetic hearts, RU was generally similarly effective as Capt or Los treatment. Conclusions. RU treatment locally might be considered as an effective therapy or preventative measure in cardiac I/R injury. Importantly, RU was the most effective at improving −dP/dt (a measure of diastolic function) when administered to diabetic hearts after ischemia. PMID:24066305

  18. A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough.

    PubMed

    Mosley, J D; Shaffer, C M; Van Driest, S L; Weeke, P E; Wells, Q S; Karnes, J H; Velez Edwards, D R; Wei, W-Q; Teixeira, P L; Bastarache, L; Crawford, D C; Li, R; Manolio, T A; Bottinger, E P; McCarty, C A; Linneman, J G; Brilliant, M H; Pacheco, J A; Thompson, W; Chisholm, R L; Jarvik, G P; Crosslin, D R; Carrell, D S; Baldwin, E; Ralston, J; Larson, E B; Grafton, J; Scrol, A; Jouni, H; Kullo, I J; Tromp, G; Borthwick, K M; Kuivaniemi, H; Carey, D J; Ritchie, M D; Bradford, Y; Verma, S S; Chute, C G; Veluchamy, A; Siddiqui, M K; Palmer, C N A; Doney, A; MahmoudPour, S H; Maitland-van der Zee, A H; Morris, A D; Denny, J C; Roden, D M

    2016-06-01

    The most common side effect of angiotensin-converting enzyme inhibitor (ACEi) drugs is cough. We conducted a genome-wide association study (GWAS) of ACEi-induced cough among 7080 subjects of diverse ancestries in the Electronic Medical Records and Genomics (eMERGE) network. Cases were subjects diagnosed with ACEi-induced cough. Controls were subjects with at least 6 months of ACEi use and no cough. A GWAS (1595 cases and 5485 controls) identified associations on chromosome 4 in an intron of KCNIP4. The strongest association was at rs145489027 (minor allele frequency=0.33, odds ratio (OR)=1.3 (95% confidence interval (CI): 1.2-1.4), P=1.0 × 10(-8)). Replication for six single-nucleotide polymorphisms (SNPs) in KCNIP4 was tested in a second eMERGE population (n=926) and in the Genetics of Diabetes Audit and Research in Tayside, Scotland (GoDARTS) cohort (n=4309). Replication was observed at rs7675300 (OR=1.32 (1.01-1.70), P=0.04) in eMERGE and at rs16870989 and rs1495509 (OR=1.15 (1.01-1.30), P=0.03 for both) in GoDARTS. The combined association at rs1495509 was significant (OR=1.23 (1.15-1.32), P=1.9 × 10(-9)). These results indicate that SNPs in KCNIP4 may modulate ACEi-induced cough risk. PMID:26169577

  19. Fixed-Dose Combinations of Renin-Angiotensin System Inhibitors and Calcium Channel Blockers in the Treatment of Hypertension: A Comparison of Angiotensin Receptor Blockers and Angiotensin-Converting Enzyme Inhibitors.

    PubMed

    Hsiao, Fu-Chih; Tung, Ying-Chang; Chou, Shing-Hsien; Wu, Lung-Sheng; Lin, Chia-Pin; Wang, Chun-Li; Lin, Yu-Sheng; Chang, Chee-Jen; Chu, Pao-Hsien

    2015-12-01

    Fixed-dose combinations (FDCs) of different regimens are recommended in guidelines for the treatment of hypertension. However, clinical studies comparing FDCs of angiotensin receptor blocker (ARB)/calcium channel blocker (CCB) and angiotensin-converting enzyme inhibitor (ACE inhibitor)/CCB in hypertensive patients are lacking.Using a propensity score matching of 4:1 ratio, this retrospective claims database study compared 2 FDC regimens, ARB/CCB and ACE inhibitor/CCB, in treating hypertensive patients with no known atherosclerotic cardiovascular disease. All patients were followed for at least 3 years or until the development of major adverse cardiovascular events (MACEs) during the study period. In addition, the effect of medication adherence on clinical outcomes was evaluated in subgroup analysis based on different portions of days covered.There was no significant difference in MACE-free survival (hazard ratio [HR]: 1.21; 95% confidence interval [CI]: 0.98-1.50; P = 0.08) and survival free from hospitalization for heart failure (HR: 1.15; 95% CI: 082-1.61; P = 0.431), new diagnosis of chronic kidney disease (HR: 0.98; 95% CI: 071-1.36; P = 0.906), and initiation of dialysis (HR: 0.99; 95% CI: 050-1.92; P = 0.965) between the 2 study groups. The results remained the same within each subgroup of patients with different adherence statuses.ARBs in FDC regimens with CCBs in the present study were shown to be as effective as ACE inhibitors at reducing the risks of MACEs, hospitalization for heart failure, new diagnosis of chronic kidney disease, and new initiation of dialysis in hypertensive patients, regardless of the medication adherence status. PMID:26705234

  20. A biochemical logic gate using an enzyme and its inhibitor. 1. The inhibitor as switching element.

    PubMed

    Sivan, S; Lotan, N

    1999-01-01

    Molecular-scale logic systems will allow for further miniaturization of information processing assemblies and contribute to a better understanding of brain function. Of much interest are the pertinent biological systems, some of the basic components of which are biomolecular switching elements and enzyme-based logic gates. In this series of accounts, results of investigations are presented on the implementation of an enzyme/inhibitor logic gate operating under the rules of Boolean algebra. In this report (part 1 of the series), consideration is given to the experimental conditions-particularly the irradiation mode-that affect the performance of proflavine as inhibitor of alpha-chymotrypsin. Also, assessments are made on the reversibility of the process involved and the long-term stability of the system. Moreover, using a theoretical conformational analysis of proflavine and its reduction products, detailed features were established regarding their three-dimensional structure, partial charge distribution, and hydrophobicity. Accordingly, an understanding was reached as to the factors affecting the interaction between these compounds and the enzyme. In part 2 of this series, the actual implementation of an AND logic gate will be presented. This gate involves proflavine and a chemically derivatized alpha-chymotrypsin, and its operation relies on the conclusions reached in this report regarding the optimal mode for controlling the inhibitory activity of proflavine. PMID:10585179

  1. Targeted in-vivo computed tomography (CT) imaging of tissue ACE using concentrated lisinopril-capped gold nanoparticle solutions

    NASA Astrophysics Data System (ADS)

    Daniel, Marie-Christine; Aras, Omer; Smith, Mark F.; Nan, Anjan; Fleiter, Thorsten

    2010-04-01

    The development of cardiac and pulmonary fibrosis have been associated with overexpression of angiotensin-converting enzyme (ACE). Moreover, ACE inhibitors, such as lisinopril, have shown a benificial effect for patients diagnosed with heart failure or systemic hypertension. Thus targeted imaging of the ACE is of crucial importance for monitoring of the tissue ACE activity as well as the treatment efficacy in heart failure. In this respect, lisinopril-capped gold nanoparticles were prepared to provide a new type of probe for targeted molecular imaging of ACE by tuned K-edge computed tomography (CT) imaging. Concentrated solutions of these modified gold nanoparticles, with a diameter around 16 nm, showed high contrast in CT imaging. These new targeted imaging agents were thus used for in vivo imaging on rat models.

  2. Effects of angiotensin-converting enzyme inhibitors and beta blockers on clinical outcomes in patients with and without coronary artery obstructions at angiography (from a Register-Based Cohort Study on Acute Coronary Syndromes).

    PubMed

    Manfrini, Olivia; Morrell, Christine; Das, Rajiv; Barth, Julian H; Hall, Alistair S; Gale, Christopher P; Cenko, Edina; Bugiardini, Raffaele

    2014-05-15

    We sought to determine the effectiveness of angiotensin-converting enzyme (ACE) inhibition and β-blocker treatment as a function of the degree of coronary artery disease (CAD) obstruction at angiography. The Evaluation of Methods and Management of Acute Coronary Events registry enrolled patients who had been hospitalized for an acute coronary syndrome. There were 1,602 patients who had cardiac catheterization that were used for this analysis. The main outcome measures were evidence-based therapies prescribed at discharge and 6-month incidence of all-cause mortality. The cohort consisted of 1,252 patients with obstructive CAD (>50% luminal diameter obstructed) and 350 patients with nonobstructive CAD. Multivariate logistic regression analysis adjusted for further medications and other clinical factors was performed. Patients with nonobstructive CAD had significantly (p <0.001) higher rates of β-blocker (77.8% vs 63.3%) and lower rates of ACE-inhibitor (57.7% vs 66.4%) prescriptions. In patients with nonobstructive CAD, ACE-inhibitor therapy was clearly associated with a lower 6-month mortality (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.03 to 0.78, p = 0.004). No significant association between β-blocker use and death was found. In patients with obstructive CAD, both β blockers (OR 0.47, 95% CI 0.32 to 0.67, p <0.001) and ACE inhibitors (OR 0.47, 95% CI 0.26 to 0.87, p = 0.01) were significantly associated with a reduced risk of 6-month mortality. In conclusion, ACE-inhibitor therapy seems to be an effective first-line treatment for preventing the occurrence of mortality in patients with nonobstructive CAD. PMID:24698468

  3. Different effects of thiol and nonthiol ace inhibitors on copper-induced lipid and protein oxidative modification.

    PubMed

    Fernandes, A C; Filipe, P M; Freitas, J P; Manso, C F

    1996-01-01

    Differences among angiotensin-converting enzyme inhibitors (ACEI) in scavenging reactive oxygen species were described and mainly attributed to the presence or absence of a thiol group. Plasma constituents and red cells are known targets for oxidative damage. Transition metals, like copper, are well known catalizers of free radical generation. In the present study we compared the abilities of captopril (a thiol ACEI), enalaprilat, and lisinopril (two nonthiol ACEI) for inhibiting copper-induced thiobarbituric acid reactive substances (TBARS) formation and fluorescence generation in whole human plasma and low-density lipoprotein. The effects of those ACEI on copper/hydrogen peroxide-induced fluorescence development and electrophoretic mobility modification in albumin and on copper-induced TBARS formation and hemolysis in human red cells were also compared. Captopril was more effective than the two nonthiol ACEI in inhibiting plasma and LDL lipid peroxidation, but it was ineffective in inhibiting the albumin oxidative modification that was moderately inhibited by enalaprilat and lisinopril. On the contrary, the inhibitory effects of the three ACEI on copper-induced lipid peroxidation and hemolysis in red cell suspensions were more uniform. This as yet unreported red cell protective effect may deserve pharmacological evaluation. Our results show that captopril is a more effective antioxidant than the nonthiol ACEI in some systems. However, the nonthiol ACEI also have the ability to partially protect some targets against oxidative damage. These observations suggest that the presence of a thiol group in the ACEI structure is not the only determinant for the antioxidant properties. PMID:8904291

  4. A genome-wide association study identifies variants in KCNIP4 associated with ACE inhibitor-induced cough

    PubMed Central

    Mosley, J D; Shaffer, C M; Van Driest, S L; Weeke, P E; Wells, Q S; Karnes, J H; Velez Edwards, D R; Wei, W-Q; Teixeira, P L; Bastarache, L; Crawford, D C; Li, R; Manolio, T A; Bottinger, E P; McCarty, C A; Linneman, J G; Brilliant, M H; Pacheco, J A; Thompson, W; Chisholm, R L; Jarvik, G P; Crosslin, D R; Carrell, D S; Baldwin, E; Ralston, J; Larson, E B; Grafton, J; Scrol, A; Jouni, H; Kullo, I J; Tromp, G; Borthwick, K M; Kuivaniemi, H; Carey, D J; Ritchie, M D; Bradford, Y; Verma, S S; Chute, C G; Veluchamy, A; Siddiqui, M K; Palmer, C N A; Doney, A; MahmoudPour, S H; Maitland-van der Zee, A H; Morris, A D; Denny, J C; Roden, D M

    2016-01-01

    The most common side effect of angiotensin-converting enzyme inhibitor (ACEi) drugs is cough. We conducted a genome-wide association study (GWAS) of ACEi-induced cough among 7080 subjects of diverse ancestries in the Electronic Medical Records and Genomics (eMERGE) network. Cases were subjects diagnosed with ACEi-induced cough. Controls were subjects with at least 6 months of ACEi use and no cough. A GWAS (1595 cases and 5485 controls) identified associations on chromosome 4 in an intron of KCNIP4. The strongest association was at rs145489027 (minor allele frequency=0.33, odds ratio (OR)=1.3 (95% confidence interval (CI): 1.2–1.4), P=1.0 × 10−8). Replication for six single-nucleotide polymorphisms (SNPs) in KCNIP4 was tested in a second eMERGE population (n=926) and in the Genetics of Diabetes Audit and Research in Tayside, Scotland (GoDARTS) cohort (n=4309). Replication was observed at rs7675300 (OR=1.32 (1.01–1.70), P=0.04) in eMERGE and at rs16870989 and rs1495509 (OR=1.15 (1.01–1.30), P=0.03 for both) in GoDARTS. The combined association at rs1495509 was significant (OR=1.23 (1.15–1.32), P=1.9 × 10−9). These results indicate that SNPs in KCNIP4 may modulate ACEi-induced cough risk. PMID:26169577

  5. Diagnostic use of angiotensin converting enzyme inhibitors in radioisotope evaluation of unilateral renal artery stenosis

    SciTech Connect

    Kremer Hovinga, T.K.; de Jong, P.E.; Piers, D.A.; Beekhuis, H.; van der Hem, G.K.; de Zeeuw, D.

    1989-05-01

    Iodine-123 hippurate renography, (/sup 99m/Tc)diethylenetriaminepentaacetic acid (DTPA) renography, and (/sup 99m/Tc)dimercapto succinic acid (DMSA) renal scintigraphy were performed before and during angiotensin converting enzyme (ACE) inhibition in a group of 15 hypertensive patients with angiographically ''significant'' unilateral renal artery stenosis. Visual and quantitative evaluation of the three radioisotope methods before ACE inhibition already disclosed abnormalities suggestive of renal artery stenosis in a high percentage (87%, 60%, and 60%, respectively) in this group of patients, but ACE inhibition further improved the diagnostic yield in all three methods (93%, 86%, and 80%). Iodine-123 hippurate renography was at least as useful as (/sup 99m/Tc)DTPA renography in this respect, while (/sup 99m/Tc)DMSA scintigraphy can be used particularly in segmental stenosis. Despite a large drop in blood pressure after ACE inhibition little adverse reactions were seen and overall renal function was fairly well maintained, the exceptions noted in patients with initially a more impaired renal function.

  6. Cell cycle dependence of ACE-2 explains downregulation in idiopathic pulmonary fibrosis.

    PubMed

    Uhal, Bruce D; Dang, MyTrang; Dang, Vinh; Llatos, Roger; Cano, Esteban; Abdul-Hafez, Amal; Markey, Jonathan; Piasecki, Christopher C; Molina-Molina, Maria

    2013-07-01

    Alveolar epithelial type II cells, a major source of angiotensin-converting enzyme (ACE)-2 in the adult lung, are normally quiescent but actively proliferate in lung fibrosis and downregulate this protective enzyme. It was, therefore, hypothesised that ACE-2 expression might be related to cell cycle progression. To test this hypothesis, ACE-2 mRNA levels, protein levels and enzymatic activity were examined in fibrotic human lungs and in the alveolar epithelial cell lines A549 and MLE-12 studied at postconfluent (quiescent) versus subconfluent (proliferating) densities. ACE-2 mRNA, immunoreactive protein and enzymatic activity were all high in quiescent cells, but were severely downregulated or absent in actively proliferating cells. Upregulation of the enzyme in cells that were progressing to quiescence was completely inhibited by the transcription blocker actinomycin D or by SP600125, an inhibitor of c-Jun N-terminal kinase (JNK). In lung biopsy specimens obtained from patients with idiopathic pulmonary fibrosis, immunoreactive enzyme was absent in alveolar epithelia that were positive for proliferation markers, but was robustly expressed in alveolar epithelia devoid of proliferation markers. These data explain the loss of ACE-2 in lung fibrosis and demonstrate cell cycle-dependent regulation of this protective enzyme by a JNK-mediated transcriptional mechanism. PMID:23100504

  7. ACE inhibition, ACE2 and angiotensin-(1-7) axis in kidney and cardiac inflammation and fibrosis.

    PubMed

    Simões E Silva, Ana Cristina; Teixeira, Mauro Martins

    2016-05-01

    The Renin Angiotensin System (RAS) is a pivotal physiological regulator of heart and kidney homeostasis, but also plays an important role in the pathophysiology of heart and kidney diseases. Recently, new components of the RAS have been discovered, including angiotensin converting enzyme 2 (ACE2), Angiotensin(Ang)-(1-7), Mas receptor, Ang-(1-9) and Alamandine. These new components of RAS are formed by the hydrolysis of Ang I and Ang II and, in general, counteract the effects of Ang II. In experimental models of heart and renal diseases, Ang-(1-7), Ang-(1-9) and Alamandine produced vasodilation, inhibition of cell growth, anti-thrombotic, anti-inflammatory and anti-fibrotic effects. Recent pharmacological strategies have been proposed to potentiate the effects or to enhance the formation of Ang-(1-7) and Ang-(1-9), including ACE2 activators, Ang-(1-7) in hydroxypropyl β-cyclodextrin, cyclized form of Ang-(1-7) and nonpeptide synthetic Mas receptor agonists. Here, we review the role and effects of ACE2, ACE2 activators, Ang-(1-7) and synthetic Mas receptor agonists in the control of inflammation and fibrosis in cardiovascular and renal diseases and as counter-regulators of the ACE-Ang II-AT1 axis. We briefly comment on the therapeutic potential of the novel members of RAS, Ang-(1-9) and alamandine, and the interactions between classical RAS inhibitors and new players in heart and kidney diseases. PMID:26995300

  8. Computational optimization of AG18051 inhibitor for amyloid-beta binding alcohol dehydrogenase enzyme

    NASA Astrophysics Data System (ADS)

    Marques, Alexandra T.; Antunes, Agostinho; Fernandes, Pedro A.; Ramos, Maria J.

    Amyloid-beta (Abeta) binding alcohol dehydrogenase (ABAD) is a multifunctional enzyme involved in maintaining the homeostasis. The enzyme can also mediate some diseases, including genetic diseases, Alzheimer's disease, and possibly some prostate cancers. Potent inhibitors of ABAD might facilitate a better clarification of the functions of the enzyme under normal and pathogenic conditions and might also be used for therapeutic intervention in disease conditions mediated by the enzyme. The AG18051 is the only presently available inhibitor of ABAD. It binds in the active-site cavity of the enzyme and reacts with the NAD+ cofactor to form a covalent adduct. In this work, we use computational methods to perform a rational optimization of the AG18051 inhibitor, through the introduction of chemical substitutions directed to improve the affinity of the inhibitor to the enzyme. The molecular mechanics-Poisson-Boltzmann surface area methodology was used to predict the relative free binding energy of the different modified inhibitor-NAD-enzyme complexes. We show that it is possible to increase significantly the affinity of the inhibitor to the enzyme with small modifications, without changing the overall structure and ADME (absorption, distribution, metabolism, and excretion) properties of the original inhibitor.

  9. Pharmacology of a phosphorus-containing novel angiotensin converting enzyme inhibitor, SQ 29 852 in anesthetized dogs.

    PubMed

    Ohara, N; Yokota, S; Konishi, C; Shukunobe, K; Ono, H

    1991-12-01

    The effects of (S)-1[6-amino-2[[hydrozy(4- phenylbutyl)phosphinyl]oxy]-1-oxohexyl]-L-proline (SQ 29 852), a phosphorus-containing novel angiotensin converting enzyme inhibitor (ACEI), which is synthesized aiming an ACEI with long-lasting activity and with few side effects, were studied using anesthetized dogs. SQ 29 852 was equipotent with captopril to modify blood pressure response of the animals to angiotensin I (Ang I) and bradykinin (Bdk). An intravenous infusion of SQ 29 852 at 0.1 mg/kg/min for 30 min caused a remarkable hypotension without reflex tachycardia in open-chest dogs. In these animals cardiac contractility (dP/dtmax of left ventricular pressure) appeared to be reduced by SQ 29 852 without any changes in right atrial pressure (RAP), left ventricular end-diastolic pressure (LVEDP) and aortic blood flow (AoF, cardiac output). In sodium-restricted dogs, the hypotension and renal vasodilation by SQ 29 852 (at 0.01, 0.1, and 1 mg/kg, i.v.) were slightly pronounced compared with animals fed with normal diet. It is demonstrated from these results that SQ 29 852 has comparable potency with captopril to inhibit angiotensin converting enzyme (ACE) activity and as common a pharmacological profile as ACEI. SQ 29 852 may be a favorable antihypertensive agent, if its long-lasting activity and few side effects are confirmed. PMID:1812274

  10. Isolation, Purification and Molecular Mechanism of a Peanut Protein-Derived ACE-Inhibitory Peptide

    PubMed Central

    Shi, Aimin; Liu, Hongzhi; Liu, Li; Hu, Hui; Wang, Qiang; Adhikari, Benu

    2014-01-01

    Although a number of bioactive peptides are capable of angiotensin I-converting enzyme (ACE) inhibitory effects, little is known regarding the mechanism of peanut peptides using molecular simulation. The aim of this study was to obtain ACE inhibiting peptide from peanut protein and provide insight on the molecular mechanism of its ACE inhibiting action. Peanut peptides having ACE inhibitory activity were isolated through enzymatic hydrolysis and ultrafiltration. Further chromatographic fractionation was conducted to isolate a more potent peanut peptide and its antihypertensive activity was analyzed through in vitro ACE inhibitory tests and in vivo animal experiments. MALDI-TOF/TOF-MS was used to identify its amino acid sequence. Mechanism of ACE inhibition of P8 was analyzed using molecular docking and molecular dynamics simulation. A peanut peptide (P8) having Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence was obtained which had the highest ACE inhibiting activity of 85.77% (half maximal inhibitory concentration (IC50): 0.0052 mg/ml). This peanut peptide is a competitive inhibitor and show significant short term (12 h) and long term (28 days) antihypertensive activity. Dynamic tests illustrated that P8 can be successfully docked into the active pocket of ACE and can be combined with several amino acid residues. Hydrogen bond, electrostatic bond and Pi-bond were found to be the three main interaction contributing to the structural stability of ACE-peptide complex. In addition, zinc atom could form metal-carboxylic coordination bond with Tyr, Met residues of P8, resulting into its high ACE inhibiting activity. Our finding indicated that the peanut peptide (P8) having a Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence can be a promising candidate for functional foods and prescription drug aimed at control of hypertension. PMID:25347076

  11. Inhibitors of endopeptidase and angiotensin-converting enzyme lead to an amplification of the morphological changes and an upregulation of the substance P system in a muscle overuse model

    PubMed Central

    2014-01-01

    Background We have previously observed, in studies on an experimental overuse model, that the tachykinin system may be involved in the processes of muscle inflammation (myositis) and other muscle tissue alterations. To further evaluate the significance of tachykinins in these processes, we have used inhibitors of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE), substances which are known to terminate the activity of various endogenously produced substances, including tachykinins. Methods Injections of inhibitors of NEP and ACE, as well as the tachykinin substance P (SP), were given locally outside the tendon of the triceps surae muscle of rabbits subjected to marked overuse of this muscle. A control group was given NaCl injections. Evaluations were made at 1 week, a timepoint of overuse when only mild inflammation and limited changes in the muscle structure are noted in animals not treated with inhibitors. Both the soleus and gastrocnemius muscles were examined morphologically and with immunohistochemistry and enzyme immunoassay (EIA). Results A pronounced inflammation (myositis) and changes in the muscle fiber morphology, including muscle fiber necrosis, occurred in the overused muscles of animals given NEP and ACE inhibitors. The morphological changes were clearly more prominent than for animals subjected to overuse and NaCl injections (NaCl group). A marked SP-like expression, as well as a marked expression of the neurokinin-1 receptor (NK-1R) was found in the affected muscle tissue in response to injections of NEP and ACE inhibitors. The concentration of SP in the muscles was also higher than that for the NaCl group. Conclusions The observations show that the local injections of NEP and ACE inhibitors led to marked SP-like and NK-1R immunoreactions, increased SP concentrations, and an amplification of the morphological changes in the tissue. The injections of the inhibitors thus led to a more marked myositis process and an upregulation of

  12. Possible involvement of ATP-dependent K-channel related mechanisms in the antihypertensive and cough suppressant effects of the novel ACE inhibitor (2S, 3aS, 7aS)-1-(N2-nicotinoyl-L-lysyl-gamma-D-glutamyl)octahydro-1H- indole-2-carboxylic acid.

    PubMed

    Nagata, S; Takeyama, K; Hosoki, K; Karasawa, T

    1997-06-01

    The antihypertensive and cough suppressant mechanisms of DU-1777 ((2S,3aS,7aS)-1-(N2-nicotinoyl-L-lsyl-gamma-D-glutamyl )octahydro-1H-indole-2 -carboxylic acid, CAS 116662-73-8), a new long-acting angiotensin-1-converting enzyme (ACE) inhibitor, were investigated in vivo and in vitro. The antihypertensive effects of DU-1777 at 10 mg/kg p.o. and cromakalim at 0.3 mg/kg p.o. were partially (about 60%) or fully antagonized by glibenclamide at 10 mg/kg i.v. in 2-kidney, 1-clip renal hypertensive rats (2K-1C RHR). The antihypertensive effects of a Ca blocker (nifedipine) and other ACE inhibitors (captopril, alacepril, enalapril, lisinopril, imidapril and quanapril) were not antagonized by glibenclamide. In deoxycorticosterone acetate-salt hypertensive rats (DOCA-HR), the antihypertensive effects of DU-1777 at 3-30 mg/kg p.o. were fully antagonized by glibenclamide. However, in vitro, DU-1777 (10(-6)-10(-3) mol/l) did not affect aortic ring contractions induced by high K (30 mmol/l). In guinea pig, citric acid induced cough was increased by ACE inhibitors, captopril, alacepril, enalapril and lisinopril (10 and 30 mg/kg p.o.). DU-1777 had a tendency to decrease citric acid induced cough and the effect was antagonized by glibenclamide. These results suggest that while DU-1777 itself does not open ATP-dependent K channel, it indirectly produces these effects through unknown mechanisms in vivo. Moreover, these effects contributed to the antihypertensive effect in DOCA-HR and cough suppressant effect in guinea pigs. PMID:9239450

  13. Persistent change in cardiac fibroblast physiology after transient ACE inhibition.

    PubMed

    D'Souza, K M; Biwer, L A; Madhavpeddi, L; Ramaiah, P; Shahid, W; Hale, T M

    2015-10-01

    Transient angiotensin-converting enzyme (ACE) inhibition induces persistent changes that protect against future nitric oxide synthase (NOS) inhibitor-induced cardiac fibrosis and inflammation. Given the role of fibroblasts in mediating these effects, the present study investigates whether prior ACE inhibition produced persistent changes in cardiac fibroblast physiology. Adult male spontaneously hypertensive rats (SHRs) were treated with vehicle (C+L) or the ACE inhibitor, enalapril (E+L) for 2 wk followed by a 2-wk washout period and a subsequent 7-day challenge with the NOS inhibitor N(ω)-nitro-l-arginine methyl ester. A third set of untreated SHRs served as controls. At the end of the study period, cardiac fibroblasts were isolated from control, C+L, and E+L left ventricles to assess proliferation rate, collagen expression, and chemokine release in vitro. After 7 days of NOS inhibition, there were areas of myocardial injury but no significant change in collagen deposition in E+L and C+L hearts in vivo. In vitro, cardiac fibroblasts isolated from C+L but not E+L hearts were hyperproliferative, demonstrated increased collagen type I gene expression, and an elevated secretion of the macrophage-recruiting chemokines monocyte chemoattractant protein-1 and granulocyte macrophage-colony stimulating factor. These findings demonstrate that in vivo N(ω)-nitro-l-arginine methyl ester treatment produces phenotypic changes in fibroblasts that persist in vitro. Moreover, this is the first demonstration that transient ACE inhibition can produce a persistent modification of the cardiac fibroblast phenotype to one that is less inflammatory and fibrogenic. It may be that the cardioprotective effects of ACE inhibition are related in part to beneficial changes in cardiac fibroblast physiology. PMID:26371174

  14. Angiotensin-Converting Enzyme Inhibitors and Active Tuberculosis

    PubMed Central

    Wu, Jiunn-Yih; Lee, Meng-Tse Gabriel; Lee, Si-Huei; Lee, Shih-Hao; Tsai, Yi-Wen; Hsu, Shou-Chien; Chang, Shy-Shin; Lee, Chien-Chang

    2016-01-01

    Abstract Numerous epidemiological data suggest that the use of angiotensin-converting enzyme inhibitors (ACEis) can improve the clinical outcomes of pneumonia. Tuberculosis (TB) is an airborne bacteria like pneumonia, and we aimed to find out whether the use of ACEis can decrease the risk of active TB. We conducted a nested case–control analysis by using a 1 million longitudinally followed cohort, from Taiwan national health insurance research database. The rate ratios (RRs) for TB were estimated by conditional logistic regression, and adjusted using a TB-specific disease risk score (DRS) with 71 TB-related covariates. From January, 1997 to December, 2011, a total of 75,536 users of ACEis, and 7720 cases of new active TB were identified. Current use (DRS adjusted RR, 0.87 [95% CI, 0.78–0.97]), but not recent and past use of ACEis, was associated with a decrease in risk of active TB. Interestingly, it was found that chronic use (>90 days) of ACEis was associated with a further decrease in the risk of TB (aRR, 0.74, [95% CI, 0.66–0.83]). There was also a duration response effect, correlating decrease in TB risk with longer duration of ACEis use. The decrease in TB risk was also consistent across all patient subgroups (age, sex, heart failure, cerebrovascular diseases, myocardial infraction, renal diseases, and diabetes) and patients receiving other cardiovascular medicine. In this large population-based study, we found that subjects with recent and chronic use of ACEis were associated with decrease in TB risk. PMID:27175655

  15. A new high-resolution crystal structure of the Drosophila melanogaster angiotensin converting enzyme homologue, AnCE.

    PubMed

    Harrison, Charlotte; Acharya, K Ravi

    2015-01-01

    Angiotensin converting enzyme (ACE) is a zinc-dependent dipeptidyl carboxypeptidase with an essential role in blood pressure homeostasis in mammals. ACE has long been targeted in the treatment of hypertension through ACE inhibitors, however current inhibitors are known to cause severe side effects. Therefore, there is a requirement for a new generation of ACE inhibitors and structural information will be invaluable in their development. ACE is a challenging enzyme to work with due to its extensive glycosylation. As such, the Drosophila melanogaster ACE homologue, AnCE, which shares ∼60% sequence similarity with human ACE, can be used as a model for studying inhibitor binding. The presence of ligands originating from the crystallisation condition at the AnCE active site has proved an obstacle to studying the binding of new inhibitor precursors. Here we present the crystal structure of AnCE (in a new crystal form) at 1.85 Å resolution, using crystals grown under different conditions. This new structure may be more suitable for studying the binding of new compounds, with the potential of developing a new generation of improved ACE inhibitors. PMID:26380810

  16. In vitro autoradiographic localization of angiotensin-converting enzyme in sarcoid lymph nodes

    SciTech Connect

    Allen, R.K.; Chai, S.Y.; Dunbar, M.S.; Mendelsohn, F.A.

    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 fibrosis 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.

  17. Molecular evidence for the expression of angiotensin converting enzyme in hemocytes of Locusta migratoria: stimulation by bacterial lipopolysaccharide challenge.

    PubMed

    Macours, N; Hens, K; Francis, C; De Loof, A; Huybrechts, R

    2003-08-01

    The presence of angiotensin converting enzyme (ACE) in insects has been reported many times, but numerous questions about the functional role of this enzyme in insects remain. Here we show by RT-PCR experiments that ACE has a wide tissue distribution in Locusta migratoria, suggesting diverse roles for this enzyme in the locust. Immune challenge through injection of bacterial lipopolysaccharides resulted in a tenfold increase of ACE gene transcripts in the hemocytes and is suggestive for a role of ACE in the cellular defense of the locust. However, phenotypic knockout experiments with the ACE inhibitor captopril showed that ACE is not essential for the efficient clearance of injected E. coli bacteria. PMID:12880654

  18. Enzyme inhibitors in tuber crops and their thermal stability.

    PubMed

    Prathibha, S; Nambisan, B; Leelamma, S

    1995-10-01

    Tubers of Cassava (Manihot esculenta), yams (Dioscorea esculenta), aroids (Amorphophallus campanulatus, Colocasia esculenta, Xanthosoma sagittfolium) and Coleus (Solenostemon rotundifolius) were screened for inhibitory activities against amylase, trypsin and chymotrypsin. Coleus tuber possessed the highest anti-amylase activity, whereas Colocasia tuber was the most potent source of anti-tryptic and anti-chymotryptic activity. Xanthosoma tubers exhibited amylase inhibitory activity and Amorphophallus tubers antiprotease activity. Dioscorea esculenta had low levels of amylase and chymotrypsin inhibitors, while Cassava tubers were totally free of inhibitors. When tubers were processed by pressure cooking, there was significant reduction/complete elimination in inhibitory activity. Partial retention of inhibition was observed in the case of amylase inhibitor in Dioscorea, chymotrypsin inhibitor in Colocasia and trypsin inhibitor in Colocasia, Coleus and Amorphophallus. In vitro experiments on heat stability of the different inhibitors revealed almost similar pattern of inactivation. PMID:8833431

  19. Angiotensin I-converting enzyme inhibitor derived from cross-linked oyster protein.

    PubMed

    Xie, Cheng-Liang; Kim, Jin-Soo; Ha, Jong-Myung; Choung, Se-Young; Choi, Yeung-Joon

    2014-01-01

    Following cross-linking by microbial transglutaminase, modified oyster proteins were hydrolyzed to improve inhibitory activity against angiotensin-converting enzyme (ACE) inhibitory activity with the use of a single protease, or a combination of six proteases. The oyster hydrolysate with the lowest 50% ACE inhibitory concentration (IC50) of 0.40 mg/mL was obtained by two-step hydrolysis of the cross-linked oyster protein using Protamex and Neutrase. Five ACE inhibitory peptides were purified from the oyster hydrolysate using a multistep chromatographic procedure comprised of ion-exchange, size exclusion, and reversed-phase liquid chromatography. Their sequences were identified as TAY, VK, KY, FYN, and YA, using automated Edman degradation and mass spectrometry. These peptides were synthesized, and their IC50 values were measured to be 16.7, 29.0, 51.5, 68.2, and 93.9 μM, respectively. Toxicity of the peptides on the HepG2 cell line was not detected. The oyster hydrolysate also significantly decreased the systolic blood pressure of spontaneously hypertensive rats (SHR). The antihypertensive effect of the oyster hydrolysate on SHR was rapid and long-lasting, compared to commercially obtained sardine hydrolysate. These results suggest that the oyster hydrolysate could be a source of effective nutraceuticals against hypertension. PMID:25140307

  20. Angiotensin I-Converting Enzyme Inhibitor Derived from Cross-Linked Oyster Protein

    PubMed Central

    Xie, Cheng-Liang; Kim, Jin-Soo; Ha, Jong-Myung; Choung, Se-Young

    2014-01-01

    Following cross-linking by microbial transglutaminase, modified oyster proteins were hydrolyzed to improve inhibitory activity against angiotensin-converting enzyme (ACE) inhibitory activity with the use of a single protease, or a combination of six proteases. The oyster hydrolysate with the lowest 50% ACE inhibitory concentration (IC50) of 0.40 mg/mL was obtained by two-step hydrolysis of the cross-linked oyster protein using Protamex and Neutrase. Five ACE inhibitory peptides were purified from the oyster hydrolysate using a multistep chromatographic procedure comprised of ion-exchange, size exclusion, and reversed-phase liquid chromatography. Their sequences were identified as TAY, VK, KY, FYN, and YA, using automated Edman degradation and mass spectrometry. These peptides were synthesized, and their IC50 values were measured to be 16.7, 29.0, 51.5, 68.2, and 93.9 μM, respectively. Toxicity of the peptides on the HepG2 cell line was not detected. The oyster hydrolysate also significantly decreased the systolic blood pressure of spontaneously hypertensive rats (SHR). The antihypertensive effect of the oyster hydrolysate on SHR was rapid and long-lasting, compared to commercially obtained sardine hydrolysate. These results suggest that the oyster hydrolysate could be a source of effective nutraceuticals against hypertension. PMID:25140307

  1. Angiotensin converting enzyme in the brain, testis, epididymis, pituitary gland and adrenal gland

    SciTech Connect

    Strittmatter, S.M.

    1986-01-01

    (/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 1 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.

  2. ACE blood test

    MedlinePlus

    ... to help diagnose and monitor a disorder called sarcoidosis . People with sarcoidosis may have their ACE level tested regularly to ... normal ACE level may be a sign of sarcoidosis. ACE levels may rise or fall as sarcoidosis ...

  3. Nine novel angiotensin I-converting enzyme (ACE) inhibitory peptides from cuttlefish (Sepia officinalis) muscle protein hydrolysates and antihypertensive effect of the potent active peptide in spontaneously hypertensive rats.

    PubMed

    Balti, Rafik; Bougatef, Ali; Sila, Assaâd; Guillochon, Didier; Dhulster, Pascal; Nedjar-Arroume, Naima

    2015-03-01

    This study aimed to identify novel ACE inhibitory peptides from the muscle of cuttlefish. Proteins were hydrolyzed and the hydrolysates were then subjected to various types of chromatography to isolate the active peptides. Nine ACE inhibitory peptides were isolated and their molecular masses and amino acid sequences were determined using ESI-MS and ESI-MS/MS, respectively. The structures of the most potent peptides were identified as Val-Glu-Leu-Tyr-Pro, Ala-Phe-Val-Gly-Tyr-Val-Leu-Pro and Glu-Lys-Ser-Tyr-Glu-Leu-Pro. The first peptide displayed the highest ACE inhibitory activity with an IC50 of 5.22μM. Lineweaver-Burk plots suggest that Val-Glu-Leu-Tyr-Pro acts as a non-competitive inhibitor against ACE. Furthermore, antihypertensive effects in spontaneously hypertensive rats (SHR) also revealed that oral administration of Val-Glu-Leu-Tyr-Pro can decrease systolic blood pressure significantly (p<0.01). These results suggest that the Val-Glu-Leu-Tyr-Pro would be a beneficial ingredient for nutraceuticals and pharmaceuticals acting against hypertension and its related diseases. PMID:25306378

  4. Strategies for discovering and derisking covalent, irreversible enzyme inhibitors

    PubMed Central

    Johnson, Douglas S; Weerapana, Eranthie; Cravatt, Benjamin F

    2010-01-01

    This article presents several covalent inhibitors, including examples of successful drugs, as well as highly selective, irreversible inhibitors of emerging therapeutic targets, such as fatty acid amide hydolase. Covalent inhibitors have many desirable features, including increased biochemical efficiency of target disruption, less sensitivity toward pharmacokinetic parameters and increased duration of action that outlasts the pharmacokinetics of the compound. Safety concerns that must be mitigated include lack of specificity and the potential immunogenicity of protein–inhibitor adduct(s). Particular attention will be given to recent technologies, such as activity-based protein profiling, which allow one to define the proteome-wide selectivity patterns for covalent inhibitors in vitro and in vivo. For instance, any covalent inhibitor can, in principle, be modified with a ‘clickable’ tag to generate an activity probe that is almost indistinguishable from the original agent. These probes can be applied to any living system across a broad dose range to fully inventory their on and off targets. The substantial number of drugs on the market today that act by a covalent mechanism belies historical prejudices against the development of irreversibly acting therapeutic small molecules. Emerging proteomic technologies offer a means to systematically discriminate safe (selective) versus deleterious (nonselective) covalent inhibitors and thus should inspire their future design and development. PMID:20640225

  5. [Comparative evaluation of the influence of sulfhydryl and phosphate ACE inhibitors on thrombocyte aggregation in patients suffering from atrerial hypertension with metabolic syndrome].

    PubMed

    Simonenko, V B; Medvedev, I N; Tolmachev, V V

    2007-01-01

    The purpose of the study was to compare the influence of two ACE inhibitors--captopril, a sulfhydryl one, and fozinopril, a phosphate one--on the aggregation activity of thrombocytes in patients suffering from arterial hypertension (AH) with metabolic syndrome (MS). Sixty-nine patients suffering from AH with MS were examined; 36 patients were administered captopril during 16 weeks, while 33 patients were treated with fozinopril during the same period of time. Changes in anthropometric parameters, blood lipid spectrum, lipid peroxidation in blood plasma and thrombocytes, and the antioxidative protection of liquid part of blood and platelets, as well as the aggregation activity of thrombocytes were assessed. The data received were processed using Student criterion and system multifactor analysis. The study shows that the use of fozinopril in patients with AH and metabolic syndrome attenuates peroxidation syndrome and optimizes thrombocyte aggregation. Prolonged fozinopril application will stabilize the achieved effect. Captopril did not have a positive effect on the parameters under study. In conclusion, fozinopril should be applied in combination with non-drug means to lower body weight in patients suffering from AH with MS. PMID:17564032

  6. Angiotensin-converting enzyme gene insertion/deletion, not bradykinin B2 receptor -58T/C gene polymorphism, associated with angiotensin-converting enzyme inhibitor-related cough in Chinese female patients with non-insulin-dependent diabetes mellitus.

    PubMed

    Lee, Y J; Tsai, J C

    2001-11-01

    To investigate the genetic susceptibility associated with cough related to angiotensin-converting enzyme inhibitor (ACEI) therapy in patients with type 2 diabetes, 189 non-insulin-dependent diabetes mellitus (NIDDM) patients with proteinuria or hypertension treated with perindopril were studied. Cough was considered to be present if the patients had been bothered by a cough during treatment and if they had had related symptoms for at least 2 weeks without an identifiable cause. Polymerase chain reaction (PCR) coupled with single-strand conformation polymorphism (SSCP) was used to detect polymorphisms of ACE and bradykinin B2-receptor genes. After 8 weeks of treatment, 49.2% (93 of 189) of our NIDDM patients were found to be suffering from ACEI-related cough. ACEI-related cough was mainly associated with female patients, with 71.7% (76 of 106) of female and only 20.5% (17 of 83) of male patients experiencing cough after ACEI treatment. There was a significant association of ACE II genotype with ACEI-related cough. The genotype frequencies were 58.2% for II, 47.8% for ID, and 16.7% for DD in patients with ACEI-associated cough and 41.8% for II, 52.2% for ID, and 83.3% for DD in subjects without ACEI-associated cough (chi(2) = 10.268; df = 2, P =.006). As female patients made up the majority of the subjects suffering from ACEI-related cough, we further analyzed the association of ACE I/D genotype with ACEI-related cough separately by sex. Male patients with ACEI-related cough were not associated with ACE I/D genotype distribution, while female patients were strongly associated with ACE I/D genotype polymorphism (chi(2) = 16.12; df = 2; P <.001). There was no association between the bradykinin B2 receptor gene -58T/C polymorphism with ACEI-related cough. In conclusion, our results indicate that Chinese diabetic female subjects are susceptible to ACEI-related cough, and this susceptibility may be genetically predetermined. PMID:11699055

  7. Novel angiotensin I-converting enzyme inhibitory peptides derived from edible mushroom Agaricus bisporus (J.E. Lange) Imbach identified by LC-MS/MS.

    PubMed

    Lau, Ching Ching; Abdullah, Noorlidah; Shuib, Adawiyah Suriza; Aminudin, Norhaniza

    2014-04-01

    Angiotensin I-converting enzyme (ACE) inhibitors derived from foods are valuable auxiliaries to agents such as captopril. Eight highly functional ACE inhibitory peptides from the mushroom, Agaricus bisporus, were identified by LC-MS/MS. Among these peptides, the most potent ACE inhibitory activity was exhibited by AHEPVK, RIGLF and PSSNK with IC₅₀ values of 63, 116 and 129 μM, respectively. These peptides exhibited high ACE inhibitory activity after gastrointestinal digestion. Lineweaver-Burk plots suggested that AHEPVK and RIGLF act as competitive inhibitors against ACE, whereas PSSNK acts as a non-competitive inhibitor. Mushrooms can be a good component of dietary supplement due to their readily available source and, in addition, they rarely cause food allergy. Compared to ACE inhibitory peptides isolated from other edible mushrooms, AHEPVK, RIGLF and PSSNK have lower IC₅₀ values. Therefore, these peptides may serve as an ideal ingredient in the production of antihypertensive supplements. PMID:24262574

  8. Weight loss for reduction of proteinuria in diabetic nephropathy: Comparison with angiotensin-converting enzyme inhibitor therapy

    PubMed Central

    Patil, M. R.; Mishra, A.; Jain, N.; Gutch, M.; Tewari, R.

    2013-01-01

    Reduction of weight in obese type 2 diabetes mellitus (T2DM) individuals is emerging as a significant strategy in the reduction of proteinuria in diabetic nephropathy along with control of hyperglycemia, hypertension, and dyslipidemia. The objective was to evaluate the reduction in 24-h proteinuria in T2DM patients with nephropathy by weight loss, with conventional therapy (angiotensin-converting enzyme [ACE] inhibitors) as the control arm. A prospective, randomized controlled trial was conducted between June 2010 and May 2011. T2DM patients with confirmed nephropathy by 24-h urinary protein estimation with a body mass index (BMI) of >25 kg/m2 were studied. Patients who had nondiabetic nephropathy, uncontrolled hypertension (>125/75 mmHg) irrespective of antihypertensive drugs, excess weight due to edema or obesity due to other specific diseases, alcoholics, smokers, and patients who were on hemodialysis were excluded from the study. The patients were divided into three groups, namely, group A, patients on ACE inhibitor therapy; group B, patients on lifestyle modifications for weight loss; and group C, patients on an antiobesity drug (orlistat) and lifestyle modifications. At the end of 6 months, all the three groups were compared. Data were analyzed using software SPSS version 15.0. This study encompassed a total of 88 patients; 12 patients were dropped during the study period and 76 (group A: 22, group B: 23, and group C: 31) patients remained. The mean age of the patients was 58.36 ± 10.87 years (range: 30-70 years). At baseline, age, gender, mean BMI, waist-to-hip ratio (WHR), and 24-h proteinuria did not vary significantly among the three groups. At 6 months, the mean BMI significantly decreased in group C (P < 0.001) compared to that in the other two groups. Among the parameters BMI and WHR, the proportional form of BMI correlated well with the degree of reduction in proteinuria (r = 0.397, P = 0.01). Reduction in weight using lifestyle modifications and

  9. Enzyme Inhibitor Studies Reveal Complex Control of Methyl-D-Erythritol 4-Phosphate (MEP) Pathway Enzyme Expression in Catharanthus roseus

    PubMed Central

    Han, Mei; Heppel, Simon C.; Su, Tao; Bogs, Jochen; Zu, Yuangang; An, Zhigang; Rausch, Thomas

    2013-01-01

    In Catharanthus roseus, the monoterpene moiety exerts a strong flux control for monoterpene indole alkaloid (MIA) formation. Monoterpene synthesis depends on the methyl-D-erythritol 4-phosphate (MEP) pathway. Here, we have explored the regulation of this pathway in response to developmental and environmental cues and in response to specific enzyme inhibitors. For the MEP pathway entry enzyme 1-deoxy-D-xylulose 5-phosphate synthase (DXS), a new (type I) DXS isoform, CrDXS1, has been cloned, which, in contrast to previous reports on type II CrDXS, was not transcriptionally activated by the transcription factor ORCA3. Regulation of the MEP pathway in response to metabolic perturbations has been explored using the enzyme inhibitors clomazone (precursor of 5-ketochlomazone, inhibitor of DXS) and fosmidomycin (inhibitor of deoxyxylulose 5-phosphate reductoisomerase (DXR)), respectively. Young leaves of non-flowering plants were exposed to both inhibitors, adopting a non-invasive in vivo technique. Transcripts and proteins of DXS (3 isoforms), DXR, and hydroxymethylbutenyl diphosphate synthase (HDS) were monitored, and protein stability was followed in isolated chloroplasts. Transcripts for DXS1 were repressed by both inhibitors, whereas transcripts for DXS2A&B, DXR and HDS increased after clomazone treatment but were barely affected by fosmidomycin treatment. DXS protein accumulated in response to both inhibitors, whereas DXR and HDS proteins were less affected. Fosmidomycin-induced accumulation of DXS protein indicated substantial posttranscriptional regulation. Furthermore, fosmidomycin effectively protected DXR against degradation in planta and in isolated chloroplasts. Thus our results suggest that DXR protein stability may be affected by substrate binding. In summary, the present results provide novel insight into the regulation of DXS expression in C. roseus in response to MEP-pathway perturbation. PMID:23650515

  10. Influence of ACE I/D Polymorphism on Circulating Levels of Plasminogen Activator Inhibitor 1, D-Dimer, Ultrasensitive C-Reactive Protein and Transforming Growth Factor β1 in Patients Undergoing Hemodialysis

    PubMed Central

    de Carvalho, Sara Santos; Simões e Silva, Ana Cristina; Sabino, Adriano de Paula; Evangelista, Fernanda Cristina Gontijo; Gomes, Karina Braga; Dusse, Luci Maria SantAna; Rios, Danyelle Romana Alves

    2016-01-01

    Background There is substantial evidence that chronic renal and cardiovascular diseases are associated with coagulation disorders, endothelial dysfunction, inflammation and fibrosis. Angiotensin-Converting Enzyme Insertion/Deletion polymorphism (ACE I/D polymorphism) has also be linked to cardiovascular diseases. Therefore, this study aimed to compare plasma levels of ultrassensible C-reactive protein (usCRP), PAI-1, D-dimer and TGF-β1 in patients undergoing HD with different ACE I/D polymorphisms. Methods The study was performed in 138 patients at ESRD under hemodialysis therapy for more than six months. The patients were divided into three groups according to the genotype. Genomic DNA was extracted from blood cells (leukocytes). ACE I/D polymorphism was investigated by single polymerase chain reaction (PCR). Plasma levels of D-dimer, PAI-1 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA), and the determination of plasma levels of usCRP was performed by immunonephelometry. Data were analyzed by the software SigmaStat 2.03. Results Clinical characteristics were similar in patients with these three ACE I/D polymorphisms, except for interdialytic weight gain. I allele could be associated with higher interdialytic weight gain (P = 0.017). Patients genotyped as DD and as ID had significantly higher levels of PAI-1 than those with II genotype. Other laboratory parameters did not significantly differ among the three subgroups (P = 0.033). Despite not reaching statistical significance, plasma levels of usCRP were higher in patients carrying the D allele. Conclusion ACE I/D polymorphisms could be associated with changes in the regulation of sodium, fibrinolytic system, and possibly, inflammation. Our data showed that high levels of PAI-1 are detected when D allele is present, whereas greater interdialytic gain is associated with the presence of I allele. However, further studies with different experimental designs are necessary to elucidate the

  11. Inhibitors of enzymes catalyzing modifications to histone lysine residues: structure, function and activity.

    PubMed

    Lillico, Ryan; Stesco, Nicholas; Khorshid Amhad, Tina; Cortes, Claudia; Namaka, Mike P; Lakowski, Ted M

    2016-05-01

    Gene expression is partly controlled by epigenetic mechanisms including histone-modifying enzymes. Some diseases are caused by changes in gene expression that can be mitigated by inhibiting histone-modifying enzymes. This review covers the enzyme inhibitors targeting histone lysine modifications. We summarize the enzymatic mechanisms of histone lysine acetylation, deacetylation, methylation and demethylation and discuss the biochemical roles of these modifications in gene expression and in disease. We discuss inhibitors of lysine acetylation, deacetylation, methylation and demethylation defining their structure-activity relationships and their potential mechanisms. We show that there are potentially indiscriminant off-target effects on gene expression even with the use of selective epigenetic enzyme inhibitors. PMID:27173004

  12. Discovery of Bivalent Kinase Inhibitors via Enzyme-Templated Fragment Elaboration

    PubMed Central

    2015-01-01

    We have employed novel fragment-based screening methodology to discover bivalent kinase inhibitors with improved selectivity. Starting from a low molecular weight promiscuous kinase inhibitor, we appended a thiol for subsequent reaction with a library of acrylamide electrophiles. Enzyme-templated screening was performed to identify acrylamides that assemble into bivalent inhibitors of c-Src kinase. Upon identification of acrylamide fragments that improve the binding affinity of our lead thiol, we characterized the resulting bivalent inhibitors and identified a series of kinase inhibitors with improved potency and selectivity compared to the thiol-containing precursor. Provided that protein can be prepared free of endogenous reactive cysteines, our methodology is general and could be applied to nearly any enzyme of interest. PMID:26286460

  13. Systemic reduction of rice blast by inhibitors of antioxidant enzymes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systemic acquired disease resistance (SAR) of plants may result from an oxidative burst in their tissues caused by both increased production of ROS and decreased antioxidant activity, in particular, enzymatic. Here we tested whether the exogenous inhibitors of superoxide dismutase (SOD) and catalase...

  14. Contributions of Leukocytic Angiotensin-converting Enzyme to Development of Atherosclerosis

    PubMed Central

    Chen, Xiaofeng; Lu, Hong; Zhao, Mingming; Tashiro, Katsuya; Cassis, Lisa A.; Daugherty, Alan

    2013-01-01

    Objective This study determined the role of angiotensin-converting enzyme (ACE) on the development of angiotensin I (AngI)-induced atherosclerosis and the contribution of leukocyte-specific expression of this enzyme. Approach and Results To define the contribution of ACE-dependent activity to AngII synthesis in atherosclerotic development, male LDL receptor -/- mice were fed a fat-enriched diet and infused with either AngI or AngII. The same infusion rate of these peptides had equivalent effects on atherosclerotic development. Co-infusion of an ACE inhibitor, enalapril, ablated AngI augmented atherosclerosis, but had no effect on AngII-induced lesion development. ACE protein was detected in several cell types in atherosclerotic lesions, with a predominance in macrophages. This cell type secreted AngII, which was ablated by ACE inhibition. To study whether leukocyte ACE contributed to atherosclerosis, irradiated male LDL receptor -/- mice were repopulated with bone marrow-derived cells from either ACE +/+ or -/- mice and fed the fat-enriched diet for 12 weeks. Chimeric mice with ACE deficiency in bone marrow-derived cells had modestly reduced atherosclerotic lesions in aortic arches, but had no effects in aortic roots. Conclusions ACE mediates AngI-induced atherosclerosis, and ACE expression in leukocytes modestly contributes to atherosclerotic development in hypercholesterolemic mice. PMID:23846498

  15. Enzyme inhibitors to increase poly-3-hydroxybutyrate production by transgenic tobacco.

    PubMed

    Suzuki, Yoshikatsu; Kurano, Minoru; Arai, Yuko; Nakashita, Hideo; Doi, Yoshiharu; Usami, Ron; Horikoshi, Kohki; Yamaguchi, Isamu

    2002-12-01

    Chemical regulation of secondary-metabolite synthesis was investigated through the improvement of poly-3-hydroxybutyrate (PHB) production in transgenic tobacco plants by the use of enzyme inhibitors. Two tobacco lines, BC3 and rCAB8, that produce PHB in both the cytosol and plastids were used. An acetyl-CoA carboxylase inhibitor, D-(+)-Quizalofop-ethyl, increased PHB accumulation in both lines 2-fold. The accumulation rate of plastidial PHB in the rCAB8 line was 2.5-fold higher than that of cytosolic PHB in the BC3 line. A specific inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase, mevastatin, also increased PHB accumulation but only in the BC3 line. These results indicated that chemical regulation of the native metabolic flows by the specific enzyme inhibitors increased secondary-metabolite production in the transgenic tobacco plants we used. PMID:12596845

  16. Observation of high and low molecular weight inhibitors of angiotensin-converting enzyme in rat lung.

    PubMed

    Brecher, A S; Thevananther, S; Wilson, S

    1996-01-01

    Fractionation of the rat lung yielded a 54,000 g supernate, and DOC-solubilized 775 g, 3100 g and 54,000 g sediments, each of these preparations displaying an increasing angiotensin-converting enzyme activity with increasing dilution, suggesting the presence of freely reversible angiotensin-converting enzyme inhibitors. The solubilized 775 g sediment was applied to an immobilized captopril column, eluted successively with 20 mM Pi(K+), pH 7.8 buffer, buffer/0.5 M NaCl, and buffer/0.01M cysteine to obtain four major protein bands, two of which appeared with the cysteine eluant. The first two protein peaks were each pooled and subjected to ultrafiltration with 10,000 molecular weight cutoff filters. The pooled peaks, retentates and ultrafiltrates each inhibited the angiotensin-converting enzyme activity, suggesting the presence of large and small molecular weight reversible angiotensin-converting enzyme inhibitors in association with the solubilized (membranous) particulate angiotensin-converting enzyme fraction. These results expand upon earlier observations on the existence of angiotensin-converting enzyme inhibitors in mammalian serum by observing an increasing angiotensin-converting enzyme activity with increasing dilution. This activity was eluted in multiple peaks, including elution with the cysteine eluate, suggesting that the angiotensin-converting enzyme, as well as other proteins, may react covalently with the sulfhydryl functional group of the immobilized captopril in a transsulfhydration reaction cleaving the disulfide bonds in proteins. Subsequent elution with cysteine affects an additional transsulfhydration reaction, releasing the proteins from the column. It is further postulated that air oxidation of the proteins permits reformation of disulfide bonds, yielding some active angiotensin-converting enzyme. Having in mind the possibility of lipophilic angiotensin-converting enzyme inhibitors crossing the blood-brain barrier as a means of treatment of

  17. MEROPS: the database of proteolytic enzymes, their substrates and inhibitors

    PubMed Central

    Rawlings, Neil D.; Waller, Matthew; Barrett, Alan J.; Bateman, Alex

    2014-01-01

    Peptidases, their substrates and inhibitors are of great relevance to biology, medicine and biotechnology. The MEROPS database (http://merops.sanger.ac.uk) aims to fulfill the need for an integrated source of information about these. The database has hierarchical classifications in which homologous sets of peptidases and protein inhibitors are grouped into protein species, which are grouped into families, which are in turn grouped into clans. Recent developments include the following. A community annotation project has been instigated in which acknowledged experts are invited to contribute summaries for peptidases. Software has been written to provide an Internet-based data entry form. Contributors are acknowledged on the relevant web page. A new display showing the intron/exon structures of eukaryote peptidase genes and the phasing of the junctions has been implemented. It is now possible to filter the list of peptidases from a completely sequenced bacterial genome for a particular strain of the organism. The MEROPS filing pipeline has been altered to circumvent the restrictions imposed on non-interactive blastp searches, and a HMMER search using specially generated alignments to maximize the distribution of organisms returned in the search results has been added. PMID:24157837

  18. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2.

    PubMed

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-07-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  19. A theoretical study of the molecular mechanism of the GAPDH Trypanosoma cruzi enzyme involving iodoacetate inhibitor

    NASA Astrophysics Data System (ADS)

    Carneiro, Agnaldo Silva; Lameira, Jerônimo; Alves, Cláudio Nahum

    2011-10-01

    The glyceraldehyde-3-phosphate dehydrogenase enzyme (GAPDH) is an important biological target for the development of new chemotherapeutic agents against Chagas disease. In this Letter, the inhibition mechanism of GAPDH involving iodoacetate (IAA) inhibitor was studied using the hybrid quantum mechanical/molecular mechanical (QM/MM) approach and molecular dynamic simulations. Analysis of the potential energy surface and potential of mean force show that the covalent attachment of IAA inhibitor to the active site of the enzyme occurs as a concerted process. In addition, the energy terms decomposition shows that NAD+ plays an important role in stabilization of the reagents and transition state.

  20. Icatibant in the Treatment of Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

    PubMed Central

    Crooks, Neil H.; Patel, Jaimin; Diwakar, Lavanya; Smith, Fang Gao

    2014-01-01

    We describe the case of a 75-year-old woman who presented with massive tongue and lip swelling secondary to angiotensin-converting enzyme inhibitor-induced angioedema. An awake fibre-optic intubation was performed because of impending airway obstruction. As there was no improvement in symptoms after 72 hours, the selective bradykinin B2 receptor antagonist icatibant (Firazyr) was administered and the patient's trachea was successfully extubated 36 hours later. To our knowledge this is the first documented case of icatibant being used for the treatment of angiotensin-converting enzyme inhibitor-induced angioedema in the United Kingdom and represents a novel therapeutic option in its management. PMID:25328718

  1. Acylpeptide hydrolase: inhibitors and some active site residues of the human enzyme.

    PubMed

    Scaloni, A; Jones, W M; Barra, D; Pospischil, M; Sassa, S; Popowicz, A; Manning, L R; Schneewind, O; Manning, J M

    1992-02-25

    Acylpeptide hydrolase may be involved in N-terminal deacetylation of nascent polypeptide chains and of bioactive peptides. The activity of this enzyme from human erythrocytes is sensitive to anions such as chloride, nitrate, and fluoride. Furthermore, blocked amino acids act as competitive inhibitors of the enzyme. Acetyl leucine chloromethyl ketone has been employed to identify one active site residue as His-707. Diisopropylfluorophosphate has been used to identify a second active site residue as Ser-587. Chemical modification studies with a water-soluble carbodiimide implicate a carboxyl group in catalytic activity. These results and the sequence around these active site residues, especially near Ser-587, suggest that acylpeptide hydrolase contains a catalytic triad. The presence of a cysteine residue in the vicinity of the active site is suggested by the inactivation of the enzyme by sulfhydryl-modifying agents and also by a low amount of modification by the peptide chloromethyl ketone inhibitor. Ebelactone A, an inhibitor of the formyl aminopeptidase, the bacterial counterpart of eukaryotic acylpeptide hydrolase, was found to be an effective inhibitor of this enzyme. These findings suggest that acylpeptidase hydrolase is a member of a family of enzymes with extremely diverse functions. PMID:1740429

  2. Prevalence of angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism in South Indian population with hypertension and chronic kidney disease

    PubMed Central

    Shanmuganathan, R; Kumaresan, R; Giri, P

    2015-01-01

    Context: Chronic Kidney Disease (CKD) is associated with a high risk of developing further severe complications such as, cardiovascular disease and eventually End Stage Renal Disease (ESRD) leading to death. Hypertension plays a key role in the progression of renal failure and is also a chief risk factor for the occurrence of End Stage Renal Disease (ESRD). Aim: This study investigates the possible association of insertion (I) and deletion (D) polymorphism of ACE gene in patients of Chronic Kidney Disease (CKD) with and without hypertension (HT). Settings and Design: Total 120 participants with 30 members in each group (Control, HT, CKD and CKD-HT) were chosen followed by informed consent. Materials and Methods: Blood samples were collected and subjected to biochemical analyses and nested PCR amplification was performed to genotype the DNA, for ACE I/D using specific primers. Statistical Analysis: Statistical analyses were performed using SPSS version 13. Allele and genotypic frequency was calculated by direct gene counting method. Comparison of the different genotypes was done by using Chi square test. Odd's ratios were calculated with a 95% confidence interval limit. Results: The ACE genotype were distributed as II, 27 (90%); DD, 2 (6.67%) and ID, 1 (3.33%) in control, II, 1 (3.33%); DD, 5 (16.67%) and ID, 24 (80%) in HT, II, 4 (13.33%); DD, 24 (80%) and ID, 2 (6.67%) in CKD and II, 0 (0%); DD, 2 (6.67%) and ID, 28 (93.33%) in CKD-HT group. Conclusions: D allele of ACE gene confers a greater role in genetic variations underlying CKD and hypertension. This result suggest that CKD patients should be offered analysis for defects in ACE I/D polymorphisms, especially if they are hypertensive. PMID:26440392

  3. Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun

    PubMed Central

    De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K.; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

    2015-01-01

    -oxidant actions. Inhibitory activities against the targeted enzymes expressed in terms of IC50 values have shown that hydro-ethanolic extracts in all cases whether individual species or composites in varying ratios gave higher IC50 values thus showing greater effectivity. Conclusion: Current research provides the state-of-the-art of search of NEIs amongst three species by in-vitro assays which can be further utilized for bioactivity-guided isolations of such enzyme inhibitors. Further, it reports the optimized phyto-blend ratios so as to achieve synergistic anti-oxidative actions. SUMMARY The current research work focuses on the optimization of the extraction process parameters and the ratios of phyto-synergistic blends of the leaves of three common medicinal plants viz. banyan, jamun and tulsi by chemometrics. Qualitative and quantitative chemo profiling of the extracts were done by different phytochemical tests and UV spectrophotometric methods. Enzymes like alpha amylase, alpha glucosidase, aldose reductase, dipeptidyl peptidase 4, angiotensin converting enzymes are found to be pathogenic in type 2 diabetes. In vitro screening of natural enzyme inhibitors amongst individual extracts and composite blends were carried out by different assay procedures and the potency expressed in terms of IC50 values. Antioxidant potentials were estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Hydroalcoholic solvent (50:50) gave maximal yield of bio-actives with minimal chlorophyll leaching. Hydroethanolic extract of tulsi showed maximal antioxidant effect. Though all composites showed synergism, maximal effects were shown by the composite (1:1:2) in terms of polyphenol yield, antioxidant effect and inhibitory actions against the targeted enzymes. Abbreviations used: DPP4- dipeptidyl peptidase 4; AR- aldose reductase; ACE- angiotensin converting enzyme; PPAR-γ- peroxisome proliferator activated receptor-γ; NEIs- natural enzyme inhibitors; BE- binding energy; GLP-1- Glucagon

  4. Structural Characterization of Inhibitors with Selectivity against Members of a Homologous Enzyme Family

    SciTech Connect

    Pavlovsky, Alexander G.; Liu, Xuying; Faehnle, Christopher R.; Potente, Nina; Viola, Ronald E.

    2013-01-31

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. As this critical pathway is only present in plants and microbes, any disruptions will be fatal to these organisms. An early pathway enzyme, L-aspartate-{beta}-semialdehyde dehydrogenase, produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the L-aspartate-{beta}-semialdehyde dehydrogenase family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against L-aspartate-{beta}-semialdehyde dehydrogenases from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure-guided approach to the development of more potent and more selective inhibitors.

  5. Structural Characterization of Inhibitors with Selectivity against Members of a Homologous Enzyme Family

    PubMed Central

    Pavlovsky, Alexander G.; Liu, Xuying; Faehnle, Christopher R.; Potente, Nina; Viola, Ronald E.

    2012-01-01

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. Since this critical pathway is only present in plants and microbes any disruptions will be fatal to these organisms. An early pathway enzyme, L-aspartate-β-semialdehyde dehydrogenase (ASADH), produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the ASADH family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against ASADHs from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure guided approach to the development of more potent and more selective inhibitors. PMID:22039970

  6. Structural characterization of inhibitors with selectivity against members of a homologous enzyme family.

    PubMed

    Pavlovsky, Alexander G; Liu, Xuying; Faehnle, Christopher R; Potente, Nina; Viola, Ronald E

    2012-01-01

    The aspartate biosynthetic pathway provides essential metabolites for many important biological functions, including the production of four essential amino acids. As this critical pathway is only present in plants and microbes, any disruptions will be fatal to these organisms. An early pathway enzyme, l-aspartate-β-semialdehyde dehydrogenase, produces a key intermediate at the first branch point of this pathway. Developing potent and selective inhibitors against several orthologs in the l-aspartate-β-semialdehyde dehydrogenase family can serve as lead compounds for antibiotic development. Kinetic studies of two small molecule fragment libraries have identified inhibitors that show good selectivity against l-aspartate-β-semialdehyde dehydrogenases from two different bacterial species, Streptococcus pneumoniae and Vibrio cholerae, despite the presence of an identical constellation of active site amino acids in this homologous enzyme family. Structural characterization of enzyme-inhibitor complexes have elucidated different modes of binding between these structurally related enzymes. This information provides the basis for a structure-guided approach to the development of more potent and more selective inhibitors. PMID:22039970

  7. A Trypsin Inhibitor from Clitoria fairchildiana Cotyledons is Active Against Digestive Enzymes of Aedes aegypti Larvae.

    PubMed

    de Oliveira, Lucilene O; Fernandes, Kátia V S; Pádua, Dayanni de Souza; Carvalho, André de O; Lemos, Francisco J A; Gomes, Valdirene M; Oliveira, Antônia E A; Ferreira, André T da Silva; Perales, Jonas

    2015-01-01

    Aedes aegypti, the principal mosquito vector of yellow fever, dengue fever and chikungunya fever virus-transmitted diseases, is an insect closely associated with humans and their housing habitats. As there is no commercially available vaccine, prevention is the most suggested form of avoiding disease spreading and a number of studies are being developed in order to give support to vector control operations. The present study reports on the identification of a trypsin inhibitor isolated from cotyledons of the Clitoria fairchildiana amazonic tree seeds, which was able to reduce by 87.93 % the activity of digestive enzymes of fourth instar A. aegypti larva. A partial amino acid sequence showed strong similarity with sequences from several trypsin inhibitors already reported in the literature. The 13,000 Da isolated inhibitor was seen to be active solely against trypsin-like enzymes, neither acting on papain, α-amylase nor on other serine proteases, such as elastase, chymotrypsin or subtilisin. At least six from seven active digestive proteases from A. aegypti larvae, visualized by zymography, were severely affected soon after exposed to the inhibitor. The strong and specific action of the isolated inhibitor against trypsin digestive enzymes of this insect vector led us to believe that this protein may be a good candidate for a prospective alternative biocontrol method. PMID:26156641

  8. Ipriflavone as an inhibitor of human cytochrome P450 enzymes

    PubMed Central

    Monostory, Katalin; Vereczkey, László; Lévai, Ferenc; Szatmári, István

    1998-01-01

    Reduction of theophylline metabolism and elimination were observed in a theophylline-treated patient during ipriflavone administration. After withdrawal of ipriflavone, the serum theophylline level decreased to an extent similar to that found before administration of ipriflavone. The effects of ipriflavone and its major metabolites 7-hydroxy-isoflavone and 7-(1-carboxy-ethoxy)-isoflavone on cytochrome P450 activities were studied in vitro in human liver microsomes from three donors. Ipriflavone and 7-hydroxy-isoflavone competitively inhibited phenacetin O-deethylase and tolbutamide hydroxylase activity. The parent compound and its dealkylated metabolite were strong inhibitors exhibiting Ki values around 10–20 μM, while 7-(1-carboxy-ethoxy)-isoflavone had no effect on the cytochrome P450 activities investigated. 7-Hydroxy-isoflavone is the only one that influenced nifedipine oxidase activity. It competitively inhibited this activity with a Ki value of 129.5 μM. The steady state concentrations of ipriflavone and 7-hydroxy-isoflavone in plasma of patients receiving 3×200 mg daily doses of ipriflavone for 48 weeks were found to be 0.33±0.32 μM and 1.44±0.77 μM, respectively. The results indicate that the decrease in theophylline metabolism observed in a patient treated with ipriflavone may be due to a competitive interaction of ipriflavone or its metabolite, 7-hydroxy-isoflavone with CYP1A2. On the other hand, our in vitro findings predict some more interaction with CYP2C9. PMID:9517377

  9. Activity-based chemical proteomics accelerates inhibitor development for deubiquitylating enzymes.

    PubMed

    Altun, Mikael; Kramer, Holger B; Willems, Lianne I; McDermott, Jeffrey L; Leach, Craig A; Goldenberg, Seth J; Kumar, K G Suresh; Konietzny, Rebecca; Fischer, Roman; Kogan, Edward; Mackeen, Mukram M; McGouran, Joanna; Khoronenkova, Svetlana V; Parsons, Jason L; Dianov, Grigory L; Nicholson, Benjamin; Kessler, Benedikt M

    2011-11-23

    Converting lead compounds into drug candidates is a crucial step in drug development, requiring early assessment of potency, selectivity, and off-target effects. We have utilized activity-based chemical proteomics to determine the potency and selectivity of deubiquitylating enzyme (DUB) inhibitors in cell culture models. Importantly, we characterized the small molecule PR-619 as a broad-range DUB inhibitor, and P22077 as a USP7 inhibitor with potential for further development as a chemotherapeutic agent in cancer therapy. A striking accumulation of polyubiquitylated proteins was observed after both selective and general inhibition of cellular DUB activity without direct impairment of proteasomal proteolysis. The repertoire of ubiquitylated substrates was analyzed by tandem mass spectrometry, identifying distinct subsets for general or specific inhibition of DUBs. This enabled identification of previously unknown functional links between USP7 and enzymes involved in DNA repair. PMID:22118674

  10. A selective inhibitor of the UFM1-activating enzyme, UBA5.

    PubMed

    da Silva, Sara R; Paiva, Stacey-Lynn; Bancerz, Matthew; Geletu, Mulu; Lewis, Andrew M; Chen, Jijun; Cai, Yafei; Lukkarila, Julie L; Li, Honglin; Gunning, Patrick T

    2016-09-15

    Protein conjugation with ubiquitin and ubiquitin-like small molecules, such as UFM1, is important for promoting cancer cell survival and proliferation. Herein, the development of the first selective micromolar inhibitor of the UBA5 E1 enzyme that initiates UFM1 protein conjugation is described. This organometallic inhibitor incorporates adenosine and zinc(II)cyclen within its core scaffold and inhibits UBA5 noncompetitively and selectively over other E1 enzymes and a panel of human kinases. Furthermore, this compound selectively impedes the cellular proliferation (above 50μM) of cancer cells containing higher levels of UBA5. This inhibitor may be used to further probe the intracellular role of the UFM1 pathway in disease progression. PMID:27520940

  11. Insights on Cytochrome P450 Enzymes and Inhibitors Obtained Through QSAR Studies

    PubMed Central

    Sridhar, Jayalakshmi; Liu, Jiawang; Foroozesh, Maryam; Stevens, Cheryl L. Klein

    2013-01-01

    The cytochrome P450 (CYP) superfamily of heme enzymes play an important role in the metabolism of a large number of endogenous and exogenous compounds, including most of the drugs currently on the market. Inhibitors of CYP enzymes have important roles in the treatment of several disease conditions such as numerous cancers and fungal infections in addition to their critical role in drug-drug interactions. Structure activity relationships (SAR), and three-dimensional quantitative structure activity relationships (3D-QSAR) represent important tools in understanding the interactions of the inhibitors with the active sites of the CYP enzymes. A comprehensive account of the QSAR studies on the major human CYPs 1A1, 1A2, 1B1, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and a few other CYPs are detailed in this review which will provide us with an insight into the individual/common characteristics of the active sites of these enzymes and the enzyme-inhibitor interactions. PMID:22864238

  12. Reporter enzyme inhibitor study to aid assembly of orthogonal reporter gene assays.

    PubMed

    Ho, Pei-i; Yue, Kimberley; Pandey, Pramod; Breault, Lyne; Harbinski, Fred; McBride, Aaron J; Webb, Brian; Narahari, Janaki; Karassina, Natasha; Wood, Keith V; Hill, Adam; Auld, Douglas S

    2013-05-17

    Reporter gene assays (RGAs) are commonly used to measure biological pathway modulation by small molecules. Understanding how such compounds interact with the reporter enzyme is critical to accurately interpret RGA results. To improve our understanding of reporter enzymes and to develop optimal RGA systems, we investigated eight reporter enzymes differing in brightness, emission spectrum, stability, and substrate requirements. These included common reporter enzymes such as firefly luciferase (Photinus pyralis), Renilla reniformis luciferase, and β-lactamase, as well as mutated forms of R. reniformis luciferase emitting either blue- or green-shifted luminescence, a red-light emitting form of Luciola cruciata firefly luciferase, a mutated form of Gaussia princeps luciferase, and a proprietary luciferase termed "NanoLuc" derived from the luminescent sea shrimp Oplophorus gracilirostris. To determine hit rates and structure-activity relationships, we screened a collection of 42,460 PubChem compounds at 10 μM using purified enzyme preparations. We then compared hit rates and chemotypes of actives for each enzyme. The hit rates ranged from <0.1% for β-lactamase to as high as 10% for mutated forms of Renilla luciferase. Related luciferases such as Renilla luciferase mutants showed high degrees of inhibitor overlap (40-70%), while unrelated luciferases such as firefly luciferases, Gaussia luciferase, and NanoLuc showed <10% overlap. Examination of representative inhibitors in cell-based assays revealed that inhibitor-based enzyme stabilization can lead to increases in bioluminescent signal for firefly luciferase, Renilla luciferase, and NanoLuc, with shorter half-life reporters showing increased activation responses. From this study we suggest strategies to improve the construction and interpretation of assays employing these reporter enzymes. PMID:23485150

  13. Inhibitors of the Hydrolytic Enzyme Dimethylarginine Dimethylaminohydrolase (DDAH): Discovery, Synthesis and Development.

    PubMed

    Murphy, Rhys B; Tommasi, Sara; Lewis, Benjamin C; Mangoni, Arduino A

    2016-01-01

    Dimethylarginine dimethylaminohydrolase (DDAH) is a highly conserved hydrolytic enzyme found in numerous species, including bacteria, rodents, and humans. In humans, the DDAH-1 isoform is known to metabolize endogenous asymmetric dimethylarginine (ADMA) and monomethyl arginine (l-NMMA), with ADMA proposed to be a putative marker of cardiovascular disease. Current literature reports identify the DDAH family of enzymes as a potential therapeutic target in the regulation of nitric oxide (NO) production, mediated via its biochemical interaction with the nitric oxide synthase (NOS) family of enzymes. Increased DDAH expression and NO production have been linked to multiple pathological conditions, specifically, cancer, neurodegenerative disorders, and septic shock. As such, the discovery, chemical synthesis, and development of DDAH inhibitors as potential drug candidates represent a growing field of interest. This review article summarizes the current knowledge on DDAH inhibition and the derived pharmacokinetic parameters of the main DDAH inhibitors reported in the literature. Furthermore, current methods of development and chemical synthetic pathways are discussed. PMID:27187323

  14. Renal ACE immunohistochemical localization in NIDDM patients with nephropathy.

    PubMed

    Mizuiri, S; Yoshikawa, H; Tanegashima, M; Miyagi, M; Kobayashi, M; Sakai, K; Hayashi, I; Aikawa, A; Ohara, T; Hasegawa, A

    1998-02-01

    A role of renal angiotensin-converting enzyme (ACE) in diabetic nephropathy has been suggested. Immunohistochemical localization of ACE was studied in 20 non-insulin-dependent diabetes mellitus patients with diabetic nephropathy and 17 healthy kidney transplant donors, with ACE gene insertion/deletion (I/D) polymorphism also examined in the latter. Immunohistochemical studies indicated that ACE staining was significantly (P < 0.01) enhanced in glomeruli and slightly decreased in proximal tubules in diabetic patients. Glomeruli positive for ACE immunostaining were observed in 23.5% of the healthy subjects and in 80% of the diabetic patients. All patients with nodular lesions had ACE-positive glomeruli and showed significantly (P < 0.01) more intense glomerular ACE immunostaining than patients without nodular lesions. Among healthy controls, subjects with the DD genotype had ACE-positive glomeruli more frequently and tended to show slightly increased intensity on proximal tubule ACE immunostaining compared with subjects with other genotypes. These observations suggest that increased ACE localization in glomeruli is likely to be one of the factors in the increased renin-angiotensin system activity in glomeruli in patients with diabetic nephropathy. There is a possibility that ACE gene I/D polymorphism may be related to renal ACE immunohistochemical localization. PMID:9469501

  15. Effect of inhibitors of trypsin-like proteolytic enzymes Bacillus cereus T spore germination.

    PubMed Central

    Boschwitz, H; Milner, Y; Keynan, A; Halvorson, H O; Troll, W

    1983-01-01

    The germination of Bacillus cereus T spore suspensions is partially prevented by several inhibitors of trypsin-like enzymes. Leupeptin, antipain, and tosyl-lysine-chloromethyl ketone are effective inhibitors, whereas chymostatin, elastatinal, and pepstatin are inactive. A synthetic substrate of trypsin, tosyl-arginine-methyl ester, also inhibits germination. Its inhibitory effect decreases as a function of incubation time in the presence of spores and is abolished by previous hydrolysis with trypsin. Germinating, but not dormant, spore suspensions hydrolyze tosyl-arginine-methyl ester; its hydrolysis is insensitive to chloramphenicol, sulfhydryl reagents, and EDTA. A crude extract of germinated B. cereus spores contains a trypsin-like enzyme whose activity, as measured by hydrolysis of benzoyl-arginine p-nitroanilide, is sensitive to germination-inhibitory compounds such as leupeptin, tosyl-arginine-methyl ester, and tosyl-lysine-chloromethyl ketone. Spore suspensions exposed to the above inhibitors under germination conditions lose only part of their heat resistance and some 10 to 30% of their dipicolinic acid content. Part of the germinating spore population becomes "phase grey" under phase optics. Based on a study of the inhibition of germination by protease inhibitors and the activity of a protease in germination spores and spore extracts, it is suggested that the activity of a trypsin-like enzyme may be involved in the mechanism of the breaking of dormancy in spores of B. cereus T. PMID:6401704

  16. Defining balanced conditions for inhibitor screening assays that target bisubstrate enzymes.

    PubMed

    Yang, Jingsong; Copeland, Robert A; Lai, Zhihong

    2009-02-01

    High-throughput screening (HTS) is a common mechanism for identifying lead compounds for drug discovery efforts. Small molecules can inhibit enzymes by a variety of mechanisms, such as competitive, noncompetitive, and uncompetitive with respect to the substrate(s) of the catalytic reaction. To optimize the chances of finding the broadest diversity of inhibitor modalities during screening, one must run assays under ;;balanced'' conditions where the potency of inhibitors with various modes of action falls within a similar range. When an enzyme reaction involves more than one substrate, the definition and assessment of the apparent potency of inhibitors (IC(50)), in relation to their true potency (K(i)), can be nontrivial. This article provides a theoretical analysis, on the basis of the Cheng-Prusoff derivation, of the IC(50)/K( i) relationship of bisubstrate enzyme reactions following various sequential kinetic mechanisms, as well as the application and limitations of this information for defining optimal screening conditions for such enzymes. PMID:19196704

  17. Discovery of Inhibitors for the Ether Lipid-Generating Enzyme AGPS as Anti-Cancer Agents

    PubMed Central

    Piano, Valentina; Benjamin, Daniel I; Valente, Sergio; Nenci, Simone; Mai, Antonello; Aliverti, Alessandro; Nomura, Daniel K; Mattevi, Andrea

    2015-01-01

    Dysregulated ether lipid metabolism is an important hallmark of cancer cells. Previous studies have reported that lowering ether lipid levels by genetic ablation of the ether lipid-generating enzyme alkyl-glycerone phosphate synthase (AGPS) lowers key structural and oncogenic ether lipid levels and alters fatty acid, glycerophospholipid, and eicosanoid metabolism to impair cancer pathogenicity, indicating that AGPS may be a potential therapeutic target for cancer. In this study, we have performed a small-molecule screen to identify candidate AGPS inhibitors. We have identified several lead AGPS inhibitors and have structurally characterized their interactions with the enzyme and show that these inhibitors bind to distinct portions of the active site. We further show that the lead AGPS inhibitor 1a selectively lowers ether lipid levels in several types of human cancer cells and impairs their cellular survival and migration. We provide here the first report of in situ-effective pharmacological tools for inhibiting AGPS, which may provide chemical scaffolds for future AGPS inhibitor development for cancer therapy. PMID:26322624

  18. Determination of the inhibitor dissociation constant of an individual unmodified enzyme molecule in free solution.

    PubMed

    Crawford, Jeremie J; Hollett, Joshua W; Craig, Douglas B

    2016-08-01

    Single enzyme molecule assays on E. coli β-galactosidase were performed using a capillary electrophoresis-based method. Three types of assays were performed. The catalytic rate of 20 individual molecules was assayed in duplicate in the presence of 50 μM substrate. The ratio of rates for the second incubation relative to the first was 0.96 ± 0.03, showing the reproducibility of the method. In the second assay, the rates were determined in the absence and presence of 210 μM L-ribose, a competitive inhibitor. The ratio of the rate in the presence of inhibitor to that in its absence for 19 individual molecules was 0.44 ± 0.23. This large relative standard deviation suggests that each individual enzyme molecule was affected to a different extent by the presence of the inhibitor, which is consistent with KI being heterogeneous. To estimate KI for individual molecules, a third assay was performed. Each molecule was incubated in the presence of 30 and 50 μM substrate and then in the presence of 50 μM substrate plus 210 μM inhibitor. Comparison of the rates in the two substrate concentrations allowed for the determination of the individual Km of each molecule. From this value and the difference in rates in the presence and absence of inhibitor, the individual molecule KI values were determined. This value was found to differ between individual molecules and was found to increase with an increase in Km . Modeling showed that a heterogeneity in KI results in an alteration in the Michaelis-Menten curve for a population of enzymes in the presence of a competitive inhibitor. PMID:27271375

  19. Inhibition of ACE Retards Tau Hyperphosphorylation and Signs of Neuronal Degeneration in Aged Rats Subjected to Chronic Mild Stress

    PubMed Central

    AbdAlla, Said; el Hakim, Ahmed; Abdelbaset, Ahmed; Elfaramawy, Yasser; Quitterer, Ursula

    2015-01-01

    With increasing life expectancy, Alzheimer's disease (AD) and other types of age-associated dementia are on the rise worldwide. Treatment approaches for dementia are insufficient and novel therapies are not readily available. In this context repurposing of established drugs appears attractive. A well-established class of cardiovascular drugs, which targets the angiotensin II system, is such a candidate, which currently undergoes a paradigm shift with regard to the potential benefit for treatment of neurodegenerative symptoms. In search for additional evidence, we subjected aged rats to chronic unpredictable mild stress, which is known to enhance the development of AD-related neuropathological features. We report here that four weeks of chronic mild stress induced a strong upregulation of the hippocampal angiotensin-converting enzyme (Ace) at gene expression and protein level. Concomitantly, tau protein hyperphosphorylation developed. Signs of neurodegeneration were detected by the significant downregulation of neuronal structure proteins such as microtubule-associated protein 2 (Map2) and synuclein-gamma (Sncg). Ace was involved in neurodegenerative symptoms because treatment with the brain-penetrating ACE inhibitor, captopril, retarded tau hyperphosphorylation and signs of neurodegeneration. Moreover, ACE inhibitor treatment could counteract glutamate neurotoxicity by preventing the downregulation of glutamate decarboxylase 2 (Gad2). Taken together, ACE inhibition targets neurodegeneration triggered by environmental stress. PMID:26697495

  20. Protein Kinase C-δ Mediates Shedding of Angiotensin-Converting Enzyme 2 from Proximal Tubular Cells

    PubMed Central

    Xiao, Fengxia; Zimpelmann, Joseph; Burger, Dylan; Kennedy, Christopher; Hébert, Richard L.; Burns, Kevin D.

    2016-01-01

    Angiotensin-converting enzyme 2 (ACE2) degrades angiotensin (Ang) II to Ang-(1–7), and protects against diabetic renal injury. Soluble ACE2 fragments are shed from the proximal tubule, and appear at high levels in the urine with diabetes. High glucose-induced shedding of ACE2 from proximal tubular cells is mediated by the enzyme “a disintegrin and metalloproteinase-17″ (ADAM17). Here, we investigated the mechanism for constitutive shedding of ACE2. Mouse proximal tubular cells were cultured and ACE2 shedding into the media was assessed by enzyme activity assay and immunoblot analysis. Cells were incubated with pharmacologic inhibitors, or transfected with silencing (si) RNA. Incubation of proximal tubular cells with increasing concentrations of D-glucose stimulated ACE2 shedding, which peaked at 16 mM, while L-glucose (osmotic control) had no effect on shedding. In cells maintained in 7.8 mM D-glucose, ACE2 shedding was significantly inhibited by the pan-protein kinase C (PKC) competitive inhibitor sotrastaurin, but not by an inhibitor of ADAM17. Incubation of cells with the PKC-α and -β1-specific inhibitor Go6976, the PKC β1 and β2-specific inhibitor ruboxistaurin, inhibitors of matrix metalloproteinases-2,-8, and -9, or an inhibitor of ADAM10 (GI250423X) had no effect on basal ACE2 shedding. By contrast, the PKC-δ inhibitor rottlerin significantly inhibited both constitutive and high glucose-induced ACE2 shedding. Transfection of cells with siRNA directed against PKC-δ reduced ACE2 shedding by 20%, while knockdown of PKC-ε was without effect. These results indicate that constitutive shedding of ACE2 from proximal tubular cells is mediated by PKC-δ, which is also linked to high glucose-induced shedding. Targeting PKC-δ may preserve membrane-bound ACE2 in proximal tubule in disease states and diminish Ang II-stimulated adverse signaling. PMID:27313531

  1. Angiotensin I converting enzyme inhibitory peptide extracted from freshwater zooplankton.

    PubMed

    Lee, Jung Kwon; Lee, Min-Su; Park, Heum Gi; Kim, Se-Kwon; Byun, Hee-Guk

    2010-04-01

    In this study, hydrolysates obtained from the freshwater rotifer Brachionus calyciflonus were investigated for angiotensin I converting enzyme (ACE) inhibitory peptides. Freshwater rotifer protein was hydrolyzed using six separate enzymes in a batch reactor. The peptic hydrolysate had the highest ACE inhibitory activity compared to the other hydrolysates. The highest ACE inhibitory peptide was separated using Sephadex G-25 column chromatography and high-performance liquid chromatography on a C18 column. The 50% inhibitory concentration (IC(50)) value of purified ACE inhibitory peptide was 40.01 microg/mL. ACE inhibitory peptide was identified as being seven amino acid residues of Ala-Gln-Gly-Glu-Arg-His-Arg by N-terminal amino acid sequence analysis. The IC(50) value of purified ACE inhibitory peptide was 47.1 microM, and Lineweaver-Burk plots suggested that the peptide purified from rotifer protein acts as a competitive inhibitor against ACE. The results of this study suggest that peptides derived from freshwater rotifers may be beneficial as antihypertension compounds in functional foods or as pharmaceuticals. PMID:20170338

  2. Reaching the Melting Point: Degradative Enzymes and Protease Inhibitors Involved in Baculovirus Infection and Dissemination

    PubMed Central

    Ishimwe, Egide; Hodgson, Jeffrey J.; Clem, Rollie J.; Passarelli, A. Lorena

    2015-01-01

    Baculovirus infection of a host insect involves several steps, beginning with initiation of virus infection in the midgut, followed by dissemination of infection from the midgut to other tissues in the insect, and finally culminating in “melting” or liquefaction of the host, which allows for horizontal spread of infection to other insects. While all of the viral gene products are involved in ultimately reaching this dramatic infection endpoint, this review focuses on two particular types of baculovirus-encoded proteins: degradative enzymes and protease inhibitors. Neither of these types of proteins is commonly found in other virus families, but they both play important roles in baculovirus infection. The types of degradative enzymes and protease inhibitors encoded by baculoviruses are discussed, as are the roles of these proteins in the infection process. PMID:25724418

  3. Retrostatin, a new specific enzyme inhibitor against avian myeloblastosis virus reverse transcriptase.

    PubMed

    Nishio, M; Kuroda, A; Suzuki, M; Ishimaru, K; Nakamura, S; Nomi, R

    1983-07-01

    A novel enzyme inhibitor against RNA-directed DNA polymerase of avian myeloblastosis virus was produced by an isolate of a new streptomycete for which the name Streptomyces retrostaticus is proposed. This enzyme inhibitor, which was named retrostatin, did not inhibit DNA-directed DNA polymerase of Escherichia coli and DNA-directed RNA polymerase of Ehrlich ascites tumor cells. Retrostatin was produced by the microorganism together with streptonigrin. These two substances were extracted from the culture broth with ethyl acetate at acidic pH. Retrostatin is an acidic pH indicator and the free acid was recovered as a red powder. Retrostatin had weak antibiotic activities against Gram-positive bacteria and yeasts. PMID:6193091

  4. Reaching the melting point: Degradative enzymes and protease inhibitors involved in baculovirus infection and dissemination.

    PubMed

    Ishimwe, Egide; Hodgson, Jeffrey J; Clem, Rollie J; Passarelli, A Lorena

    2015-05-01

    Baculovirus infection of a host insect involves several steps, beginning with initiation of virus infection in the midgut, followed by dissemination of infection from the midgut to other tissues in the insect, and finally culminating in "melting" or liquefaction of the host, which allows for horizontal spread of infection to other insects. While all of the viral gene products are involved in ultimately reaching this dramatic infection endpoint, this review focuses on two particular types of baculovirus-encoded proteins: degradative enzymes and protease inhibitors. Neither of these types of proteins is commonly found in other virus families, but they both play important roles in baculovirus infection. The types of degradative enzymes and protease inhibitors encoded by baculoviruses are discussed, as are the roles of these proteins in the infection process. PMID:25724418

  5. Effects of a novel ACE inhibitor, 3-(3-thienyl)-l-alanyl-ornithyl-proline, on endothelial vasodilation and hepatotoxicity in l-NAME-induced hypertensive rats

    PubMed Central

    Seth, Mahesh Kumar; Hussain, M Ejaz; Pasha, Santosh; Fahim, Mohammad

    2016-01-01

    Nitric oxide (NO) is a widespread biological mediator involved in many physiological and pathological processes, eg, in the regulation of vascular tone and hypertension. Chronic inhibition of NO synthase by NG-nitro-l-arginine methyl ester (l-NAME) hydrochloride results in the development of hypertension accompanied by an increase in vascular responsiveness to adrenergic stimuli. Recently, we developed a novel sulfur-containing angiotensin-converting enzyme inhibitor: 3-(3-thienyl)-l-alanyl-ornithyl-proline (TOP). Our previous studies indicated a superior nature of the molecule as an antihypertensive agent in spontaneously hypertensive rats (showing the involvement of renin–angiotensin–aldosterone system) in comparison to captopril. The aim of the present study was to investigate the effect of TOP on NO pathway in l-NAME-induced hypertensive rats, and captopril was included as the standard treatment group. Treatment with both TOP (20 mg/kg) and captopril (40 mg/kg) prevented the development of hypertension in l-NAME model, but TOP showed better restoration of NO and normal levels of angiotensin-converting enzyme. In addition, in vitro vasorelaxation assay showed an improvement in endothelium-dependent vasodilation in both the cases. Further, the biochemical (malondialdehyde, alanine aminotransferase, and aspartate aminotransferase) and the histopathological effects of TOP on rat liver tissues revealed a protective nature of TOP in comparison to captopril in the l-NAME model. In conclusion, TOP at 50% lesser dose than captopril was found to be better in the l-NAME model. PMID:27143859

  6. Angiotensin-converting enzyme inhibitors-induced angioedema treated by C1 esterase inhibitor concentrate (Berinert®): about one case and review of the therapeutic arsenal

    PubMed Central

    Lipski, Samuel Michael; Casimir, Georges; Vanlommel, Martine; Jeanmaire, Mathieu; Dolhen, Pierre

    2015-01-01

    Key Clinical Message C1 esterase inhibitor (Berinert®) is generally used to treat severe attack of hereditary angioedema. We describe here the case of a patient who presented with a severe angioedema induced by angiotensin-converting enzyme inhibitors (ACEIs) endangering her life. It could be successfully treated with that medicine. PMID:25767713

  7. Angiotensin-converting enzyme inhibitors-induced angioedema treated by C1 esterase inhibitor concentrate (Berinert®): about one case and review of the therapeutic arsenal.

    PubMed

    Lipski, Samuel Michael; Casimir, Georges; Vanlommel, Martine; Jeanmaire, Mathieu; Dolhen, Pierre

    2015-02-01

    C1 esterase inhibitor (Berinert®) is generally used to treat severe attack of hereditary angioedema. We describe here the case of a patient who presented with a severe angioedema induced by angiotensin-converting enzyme inhibitors (ACEIs) endangering her life. It could be successfully treated with that medicine. PMID:25767713

  8. Sequence diversity of NanA manifests in distinct enzyme kinetics and inhibitor susceptibility

    NASA Astrophysics Data System (ADS)

    Xu, Zhongli; von Grafenstein, Susanne; Walther, Elisabeth; Fuchs, Julian E.; Liedl, Klaus R.; Sauerbrei, Andreas; Schmidtke, Michaela

    2016-04-01

    Streptococcus pneumoniae is the leading pathogen causing bacterial pneumonia and meningitis. Its surface-associated virulence factor neuraminidase A (NanA) promotes the bacterial colonization by removing the terminal sialyl residues from glycoconjugates on eukaryotic cell surface. The predominant role of NanA in the pathogenesis of pneumococci renders it an attractive target for therapeutic intervention. Despite the highly conserved activity of NanA, our alignment of the 11 NanAs revealed the evolutionary diversity of this enzyme. The amino acid substitutions we identified, particularly those in the lectin domain and in the insertion domain next to the catalytic centre triggered our special interest. We synthesised the representative NanAs and the mutagenized derivatives from E. coli for enzyme kinetics study and neuraminidase inhibitor susceptibility test. Via molecular docking we got a deeper insight into the differences between the two major variants of NanA and their influence on the ligand-target interactions. In addition, our molecular dynamics simulations revealed a prominent intrinsic flexibility of the linker between the active site and the insertion domain, which influences the inhibitor binding. Our findings for the first time associated the primary sequence diversity of NanA with the biochemical properties of the enzyme and with the inhibitory efficiency of neuraminidase inhibitors.

  9. Sequence diversity of NanA manifests in distinct enzyme kinetics and inhibitor susceptibility

    PubMed Central

    Xu, Zhongli; von Grafenstein, Susanne; Walther, Elisabeth; Fuchs, Julian E.; Liedl, Klaus R.; Sauerbrei, Andreas; Schmidtke, Michaela

    2016-01-01

    Streptococcus pneumoniae is the leading pathogen causing bacterial pneumonia and meningitis. Its surface-associated virulence factor neuraminidase A (NanA) promotes the bacterial colonization by removing the terminal sialyl residues from glycoconjugates on eukaryotic cell surface. The predominant role of NanA in the pathogenesis of pneumococci renders it an attractive target for therapeutic intervention. Despite the highly conserved activity of NanA, our alignment of the 11 NanAs revealed the evolutionary diversity of this enzyme. The amino acid substitutions we identified, particularly those in the lectin domain and in the insertion domain next to the catalytic centre triggered our special interest. We synthesised the representative NanAs and the mutagenized derivatives from E. coli for enzyme kinetics study and neuraminidase inhibitor susceptibility test. Via molecular docking we got a deeper insight into the differences between the two major variants of NanA and their influence on the ligand-target interactions. In addition, our molecular dynamics simulations revealed a prominent intrinsic flexibility of the linker between the active site and the insertion domain, which influences the inhibitor binding. Our findings for the first time associated the primary sequence diversity of NanA with the biochemical properties of the enzyme and with the inhibitory efficiency of neuraminidase inhibitors. PMID:27125351

  10. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides.

    PubMed

    Nguyen, G T T; Erlenkamp, G; Jäck, O; Küberl, A; Bott, M; Fiorani, F; Gohlke, H; Groth, G

    2016-01-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world's most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2',3',4',3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2',3',4'-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15-45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

  11. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

    PubMed Central

    Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

    2016-01-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2′,3′,4′,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2′,3′,4′-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

  12. Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

    NASA Astrophysics Data System (ADS)

    Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

    2016-06-01

    Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2‧,3‧,4‧,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2‧,3‧,4‧-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme.

  13. Designed Inhibitors of Insulin-Degrading Enzyme Regulate the Catabolism and Activity of Insulin

    SciTech Connect

    Leissring, Malcolm A.; Malito, Enrico; Hedouin, Sabrine; Reinstatler, Lael; Sahara, Tomoko; Abdul-Hay, Samer O.; Choudhry, Shakeel; Maharvi, Ghulam M.; Fauq, Abdul H.; Huzarska, Malwina; May, Philip S.; Choi, Sungwoon; Logan, Todd P.; Turk, Benjamin E.; Cantley, Lewis C.; Manolopoulou, Marika; Tang, Wei-Jen; Stein, Ross L.; Cuny, Gregory D.; Selkoe, Dennis J.

    2010-09-20

    Insulin is a vital peptide hormone that is a central regulator of glucose homeostasis, and impairments in insulin signaling cause diabetes mellitus. In principle, it should be possible to enhance the activity of insulin by inhibiting its catabolism, which is mediated primarily by insulin-degrading enzyme (IDE), a structurally and evolutionarily distinctive zinc-metalloprotease. Despite interest in pharmacological inhibition of IDE as an attractive anti-diabetic approach dating to the 1950s, potent and selective inhibitors of IDE have not yet emerged. We used a rational design approach based on analysis of combinatorial peptide mixtures and focused compound libraries to develop novel peptide hydroxamic acid inhibitors of IDE. The resulting compounds are {approx} 10{sup 6} times more potent than existing inhibitors, non-toxic, and surprisingly selective for IDE vis-a-vis conventional zinc-metalloproteases. Crystallographic analysis of an IDE-inhibitor complex reveals a novel mode of inhibition based on stabilization of IDE's 'closed,' inactive conformation. We show further that pharmacological inhibition of IDE potentiates insulin signaling by a mechanism involving reduced catabolism of internalized insulin. Conclusions/Significance: The inhibitors we describe are the first to potently and selectively inhibit IDE or indeed any member of this atypical zinc-metalloprotease superfamily. The distinctive structure of IDE's active site, and the mode of action of our inhibitors, suggests that it may be possible to develop inhibitors that cross-react minimally with conventional zinc-metalloproteases. Significantly, our results reveal that insulin signaling is normally regulated by IDE activity not only extracellularly but also within cells, supporting the longstanding view that IDE inhibitors could hold therapeutic value for the treatment of diabetes.

  14. Biosensors based on enzyme field-effect transistors for determination of some substrates and inhibitors.

    PubMed

    Dzyadevych, Sergei V; Soldatkin, Alexey P; Korpan, Yaroslav I; Arkhypova, Valentyna N; El'skaya, Anna V; Chovelon, Jean-Marc; Martelet, Claude; Jaffrezic-Renault, Nicole

    2003-10-01

    This paper is a review of the authors' publications concerning the development of biosensors based on enzyme field-effect transistors (ENFETs) for direct substrates or inhibitors analysis. Such biosensors were designed by using immobilised enzymes and ion-selective field-effect transistors (ISFETs). Highly specific, sensitive, simple, fast and cheap determination of different substances renders them as promising tools in medicine, biotechnology, environmental control, agriculture and the food industry. The biosensors based on ENFETs and direct enzyme analysis for determination of concentrations of different substrates (glucose, urea, penicillin, formaldehyde, creatinine, etc.) have been developed and their laboratory prototypes were fabricated. Improvement of the analytical characteristics of such biosensors may be achieved by using a differential mode of measurement, working solutions with different buffer concentrations and specific agents, negatively or positively charged additional membranes, or genetically modified enzymes. These approaches allow one to decrease the effect of the buffer capacity influence on the sensor response in an aim to increase the sensitivity of the biosensors and to extend their dynamic ranges. Biosensors for the determination of concentrations of different toxic substances (organophosphorous pesticides, heavy metal ions, hypochlorite, glycoalkaloids, etc.) were designed on the basis of reversible and/or irreversible enzyme inhibition effect(s). The conception of an enzymatic multibiosensor for the determination of different toxic substances based on the enzyme inhibition effect is also described. We will discuss the respective advantages and disadvantages of biosensors based on the ENFETs developed and also demonstrate their practical application. PMID:12904953

  15. Pistagremic acid, a novel β-secretase enzyme (BACE1) inhibitor from Pistacia integerrima Stewart.

    PubMed

    Rauf, Abdur; Uddin, Ghias; Khan, Ajmal; Siddiqui, Bina S; Arfan, Mohammad; Dalvandi, Kourosh; Ben Hadda, Taibi

    2015-01-01

    A new triterpenic compound named pistagremic acid (PA) was once again isolated from Pistaciaintegerrima. The β-secretase inhibition study was carried out. Compound PA was found significantly active against β-secretase enzyme (BACE1) with IC50 value of 350 ± 2 nM in comparison to the standard inhibitors [Asn670, Sta671, Val672]-amyloid-β/A4 precursor protein 770 fragment 662-675 (IC50 = 290.71 ± 1 nM). The selectivity of this compound was also evaluated against the acetylcholinesterase and butyrylcholinesterase enzymes. Interestingly compound PA was found to be inactive against them and showed selectivity towards β-secretase enzyme (BACE1). PMID:25588845

  16. Preparation of lisinopril-capped gold nanoparticles for molecular imaging of angiotensin-converting enzyme

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Baeta, Cesar; Aras, Omer; Daniel, Marie-Christine

    2009-05-01

    Overexpression of angiotensin-converting enzyme (ACE) has been associated with the pathophysiology of cardiac and pulmonary fibrosis. Moreover, the prescription of ACE inhibitors, such as lisinopril, has shown a favorable effect on patient outcome for patients with heart failure or systemic hypertension. Thus targeted imaging of the ACE would be of crucial importance for monitoring tissue ACE activity as well as the treatment efficacy in heart failure. In this respect, lisinopril-coated gold nanoparticles were prepared to provide a new type of probe for targeted molecular imaging of ACE by tuned K-edge computed tomography (CT) imaging. The preparation involved non-modified lisinopril, using its primary amine group as the anchoring function on the gold nanoparticles surface. The stable lisinopril-coated gold nanoparticles obtained were characterized by UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM). Their zeta potential was also measured in order to assess the charge density on the modified gold nanoparticles (GNPs).

  17. Acetylcholinesterase capillary enzyme reactor for screening and characterization of selective inhibitors.

    PubMed

    da Silva, Joyce Izidoro; de Moraes, Marcela Cristina; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalves; Cass, Quezia Bezerra; Cardoso, Carmen Lucia

    2013-01-25

    The aim of the present work is to report on the optimized preparation of capillary enzyme reactors (ICERs) based on acetylcholinesterase (AChE, EC 3.1.1.7), for the screening of selective inhibitors. The AChE-ICERs were prepared by using the homobifunctional linker glutaraldehyde through Schiff base linkage. The enzyme was anchored onto a modified fused silica capillary and employed as an LC biochromatography column for online studies, with UV-vis detection. Not only did the tailored AChE-ICER result in maintenance of the activity of the immobilized enzyme, but it also significantly improved the stability of the enzyme in the presence of organic solvents. In addition, the kinetic studies demonstrated that the enzyme retained its activity with high stability, preserving its initial activity over 10months. The absence of non-specific matrix interactions, immediate recovery of the enzymatic activity, and short analysis time were the main advantages of this AChE-ICER. The use of AChE-ICER in the ligands recognition assay was validated by evaluation of four known reversible inhibitors (galanthamine, tacrine, propidium, and rivastigmine), and the same order of inhibitory potencies described in the literature was found. The immobilized enzyme was utilized in the screening of 21 coumarin derivatives. In this library, two new potent inhibitors were identified: coumarins 20 (IC(50) 17.14±3.50μM) and 21 (IC(50) 6.35±1.20μM), which were compared to the standard galanthamine (IC(50) 12.68±2.40μM). Considering the high inhibitory activities of these compounds, with respect to the AChE-ICER, the mechanism of action was investigated. Both coumarins 20 and 21 exhibited a competitive mechanism of action, furnishing K(i) values of 8.04±0.18 and 2.67±0.18μM, respectively. The results revealed that the AChE-ICER developed herein represents a useful tool for the biological screening of inhibitor candidates and evaluation of action mechanism. PMID:22391555

  18. Chebulin: Terminalia chebula Retz. fruit-derived peptide with angiotensin-I-converting enzyme inhibitory activity.

    PubMed

    Sornwatana, Thakorn; Bangphoomi, Kunan; Roytrakul, Sittiruk; Wetprasit, Nuanchawee; Choowongkomon, Kiattawee; Ratanapo, Sunanta

    2015-01-01

    Angiotensin-I-converting enzyme (ACE) plays an important role in blood pressure regulation. In this study, an ACE-hexapeptide inhibitor (Asp-Glu-Asn-Ser-Lys-Phe) designated as chebulin was produced from the fruit protein of Terminalia chebula Retz. by pepsin digestion, ultrafiltrated through a 3 KDa cut-off membrane, a reverse-phase high-performance liquid chromatography, and nano-liquid chromatography tandem mass spectrometry analysis. Chebulin was found to inhibit ACE in a noncompetitive manner, as supported by the structural model. It bounds to ACE by the hydrogen bond, hydrophobic and ionic interactions via the interactions of C-terminal Phe (Phe-6), and N-terminal residues (Asp-1 and Glu-2) with the amino acid residues on noncatalytic sites of the ACE. The results showed that chebulin derived from fruits of T. chebula Retz. is a potential ACE-peptide inhibitor that could be used as a functional food additive for the prevention of hypertension and as an alternative to ACE inhibitor drug. PMID:25410725

  19. One-year effectiveness and safety of open-label losartan/hydrochlorothiazide combination therapy in Japanese patients with hypertension uncontrolled with ARBs or ACE inhibitors.

    PubMed

    Kita, Toshihiro; Yokota, Naoto; Ichiki, Yoshinari; Ayabe, Takao; Etoh, Takuma; Tamaki, Noboru; Kato, Johji; Eto, Tanenao; Kitamura, Kazuo

    2010-04-01

    The long-term antihypertensive efficacy and safety of losartan/hydrochlorothiazide (HCTZ) combinations have not been appropriately evaluated in Japan. In this study, treated hypertensive patients taking angiotensin-receptor blocker (ARB) or angiotensin-converting enzyme inhibitor (ACEI) regimens not at blood pressure (BP) goals proposed by the Japanese Society of Hypertension (JSH) were switched to losartan/HCTZ combinations and followed for 1 year. Data analysis included 244 patients aged 64.5+/-10.7 years, 56% male, 27% with diabetes mellitus and 36% with dyslipidemia. Pre-switching BP 157+/-16/88+/-10 mm Hg promptly decreased and maintained a steady state, reaching 132+/-15/77+/-9 mm Hg (P<0.001) 1 year later. After 1 year of treatment, 50% of patients cleared the goals of the JSH guideline for systolic BP and 79% for diastolic BP. Patients with maximal doses of ARBs tended to show larger decreases in BP (159+/-11/90+/-10 to 128+/-10/75+/-8 mm Hg, P<0.001, n=32). Clinical and laboratory adverse events were reported for 29 patients (11%), but serious abnormalities were not observed. In particular, plasma levels of uric acid (UA) were well-maintained for 1 year, and significant decreases in UA were observed in patients with higher levels of UA (>/=7.0 mg dl(-1)). Losartan/HCTZ combinations showed strong and steady hypotensive abilities and acceptable safety and tolerability in patients currently not at BP goals with regimens including ARBs or ACEIs in Japan. PMID:20075934

  20. Substrate-Free High-Throughput Screening Identifies Selective Inhibitors for Uncharacterized Enzymes

    PubMed Central

    Bachovchin, Daniel A.; Brown, Steven J.; Rosen, Hugh; Cravatt, Benjamin F.

    2009-01-01

    Target-based high-throughput screening (HTS) is essential for the discovery of small-molecule modulators of proteins. Typical screening methods for enzymes rely on extensively tailored substrate assays, which are not available for targets of poorly characterized biochemical activity. Here, we report a general, substrate-free platform for HTS that overcomes this problem by monitoring the reaction of broad-spectrum, activity-based probes with enzymes using fluorescence polarization. We show that this platform is applicable to enzymes from multiple mechanistic classes, regardless of their degree of functional annotation, and can be coupled with secondary competitive activity-based proteomic assays to rapidly determine the specificity of screening hits. Using this platform, we identified the bioactive alkaloid emetine as a selective inhibitor of the uncharacterized cancer-associated hydrolase RBBP9. We furthermore show that the detoxification enzyme GSTO1, also implicated in cancer, is inhibited by several electrophilic compounds found in public libraries, some of which display high selectivity for this enzyme. PMID:19329999

  1. Stereochemical course, isotope effects, and enzyme inhibitor studies of glaucine metabolism in fungi

    SciTech Connect

    Kerr, K.M.

    1986-01-01

    The microbial transformation of the aporphine alkaloid glaucine by the fungi Fusarium solani (ATCC 12823) and Aspergillus flavipes (ATCC 1030) proceeds with complete substrate stereoselectivity. The fungus F. solani metabolizes only S-(+)-glaucine (1) to dehydroglaucine (3), and A. flavipes metabolizes only R-(-)-glaucine (2) to dehydroglaucine. This facile microbiological reaction is useful in the destructive resolution of racemic mixtures of glaucine, and may provide a model for producing pure enantiomers (either R or S) of other aporphines from racemic mixtures. In order to extend the reaction to other aporphines and related alkaloids, the overall stereochemical course and enzyme(s) involved in the reaction, and the substrate requirements of the enzyme were investigated. The overall stereochemical course of the transformation was examined using C-7 methyl-blocked analogs of glaucine, cis- and trans-7-methylglaucine, as substrates for the fungi. Isolation and examination of residual substrates from semi-preparative scale incubations by MS, PMR, PMR with a chiral shift reagent, OR and ORD indicated that the transformation was enantioselective in the case of A. flavipes. However, only a 10% enrichment of 6aR,7R-cis-7-methylglaucine was observed in F. solani cultures. The oxidation of glaucine can be envisioned as proceeding through one of several mechanisms, each involving a different enzyme system. Deuterium isotope, induction and enzyme inhibitor experiments helped to distinguish between the three mechanisms.

  2. Exploration of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays

    PubMed Central

    Dey, Baishakhi; Mitra, Analava; Katakam, Prakash; Singla, Rajeev K

    2014-01-01

    AIM: To investigate the presence and potency of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays. METHODS: The leaf extracts of the three different Eucalyptus species [E. globulus (EG), E. citriodora (EC), E. camaldulensis (ECA)] were subjected to in vitro assay procedures to explore the prevalence of natural enzyme inhibitors (NEIs) after preliminary qualitative and quantitative phytochemical evaluations, to study their inhibitory actions against the enzymes like α-amylase, α-glucosidase, aldose reductase, angiotensin converting enzyme and dipeptidyl peptidase 4 playing pathogenic roles in type 2 diabetes. The antioxidant potential and total antioxidant capacity of the species were also evaluated. RESULTS: Major bioactive compounds like polyphenols (341.75 ± 3.63 to 496.85 ± 3.98) and flavonoids (4.89 ± 0.01 to 7.15 ± 0.02) were found in appreciable quantity in three species. Based on the IC50 values of the extracts under investigation, in all assays the effectivity was in the order of EG > ECA > EC. The results of the ferric reducing antioxidant power assay showed that the reducing ability of the species was also in the order of EG > ECA > EC. A strong correlation (R2 = 0.81-0.99) was found between the phenolic contents and the inhibitory potentials of the extracts against the targeted enzymes. CONCLUSION: These results show immense hypoglycemic potentiality of the Eucalyptus Spp. and a remarkable source of NEIs for a future phytotherapeutic approach in Type 2 diabetes. PMID:24748933

  3. Marketing ACE in Victoria.

    ERIC Educational Resources Information Center

    2001

    This publication presents options raised through various forums for marketing adult and community education (ACE) in Victoria, Australia, and suggested strategies. After an introduction (chapter 1), chapters 2 and 3 provide a broad view of the current situation for marketing ACE. Chapter 2 discusses general issues in the current position--ACE…

  4. Angiotensin-converting enzyme 2/angiotensin-(1–7)/Mas axis activates Akt signaling to ameliorate hepatic steatosis

    PubMed Central

    Cao, Xi; Yang, Fangyuan; Shi, Tingting; Yuan, Mingxia; Xin, Zhong; Xie, Rongrong; Li, Sen; Li, Hongbing; Yang, Jin-Kui

    2016-01-01

    The classical axis of renin-angiotensin system (RAS), angiotensin (Ang)-converting enzyme (ACE)/Ang II/AT1, contributes to the development of non-alcoholic fatty liver disease (NAFLD). However, the role of bypass axis of RAS (Angiotensin-converting enzyme 2 (ACE2)/Ang-(1–7)/Mas) in hepatic steatosis is still unclear. Here we showed that deletion of ACE2 aggravates liver steatosis, which is correlated with the increased expression of hepatic lipogenic genes and the decreased expression of fatty acid oxidation-related genes in the liver of ACE2 knockout (ACE2−/y) mice. Meanwhile, oxidative stress and inflammation were also aggravated in ACE2−/y mice. On the contrary, overexpression of ACE2 improved fatty liver in db/db mice, and the mRNA levels of fatty acid oxidation-related genes were up-regulated. In vitro, Ang-(1–7)/ACE2 ameliorated hepatic steatosis, oxidative stress and inflammation in free fatty acid (FFA)-induced HepG2 cells, and what’s more, Akt inhibitors reduced ACE2-mediated lipid metabolism. Furthermore, ACE2-mediated Akt activation could be attenuated by blockade of ATP/P2 receptor/Calmodulin (CaM) pathway. These results indicated that Ang-(1–7)/ACE2/Mas axis may reduce liver lipid accumulation partly by regulating lipid-metabolizing genes through ATP/P2 receptor/CaM signaling pathway. Our findings support the potential role of ACE2/Ang-(1–7)/Mas axis in prevention and treatment of hepatic lipid metabolism. PMID:26883384

  5. Angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis activates Akt signaling to ameliorate hepatic steatosis.

    PubMed

    Cao, Xi; Yang, Fangyuan; Shi, Tingting; Yuan, Mingxia; Xin, Zhong; Xie, Rongrong; Li, Sen; Li, Hongbing; Yang, Jin-Kui

    2016-01-01

    The classical axis of renin-angiotensin system (RAS), angiotensin (Ang)-converting enzyme (ACE)/Ang II/AT1, contributes to the development of non-alcoholic fatty liver disease (NAFLD). However, the role of bypass axis of RAS (Angiotensin-converting enzyme 2 (ACE2)/Ang-(1-7)/Mas) in hepatic steatosis is still unclear. Here we showed that deletion of ACE2 aggravates liver steatosis, which is correlated with the increased expression of hepatic lipogenic genes and the decreased expression of fatty acid oxidation-related genes in the liver of ACE2 knockout (ACE2(-/y)) mice. Meanwhile, oxidative stress and inflammation were also aggravated in ACE2(-/y) mice. On the contrary, overexpression of ACE2 improved fatty liver in db/db mice, and the mRNA levels of fatty acid oxidation-related genes were up-regulated. In vitro, Ang-(1-7)/ACE2 ameliorated hepatic steatosis, oxidative stress and inflammation in free fatty acid (FFA)-induced HepG2 cells, and what's more, Akt inhibitors reduced ACE2-mediated lipid metabolism. Furthermore, ACE2-mediated Akt activation could be attenuated by blockade of ATP/P2 receptor/Calmodulin (CaM) pathway. These results indicated that Ang-(1-7)/ACE2/Mas axis may reduce liver lipid accumulation partly by regulating lipid-metabolizing genes through ATP/P2 receptor/CaM signaling pathway. Our findings support the potential role of ACE2/Ang-(1-7)/Mas axis in prevention and treatment of hepatic lipid metabolism. PMID:26883384

  6. Identifying New Drug Targets for Potent Phospholipase D Inhibitors: Combining Sequence Alignment, Molecular Docking, and Enzyme Activity/Binding Assays.

    PubMed

    Djakpa, Helene; Kulkarni, Aditya; Barrows-Murphy, Scheneque; Miller, Greg; Zhou, Weihong; Cho, Hyejin; Török, Béla; Stieglitz, Kimberly

    2016-05-01

    Phospholipase D enzymes cleave phospholipid substrates generating choline and phosphatidic acid. Phospholipase D from Streptomyces chromofuscus is a non-HKD (histidine, lysine, and aspartic acid) phospholipase D as the enzyme is more similar to members of the diverse family of metallo-phosphodiesterase/phosphatase enzymes than phospholipase D enzymes with active site HKD repeats. A highly efficient library of phospholipase D inhibitors based on 1,3-disubstituted-4-amino-pyrazolopyrimidine core structure was utilized to evaluate the inhibition of purified S. chromofuscus phospholipase D. The molecules exhibited inhibition of phospholipase D activity (IC50 ) in the nanomolar range with monomeric substrate diC4 PC and micromolar range with phospholipid micelles and vesicles. Binding studies with vesicle substrate and phospholipase D strongly indicate that these inhibitors directly block enzyme vesicle binding. Following these compelling results as a starting point, sequence searches and alignments with S. chromofuscus phospholipase D have identified potential new drug targets. Using AutoDock, inhibitors were docked into the enzymes selected from sequence searches and alignments (when 3D co-ordinates were available) and results analyzed to develop next-generation inhibitors for new targets. In vitro enzyme activity assays with several human phosphatases demonstrated that the predictive protocol was accurate. The strategy of combining sequence comparison, docking, and high-throughput screening assays has helped to identify new drug targets and provided some insight into how to make potential inhibitors more specific to desired targets. PMID:26691755

  7. Identification of activating enzymes of a novel FBPase inhibitor prodrug, CS-917

    PubMed Central

    Kubota, Kazuishi; Inaba, Shin-ichi; Nakano, Rika; Watanabe, Mihoko; Sakurai, Hidetaka; Fukushima, Yumiko; Ichikawa, Kimihisa; Takahashi, Tohru; Izumi, Takashi; Shinagawa, Akira

    2015-01-01

    CS-917 (MB06322) is a selective small compound inhibitor of fructose 1,6-bisphosphatase (FBPase), which is expected to be a novel drug for the treatment of type 2 diabetes by inhibiting gluconeogenesis. CS-917 is a bisamidate prodrug and activation of CS-917 requires a two-step enzyme catalyzed reaction. The first-step enzyme, esterase, catalyzes the conversion of CS-917 into the intermediate form (R-134450) and the second-step enzyme, phosphoramidase, catalyzes the conversion of R-134450 into the active form (R-125338). In this study, we biochemically purified the CS-917 esterase activity in monkey small intestine and liver. We identified cathepsin A (CTSA) and elastase 3B (ELA3B) as CS-917 esterases in the small intestine by mass spectrometry, whereas we found CTSA and carboxylesterase 1 (CES1) in monkey liver. We also purified R-134450 phosphoramidase activity in monkey liver and identified sphingomyelin phosphodiesterase, acid-like 3A (SMPADL3A), as an R-134450 phosphoramidase, which has not been reported to have any enzyme activity. Recombinant human CTSA, ELA3B, and CES1 showed CS-917 esterase activity and recombinant human SMPDL3A showed R-134450 phosphoramidase activity, which confirmed the identification of those enzymes. Identification of metabolic enzymes responsible for the activation process is the requisite first step to understanding the activation process, pharmacodynamics and pharmacokinetics of CS-917 at the molecular level. This is the first identification of a phosphoramidase other than histidine triad nucleotide-binding protein (HINT) family enzymes and SMPDL3A might generally contribute to activation of the other bisamidate prodrugs. PMID:26171222

  8. The association of angiotensin-converting enzyme with biomarkers for Alzheimer’s disease

    PubMed Central

    2014-01-01

    Introduction Lower angiotensin-converting enzyme (ACE) activity could increase the risk of Alzheimer’s disease (AD) as ACE functions to degrade amyloid-β (Aβ). Therefore, we investigated whether ACE protein and activity levels in cerebrospinal fluid (CSF) and serum were associated with CSF Aβ, total tau (tau) and tau phosphorylated at threonine 181 (ptau). Methods We included 118 subjects from our memory clinic-based Amsterdam Dementia Cohort (mean age 66 ± 8 years) with subjective memory complaints (n = 40) or AD (n = 78), who did not use antihypertensive drugs. We measured ACE protein levels (ng/ml) and activity (RFU) in CSF and serum, and amyloid β1–42, tau and ptau (pg/ml) in CSF. Results Cross-sectional regression analyses showed that ACE protein level and activity in CSF and serum were lower in patients with AD compared to controls. Lower CSF ACE protein level, and to a lesser extent serum ACE protein level and CSF ACE activity, were associated with lower CSF Aβ, indicating more brain Aβ pathology; adjusted regression coefficients (B) (95% CI) per SD increase were 0.09 (0.04; 0.15), 0.06 (0.00; 0.12) and 0.05 (0.00; 0.11), respectively. Further, lower CSF ACE protein level was associated with lower CSF tau and ptau levels; adjusted B’s (95% CI) per SD increase were 0.15 (0.06; 0.25) and 0.17 (0.10; 0.25), respectively. Conclusions These results strengthen the hypothesis that ACE degrades Aβ. This could suggest that lowering ACE levels by for example ACE-inhibitors might have adverse consequences for patients with, or at risk for AD. PMID:24987467

  9. Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

    PubMed

    Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

    2016-08-26

    Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach. PMID:27498895

  10. Activity Based Profiling of Deubiquitylating Enzymes and Inhibitors in Animal Tissues.

    PubMed

    McLellan, Lauren; Forder, Cassie; Cranston, Aaron; Harrigan, Jeanine; Jacq, Xavier

    2016-01-01

    The attachment of ubiquitin or ubiquitin-like modifiers to proteins is an important signal for the regulation of a variety of biological processes including the targeting of substrates for degradation, receptor internalization, regulation of gene expression, and DNA repair. Posttranslational modification of proteins by ubiquitin controls many cellular processes, and aberrant ubiquitylation can contribute to cancer, immunopathologies, and neurodegeneration. Thus, deubiquitylating enzymes (DUBs) that remove ubiquitin from proteins have become attractive therapeutic targets. Monitoring the activity of DUBs in cells or in tissues is critical for understanding the biological function of DUBs in particular pathways and is essential for determining the physiological specificity and potency of small-molecule DUB inhibitors. Here, we describe a method for the homogenization of animal tissues and incubation of tissue lysates with ubiquitin-based activity probes to monitor DUB activity in mouse tissues and target engagement following treatment of animals with small-molecule DUB inhibitors. PMID:27613053

  11. Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy

    PubMed Central

    Saleem, Saba; Azam, Aisha; Maqsood, Sundus Ijaz; Muslim, Irfan; Bashir, Shaheena; Fazal, Nosheen; Riaz, Moeen; Ali, Syeda Hafiza Benish; Niazi, Muhammad Khizar; Ishaq, Mazhar; Waheed, Nadia Khalida; Qamar, Raheel; Azam, Maleeha

    2015-01-01

    In the present study we determined the association of angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms with diabetic retinopathy (DR) and its sub-clinical classes in Pakistani type 2 diabetic patients. A total of 353 diabetic subjects including 160 DR and 193 diabetic non retinopathy (DNR) as well as 198 healthy controls were genotyped by allele specific polymerase chain reaction (PCR) for ACE Insertion/Deletion (ID) polymorphism, rs4646994 in intron 16 and PAI-1 4G/5G (deletion/insertion) polymorphism, rs1799768 in promoter region of the gene. To statistically assess the genotype-phenotype association, multivariate logistic regression analysis was applied to the genotype data of DR, DNR and control individuals as well as the subtypes of DR. The ACE genotype ID was found to be significantly associated with DR (p = 0.009, odds ratio (OR) 1.870 [95% confidence interval (CI) = 1.04–3.36]) and its sub-clinical class non-proliferative DR (NPDR) (p = 0.006, OR 2.250 [95% CI = 1.098–4.620]), while PAI polymorphism did not show any association with DR in the current cohort. In conclusion in Pakistani population the ACE ID polymorphism was observed to be significantly associated with DR and NPDR, but not with the severe form of the disease i.e. proliferative DR (PDR). PMID:26658948

  12. Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy.

    PubMed

    Saleem, Saba; Azam, Aisha; Maqsood, Sundus Ijaz; Muslim, Irfan; Bashir, Shaheena; Fazal, Nosheen; Riaz, Moeen; Ali, Syeda Hafiza Benish; Niazi, Muhammad Khizar; Ishaq, Mazhar; Waheed, Nadia Khalida; Qamar, Raheel; Azam, Maleeha

    2015-01-01

    In the present study we determined the association of angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms with diabetic retinopathy (DR) and its sub-clinical classes in Pakistani type 2 diabetic patients. A total of 353 diabetic subjects including 160 DR and 193 diabetic non retinopathy (DNR) as well as 198 healthy controls were genotyped by allele specific polymerase chain reaction (PCR) for ACE Insertion/Deletion (ID) polymorphism, rs4646994 in intron 16 and PAI-1 4G/5G (deletion/insertion) polymorphism, rs1799768 in promoter region of the gene. To statistically assess the genotype-phenotype association, multivariate logistic regression analysis was applied to the genotype data of DR, DNR and control individuals as well as the subtypes of DR. The ACE genotype ID was found to be significantly associated with DR (p = 0.009, odds ratio (OR) 1.870 [95% confidence interval (CI) = 1.04-3.36]) and its sub-clinical class non-proliferative DR (NPDR) (p = 0.006, OR 2.250 [95% CI = 1.098-4.620]), while PAI polymorphism did not show any association with DR in the current cohort. In conclusion in Pakistani population the ACE ID polymorphism was observed to be significantly associated with DR and NPDR, but not with the severe form of the disease i.e. proliferative DR (PDR). PMID:26658948

  13. Δ9-Tetrahydrocannabinol and Endocannabinoid Degradative Enzyme Inhibitors Attenuate Intracranial Self-Stimulation in Mice

    PubMed Central

    Grim, Travis W.; Owens, Robert A.; Lazenka, Matthew F.; Sim-Selley, Laura J.; Abdullah, Rehab A.; Niphakis, Micah J.; Vann, Robert E.; Cravatt, Benjamin F.; Wiley, Jenny L.; Negus, S. Stevens; Lichtman, Aron H.

    2015-01-01

    A growing body of evidence implicates endogenous cannabinoids as modulators of the mesolimbic dopamine system and motivated behavior. Paradoxically, the reinforcing effects of Δ9-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis, have been difficult to detect in preclinical rodent models. In this study, we investigated the impact of THC and inhibitors of the endocannabinoid hydrolytic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on operant responding for electrical stimulation of the medial forebrain bundle [intracranial self-stimulation (ICSS)], which is known to activate the mesolimbic dopamine system. These drugs were also tested in assays of operant responding for food reinforcement and spontaneous locomotor activity. THC and the MAGL inhibitor JZL184 (4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) attenuated operant responding for ICSS and food, and also reduced spontaneous locomotor activity. In contrast, the FAAH inhibitor PF-3845 (N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) was largely without effect in these assays. Consistent with previous studies showing that combined inhibition of FAAH and MAGL produces a substantially greater cannabimimetic profile than single enzyme inhibition, the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) produced a similar magnitude of ICSS depression as that produced by THC. ICSS attenuation by JZL184 was associated with increased brain levels of 2-arachidonoylglycerol (2-AG), whereas peak effects of SA-57 were associated with increased levels of both N-arachidonoylethanolamine (anandamide) and 2-AG. The cannabinoid receptor type 1 receptor antagonist rimonabant, but not the cannabinoid receptor type 2 receptor antagonist SR144528, blocked the attenuating effects of THC, JZL184, and SA-57 on ICSS

  14. Δ9-tetrahydrocannabinol and endocannabinoid degradative enzyme inhibitors attenuate intracranial self-stimulation in mice.

    PubMed

    Wiebelhaus, Jason M; Grim, Travis W; Owens, Robert A; Lazenka, Matthew F; Sim-Selley, Laura J; Abdullah, Rehab A; Niphakis, Micah J; Vann, Robert E; Cravatt, Benjamin F; Wiley, Jenny L; Negus, S Stevens; Lichtman, Aron H

    2015-02-01

    A growing body of evidence implicates endogenous cannabinoids as modulators of the mesolimbic dopamine system and motivated behavior. Paradoxically, the reinforcing effects of Δ(9)-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis, have been difficult to detect in preclinical rodent models. In this study, we investigated the impact of THC and inhibitors of the endocannabinoid hydrolytic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on operant responding for electrical stimulation of the medial forebrain bundle [intracranial self-stimulation (ICSS)], which is known to activate the mesolimbic dopamine system. These drugs were also tested in assays of operant responding for food reinforcement and spontaneous locomotor activity. THC and the MAGL inhibitor JZL184 (4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) attenuated operant responding for ICSS and food, and also reduced spontaneous locomotor activity. In contrast, the FAAH inhibitor PF-3845 (N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) was largely without effect in these assays. Consistent with previous studies showing that combined inhibition of FAAH and MAGL produces a substantially greater cannabimimetic profile than single enzyme inhibition, the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) produced a similar magnitude of ICSS depression as that produced by THC. ICSS attenuation by JZL184 was associated with increased brain levels of 2-arachidonoylglycerol (2-AG), whereas peak effects of SA-57 were associated with increased levels of both N-arachidonoylethanolamine (anandamide) and 2-AG. The cannabinoid receptor type 1 receptor antagonist rimonabant, but not the cannabinoid receptor type 2 receptor antagonist SR144528, blocked the attenuating effects of THC, JZL184, and SA-57 on

  15. Complete reconstruction of an enzyme-inhibitor binding process by molecular dynamics simulations

    PubMed Central

    Buch, Ignasi; Giorgino, Toni; De Fabritiis, Gianni

    2011-01-01

    The understanding of protein–ligand binding is of critical importance for biomedical research, yet the process itself has been very difficult to study because of its intrinsically dynamic character. Here, we have been able to quantitatively reconstruct the complete binding process of the enzyme-inhibitor complex trypsin-benzamidine by performing 495 molecular dynamics simulations of free ligand binding of 100 ns each, 187 of which produced binding events with an rmsd less than 2 Å compared to the crystal structure. The binding paths obtained are able to capture the kinetic pathway of the inhibitor diffusing from solvent (S0) to the bound (S4) state passing through two metastable intermediate states S2 and S3. Rather than directly entering the binding pocket the inhibitor appears to roll on the surface of the protein in its transition between S3 and the final binding pocket, whereas the transition between S2 and the bound pose requires rediffusion to S3. An estimation of the standard free energy of binding gives ΔG° = -5.2 ± 0.4 kcal/mol (cf. the experimental value -6.2 kcal/mol), and a two-states kinetic model kon = (1.5 ± 0.2) × 108 M-1 s-1 and koff = (9.5 ± 3.3) × 104 s-1 for unbound to bound transitions. The ability to reconstruct by simple diffusion the binding pathway of an enzyme-inhibitor binding process demonstrates the predictive power of unconventional high-throughput molecular simulations. Moreover, the methodology is directly applicable to other molecular systems and thus of general interest in biomedical and pharmaceutical research. PMID:21646537

  16. QM/MM investigation of the catalytic mechanism of angiotensin-converting enzyme.

    PubMed

    Mu, Xia; Zhang, Chunchun; Xu, Dingguo

    2016-06-01

    Angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II and degrades bradykinin and other vasoactive peptides. ACE inhibitors are used to treat diseases such as hypertension and heart failure. It is thus highly desirable to understand the catalytic mechanism of ACE, as this should facilitate the design of more powerful and selective ACE inhibitors. ACE exhibits two different active domains, the C-domain and the N-domain. In this work, we systematically investigated the inhibitor- and substrate-binding patterns in the N-domain of human ACE using a combined quantum mechanical and molecular mechanical approach. The hydrolysis of hippuryl-histidyl-leucine (HHL) as catalyzed by the N-domain of human somatic ACE was explored, and the effects of chloride ion on the overall reaction were also investigated. Two models, one with and one without a chloride ion at the first binding position, were then designed to examine the chloride dependence of inhibitor-substrate binding and the catalytic mechanism. Our calculations indicate that the hydrolysis reaction follows a stepwise general base/general acid catalysis path. The estimated mean free energy barrier height in the two models is about 15.6 kcal/mol, which agrees very well with the experimentally estimated value of 15.8 kcal/mol. Our simulations thus suggest that the N-domain is in a mixed form during ACE-catalyzed hydrolysis, with the single-chloride-ion and the double-chloride-ion forms existing simultaneously. Graphical Abstract Superposition of ACE C- and N- domains. PMID:27184002

  17. Release of angiotensin converting enzyme-inhibitor peptides during in vitro gastrointestinal digestion of Parmigiano Reggiano PDO cheese and their absorption through an in vitro model of intestinal epithelium.

    PubMed

    Basiricò, L; Catalani, E; Morera, P; Cattaneo, S; Stuknytė, M; Bernabucci, U; De Noni, I; Nardone, A

    2015-11-01

    The occurrence of 8 bovine casein-derived peptides (VPP, IPP, RYLGY, RYLG, AYFYPEL, AYFYPE, LHLPLP, and HLPLP) reported as angiotensin converting enzyme-inhibitors (ACE-I) was investigated in the 3-kDa ultrafiltered water-soluble extract (WSE) of Parmigiano Reggiano (PR) cheese samples by ultra-performance liquid chromatography coupled to high-resolution mass spectrometry via an electrospray ionization source. Only VPP, IPP, LHLPLP, and HLPLP were revealed in the WSE, and their total amount was in the range of 8.46 to 21.55 mg/kg of cheese. Following in vitro static gastrointestinal digestion, the same ACE-I peptides along with the newly formed AYFYPEL and AYFYPE were found in the 3 kDa WSE of PR digestates. Digestates presented high amounts (1,880-3,053 mg/kg) of LHLPLP, whereas the remaining peptides accounted for 69.24 to 82.82 mg/kg. The half-maximal inhibitory concentration (IC50) values decreased from 7.92 ± 2.08 in undigested cheese to 3.20 ± 1.69 after in vitro gastrointestinal digestion. The 3-kDa WSE of digested cheeses were used to study the transport of the 8 ACE-I peptides across the monolayers of the Caco-2 cell culture grown on a semipermeable membrane of the transwells. After 1h of incubation, 649.20 ± 148.85 mg/kg of LHLPLP remained in the apical compartment, whereas VPP, IPP, AYFYPEL, AYFYPE, and HLPLP accounted in total for less than 36.78 mg/kg. On average, 0.6% of LHLPLP initially present in the digestates added to the apical compartment were transported intact to the basolateral chamber after the same incubation time. Higher transport rate (2.9%) was ascertained for the peptide HLPLP. No other intact ACE-I peptides were revealed in the basolateral compartment. For the first time, these results demonstrated that the ACE-I peptides HLPLP and LHLPLP present in the in vitro digestates of PR cheese are partially absorbed through an in vitro model of human intestinal epithelium. PMID:26364103

  18. Nantenine as an acetylcholinesterase inhibitor: SAR, enzyme kinetics and molecular modeling investigations

    PubMed Central

    Pecic, Stevan; McAnuff, Marie A.; Harding, Wayne W.

    2015-01-01

    Nantenine, as well as a number of flexible analogs, were evaluated for acetylcholinesterase (AChE) inhibitory activity in microplate spectrophotometric assays based on Ellman’s method. It was found that the rigid aporphine core of nantenine is an important structural requirement for its anticholinesterase activity. Nantenine showed mixed inhibition kinetics in enzyme assays. Molecular docking experiments suggest that nantenine binds preferentially to the catalytic site of AChE but is also capable of interacting with the peripheral anionic site (PAS) of the enzyme, thus accounting for its mixed inhibition profile. The aporphine core of nantenine may thus be a useful template for the design of novel PAS or dual-site AChE inhibitors. Inhibiting the PAS is desirable for prevention of aggregation of the amyloid peptide Aβ, a major causative factor in the progression of Alzheimer’s disease (AD). PMID:20583856

  19. Strong suppression of the renin-angiotensin system has a renal-protective effect in hypertensive patients: high-dose ARB with ACE inhibitor (Hawaii) study.

    PubMed

    Ohishi, Mitsuru; Takeya, Yasushi; Tatara, Yuji; Yamamoto, Koichi; Onishi, Miyuki; Maekawa, Yoshihiro; Kamide, Kei; Rakugi, Hiromi

    2010-11-01

    The principal means for reducing proteinuria in patients with chronic kidney disease are strong blockade of the renin-angiotensin system and strict regulation of blood pressure (BP). This study compared the efficacy of the maximum permissible doses of two common angiotensin receptor blockers (ARBs), namely valsartan (maximum dose=160 mg per day) and olmesartan (maximum dose=40 mg per day). We also investigated whether a high-dose ARB or the combination of an angiotensin-converting enzyme inhibitor with a high-dose ARB would be more renal protective. We recruited 87 poorly controlled hypertensive patients. In the first study, 50 patients without proteinuria were switched from valsartan (160 mg per day) to olmesartan (40 mg per day) for 4 months. In the second study, 37 patients with proteinuria were randomized to either switch from valsartan 160 mg per day to 40 mg per day olmesartan (n=19; Olm-G) or addition of 2.5-10 mg per day imidapril (stepped up by 2.5 mg per month) to valsartan at 160 mg per day (n=18; Imi-G). After 4 months, the BP level decreased (first study) from 157/88 mm Hg to 145/82 mm Hg (P<0.001) and (second study) from 149/86 mm Hg to 135/77 mm Hg and 145/82 mm Hg for Olm-G and Imi-G, respectively. Furthermore, in the second study, urinary protein/creatinine excretion was reduced from 2.0±1.8 g g⁻¹ to 0.8±0.8 g g⁻¹ (P=0.0242) in Olm-G and from 1.4±1.3 g g⁻¹ to 0.9±1.0 g g⁻¹ (P=0.0398) in Imi-G. The significance persisted after adjustment for BP or other risk factors. Our results suggested that the maximum dose of olmesartan was more effective than that of valsartan and comparable with the combination of valsartan and imidapril for reducing BP and proteinuria in poorly controlled hypertensive patients. PMID:20703230

  20. Investigation of the energy barrier to the rotation of amide CN bonds in ACE inhibitors by NMR, dynamic HPLC and DFT.

    PubMed

    Bouabdallah, S; Ben Dhia, M T; Driss, M R; Touil, S

    2016-09-01

    The isomerizations of Enalapril, Perindopril, Enalaprilat and Lisinopril have been investigated using NMR spectroscopic, dynamic chromatographic, unified equation and DFT theoretical calculations. The thermodynamic parameters (ΔH, ΔS and ΔG) were determined by varying the temperature in the NMR experiments. At the coalescence temperature, we can evaluate the isomerization barrier to the rotation (ΔG(≠)) around the amide bond. Using dynamics chromatography and an unified equation introduced by Trap, we can determine isomerization rate constants and Gibbs activation energies. Molecular mechanics calculations also provided evidence for the presence of low energy conformers for the ACE due to restricted amide rotation. With the value of barriers (ΔE) between them of the order of (20kJmol(-1)), which is in agreement with the dynamic NMR results and DFT calculations. PMID:27344631

  1. Proangiogenic effect of angiotensin-converting enzyme inhibition is mediated by the bradykinin B(2) receptor pathway.

    PubMed

    Silvestre, J S; Bergaya, S; Tamarat, R; Duriez, M; Boulanger, C M; Levy, B I

    2001-10-12

    Recent studies have suggested a proangiogenic effect of angiotensin-converting enzyme (ACE) inhibition. We hypothesized that such a proangiogenic effect of ACE inhibition may be mediated, in part, by bradykinin (BK) B(2)-receptor pathway. This study therefore examined the neovascularization induced by ACE inhibitor treatment in B(2) receptor-deficient mice (B(2)(-/-)) in a model of surgically induced hindlimb ischemia. After artery femoral occlusion, wild-type and B(2)(-/-) mice were treated with or without ACE inhibitor (perindopril, 3 mg/kg/d) for 28 days. Angiogenesis was then quantitated by microangiography, capillary density measurement, and laser Doppler perfusion imaging. The protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) were determined by Western blot. In wild-type animals, vessel density and capillary number in the ischemic leg were raised by 1.8- and 1.4-fold, respectively, in mice treated with ACE inhibitor when compared with the nontreated animals (P<0.01). This corresponded to an improved ischemic/nonischemic leg perfusion ratio by 1.5-fold in ACE inhibitor-treated animals when compared with the untreated ones (0.87+/-0.07 versus 0.59+/-0.05, respectively, P<0.01). Activation of the angiogenic process was also associated with a 1.7-fold increase in tissue eNOS protein level in mice treated with ACE inhibitor (P<0.05 versus control) but not with changes in VEGF protein level. Conversely, ACE inhibition did not affect vessel density, blood flow, and eNOS protein level in ischemic hindlimb of B(2)(-/-) mice. Therefore, proangiogenic effect of ACE inhibition is mediated by B(2)-receptor signaling and was associated with upregulation of eNOS content, independently of VEGF expression. PMID:11597990

  2. Catalytic properties of recombinant dipeptidyl carboxypeptidase from Escherichia coli: a comparative study with angiotensin I-converting enzyme.

    PubMed

    Cunha, Carlos Eduardo L; Magliarelli, Helena de Fátima; Paschoalin, Thaysa; Nchinda, Aloysius T; Lima, Jackson C; Juliano, Maria A; Paiva, Paulo B; Sturrock, Edward D; Travassos, Luiz R; Carmona, Adriana K

    2009-09-01

    Dipeptidyl carboxypeptidase from Escherichia coli (EcDcp) is a zinc metallopeptidase with catalytic properties closely resembling those of angiotensin I-converting enzyme (ACE). However, EcDcp and ACE are classified in different enzyme families (M3 and M2, respectively) due to differences in their primary sequences. We cloned and expressed EcDcp and studied in detail the enzyme's S(3) to S(1)' substrate specificity using positional-scanning synthetic combinatorial (PS-SC) libraries of fluorescence resonance energy transfer (FRET) peptides. These peptides contain ortho-aminobenzoic acid (Abz) and 2,4-dinitrophenyl (Dnp) as donor/acceptor pair. In addition, using FRET substrates developed for ACE [Abz-FRK(Dnp)P-OH, Abz-SDK(Dnp)P-OH and Abz-LFK(Dnp)-OH] as well as natural ACE substrates (angiotensin I, bradykinin, and Ac-SDKP-OH), we show that EcDcp has catalytic properties very similar to human testis ACE. EcDcp inhibition studies were performed with the ACE inhibitors captopril (K(i)=3 nM) and lisinopril (K(i)=4.4 microM) and with two C-domain-selective ACE inhibitors, 5-S-5-benzamido-4-oxo-6-phenylhexanoyl-L-tryptophan (kAW; K(i)=22.0 microM) and lisinopril-Trp (K(i)=0.8 nM). Molecular modeling was used to provide the basis for the differences found in the inhibitors potency. The phylogenetic relationship of EcDcp and related enzymes belonging to the M3 and M2 families was also investigated and the results corroborate the distinct origins of EcDcp and ACE. PMID:19558329

  3. Developing an irreversible inhibitor of human DDAH-1, an enzyme upregulated in melanoma.

    PubMed

    Wang, Yun; Hu, Shougang; Gabisi, Abdul M; Er, Joyce A V; Pope, Arthur; Burstein, Gayle; Schardon, Christopher L; Cardounel, Arturo J; Ekmekcioglu, Suhendan; Fast, Walter

    2014-04-01

    Inhibitors of the human enzyme dimethylarginine dimethylaminohydrolase-1 (DDAH-1) can raise endogenous levels of asymmetric dimethylarginine (ADMA) and lead to a subsequent inhibition of nitric oxide synthesis. In this study, N(5) -(1-imino-2-chloroethyl)-L-ornithine (Cl-NIO) is shown to be a potent time- and concentration-dependent inhibitor of purified human DDAH-1 (KI =1.3±0.6 μM; kinact =0.34±0.07 min(-1) ), with >500-fold selectivity against two arginine-handling enzymes in the same pathway. An activity probe is used to measure the "in cell" IC50 value (6.6±0.2 μM) for Cl-NIO inhibition of DDAH-1 artificially expressed within cultured HEK293T cells. A screen of diverse melanoma cell lines reveals that a striking 50/64 (78 %) of melanoma lines tested showed increased levels of DDAH-1 relative to normal melanocyte control lines. Treatment of the melanoma A375 cell line with Cl-NIO shows a subsequent decrease in cellular nitric oxide production. Cl-NIO is a promising tool for the study of methylarginine-mediated nitric oxide control and a potential therapeutic lead compound for other indications with elevated nitric oxide production, such as septic shock and idiopathic pulmonary fibrosis. PMID:24574257

  4. Developing an irreversible inhibitor of human DDAH-1, an enzyme upregulated in melanoma

    PubMed Central

    Wang, Yun; Hu, Shougang; Gabisi, Abdul M.; Er, Joyce A. V.; Pope, Arthur; Burstein, Gayle; Schardon, Christopher L.

    2015-01-01

    Inhibitors of the human enzyme dimethylarginine dimethylaminohydrolase-1 (DDAH-1) can raise endogenous levels of asymmetric dimethylarginine (ADMA) and lead to a subsequent inhibition of nitric oxide synthesis. Herein, N5-(1-imino-2-chloroethyl)-L-ornithine (Cl-NIO) is shown to be a potent time- and concentration-dependent inhibitor of purified human DDAH-1 (KI = 1.3 ± 0.6 μM; kinact = 0.34 ± 0.07 min−1), with > 500-fold selectivity against two arginine-handling enzymes in the same pathway. An activity probe is used to measure the “in cell” IC50 value (6.6 ± 0.2 μM) for Cl-NIO inhibition of DDAH-1 artificially expressed within cultured HEK293T cells. A screen of diverse melanoma cell lines reveals that a striking 50 / 64 (78 %) of melanoma lines tested showed increased levels of DDAH-1 in comparison to normal melanocyte control lines. Treatment of the melanoma A375 cell line with Cl-NIO shows a subsequent decrease in cellular nitric oxide production. Cl-NIO represents a promising tool for the study of methylarginine-mediated nitric oxide control and a potential therapeutic lead compound for other indications with elevated nitric oxide production such as septic shock and idiopathic pulmonary fibrosis. PMID:24574257

  5. Targeting histone methylation for cancer therapy: enzymes, inhibitors, biological activity and perspectives.

    PubMed

    Song, Yongcheng; Wu, Fangrui; Wu, Jingyu

    2016-01-01

    Post-translational methylation of histone lysine or arginine residues plays important roles in gene regulation and other physiological processes. Aberrant histone methylation caused by a gene mutation, translocation, or overexpression can often lead to initiation of a disease such as cancer. Small molecule inhibitors of such histone modifying enzymes that correct the abnormal methylation could be used as novel therapeutics for these diseases, or as chemical probes for investigation of epigenetics. Discovery and development of histone methylation modulators are in an early stage and undergo a rapid expansion in the past few years. A number of highly potent and selective compounds have been reported, together with extensive preclinical studies of their biological activity. Several compounds have been in clinical trials for safety, pharmacokinetics, and efficacy, targeting several types of cancer. This review summarizes the biochemistry, structures, and biology of cancer-relevant histone methylation modifying enzymes, small molecule inhibitors and their preclinical and clinical antitumor activities. Perspectives for targeting histone methylation for cancer therapy are also discussed. PMID:27316347

  6. Novel angiotensin I-converting enzyme inhibitory peptides derived from an edible mushroom, Pleurotus cystidiosus O.K. Miller identified by LC-MS/MS

    PubMed Central

    2013-01-01

    Background Angiotensin I-converting enzyme (ACE) inhibitors have been reported to reduce mortality in patients with hypertension. Compared to chemosynthetic drugs, ACE inhibitors derived from natural sources such as food proteins are believed to be safer for consumption and to have fewer adverse effects. Some edible mushrooms have been reported to significantly reduce blood pressure after oral administration. In addition, mushrooms are known to be rich in protein content. This makes them a potential source of ACE inhibitory peptides. Hence, the objective of the current study was to isolate and characterise ACE inhibitory peptides from an edible mushroom, Pleurotus cystidiosus. Methods ACE inhibitory proteins were isolated from P. cystidiosus based on the bioassay guided purification steps, i.e. ammonium sulphate precipitation, reverse phase high performance liquid chromatography and size exclusion chromatography. Active fraction was then analysed by LC-MS/MS and potential ACE inhibitory peptides identified were chemically synthesized. Effect of in vitro gastrointestinal digestions on the ACE inhibitory activity of the peptides and their inhibition patterns were evaluated. Results Two potential ACE inhibitory peptides, AHEPVK and GPSMR were identified from P. cystidiosus with molecular masses of 679.53 and 546.36 Da, respectively. Both peptides exhibited potentially high ACE inhibitory activity with IC50 values of 62.8 and 277.5 μM, respectively. SEC chromatograms and BIOPEP analysis of these peptides revealed that the peptide sequence of the hexapeptide, AHEPVK, was stable throughout gastrointestinal digestion. The pentapeptide, GPSMR, was hydrolysed after digestion and it was predicted to release a dipeptide ACE inhibitor, GP, from its precursor. The Lineweaver-Burk plot of AHEPVK showed that this potent and stable ACE inhibitor has a competitive inhibitory effect against ACE. Conclusion The present study indicated that the peptides from P. cystidiosus could be

  7. Top-down Targeted Metabolomics Reveals a Sulfur-Containing Metabolite with Inhibitory Activity against Angiotensin-Converting Enzyme in Asparagus officinalis.

    PubMed

    Nakabayashi, Ryo; Yang, Zhigang; Nishizawa, Tomoko; Mori, Tetsuya; Saito, Kazuki

    2015-05-22

    The discovery of bioactive natural compounds containing sulfur, which is crucial for inhibitory activity against angiotensin-converting enzyme (ACE), is a challenging task in metabolomics. Herein, a new S-containing metabolite, asparaptine (1), was discovered in the spears of Asparagus officinalis by targeted metabolomics using mass spectrometry for S-containing metabolites. The contribution ratio (2.2%) to the IC50 value in the crude extract showed that asparaptine (1) is a new ACE inhibitor. PMID:25922884

  8. The pharmacological mechanism of angiotensin-converting enzyme inhibition by green tea, Rooibos and enalaprilat - a study on enzyme kinetics.

    PubMed

    Persson, Ingrid A-L

    2012-04-01

    Green tea (Camellia sinensis L.) and Rooibos (Aspalathus linearis Dahlg.) inhibit angiotensin-converting enzyme (ACE) in vitro and in vivo. The ACE inhibitor enalaprilat has been described previously as a competitive inhibitor and sometimes as a non-competitive inhibitor. The aim of this study was to investigate the pharmacological mechanism of ACE inhibition of green tea and Rooibos by enzyme kinetics, and to compare this with enalaprilat. A Michaelis-Menten kinetics and Lineweaver-Burk graph showed mean values of V(max)  = 3.73 µM and K(m)  = 0.71 µM for green tea, of V(max)  = 6.76 µM and K(m)  = 0.78 µM for Rooibos, of V(max)  = 12.54 µM and K(m)  = 2.77 µM for enalaprilat, and of V(max)  = 51.33 µM and K(m)  = 9.22 µM for the PBS control. Incubating serum with green tea or Rooibos saturated with zinc chloride did not change the inhibitory effect. Enalaprilat preincubated with zinc chloride showed a decrease in the inhibitory effect. In conclusion, green tea, Rooibos and enalaprilat seem to inhibit ACE activity using a mixed inhibitor mechanism. PMID:22095883

  9. Anti-diabetic activity of insulin-degrading enzyme inhibitors mediated by multiple hormones.

    PubMed

    Maianti, Juan Pablo; McFedries, Amanda; Foda, Zachariah H; Kleiner, Ralph E; Du, Xiu Quan; Leissring, Malcolm A; Tang, Wei-Jen; Charron, Maureen J; Seeliger, Markus A; Saghatelian, Alan; Liu, David R

    2014-07-01

    Despite decades of speculation that inhibiting endogenous insulin degradation might treat type-2 diabetes, and the identification of IDE (insulin-degrading enzyme) as a diabetes susceptibility gene, the relationship between the activity of the zinc metalloprotein IDE and glucose homeostasis remains unclear. Although Ide(-/-) mice have elevated insulin levels, they exhibit impaired, rather than improved, glucose tolerance that may arise from compensatory insulin signalling dysfunction. IDE inhibitors that are active in vivo are therefore needed to elucidate IDE's physiological roles and to determine its potential to serve as a target for the treatment of diabetes. Here we report the discovery of a physiologically active IDE inhibitor identified from a DNA-templated macrocycle library. An X-ray structure of the macrocycle bound to IDE reveals that it engages a binding pocket away from the catalytic site, which explains its remarkable selectivity. Treatment of lean and obese mice with this inhibitor shows that IDE regulates the abundance and signalling of glucagon and amylin, in addition to that of insulin. Under physiological conditions that augment insulin and amylin levels, such as oral glucose administration, acute IDE inhibition leads to substantially improved glucose tolerance and slower gastric emptying. These findings demonstrate the feasibility of modulating IDE activity as a new therapeutic strategy to treat type-2 diabetes and expand our understanding of the roles of IDE in glucose and hormone regulation. PMID:24847884

  10. Anti-diabetic activity of insulin-degrading enzyme inhibitors mediated by multiple hormones

    PubMed Central

    Maianti, Juan Pablo; McFedries, Amanda; Foda, Zachariah H.; Kleiner, Ralph E.; Du, Xiu Quan; Leissring, Malcolm A.; Tang, Wei-Jen; Charron, Maureen J.; Seeliger, Markus A.; Saghatelian, Alan; Liu, David R.

    2014-01-01

    Despite decades of speculation that inhibiting endogenous insulin degradation might treat type-2 diabetes1, 2, and the identification of IDE (insulin-degrading enzyme) as a diabetes susceptibility gene3, 4, the relationship between the activity of the zinc metalloprotein IDE and glucose homeostasis remains unclear. Although Ide−/− mice have elevated insulin levels, they exhibit impaired, rather than improved, glucose tolerance that may arise from compensatory insulin signalling dysfunction5, 6. IDE inhibitors that are active in vivo are therefore needed to elucidate IDE’s physiological roles and to determine its potential to serve as a target for the treatment of diabetes. Here we report the discovery of a physiologically active IDE inhibitor identified from a DNA-templated macrocycle library. An X-ray structure of the macrocycle bound to IDE reveals that it engages a binding pocket away from the catalytic site, which explains its remarkable selectivity. Treatment of lean and obese mice with this inhibitor shows that IDE regulates the abundance and signalling of glucagon and amylin, in addition to that of insulin. Under physiological conditions that augment insulin and amylin levels, such as oral glucose administration, acute IDE inhibition leads to substantially improved glucose tolerance and slower gastric emptying. These findings demonstrate the feasibility of modulating IDE activity as a new therapeutic strategy to treat type-2 diabetes and expand our understanding of the roles of IDE in glucose and hormone regulation. PMID:24847884

  11. Yucasin is a potent inhibitor of YUCCA, a key enzyme in auxin biosynthesis.

    PubMed

    Nishimura, Takeshi; Hayashi, Ken-Ichiro; Suzuki, Hiromi; Gyohda, Atsuko; Takaoka, Chihiro; Sakaguchi, Yusuke; Matsumoto, Sachiko; Kasahara, Hiroyuki; Sakai, Tatsuya; Kato, Jun-Ichi; Kamiya, Yuji; Koshiba, Tomokazu

    2014-02-01

    Indole-3-acetic acid (IAA), an auxin plant hormone, is biosynthesized from tryptophan. The indole-3-pyruvic acid (IPyA) pathway, involving the tryptophan aminotransferase TAA1 and YUCCA (YUC) enzymes, was recently found to be a major IAA biosynthetic pathway in Arabidopsis. TAA1 catalyzes the conversion of tryptophan to IPyA, and YUC produces IAA from IPyA. Using a chemical biology approach with maize coleoptiles, we identified 5-(4-chlorophenyl)-4H-1,2,4-triazole-3-thiol (yucasin) as a potent inhibitor of IAA biosynthesis in YUC-expressing coleoptile tips. Enzymatic analysis of recombinant AtYUC1-His suggested that yucasin strongly inhibited YUC1-His activity against the substrate IPyA in a competitive manner. Phenotypic analysis of Arabidopsis YUC1 over-expression lines (35S::YUC1) demonstrated that yucasin acts in IAA biosynthesis catalyzed by YUC. In addition, 35S::YUC1 seedlings showed resistance to yucasin in terms of root growth. A loss-of-function mutant of TAA1, sav3-2, was hypersensitive to yucasin in terms of root growth and hypocotyl elongation of etiolated seedlings. Yucasin combined with the TAA1 inhibitor l-kynurenine acted additively in Arabidopsis seedlings, producing a phenotype similar to yucasin-treated sav3-2 seedlings, indicating the importance of IAA biosynthesis via the IPyA pathway in root growth and leaf vascular development. The present study showed that yucasin is a potent inhibitor of YUC enzymes that offers an effective tool for analyzing the contribution of IAA biosynthesis via the IPyA pathway to plant development and physiological processes. PMID:24299123

  12. Characterization of Cellulase Enzyme Inhibitors Formed During the Chemical Pretreatments of Rice Straw

    NASA Astrophysics Data System (ADS)

    Rajan, Kalavathy

    Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning of lignocellulosic biomass, using chemical, physico-chemical, mechanical and biological pretreatments, is often practiced such that biomass becomes available to downstream processing. Pretreatments, such as dilute acid and hot water, are effective means of biomass conversion. However, despite their processing importance, preconditioning biomass also results in the production of carbohydrate and lignin degradation products that are inhibitory to downstream saccharification enzymes. The saccharification enzyme cocktail is made up of endo-cellulase, exo-cellulase and beta-glucosidase enzymes, whose role is to cleave cellulose polymers into glucose monomers. Specifically, endo-cellulase and exo-cellulase enzymes cleave cellulose chains in the middle and at the end, resulting in cellobiose molecules, which are hydrolyzed into glucose by beta-glucosidase. Unfortunately, degradation compounds generated during pretreatment inhibit the saccharification enzyme cocktail. Various research groups have identified specific classes of inhibitors formed during biomass pretreatment and have studied their inhibitory effect on the saccharification cocktail. These various research groups prepared surrogate solutions in an attempt to

  13. Effect of inhibitors of arachidonic acid metabolism on efflux of intracellular enzymes from skeletal muscle following experimental damage.

    PubMed Central

    Jackson, M J; Wagenmakers, A J; Edwards, R H

    1987-01-01

    The role of arachidonic acid metabolism in the efflux of intracellular enzymes from damaged skeletal muscle has been examined in vitro using inhibitors of cyclo-oxygenase and lipoxygenase enzymes. Damage to skeletal muscle induced by either calcium ionophore A23187 (25 microM) or dinitrophenol (1 mM) caused an increase in the efflux of prostaglandins E2 and F2 alpha together with a large efflux of intracellular creatine kinase. Use of a cyclo-oxygenase inhibitor completely prevented the efflux of prostaglandins, but had no effect on creatine kinase efflux. However, several agents having the ability to inhibit lipoxygenase enzymes dramatically reduced creatine kinase efflux following damage. These data suggest that a product or products of lipoxygenase enzymes may be mediators of the changes in plasma membrane integrity which permit efflux of intracellular enzymes as a consequence of skeletal muscle damage. PMID:3109374

  14. Enzyme-Coupled Nanoparticles-Assisted Laser Desorption Ionization Mass Spectrometry for Searching for Low-Mass Inhibitors of Enzymes in Complex Mixtures

    NASA Astrophysics Data System (ADS)

    Salwiński, Aleksander; Da Silva, David; Delépée, Raphaël; Maunit, Benoît

    2014-04-01

    In this report, enzyme-coupled magnetic nanoparticles (EMPs) were shown to be an effective affinity-based tool for finding specific interactions between enzymatic targets and the low-mass molecules in complex mixtures using classic MALDI-TOF apparatus. EMPs used in this work act as nonorganic matrix enabling ionization of small molecules without any interference in the low-mass range (enzyme-coupled nanoparticles-assisted laser desorption ionization MS, ENALDI MS) and simultaneously carry the superficial specific binding sites to capture inhibitors present in a studied mixture. We evaluated ENALDI approach in two complementary variations: `ion fading' (IF-ENALDI), based on superficial adsorption of inhibitors and `ion hunting' (IH-ENALDI), based on selective pre-concentration of inhibitors. IF-ENALDI was applied for two sets of enzyme-inhibitor pairs: tyrosinase-glabridin and trypsin-leupeptin and for the real plant sample: Sparrmannia discolor leaf and stem methanol extract. The efficacy of IH-ENALDI was shown for the pair of trypsin-leupeptin. Both ENALDI approaches pose an alternative for bioassay-guided fractionation, the common method for finding inhibitors in the complex mixtures.

  15. Exploration of Sitagliptin as a potential inhibitor for the M1 Alanine aminopeptidase enzyme in Plasmodium falciparum using computational docking

    PubMed Central

    Krishnamoorthy, Mohana; Achary, Anant

    2013-01-01

    Plasmodium falciparum has limited capacity for de novo amino acid synthesis and rely on degradation of host hemoglobin to maintain protein metabolism and synthesis of proteins. M1 alanine aminopeptidase enzyme of the parasite involved in the terminal degradation of host hemoglobin was subjected to in silico screening with low molecular weight protease inhibitors. The km (avg) of the enzyme M1 alanine aminopeptidase for the substrate DL – Alanine β Napthylamide Hydrochloride was estimated as 322.05µM. The molecular interactions between the enzyme and the substrate and the mechanism of enzyme action were analyzed which paved way for inhibition strategies. Among all the inhibitors screened, Sitagliptin was found to be most potent inhibitor with ki of 0.152 µM in its best orientation whereas the ki(avg) was 2.0055 µM. The ki of Sitagliptin is lower than the km of M1 alanine aminopeptidase for the substrate DL – Alanine β Napthylamide Hydrochloride (322.05 µM) and Ki of the known inhibitor Bestatin. Therefore Sitagliptin may serve as a potent competitive inhibitor of the enzyme M1 alanine aminopeptidase of Plasmodium falciparum. PMID:23559748

  16. Angiotensin-converting enzyme is a GPI-anchored protein releasing factor crucial for fertilization.

    PubMed

    Kondoh, Gen; Tojo, Hiromasa; Nakatani, Yuka; Komazawa, Nobuyasu; Murata, Chie; Yamagata, Kazuo; Maeda, Yusuke; Kinoshita, Taroh; Okabe, Masaru; Taguchi, Ryo; Takeda, Junji

    2005-02-01

    The angiotensin-converting enzyme (ACE) is a key regulator of blood pressure. It is known to cleave small peptides, such as angiotensin I and bradykinin and changes their biological activities, leading to upregulation of blood pressure. Here we describe a new activity for ACE: a glycosylphosphatidylinositol (GPI)-anchored protein releasing activity (GPIase activity). Unlike its peptidase activity, GPIase activity is weakly inhibited by the tightly binding ACE inhibitor and not inactivated by substitutions of core amino acid residues for the peptidase activity, suggesting that the active site elements for GPIase differ from those for peptidase activity. ACE shed various GPI-anchored proteins from the cell surface, and the process was accelerated by the lipid raft disruptor filipin. The released products carried portions of the GPI anchor, indicating cleavage within the GPI moiety. Further analysis by high-performance liquid chromatography-mass spectrometry predicted the cleavage site at the mannose-mannose linkage. GPI-anchored proteins such as TESP5 and PH-20 were released from the sperm membrane of wild-type mice but not in Ace knockout sperm in vivo. Moreover, peptidase-inactivated E414D mutant ACE and also PI-PLC rescued the egg-binding deficiency of Ace knockout sperms, implying that ACE plays a crucial role in fertilization through this activity. PMID:15665832

  17. Smooth muscle cell conditioned medium elevates angiotensin-converting enzyme of bovine pulmonary artery endothelial cells.

    PubMed

    Yu, F S; Lee, S L; Fanburg, B L

    1989-11-01

    Conditioned medium obtained from bovine pulmonary artery smooth muscle cells (SMC) in culture was found to elevate angiotensin-I-converting enzyme (ACE) of bovine pulmonary artery endothelial cells (EC) by 2- to 3-fold upon incubation for 24 to 48 h. The elevation in ACE was time dependent and inhibited by 10(-6) M cycloheximide, making it likely that the elevation was related to new protein synthesis by EC. Conditioned medium from EC failed to produce the same effect. The stimulatory effect of SMC conditioned medium on EC ACE was uninfluenced by exposures to anoxia as compared with room air, either during conditioning of medium or while assaying the effect of conditioned medium on EC ACE. Inhibitors of prostaglandin metabolism and calcium transport failed to influence the stimulatory effect of SMC conditioned medium on EC ACE. The stimulatory effect on EC ACE by conditioned medium was additive to that produced by Ca2+ ionophore A23187 and 3-isobutyl-1-methylxanthine and, similar to baseline ACE, was inhibited by 3 x 10(-8) M ouabain. Thus, SMC produce a factor that regulates the level of EC ACE. PMID:2484059

  18. Development and Validation of a Clinical Prediction Rule for Angiotensin-converting Enzyme Inhibitor-induced Cough

    PubMed Central

    Morimoto, Takeshi; Gandhi, Tejal K; Fiskio, Julie M; Seger, Andrew C; So, Joseph W; Cook, E Francis; Fukui, Tsuguya; Bates, David W

    2004-01-01

    BACKGROUND Angiotensin-converting enzyme inhibitors are effective for many cardiovascular diseases and are widely prescribed, but cough sometimes necessitates their withdrawal. OBJECTIVE To develop and validate a model that predicts, by using information available at first prescription, whether a patient will develop cough within 6 months. DESIGN Retrospective cohort study with derivation and validation sets. SETTING Outpatient clinics affiliated with an urban tertiary care hospital. PATIENTS Clinical data were collected from electronic charts. The derivation set included 1,125 patients and the validation set included 567 patients. INTERVENTIONS None. MEASUREMENTS Angiotensin-converting enzyme inhibitorinduced cough assessed by predetermined criteria. RESULTS In the total cohort, 12% of patients developed angiotensin-converting enzyme inhibitor-induced cough. Independent multivariate predictors of cough were older age, female gender, non-African American (with East Asian having highest risk), no history of previous angiotensin-converting enzyme inhibitor use, and history of cough due to another angiotensin-converting enzyme inhibitor. Patients with a history of angiotensin-converting enzyme inhibitor-induced cough were 29 times more likely to develop a cough than those without this history. These factors were used to develop a model stratifying patients into 4 risk groups. In the derivation set, low-risk, average-risk, intermediate-risk, and highrisk groups had a 6%, 9%, 22%, and 55% probability of cough, respectively. In the validation set, 4%, 14%, 20%, and 60% of patients in these 4 groups developed cough, respectively. CONCLUSIONS This model may help clinicians predict the likelihood of a particular patient developing cough from an angiotensin-converting enzyme inhibitor at the time of prescribing, and may also assist with subsequent clinical decisions. PMID:15209608

  19. Rapid identification of cholinesterase inhibitors from the seedcases of mangosteen using an enzyme affinity assay.

    PubMed

    Ryu, Hyung Won; Oh, Sei-Ryang; Curtis-Long, Marcus J; Lee, Ji Hye; Song, Hyuk-Hwan; Park, Ki Hun

    2014-02-12

    Enzyme binding affinity has been recently introduced as a selective screening method to identify bioactive substances within complex mixtures. We used an assay which identified small molecule binders of acetylcholinesterase (AChE) using the following series of steps: incubation of enzyme with extract; centrifugation and filtration; identification of small molecule content in the flow through. The crude extract contained 10 peaks in the UPLC chromatogram. However, after incubation the enzyme, six peaks were reduced, indicating these compounds bound AChE. All these isolated compounds (2, 3, and 5-8) significantly inhibited human AChE with IC₅₀s = 5.4-15.0 μM and butyrylcholinsterase (IC₅₀s = 0.7-11.0 μM). All compounds exhibited reversible mixed kinetics. Consistent with the binding screen and fluorescence quenching, γ-mangostin 6 had a much higher affinity for AChE than 9-hydroxycalabaxanthone 9. This validates this screening protocol as a rapid method to identify inhibitors of AChE. PMID:24446804

  20. A biochemical logic gate using an enzyme and its inhibitor. Part II: The logic gate.

    PubMed

    Sivan, Sarit; Tuchman, Samuel; Lotan, Noah

    2003-06-01

    Enzyme-Based Logic Gates (ENLOGs) are key components in bio-molecular systems for information processing. This report and the previous one in this series address the characterization of two bio-molecular switching elements, namely the alpha-chymotrypsin (alphaCT) derivative p-phenylazobenzoyl-alpha-chymotrypsin (PABalphaCT) and its inhibitor (proflavine), as well as their assembly into a logic gate. The experimental output of the proposed system is expressed in terms of enzymic activity and this was translated into logic output (i.e. "1" or "0") relative to a predetermined threshold value. We have found that an univalent link exists between the dominant isomers of PABalphaCT (cis or trans), the dominant form of either acridine (proflavine) or acridan and the logic output of the system. Thus, of all possible combinations, only the trans-PABalphaCT and the acridan lead to an enzymic activity that can be defined as logic output "1". The system operates under the rules of Boolean algebra and performs as an "AND" logic gate. PMID:12753934

  1. Does the addition of losartan improve the beneficial effects of ACE inhibitors in patients with anterior myocardial infarction? A pilot study

    PubMed Central

    Di, P; Bucca, V; Scalzo, S; Cannizzaro, S; Giubilato, A; Paterna, S

    1999-01-01

    (141) pg/ml; AII 12.77 (4.79) v 12.65 (4.71) pg/ml) or 10 days after admission (NA 283 (93) v 277 (98) pg/ml; AII 5.31 (2.25) v 6.09 (3.31) pg/ml). However, patients in group C had higher plasma concentrations of AII (14.79 (5.7) pg/ml on the third day and 7.98 (4.92) pg/ml on the 10th day) than patients in either group A or B (p = 0.006). After 90 days following treatment, group B (captopril plus losartan) patients had a smaller ESV than patients in group A (captopril) and group C (losartan).
CONCLUSION—The data suggest that the combination of captopril plus losartan is feasible in the early treatment of acute myocardial infarction patients, and it appears that this combination has more effect on ESV than captopril alone in the short term.


Keywords: acute myocardial infarction; angiotensin converting enzyme inhibitors; captopril; losartan PMID:10336919

  2. A cautionary tale of structure-guided inhibitor development against an essential enzyme in the aspartate-biosynthetic pathway.

    PubMed

    Pavlovsky, Alexander G; Thangavelu, Bharani; Bhansali, Pravin; Viola, Ronald E

    2014-12-01

    The aspartate pathway is essential for the production of the amino acids required for protein synthesis and of the metabolites needed in bacterial development. This pathway also leads to the production of several classes of quorum-sensing molecules that can trigger virulence in certain microorganisms. The second enzyme in this pathway, aspartate β-semialdehyde dehydrogenase (ASADH), is absolutely required for bacterial survival and has been targeted for the design of selective inhibitors. Fragment-library screening has identified a new set of inhibitors that, while they do not resemble the substrates for this reaction, have been shown to bind at the active site of ASADH. Structure-guided development of these lead compounds has produced moderate inhibitors of the target enzyme, with some selectivity observed between the Gram-negative and Gram-positive orthologs of ASADH. However, many of these inhibitor analogs and derivatives have not yet achieved the expected enhanced affinity. Structural characterization of these enzyme-inhibitor complexes has provided detailed explanations for the barriers that interfere with optimal binding. Despite binding in the same active-site region, significant changes are observed in the orientation of these bound inhibitors that are caused by relatively modest structural alterations. Taken together, these studies present a cautionary tale for issues that can arise in the systematic approach to the modification of lead compounds that are being used to develop potent inhibitors. PMID:25478842

  3. Discriminative Stimulus Properties of the Endocannabinoid Catabolic Enzyme Inhibitor SA-57 in Mice.

    PubMed

    Owens, Robert A; Ignatowska-Jankowska, Bogna; Mustafa, Mohammed; Beardsley, Patrick M; Wiley, Jenny L; Jali, Abdulmajeed; Selley, Dana E; Niphakis, Micah J; Cravatt, Benjamin F; Lichtman, Aron H

    2016-08-01

    Whereas the inhibition of fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), the respective major hydrolytic enzymes of N-arachidonoyl ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), elicits no or partial substitution for Δ(9)-tetrahydrocannabinol (THC) in drug-discrimination procedures, combined inhibition of both enzymes fully substitutes for THC, as well as produces a constellation of cannabimimetic effects. The present study tested whether C57BL/6J mice would learn to discriminate the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) from vehicle in the drug-discrimination paradigm. In initial experiments, 10 mg/kg SA-57 fully substituted for CP55,940 ((-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol), a high-efficacy CB1 receptor agonist in C57BL/6J mice and for AEA in FAAH (-/-) mice. Most (i.e., 23 of 24) subjects achieved criteria for discriminating SA-57 (10 mg/kg) from vehicle within 40 sessions, with full generalization occurring 1 to 2 hours postinjection. CP55,940, the dual FAAH-MAGL inhibitor JZL195 (4-​nitrophenyl 4-​(3-​phenoxybenzyl)piperazine-​1-​carboxylate), and the MAGL inhibitors MJN110 (2,5-dioxopyrrolidin-1-yl 4-(bis(4-chlorophenyl)methyl)piperazine-1-carboxylate) and JZL184 (4-[Bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) fully substituted for SA-57. Although the FAAH inhibitors PF-3845 ((N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) and URB597 (cyclohexylcarbamic acid 3'-(aminocarbonyl)-[1,1'-biphenyl]-3-yl ester) did not substitute for SA-57, PF-3845 produced a 2-fold leftward shift in the MJN110 substitution dose-response curve. In addition, the CB1 receptor antagonist rimonabant blocked the generalization of SA-57, as well as substitution of CP55,940, JZL195, MJN110, and JZL184. These findings

  4. Omapatrilat, an Angiotensin-Converting Enzyme and Neutral Endopeptidase Inhibitor, Attenuates Early Atherosclerosis in Diabetic and in Nondiabetic Low-Density Lipoprotein Receptor–Deficient Mice

    PubMed Central

    Levy, Zohar; Dvir, Ayana; Shaish, Aviv; Trestman, Svetlana; Cohen, Hofit; Levkovietz, Hana; Rhachmani, Rita; Harats, Dror

    2003-01-01

    Omapatrilat inhibits both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). ACE inhibitors have been shown to inhibit atherosclerosis in apoE-deficient mice and in several other animal models but failed in low-density lipoprotein (LDL) receptor– deficient mice despite effective inhibition of the reninangiotensin- aldosterone system. The aim of the present study was to examine the effect of omapatrilat on atherogenesis in diabetic and nondiabetic LDL receptor–deficient mice. LDL receptor–deficient male mice were randomly divided into 4 groups (n = 11 each). Diabetes was induced in 2 groups by low-dose STZ, the other 2 groups served as nondiabetic controls. Omapatrilat (70 mg/kg/day) was administered to one of the diabetic and to one of the nondiabetic groups. The diabetic and the nondiabetic mice were sacrificed after 3 and 5 weeks, respectively. The aortae were examined and the atherosclerotic plaque area was measured. The atherosclerotic plaque area was significantly smaller in the omapatrilat-treated mice, both diabetic and nondiabetic, as compared to nontreated controls. The mean plaque area of omapatrilattreated nondiabetic mice was 9357 ± 7293 μm2, versus 71977 ± 34610 μm2 in the nontreated mice (P = .002). In the diabetic animals, the plaque area was 8887 ± 5386 μm2 and 23220 ± 10400 μm2, respectively for treated and nontreated mice (P = .001). Plasma lipids were increased by omapatrilat: Meanplasma cholesterol in treated mice, diabetic and nondiabetic combined, was 39.31 ± 6.00 mmol/L, versus 33.12 ± 7.64 mmol/L in the nontreated animals (P = .008). The corresponding combined mean values of triglycerides were 4.83 ± 1.93 versus 3.00 ± 1.26 mmol/L (P = .02). Omapatrilat treatment did not affect weight or plasma glucose levels. Treatment with omapatrilat inhibits atherogenesis in diabetic as well as nondiabetic LDL receptor–deficient mice despite an increase in plasma lipids, suggesting a direct effect on the arterial

  5. Flavonoids: true or promiscuous inhibitors of enzyme? The case of deoxyxylulose phosphate reductoisomerase.

    PubMed

    Tritsch, Denis; Zinglé, Catherine; Rohmer, Michel; Grosdemange-Billiard, Catherine

    2015-04-01

    Flavonoids, due to their physical and chemical properties (among them hydrophobicity and metal chelation abilities), are potential inhibitors of the 1-deoxyxylulose 5-phosphate reductoisomerase and most of the tested flavonoids effectively inhibited its activity with encouraging IC50 values in the micromolar range. The addition of 0.01% Triton X100 in the assays led however, to a dramatic decrease of the inhibition revealing that a non-specific inhibition probably takes place. Our study highlights the possibility of erroneous conclusions regarding the inhibition of enzymes by flavonoids that are able to produce aggregates in micromolar range. Therefore, the addition of a detergent in the assays prevents possible false positive hits in high throughput screenings. PMID:25800132

  6. Study on SSAO enzyme activity and anti-inflammatory effect of SSAO inhibitors in animal model of inflammation.

    PubMed

    Tábi, Tamás; Szökő, Eva; Mérey, Anita; Tóth, Veronika; Mátyus, Péter; Gyires, Klára

    2013-06-01

    SSAO/VAP-1 participates in the accumulation of leukocytes at the site of inflammation. A new SSAO inhibitor, SzV-1287 was demonstrated to inhibit both acute and chronic inflammation in rats more effectively than the known enzyme inhibitor, LJP-1207. Surprisingly, the SSAO activity was not increased, but decreased both in acute and chronic inflammation. Though experiments are in progress to clarify these findings, the enzyme might play a role in the very early phase of inflammation and be inactivated during leukocyte extravasation. PMID:23263543

  7. Prophylactic treatment of migraine with angiotensin converting enzyme inhibitor (lisinopril): randomised, placebo controlled, crossover study

    PubMed Central

    Schrader, Harald; Stovner, Lars Jacob; Helde, Grethe; Sand, Trond; Bovim, Gunnar

    2001-01-01

    Objective To determine the efficacy of an angiotensin converting enzyme inhibitor in the prophylaxis of migraine. Design Double blind, placebo controlled, crossover study. Setting Neurological outpatient clinic. Participants Sixty patients aged 19-59 years with migraine with two to six episodes a month. Interventions Treatment period of 12 weeks with one 10 mg lisinopril tablet once daily for one week then two 10 mg lisinopril tablets once daily for 11 weeks, followed by a two week wash out period. Second treatment period of one placebo tablet once daily for one week and then two placebo tablets for 11 weeks. Thirty participants followed this schedule, and 30 received placebo followed by lisinopril. Main outcome measures Primary end points: number of hours with headache, number of days with headache, number of days with migraine. Secondary end points: headache severity index, use of drugs for symptomatic relief, quality of life and number of days taken as sick leave, acceptability of treatment. Results In the 47 participants with complete data, hours with headache, days with headache, days with migraine, and headache severity index were significantly reduced by 20% (95% confidence interval 5% to 36%), 17% (5% to 30%), 21% (9% to 34%), and 20% (3% to 37%), respectively, with lisinopril compared with placebo. Days with migraine were reduced by at least 50% in 14 participants for active treatment versus placebo and 17 patients for active treatment versus run-in period. Days with migraine were fewer by at least 50% in 14 participants for active treatment versus placebo. Intention to treat analysis of data from 55 patients supported the differences in favour of lisinopril for the primary end points. Conclusion The angiotensin converting enzyme inhibitor, lisinopril, has a clinically important prophylactic effect in migraine. PMID:11141144

  8. Curcumin binds in silico to anti-cancer drug target enzyme MMP-3 (human stromelysin-1) with affinity comparable to two known inhibitors of the enzyme

    PubMed Central

    Jerah, Ahmed; Hobani, Yahya; Kumar, B Vinod; Bidwai, Anil

    2015-01-01

    In silico interaction of curcumin with the enzyme MMP-3 (human stromelysin-1) was studied by molecular docking using AutoDock 4.2 as the docking software application. AutoDock 4.2 software serves as a valid and acceptable docking application to study the interactions of small compounds with proteins. Interactions of curcumin with MMP-3 were compared to those of two known inhibitors of the enzyme, PBSA and MPPT. The calculated free energy of binding (ΔG binding) shows that curcumin binds with affinity comparable to or better than the two known inhibitors. Binding interactions of curcumin with active site residues of the enzyme are also predicted. Curcumin appears to bind in an extendended conformation making extensive VDW contacts in the active site of the enzyme. Hydrogen bonding and pi-pi interactions with key active site residues is also observed. Thus, curcumin can be considered as a good lead compound in the development of new inhibitors of MMP-3 which is a potential target of anticancer drugs. The results of these studies can serve as a starting point for further computational and experimental studies. PMID:26420919

  9. Curcumin binds in silico to anti-cancer drug target enzyme MMP-3 (human stromelysin-1) with affinity comparable to two known inhibitors of the enzyme.

    PubMed

    Jerah, Ahmed; Hobani, Yahya; Kumar, B Vinod; Bidwai, Anil

    2015-01-01

    In silico interaction of curcumin with the enzyme MMP-3 (human stromelysin-1) was studied by molecular docking using AutoDock 4.2 as the docking software application. AutoDock 4.2 software serves as a valid and acceptable docking application to study the interactions of small compounds with proteins. Interactions of curcumin with MMP-3 were compared to those of two known inhibitors of the enzyme, PBSA and MPPT. The calculated free energy of binding (ΔG binding) shows that curcumin binds with affinity comparable to or better than the two known inhibitors. Binding interactions of curcumin with active site residues of the enzyme are also predicted. Curcumin appears to bind in an extendended conformation making extensive VDW contacts in the active site of the enzyme. Hydrogen bonding and pi-pi interactions with key active site residues is also observed. Thus, curcumin can be considered as a good lead compound in the development of new inhibitors of MMP-3 which is a potential target of anticancer drugs. The results of these studies can serve as a starting point for further computational and experimental studies. PMID:26420919

  10. The Use of Plasma-Derived Complement C1-Esterase Inhibitor Concentrate (Berinert®) in the Treatment of Angiotensin Converting Enzyme-Inhibitor Related Angioedema

    PubMed Central

    Hermanrud, Thorbjørn; Duus, Nicolaj; Bygum, Anette; Rasmussen, Eva Rye

    2016-01-01

    Angioedema of the upper airways is a severe and potentially life-threatening condition. The incidence has been increasing in the past two decades, primarily due to pharmaceuticals influencing the generation or degradation of the vasoactive molecule bradykinin. Plasma-derived C1-esterase inhibitor concentrate is a well-established treatment option of hereditary and acquired complement C1-esterase inhibitor deficiency, which are also mediated by an increased level of bradykinin resulting in recurrent angioedema. We here present a case of severe angiotensin converting enzyme-inhibitor related angioedema (ACEi-AE) of the hypopharynx that completely resolved rapidly after the infusion of plasma-derived C1-inhibitor concentrate adding to the sparse reports in the existing literature. PMID:27123347

  11. The Use of Plasma-Derived Complement C1-Esterase Inhibitor Concentrate (Berinert®) in the Treatment of Angiotensin Converting Enzyme-Inhibitor Related Angioedema.

    PubMed

    Hermanrud, Thorbjørn; Duus, Nicolaj; Bygum, Anette; Rasmussen, Eva Rye

    2016-01-01

    Angioedema of the upper airways is a severe and potentially life-threatening condition. The incidence has been increasing in the past two decades, primarily due to pharmaceuticals influencing the generation or degradation of the vasoactive molecule bradykinin. Plasma-derived C1-esterase inhibitor concentrate is a well-established treatment option of hereditary and acquired complement C1-esterase inhibitor deficiency, which are also mediated by an increased level of bradykinin resulting in recurrent angioedema. We here present a case of severe angiotensin converting enzyme-inhibitor related angioedema (ACEi-AE) of the hypopharynx that completely resolved rapidly after the infusion of plasma-derived C1-inhibitor concentrate adding to the sparse reports in the existing literature. PMID:27123347

  12. From gene to protein—experimental and clinical studies of ACE2 in blood pressure control and arterial hypertension

    PubMed Central

    Patel, Sheila K.; Velkoska, Elena; Freeman, Melanie; Wai, Bryan; Lancefield, Terase F.; Burrell, Louise M.

    2014-01-01

    Hypertension is a major risk factor for stroke, coronary events, heart and renal failure, and the renin-angiotensin system (RAS) plays a major role in its pathogenesis. Within the RAS, angiotensin converting enzyme (ACE) converts angiotensin (Ang) I into the vasoconstrictor Ang II. An “alternate” arm of the RAS now exists in which ACE2 counterbalances the effects of the classic RAS through degradation of Ang II, and generation of the vasodilator Ang 1-7. ACE2 is highly expressed in the heart, blood vessels, and kidney. The catalytically active ectodomain of ACE2 undergoes shedding, resulting in ACE2 in the circulation. The ACE2 gene maps to a quantitative trait locus on the X chromosome in three strains of genetically hypertensive rats, suggesting that ACE2 may be a candidate gene for hypertension. It is hypothesized that disruption of tissue ACE/ACE2 balance results in changes in blood pressure, with increased ACE2 expression protecting against increased blood pressure, and ACE2 deficiency contributing to hypertension. Experimental hypertension studies have measured ACE2 in either the heart or kidney and/or plasma, and have reported that deletion or inhibition of ACE2 leads to hypertension, whilst enhancing ACE2 protects against the development of hypertension, hence increasing ACE2 may be a therapeutic option for the management of high blood pressure in man. There have been relatively few studies of ACE2, either at the gene or the circulating level in patients with hypertension. Plasma ACE2 activity is low in healthy subjects, but elevated in patients with cardiovascular risk factors or cardiovascular disease. Genetic studies have investigated ACE2 gene polymorphisms with either hypertension or blood pressure, and have produced largely inconsistent findings. This review discusses the evidence regarding ACE2 in experimental hypertension models and the association between circulating ACE2 activity and ACE2 polymorphisms with blood pressure and arterial

  13. Enzyme

    MedlinePlus

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  14. Broad 4-hydroxyphenylpyruvate dioxygenase inhibitor herbicide tolerance in soybean with an optimized enzyme and expression cassette.

    PubMed

    Siehl, Daniel L; Tao, Yumin; Albert, Henrik; Dong, Yuxia; Heckert, Matthew; Madrigal, Alfredo; Lincoln-Cabatu, Brishette; Lu, Jian; Fenwick, Tamara; Bermudez, Ericka; Sandoval, Marian; Horn, Caroline; Green, Jerry M; Hale, Theresa; Pagano, Peggy; Clark, Jenna; Udranszky, Ingrid A; Rizzo, Nancy; Bourett, Timothy; Howard, Richard J; Johnson, David H; Vogt, Mark; Akinsola, Goke; Castle, Linda A

    2014-11-01

    With an optimized expression cassette consisting of the soybean (Glycine max) native promoter modified for enhanced expression driving a chimeric gene coding for the soybean native amino-terminal 86 amino acids fused to an insensitive shuffled variant of maize (Zea mays) 4-hydroxyphenylpyruvate dioxygenase (HPPD), we achieved field tolerance in transgenic soybean plants to the HPPD-inhibiting herbicides mesotrione, isoxaflutole, and tembotrione. Directed evolution of maize HPPD was accomplished by progressively incorporating amino acids from naturally occurring diversity and novel substitutions identified by saturation mutagenesis, combined at random through shuffling. Localization of heterologously expressed HPPD mimicked that of the native enzyme, which was shown to be dually targeted to chloroplasts and the cytosol. Analysis of the native soybean HPPD gene revealed two transcription start sites, leading to transcripts encoding two HPPD polypeptides. The N-terminal region of the longer encoded peptide directs proteins to the chloroplast, while the short form remains in the cytosol. In contrast, maize HPPD was found almost exclusively in chloroplasts. Evolved HPPD enzymes showed insensitivity to five inhibitor herbicides. In 2013 field trials, transgenic soybean events made with optimized promoter and HPPD variant expression cassettes were tested with three herbicides and showed tolerance to four times the labeled rates of mesotrione and isoxaflutole and two times the labeled rates of tembotrione. PMID:25192697

  15. Extracts, anthocyanins and procyanidins from Aronia melanocarpa as radical scavengers and enzyme inhibitors.

    PubMed

    Bräunlich, Marie; Slimestad, Rune; Wangensteen, Helle; Brede, Cato; Malterud, Karl E; Barsett, Hilde

    2013-03-01

    Extracts, subfractions, isolated anthocyanins and isolated procyanidins B2, B5 and C1 from the berries and bark of Aronia melanocarpa were investigated for their antioxidant and enzyme inhibitory activities. Four different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH) radical, inhibition of 15-lipoxygenase (15-LO), inhibition of xanthine oxidase (XO) and inhibition of α-glucosidase. Among the anthocyanins, cyanidin 3-arabinoside possessed the strongest and cyanidin 3-xyloside the weakest radical scavenging and enzyme inhibitory activity. These effects seem to be influenced by the sugar units linked to the anthocyanidin. Subfractions enriched in procyanidins were found to be potent α-glucosidase inhibitors; they possessed high radical scavenging properties, strong inhibitory activity towards 15-LO and moderate inhibitory activity towards XO. Trimeric procyanidin C1 showed higher activity in the biological assays compared to the dimeric procyanidins B2 and B5. This study suggests that different polyphenolic compounds of A. melanocarpa can have beneficial effects in reducing blood glucose levels due to inhibition of α-glucosidase and may have a potential to alleviate oxidative stress. PMID:23459328

  16. Development of inhibitor-directed enzyme prodrug therapy (IDEPT) for prostate cancer.

    PubMed

    Martin, Stacy E; Ganguly, Tanushree; Munske, Gerhard R; Fulton, Melody D; Hopkins, Mark R; Berkman, Clifford E; Black, Margaret E

    2014-10-15

    Prostate cancer (PCa) is the second most common cause of cancer death among American men after lung cancer. Unfortunately, current therapies do not provide effective treatments for patients with advanced, metastatic, or hormone refractory disease. Therefore, we seek to generate therapeutic agents for a novel PCa treatment strategy by delivering a suicide enzyme (yCDtriple) to a cell membrane bound biomarker found on PCa cells (prostate-specific membrane antigen (PSMA)). This approach has resulted in a new PCa treatment strategy reported here as inhibitor-directed enzyme prodrug therapy (IDEPT). The therapeutic agents described were generated using a click chemistry reaction between the unnatural amino acid (p-azidophenylalanine (pAzF)) incorporated into yCDtriple and the dibenzylcyclooctyne moiety of our PSMA targeting agent (DBCO-PEG4-AH2-TG97). After characterization of the therapeutic agents, we demonstrate significant PCa cell killing of PSMA-positive cells. Importantly, we demonstrate that this click chemistry approach can be used to efficiently couple a therapeutic protein to a targeting agent and may be applicable to the ablation of other types of cancers and/or malignancies. PMID:25157916

  17. Extracts, Anthocyanins and Procyanidins from Aronia melanocarpa as Radical Scavengers and Enzyme Inhibitors

    PubMed Central

    Bräunlich, Marie; Slimestad, Rune; Wangensteen, Helle; Brede, Cato; Malterud, Karl E.; Barsett, Hilde

    2013-01-01

    Extracts, subfractions, isolated anthocyanins and isolated procyanidins B2, B5 and C1 from the berries and bark of Aronia melanocarpa were investigated for their antioxidant and enzyme inhibitory activities. Four different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH) radical, inhibition of 15-lipoxygenase (15-LO), inhibition of xanthine oxidase (XO) and inhibition of α-glucosidase. Among the anthocyanins, cyanidin 3-arabinoside possessed the strongest and cyanidin 3-xyloside the weakest radical scavenging and enzyme inhibitory activity. These effects seem to be influenced by the sugar units linked to the anthocyanidin. Subfractions enriched in procyanidins were found to be potent α-glucosidase inhibitors; they possessed high radical scavenging properties, strong inhibitory activity towards 15-LO and moderate inhibitory activity towards XO. Trimeric procyanidin C1 showed higher activity in the biological assays compared to the dimeric procyanidins B2 and B5. This study suggests that different polyphenolic compounds of A. melanocarpa can have beneficial effects in reducing blood glucose levels due to inhibition of α-glucosidase and may have a potential to alleviate oxidative stress. PMID:23459328

  18. Chemoenzymatic syntheses of linear and branched hemithiomaltodextrins as potential inhibitors for starch-debranching enzymes.

    PubMed

    Greffe, Lionel; Jensen, Morten T; Chang-Pi-Hin, Florent; Fruchard, Sandra; O'Donohue, Michael J; Svensson, Birte; Driguez, Hugues

    2002-12-01

    Oligosaccharides embodying the S-maltosyl-6-thiomaltosyl structure have been readily synthesised by using convergent chemoenzymatic approaches. The key steps for the preparation of these molecules involved: 1) transglycosylation reactions of maltosyl fluorides onto suitable acceptors catalysed by the bacterial transglycosylase, cyclodextrin glycosyltransferase (CGTase), and 2) the SN2-type displacement of a 6-halide from acetylated acceptors by activated 1-thioglycoses. The target molecules, which were obtained in good overall yields, proved to be useful for investigating substrate binding in the active sites of several enzymes that act upon the alpha-1,6-linkage of pullulan and/or amylopectin. The compounds exhibit Ki values in the 2.5-1350 microM range with the different enzymes, and the highest affinity found by using these molecules was seen for the pullulanase from Bacillus acidopullulyticus. Both barley-malt limit dextrinase and pullulanase type II from Thermococcus hydrothermalis only recognised the longest linear thiooligosaccharide, while a branched heptasaccharide was the strongest inhibitor of pullulanase from Klebsiella planticola. PMID:12561317

  19. Three-dimensional Structure of a Kunitz-type Inhibitor in Complex with an Elastase-like Enzyme.

    PubMed

    García-Fernández, Rossana; Perbandt, Markus; Rehders, Dirk; Ziegelmüller, Patrick; Piganeau, Nicolas; Hahn, Ulrich; Betzel, Christian; Chávez, María de Los Ángeles; Redecke, Lars

    2015-05-29

    Elastase-like enzymes are involved in important diseases such as acute pancreatitis, chronic inflammatory lung diseases, and cancer. Structural insights into their interaction with specific inhibitors will contribute to the development of novel anti-elastase compounds that resist rapid oxidation and proteolysis. Proteinaceous Kunitz-type inhibitors homologous to the bovine pancreatic trypsin inhibitor (BPTI) provide a suitable scaffold, but the structural aspects of their interaction with elastase-like enzymes have not been elucidated. Here, we increased the selectivity of ShPI-1, a versatile serine protease inhibitor from the sea anemone Stichodactyla helianthus with high biomedical and biotechnological potential, toward elastase-like enzymes by substitution of the P1 residue (Lys(13)) with leucine. The variant (rShPI-1/K13L) exhibits a novel anti-porcine pancreatic elastase (PPE) activity together with a significantly improved inhibition of human neuthrophil elastase and chymotrypsin. The crystal structure of the PPE·rShPI-1/K13L complex determined at 2.0 Å resolution provided the first details of the canonical interaction between a BPTI-Kunitz-type domain and elastase-like enzymes. In addition to the essential impact of the variant P1 residue for complex stability, the interface is improved by increased contributions of the primary and secondary binding loop as compared with similar trypsin and chymotrypsin complexes. A comparison of the interaction network with elastase complexes of canonical inhibitors from the chelonian in family supports a key role of the P3 site in ShPI-1 in directing its selectivity against pancreatic and neutrophil elastases. Our results provide the structural basis for site-specific mutagenesis to further improve the binding affinity and/or direct the selectivity of BPTI-Kunitz-type inhibitors toward elastase-like enzymes. PMID:25878249

  20. Three-dimensional Structure of a Kunitz-type Inhibitor in Complex with an Elastase-like Enzyme*

    PubMed Central

    García-Fernández, Rossana; Perbandt, Markus; Rehders, Dirk; Ziegelmüller, Patrick; Piganeau, Nicolas; Hahn, Ulrich; Betzel, Christian; Chávez, María de los Ángeles; Redecke, Lars

    2015-01-01

    Elastase-like enzymes are involved in important diseases such as acute pancreatitis, chronic inflammatory lung diseases, and cancer. Structural insights into their interaction with specific inhibitors will contribute to the development of novel anti-elastase compounds that resist rapid oxidation and proteolysis. Proteinaceous Kunitz-type inhibitors homologous to the bovine pancreatic trypsin inhibitor (BPTI) provide a suitable scaffold, but the structural aspects of their interaction with elastase-like enzymes have not been elucidated. Here, we increased the selectivity of ShPI-1, a versatile serine protease inhibitor from the sea anemone Stichodactyla helianthus with high biomedical and biotechnological potential, toward elastase-like enzymes by substitution of the P1 residue (Lys13) with leucine. The variant (rShPI-1/K13L) exhibits a novel anti-porcine pancreatic elastase (PPE) activity together with a significantly improved inhibition of human neuthrophil elastase and chymotrypsin. The crystal structure of the PPE·rShPI-1/K13L complex determined at 2.0 Å resolution provided the first details of the canonical interaction between a BPTI-Kunitz-type domain and elastase-like enzymes. In addition to the essential impact of the variant P1 residue for complex stability, the interface is improved by increased contributions of the primary and secondary binding loop as compared with similar trypsin and chymotrypsin complexes. A comparison of the interaction network with elastase complexes of canonical inhibitors from the chelonian in family supports a key role of the P3 site in ShPI-1 in directing its selectivity against pancreatic and neutrophil elastases. Our results provide the structural basis for site-specific mutagenesis to further improve the binding affinity and/or direct the selectivity of BPTI-Kunitz-type inhibitors toward elastase-like enzymes. PMID:25878249

  1. Regulation of alveolar epithelial cell survival by the ACE-2/angiotensin 1-7/Mas axis.

    PubMed

    Uhal, Bruce D; Li, Xiaopeng; Xue, Anita; Gao, Xu; Abdul-Hafez, Amal

    2011-09-01

    Earlier work from this laboratory demonstrated that apoptosis of alveolar epithelial cells (AECs) requires autocrine generation of angiotensin (ANG) II. More recent studies showed that angiotensin converting enzyme-2 (ACE-2), which degrades ANGII to form ANG1-7, is protective but severely downregulated in human and experimental lung fibrosis. Here it was theorized that ACE-2 and its product ANG1-7 might therefore regulate AEC apoptosis. To evaluate this hypothesis, the AEC cell line MLE-12 and primary cultures of rat AECs were exposed to the profibrotic apoptosis inducers ANGII or bleomycin (Bleo). Markers of apoptosis (caspase-9 or -3 activation and nuclear fragmentation), steady-state ANGII and ANG1-7, and JNK phosphorylation were measured thereafter. In the absence of Bleo, inhibition of ACE-2 by small interfering RNA or by a competitive inhibitor (DX600 peptide) caused a reciprocal increase in autocrine ANGII and corresponding decrease in ANG1-7 in cell culture media (both P < 0.05) and, moreover, induced AEC apoptosis. At baseline (without inhibitor), ANG1-7 in culture media was 10-fold higher than ANGII (P < 0.01). Addition of purified ANGII or bleomycin-induced caspase activation, nuclear fragmentation, and JNK phosphorylation in cultured AECs. However, preincubation with ANG1-7 (0.1 μM) prevented JNK phosphorylation and apoptosis. Moreover, pretreatment with A779, a specific blocker of the ANG1-7 receptor mas, prevented ANG1-7 blockade of JNK phosphorylation, caspase activation, and nuclear fragmentation. These data demonstrate that ACE-2 regulates AEC survival by balancing the proapoptotic ANGII and its antiapoptotic degradation product ANG1-7. They also suggest that ANG1-7 inhibits AEC apoptosis through the ANG1-7 receptor mas. PMID:21665960

  2. Structure-Based Design of Inhibitors of the Crucial Cysteine Biosynthetic Pathway Enzyme O-Acetyl Serine Sulfhydrylase.

    PubMed

    Mazumder, Mohit; Gourinath, Samudrala

    2016-01-01

    The cysteine biosynthetic pathway is of fundamental importance for the growth, survival, and pathogenicity of the many pathogens. This pathway is present in many species but is absent in mammals. The ability of pathogens to counteract the oxidative defences of a host is critical for the survival of these pathogens during their long latent phases, especially in anaerobic pathogens such as Entamoeba histolytica, Leishmania donovani, Trichomonas vaginalis, and Salmonella typhimurium. All of these organisms rely on the de novo cysteine biosynthetic pathway to assimilate sulphur and maintain a ready supply of cysteine. The de novo cysteine biosynthetic pathway, on account of its being important for the survival of pathogens and at the same time being absent in mammals, is an important drug target for diseases such as amoebiasis, trichomoniasis & tuberculosis. Cysteine biosynthesis is catalysed by two enzymes: serine acetyl transferase (SAT) followed by O-acetylserine sulfhydrylase (OASS). OASS is well studied, and with the availability of crystal structures of this enzyme in different conformations, it is a suitable template for structure-based inhibitor development. Moreover, OASS is highly conserved, both structurally and sequence-wise, among the above-mentioned organisms. There have been several reports of inhibitor screening and development against this enzyme from different organisms such as Salmonella typhimurium, Mycobacterium tuberculosis and Entamoeba histolytica. All of these inhibitors have been reported to display micromolar to nanomolar binding affinities for the open conformation of the enzyme. In this review, we highlight the structural similarities of this enzyme in different organisms and the attempts for inhibitor development so far. We also propose that the intermediate state of the enzyme may be the ideal target for the design of effective highaffinity inhibitors. PMID:26303427

  3. Determination of angiotensin I-converting enzyme activity in cell culture using fluorescence resonance energy transfer peptides.

    PubMed

    Sabatini, R A; Bersanetti, P A; Farias, S L; Juliano, L; Juliano, M A; Casarini, D E; Carmona, A K; Paiva, A C M; Pesquero, J B

    2007-04-15

    An assay using fluorescence resonance energy transfer peptides was developed to assess angiotensin I-converting enzyme (ACE) activity directly on the membrane of transfected Chinese hamster ovary cells (CHO) stably expressing the full-length somatic form of the enzyme. The advantage of the new method is the possibility of using selective substrates for the two active sites of the enzyme, namely Abz-FRK(Dnp)P-OH for somatic ACE, Abz-SDK(Dnp)P-OH for the N domain, and Abz-LFK(Dnp)-OH for the C domain. Hydrolysis of a peptide bond between the donor/acceptor pair (Abz/Dnp) generates detectable fluorescence, allowing quantitative measurement of the enzymatic activity. The kinetic parameter K(m) for the hydrolysis of the three substrates by ACE in this system was also determined and the values are comparable to those obtained using the purified enzyme in solution. The specificity of the activity was demonstrated by the complete inhibition of the hydrolysis by the ACE inhibitor lisinopril. Therefore, the results presented in this work show for the first time that determination of ACE activity directly on the surface of intact CHO cells is feasible and that the method is reliable and sensitive. In conclusion, we describe a methodology that may represent a new tool for the assessment of ACE activity which will open the possibility to study protein interactions in cells in culture. PMID:17320031

  4. ACE and AGTR1 polymorphisms in elite rhythmic gymnastics.

    PubMed

    Di Cagno, Alessandra; Sapere, Nadia; Piazza, Marina; Aquino, Giovanna; Iuliano, Enzo; Intrieri, Mariano; Calcagno, Giuseppe

    2013-02-01

    In the angiotensin-converting enzyme (ACE) gene, Alu deletion, in intron 16, is associated with higher concentrations of ACE serum activity and this may be associated with elite sprint and power performance. The Alu insertion is associated with lower ACE levels and this could lead to endurance performance. Moreover, recent studies have identified a single-nucleotide polymorphism of the angiotensin type 1 receptor gene AGTR1, which seems to be related to ACE activity. The aim of this study was to examine the involvement of the ACE and the AGTR1 gene polymorphisms in 28 Italian elite rhythmic gymnasts (age range 21 ± 7.6 years), and compare them to 23 middle level rhythmic gymnasts (age range 17 ± 10.9 years). The ACE D allele was significantly more frequent in elite athletes than in the control population (χ(2)=4.07, p=0.04). Comparisons between the middle level and elite athletes revealed significant differences (p<0.0001) for the ACE DD genotype (OR=6.48, 95% confidence interval=1.48-28.34), which was more frequent in elite athletes. There were no significant differences in the AGTR1 A/C genotype or allele distributions between the middle level and elite athletes. In conclusion, the ACE D allele genotype could be a contributing factor to high-performance rhythmic gymnastics that should be considered in athlete development and could help to identify which skills should be trained for talent promotion. PMID:23145508

  5. Interactions between carnosine and captopril on free radical scavenging activity and angiotensin-converting enzyme activity in vitro.

    PubMed

    Nakagawa, Kazuo; Ueno, Akemi; Nishikawa, Yukari

    2006-01-01

    Interactions between carnosine (beta-alanyl-L-histidine), being plentiful in skeletal muscles and neuronal tissues, and captopril, a widely used angiotensin-converting enzyme (ACE) inhibitor, were examined concerning free radical scavenging activity and ACE activity in vitro. Not only captopril, but also carnosine, at concentrations less than those ordinarily found in muscles and neuronal tissues, significantly scavenged 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonate) (ABTS) radical cations, and inhibited ACE activity. Cupric ions reversed the ABTS scavenging activity of carnosine and captopril, whereas cupric ions strengthened the inhibitory action of carnosine on ACE activity. In contrast, cupric ions antagonized the inhibition of ACE activity induced by ethylenediaminetetraacetic acid, indicating that the inhibitory effect of carnosine on ACE activity is not related to the chelating action of carnosine. On the other hand, carnosine and captopril synergistically enhanced the free radical scavenging activity, but not the inhibitory effect on the ACE activity. These data suggest that carnosine in its concurrent use with captopril could act as a beneficial free radical scavenger, with less danger of overdose, in the inhibition of ACE activity. PMID:16394648

  6. 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

  7. Identification of prolyl carboxypeptidase as an alternative enzyme for processing of renal angiotensin II using mass spectrometry

    PubMed Central

    Grobe, Nadja; Weir, Nathan M.; Leiva, Orly; Ong, Frank S.; Bernstein, Kenneth E.; Schmaier, Alvin H.; Morris, Mariana

    2013-01-01

    Angiotensin-converting enzyme 2 (ACE2) catalyzes conversion of ANG II to ANG-(1–7). The present study uses newly established proteomic approaches and genetic mouse models to examine the contribution of alternative renal peptidases to ACE2-independent formation of ANG-(1–7). In situ and in vitro mass spectrometric characterization showed that substrate concentration and pH control renal ANG II processing. At pH ≥6, ANG-(1–7) formation was significantly reduced in ACE2 knockout (KO) mice. However, at pH <6, formation of ANG-(1–7) in ACE2 KO mice was similar to that in wild-type (WT) mice, suggesting alternative peptidases for renal ANG II processing. Furthermore, the dual prolyl carboxypeptidase (PCP)-prolyl endopeptidase (PEP) inhibitor Z-prolyl-prolinal reduced ANG-(1–7) formation in ACE2 KO mice, while the ACE2 inhibitor MLN-4760 had no effect. Unlike the ACE2 KO mice, ANG-(1–7) formation from ANG II in PEP KO mice was not different from that in WT mice at any tested pH. However, at pH 5, this reaction was significantly reduced in kidneys and urine of PCP-depleted mice. In conclusion, results suggest that ACE2 metabolizes ANG II in the kidney at neutral and basic pH, while PCP catalyzes the same reaction at acidic pH. This is the first report demonstrating that renal ANG-(1–7) formation from ANG II is independent of ACE2. Elucidation of ACE2-independent ANG-(1–7) production pathways may have clinically important implications in patients with metabolic and renal disease. PMID:23392115

  8. A focused parameter update: hereditary angioedema, acquired C1 inhibitor deficiency, and angiotensin-converting enzyme inhibitor-associated angioedema.

    PubMed

    Zuraw, Bruce L; Bernstein, Jonathan A; Lang, David M; Craig, Timothy; Dreyfus, David; Hsieh, Fred; Khan, David; Sheikh, Javed; Weldon, David; Bernstein, David I; Blessing-Moore, Joann; Cox, Linda; Nicklas, Richard A; Oppenheimer, John; Portnoy, Jay M; Randolph, Christopher R; Schuller, Diane E; Spector, Sheldon L; Tilles, Stephen A; Wallace, Dana

    2013-06-01

    These parameters were developed by the Joint Task Force on Practice Parameters (JTFPP), representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "A focused parameter update: Hereditary angioedema, acquired C1 inhibitor deficiency, and angiotensin-converting enzyme inhibitor-associated angioedema." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the JTFPP, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma and Immunology. The Joint Task Force on Practice Parameters understands that the cost of diagnostic tests and therapeutic agents is an important concern that might appropriately influence the work-up and treatment chosen for a given patient. The JTFPP recognizes that the emphasis of our primary recommendations regarding a medication might vary, for example, depending on third-party payer issues and product patent expiration dates. However, because the cost of a given test or agent is so widely variable and there is a paucity of pharmacoeconomic data, the JTFPP generally does not consider cost when formulating practice parameter recommendations. In some instances the cost benefit of an intervention is considered relevant, and commentary might be provided. These parameters are not designed for use by pharmaceutical companies in drug promotion

  9. Mushroom tyrosinase: A model system to combine experimental investigation of enzyme-catalyzed reactions, data handling using R, and enzyme-inhibitor structural studies.

    PubMed

    Nairn, Robert; Cresswell, Will; Nairn, Jacqueline

    2015-01-01

    The activity of mushroom tyrosinase can be measured by monitoring the conversion of phenolic compounds into quinone derivatives using spectrophotometry. This article describes a series of experiments which characterize the functional properties of tyrosinase, the analysis of the resulting data using R to determine the kinetic parameters, and the exploration of the structural properties of tyrosinase-inhibitor complexes. Tyrosinase assay development and subsequent activity measurements, in the presence of varying pH, substrate concentration and inhibitors, offers the opportunity to learn the enzyme characterization skills relevant to a research laboratory setting. Combining the activity studies with an exploration of the nature of the tyrosinase-inhibitor interactions enables a structural understanding of the experimental observations. PMID:26331629

  10. Identification of selective inhibitors of uncharacterized enzymes by high-throughput screening with fluorescent activity-based probes.

    PubMed

    Bachovchin, Daniel A; Brown, Steven J; Rosen, Hugh; Cravatt, Benjamin F

    2009-04-01

    High-throughput screening to discover small-molecule modulators of enzymes typically relies on highly tailored substrate assays, which are not available for poorly characterized enzymes. Here we report a general, substrate-free method for identifying inhibitors of uncharacterized enzymes. The assay measures changes in the kinetics of covalent active-site labeling with broad-spectrum, fluorescent probes in the presence of inhibitors by monitoring the fluorescence polarization signal. We show that this technology is applicable to enzymes from at least two mechanistic classes, regardless of their degree of functional annotation, and can be coupled with secondary proteomic assays that use competitive activity-based profiling to rapidly determine the specificity of screening hits. Using this method, we identify the bioactive alkaloid emetine as a selective inhibitor of the uncharacterized cancer-associated hydrolase RBBP9. Furthermore, we show that the detoxification enzyme GSTO1, also implicated in cancer, is inhibited by several electrophilic compounds found in public libraries, some of which display high selectivity for this protein. PMID:19329999

  11. ACES--Today and Tomorrow.

    ERIC Educational Resources Information Center

    Hackney, Harold

    1991-01-01

    Presents text of Presidential Address delivered March 24, 1991, at the Association for Counselor Education and Supervision (ACES) luncheon, part of the American Association for Counseling and Development Convention held in Reno, Nevada. Comments on past, present, and future of ACES, particularly on future challenges and role of ACES. (ABL)

  12. Versatile O-GlcNAc transferase assay for high-throughput identification of enzyme variants, substrates, and inhibitors.

    PubMed

    Kim, Eun J; Abramowitz, Lara K; Bond, Michelle R; Love, Dona C; Kang, Dong W; Leucke, Hans F; Kang, Dae W; Ahn, Jong-Seog; Hanover, John A

    2014-06-18

    The dynamic glycosylation of serine/threonine residues on nucleocytoplasmic proteins with a single N-acetylglucosamine (O-GlcNAcylation) is critical for many important cellular processes. Cellular O-GlcNAc levels are highly regulated by two enzymes: O-GlcNAc transferase (OGT) is responsible for GlcNAc addition and O-GlcNAcase (OGA) is responsible for removal of the sugar. The lack of a rapid and simple method for monitoring OGT activity has impeded the efficient discovery of potent OGT inhibitors. In this study we describe a novel, single-well OGT enzyme assay that utilizes 6 × His-tagged substrates, a chemoselective chemical reaction, and unpurified OGT. The high-throughput Ni-NTA Plate OGT Assay will facilitate discovery of potent OGT-specific inhibitors on versatile substrates and the characterization of new enzyme variants. PMID:24866374

  13. Chalcone-based small-molecule inhibitors attenuate malignant phenotype via targeting deubiquitinating enzymes.

    PubMed

    Issaenko, Olga A; Amerik, Alexander Yu

    2012-05-01

    The ubiquitin-proteasome system (UPS) is usurped by many if not all cancers to regulate their survival, proliferation, invasion, angiogenesis and metastasis. Bioflavonoids curcumin and chalcones exhibit anti-neoplastic selectivity through inhibition of the 26S proteasome-activity within the UPS. Here, we provide evidence for a novel mechanism of action of chalcone-based derivatives AM146, RA-9 and RA-14, which exert anticancer activity by targeting deubiquitinating enzymes (DUB) without affecting 20S proteasome catalytic-core activity. The presence of the α,β-unsaturated carbonyl group susceptible to nucleophilic attack from the sulfhydryl of cysteines in the active sites of DUB determines the capacity of novel small-molecules to act as cell-permeable, partly selective DUB inhibitors and induce rapid accumulation of polyubiquitinated proteins and deplete the pool of free ubiquitin. These chalcone-derivatives directly suppress activity of DUB UCH-L1, UCH-L3, USP2, USP5 and USP8, which are known to regulate the turnover and stability of key regulators of cell survival and proliferation. Inhibition of DUB-activity mediated by these compounds downregulates cell-cycle promoters, e.g., cyclin D1 and upregulates tumor suppressors p53, p27(Kip1) and p16(Ink4A). These changes are associated with arrest in S-G 2/M, abrogated anchorage-dependent growth and onset of apoptosis in breast, ovarian and cervical cancer cells without noticeable alterations in primary human cells. Altogether, this work provides evidence of antitumor activity of novel chalcone-based derivatives mediated by their DUB-targeting capacity; supports the development of pharmaceuticals to directly target DUB as a most efficient strategy compared with proteasome inhibition and also provides a clear rationale for the clinical evaluation of these novel small-molecule DUB inhibitors. PMID:22510564

  14. Highly sensitive and selective fluorescence assays for rapid screening of endothelin-converting enzyme inhibitors.

    PubMed Central

    Luciani, N; de Rocquigny, H; Turcaud, S; Romieu, A; Roques, B P

    2001-01-01

    The highly potent vasoconstrictor peptide endothelin (ET) is generated from an inactive precursor, big endothelin (bET), by endothelin-converting enzyme (ECE). ECE is a phosphoramidon-sensitive zinc metallopeptidase, which is closely related to neprilysin (neutral endopeptidase). It is possible that compounds which inhibit the formation of ET may be used as new drugs for the treatment of cardiovascular diseases. Such an approach requires a fast, simple and selective assay to measure ECE activity, allowing rapid screening of inhibitors. We describe here two new ECE substrates based on the concept of 'intramolecularly quenched fluorescence' which may fulfill this aim. One, S(1) [Pya(21)-Nop(22)-bET-1(19--35)], is the (19--35) fragment of the natural peptide big-ET-1(1--38), which is modified by introducing the fluorescent amino acid, pyrenylalanine (Pya), in position 21 and a quencher, p-nitrophenylalanine (Nop), in position 22. The second substrate (S(2)) is a small peptide, Ac-Ser-Gly-Pya-Lys-Ala-Phe-Ala-Nop-Gly-Lys-NH(2), from a biased substrate peptide library. The recombinant, hECE-1c, cleaved both Pya(21)-Nop(22)-bET-1(19--35) and the natural substrate selectively between residues 21 and 22, whereas cleavage occurred between alanine and phenylalanine in the small peptide. In both cases, this generated intense fluorescence emission. The synthesis and kinetic parameters of these substrates are described. These assays, which can be used directly on tissue homogenates, are the most sensitive and selective described to date for ECE, and are easily automated for a high-throughput screening of inhibitors. PMID:11389689

  15. NGS Transcriptomes and Enzyme Inhibitors Unravel Complexity of Picrosides Biosynthesis in Picrorhiza kurroa Royle ex. Benth

    PubMed Central

    Shitiz, Kirti; Sharma, Neha; Pal, Tarun; Sood, Hemant; Chauhan, Rajinder S.

    2015-01-01

    Picrorhiza kurroa is an important medicinal herb valued for iridoid glycosides, Picroside-I (P-I) and Picroside-II (P-II), which have several pharmacological activities. Genetic interventions for developing a picroside production platform would require knowledge on biosynthetic pathway and key control points, which does not exist as of today. The current study reports that geranyl pyrophosphate (GPP) moiety is mainly contributed by the non-mevalonate (MEP) route, which is further modified to P-I and P-II through phenylpropanoid and iridoid pathways, in total consisting of 41 and 35 enzymatic steps, respectively. The role of the MEP pathway was ascertained through enzyme inhibitors fosmidomycin and mevinolin along with importance of other integrating pathways using glyphosate, aminooxy acetic acid (AOA) and actinomycin D, which overall resulted in 17%-92% inhibition of P-I accumulation. Retrieval of gene sequences for enzymatic steps from NGS transcriptomes and their expression analysis vis-à-vis picrosides content in different tissues/organs showed elevated transcripts for twenty genes, which were further shortlisted to seven key genes, ISPD, DXPS, ISPE, PMK, 2HFD, EPSPS and SK, on the basis of expression analysis between high versus low picrosides content strains of P. kurroa so as to eliminate tissue type/ developmental variations in picrosides contents. The higher expression of the majority of the MEP pathway genes (ISPD, DXPS and ISPE), coupled with higher inhibition of DXPR enzyme by fosmidomycin, suggested that the MEP route contributed to the biosynthesis of P-I in P. kurroa. The outcome of the study is expected to be useful in designing a suitable genetic intervention strategy towards enhanced production of picrosides. Possible key genes contributing to picroside biosynthesis have been identified with potential implications in molecular breeding and metabolic engineering of P. kurroa. PMID:26658062

  16. NGS Transcriptomes and Enzyme Inhibitors Unravel Complexity of Picrosides Biosynthesis in Picrorhiza kurroa Royle ex. Benth.

    PubMed

    Shitiz, Kirti; Sharma, Neha; Pal, Tarun; Sood, Hemant; Chauhan, Rajinder S

    2015-01-01

    Picrorhiza kurroa is an important medicinal herb valued for iridoid glycosides, Picroside-I (P-I) and Picroside-II (P-II), which have several pharmacological activities. Genetic interventions for developing a picroside production platform would require knowledge on biosynthetic pathway and key control points, which does not exist as of today. The current study reports that geranyl pyrophosphate (GPP) moiety is mainly contributed by the non-mevalonate (MEP) route, which is further modified to P-I and P-II through phenylpropanoid and iridoid pathways, in total consisting of 41 and 35 enzymatic steps, respectively. The role of the MEP pathway was ascertained through enzyme inhibitors fosmidomycin and mevinolin along with importance of other integrating pathways using glyphosate, aminooxy acetic acid (AOA) and actinomycin D, which overall resulted in 17%-92% inhibition of P-I accumulation. Retrieval of gene sequences for enzymatic steps from NGS transcriptomes and their expression analysis vis-à-vis picrosides content in different tissues/organs showed elevated transcripts for twenty genes, which were further shortlisted to seven key genes, ISPD, DXPS, ISPE, PMK, 2HFD, EPSPS and SK, on the basis of expression analysis between high versus low picrosides content strains of P. kurroa so as to eliminate tissue type/ developmental variations in picrosides contents. The higher expression of the majority of the MEP pathway genes (ISPD, DXPS and ISPE), coupled with higher inhibition of DXPR enzyme by fosmidomycin, suggested that the MEP route contributed to the biosynthesis of P-I in P. kurroa. The outcome of the study is expected to be useful in designing a suitable genetic intervention strategy towards enhanced production of picrosides. Possible key genes contributing to picroside biosynthesis have been identified with potential implications in molecular breeding and metabolic engineering of P. kurroa. PMID:26658062

  17. Chinese medicinal formula Fufang Xueshuantong capsule could inhibit the activity of angiotensin converting enzyme

    PubMed Central

    Sheng, Shujing; Wang, Yonggang; Long, Chaofeng; Su, Weiwei; Rong, Xia

    2014-01-01

    Fufang Xueshuantong (FXST) capsule, a Chinese medicinal formula composed of four herbals – Panax notoginseng, Radix Astragali, Radix Salvia Miltiorrhizae and Radix Scrophulariaceae, has been used to treat cardiovascular diseases for many years, but the pharmacological mechanisms underlying its effects has not been clarified. This study investigates if a connection between FXST and angiotensin converting enzyme (ACE) might be an explanation for its pharmacological effects. ACE inhibition assay was performed on FXST capsule, 50% ethanol extracts from the four herbals and three selected saponins most abundant in P. notoginseng (Ginsenoside Rg1, Ginsenoside Rb1 and Notoginsenoside R1) using a biochemical test. Reversed-phase high-performance liquid chromatography of liberated hippuric acid from the ACE assay was conducted to determine the inhibitory effect. As a result, FXST and extracts from P. notoginseng showed a significant and dose-dependent inhibition on ACE activity with the IC50 values of 115 μg/ml and 179 μg/ml, respectively. But extracts from the other three herbals and the three selected saponins had no significant effect on ACE inhibition. Compared to other reported plant extracts, FXST could be considered as an effective ACE inhibitor. The inhibition of ACE activity supports the traditional use of FXST on blood circulation and the inhibitory property of FXST is mainly caused by P. notoginseng. PMID:26019516

  18. Accelerated transport and maturation of lysosomal alpha-galactosidase A in Fabry lymphoblasts by an enzyme inhibitor.

    PubMed

    Fan, J Q; Ishii, S; Asano, N; Suzuki, Y

    1999-01-01

    Fabry disease is a disorder of glycosphingolipid metabolism caused by deficiency of lysosomal alpha-galactosidase A (alpha-Gal A), resulting in renal failure along with premature myocardial infarction and strokes. No effective treatment of this disorder is available at present. Studies of residual activities of mutant enzymes in many Fabry patients showed that some of them had kinetic properties similar to those for normal alpha-Gal A, but were significantly less stable, especially in conditions of neutral pH (refs. 3-5). The biosynthetic processing was delayed in cultured fibroblasts of a Fabry patient, and the mutant protein formed an aggregate in endoplasmic reticulum, indicating that the enzyme deficiency in some mutants was mainly caused by abortive exit from the endoplasmic reticulum, leading to excessive degradation of the enzyme. We report here that 1-deoxy-galactonojirimycin (DGJ), a potent competitive inhibitor of alpha-Gal A, effectively enhanced alpha-Gal A activity in Fabry lymphoblasts, when administrated at concentrations lower than that usually required for intracellular inhibition of the enzyme. DGJ seemed to accelerate transport and maturation of the mutant enzyme. Oral administration of DGJ to transgenic mice overexpressing a mutant alpha-Gal A substantially elevated the enzyme activity in some organs. We propose a new molecular therapeutic strategy for genetic metabolic diseases of administering competitive inhibitors as 'chemical chaperons' at sub-inhibitory intracellular concentrations. PMID:9883849

  19. High Throughput Enzyme Inhibitor Screening by Functionalized Magnetic Carbonaceous Microspheres and Graphene Oxide-Based MALDI-TOF-MS

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Li, Yan; Liu, Junyan; Deng, Chunhui; Zhang, Xiangmin

    2011-12-01

    In this work, a high throughput methodology for screening enzyme inhibitors has been demonstrated by combining enzyme immobilized magnetic carbonaceous microspheres and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with grapheme oxide as matrix. First, model enzyme acetylcholinesterase (AChE) was immobilized onto the 3-glycidoxypropyltrimethoxysilane (GLYMO)-modified magnetic carbonaceous (MC) microspheres, displaying a high enzyme activity and stability, and also facilitating the separation of enzyme from substrate and product. The efficiency of immobilized AChE was monitored by biochemical assay, which was carried out by mixing enzyme-immobilized MC microspheres with model substrate acetylcholine (ACh), and subsequent quantitative determination of substrate ACh and product choline using graphene oxide-based MALDI-TOF-MS with no background inference. The limit of detection (LOD) for ACh was 0.25 fmol/μL, and excellent linearity (R2 = 0.9998) was maintained over the range of 0.5 and 250 fmol/μL. Choline was quantified over the range of 0.05 and 15 pmol/μL, also with excellent linearity (R2 = 0.9994) and low LOD (0.15 fmol/μL). Good accuracy and precision were obtained for all concentrations within the range of the standard curves. All together, eight compounds (four known AChE inhibitors and four control chemical compounds with no AChE inhibit effect) were tested with our promoted methodology, and the obtained results demonstrated that our high throughput screening methodology could be a great help to the routine enzyme inhibitor screening.

  20. CES1 genetic variation affects the activation of angiotensin-converting enzyme inhibitors.

    PubMed

    Wang, X; Wang, G; Shi, J; Aa, J; Comas, R; Liang, Y; Zhu, H-J

    2016-06-01

    The aim of the study was to determine the effect of carboxylesterase 1 (CES1) genetic variation on the activation of angiotensin-converting enzyme inhibitor (ACEI) prodrugs. In vitro incubation study of human liver, intestine and kidney s9 fractions demonstrated that the ACEI prodrugs enalapril, ramipril, perindopril, moexipril and fosinopril are selectively activated by CES1 in the liver. The impact of CES1/CES1VAR and CES1P1/CES1P1VAR genotypes and diplotypes on CES1 expression and activity on enalapril activation was investigated in 102 normal human liver samples. Neither the genotypes nor the diplotypes affected hepatic CES1 expression and activity. Moreover, among several CES1 nonsynonymous variants studied in transfected cell lines, the G143E (rs71647871) was a loss-of-function variant for the activation of all ACEIs tested. The CES1 activity on enalapril activation in human livers with the 143G/E genotype was approximately one-third of that carrying the 143G/G. Thus, some functional CES1 genetic variants (for example, G143E) may impair ACEI activation, and consequently affect therapeutic outcomes of ACEI prodrugs. PMID:26076923

  1. [Psychotropic effects of angiotensin-converting enzyme inhibitors: what are the arguments?].

    PubMed

    Mesure, G; Fallet, A; Chevalier, J F

    1995-01-01

    The authors report a case of acute mania induced by perindopril (Coversyl) in a 57 year old man with no prior history of mental illness. This Angiotensin-Converting Enzyme Inhibitor (ACEI) had been introduced eight days prior to the first signs of excitation, in order to treat recently diagnosed arterial hypertension. Without proof of reintroduction, and on the basis of clinical observations, the attribution appears plausible. Similar observations have been made for other molecules in this class of medication, such as captopril (Lopril). A review of literature regroups recent data concerning psychotropic effects of ACEIs. Several reports claim that captopril clearly acts as an antidepressant. Studies on the mood or the quality of life of treated hypertensive patients show ACEIs to have an euphoric-type positive effect compared to other anti-hypertensive treatments. Captopril and perindopril also act like potential antidepressants in experimental models of antidepression. Furthermore, pharmacologic data confirm that the most lipophilic ACEIs penetrate the central nervous system and argue in favor of the role of these molecules in activating central opioides. As these data provide evidence of mood swing in some patients, but also of an overall benefit in hypertensive populations, the clinical importance of the antidepressant effect of ACEIs needs further investigations. PMID:8529571

  2. Comprehensive mutant enzyme and viral variant assessment of human immunodeficiency virus type 1 reverse transcriptase resistance to nonnucleoside inhibitors.

    PubMed Central

    Byrnes, V W; Sardana, V V; Schleif, W A; Condra, J H; Waterbury, J A; Wolfgang, J A; Long, W J; Schneider, C L; Schlabach, A J; Wolanski, B S

    1993-01-01

    The nonnucleoside reverse transcriptase (RT) inhibitors comprise a class of structurally diverse compounds that are functionally related and specific for the human immunodeficiency virus type 1 RT. Viral variants resistant to these compounds arise readily in cell culture and in treated, infected human. Therefore, the eventual clinical usefulness of the nonnucleoside inhibitors will rely on a thorough understanding of the genetic and biochemical bases for resistance. A study was performed to assess the effects of substitutions at each RT amino acid residue that influences the enzyme's susceptibility to the various nonnucleoside compounds. Single substitutions were introduced into both purified enzyme and virus. The resulting patterns of resistance were markedly distinct for each of the tested inhibitors. For instance, a > 50-fold loss of enzyme susceptibility to BI-RG-587 was engendered by any of four individual substitutions, while the same level of relative resistance to the pyridinone derivatives was mediated only by substitution at residue 181. Similarly, substitution at residue 181. Similarly, substitution at residue 106 had a noted effect on virus resistance to BI-RG-587 but not to the pyridinones. The opposite effect was mediated by a substitution at residue 179. Such knowledge of nonucleoside inhibitor resistance profiles may help in understanding the basis for resistant virus selection during clinical studies of these compounds. PMID:7692811

  3. Isolation of a new phlorotannin, a potent inhibitor of carbohydrate-hydrolyzing enzymes, from the brown alga Sargassum patens.

    PubMed

    Kawamura-Konishi, Yasuko; Watanabe, Natsuko; Saito, Miki; Nakajima, Noriyuki; Sakaki, Toshiyuki; Katayama, Takane; Enomoto, Toshiki

    2012-06-01

    Ethanol extracts from 15 kinds of marine algae collected from the coast of the Noto Peninsula in Japan were examined for their inhibitory effects on human salivary α-amylase. Four extracts significantly suppressed the enzyme activity. An inhibitor was purified from the extract of Sargassum patens . The compound was a new phloroglucinol derivative, 2-(4-(3,5-dihydroxyphenoxy)-3,5-dihydroxyphenoxy) benzene-1,3,5-triol (DDBT), which strongly suppressed the hydrolysis of amylopectin by human salivary and pancreatic α-amylases. The 50% inhibitory activity (IC(50)) for α-amylase inhibition of DDBT (3.2 μg/mL) was much lower than that of commercially available α-amylase inhibitors, acarbose (26.3 μg/mL), quercetagetin (764 μg/mL), and α-amylase inhibitor from Triticum aestivum (88.3 μg/mL). A kinetic study indicated that DDBT was a competitive α-amylase inhibitor with a K(i) of 1.8 μg/mL. DDBT also inhibited rat intestinal α-glucosidase with an IC(50) value of 25.4 μg/mL for sucrase activity and 114 μg/mL for maltase activity. These results suggest that DDBT, a potent inhibitor of carbohydrate-hydrolyzing enzymes, may be useful as a natural nutraceutical to prevent diabetes. PMID:22594840

  4. Steroidomimetic aminomethyl spiroacetals as novel inhibitors of the enzyme Δ8,7-sterol isomerase in cholesterol biosynthesis.

    PubMed

    Krojer, Melanie; Müller, Christoph; Bracher, Franz

    2014-02-01

    Grundmann's ketone is converted to a spiroacetal containing a 5-hydroxymethyl-5-nitro-1,3-dioxane moiety whose hydroxymethyl group can be esterified or directly substituted with primary and secondary amines. Among the resulting aminomethyl spiroacetals, several ones bearing diamino residues were found to be inhibitors of the enzyme Δ8,7-isomerase in cholesterol biosynthesis. The complex bicyclic building block derived from Grundmann's ketone could be replaced by a properly substituted tetraline scaffold, without noteworthy loss in activity. This opens the opportunity to perform further structural modifications for the design of new steroidomimetic inhibitors of human Δ8,7-isomerase. PMID:24493593

  5. An ACE diagnosis.

    PubMed

    Nasher, Omar; Gupta, Anindya

    2013-01-01

    Gaucher's disease is not commonly considered in the differential diagnosis of adult patients with hepatosplenomegaly and increased serum ACE. A 19-year-old girl presented with recurrent epigastric and left hypochondrial pain over a period of 9 years, associated with episodes of nausea and diarrhoea. She was extensively investigated and found to have splenomegaly and raised serum ACE. A screen for haematological disorders was negative. She reported an insect bite during an overseas holiday preceding her symptoms. She was therefore also screened for infectious causes of hepatosplenomegaly but without success. Later on in life, she reported joint pain and discomfort. Sarcoidosis was thought to be the putative cause on more than one occasion. However, the presence of splenomegaly and her relatively young age, led the rheumatologist to the correct diagnosis. PMID:23417380

  6. An ACE diagnosis

    PubMed Central

    Nasher, Omar; Gupta, Anindya

    2013-01-01

    Gaucher's disease is not commonly considered in the differential diagnosis of adult patients with hepatosplenomegaly and increased serum ACE. A 19-year-old girl presented with recurrent epigastric and left hypochondrial pain over a period of 9 years, associated with episodes of nausea and diarrhoea. She was extensively investigated and found to have splenomegaly and raised serum ACE. A screen for haematological disorders was negative. She reported an insect bite during an overseas holiday preceding her symptoms. She was therefore also screened for infectious causes of hepatosplenomegaly but without success. Later on in life, she reported joint pain and discomfort. Sarcoidosis was thought to be the putative cause on more than one occasion. However, the presence of splenomegaly and her relatively young age, led the rheumatologist to the correct diagnosis. PMID:23417380

  7. Targeting the Motion of Shikimate Kinase: Development of Competitive Inhibitors that Stabilize an Inactive Open Conformation of the Enzyme.

    PubMed

    Prado, Verónica; Lence, Emilio; Maneiro, María; Vázquez-Ucha, Juan C; Beceiro, Alejandro; Thompson, Paul; Hawkins, Alastair R; González-Bello, Concepción

    2016-06-01

    The large conformational changes observed by Molecular Dynamics simulation studies on the product release in the LID and shikimic acid binding (SB) domains of the shikimate kinase (SK) enzyme have been exploited in the development of reversible competitive inhibitors against SK from Mycobacterium tuberculosis and Helicobacter pylori. This enzyme is a recognized target for antibiotic drug discovery. The reported C5-substituted shikimic acid analogues interact with the dynamic apolar pocket that surrounds the C4 and C5 hydroxyl groups of the natural substrate, cause the opening of the LID and SB domains, and capture the essential arginine far from the ATP binding site as required for catalysis. The 3-nitrobenzyl 3e and 5-benzothiophenyl derivatives 3i proved to be the most potent inhibitors. An ester prodrug of 3i was the most efficient derivative in achieving good in vitro activity against H. pylori, having a MIC value of 4 μg/mL. PMID:27191386

  8. A potent specific inhibitor of 6-phosphogluconate dehydrogenase of Cryptococcus neoformans and of certain other fungal enzymes.

    PubMed

    Niehaus, W G; Flynn, T

    1993-09-01

    A particular lot of the zwitterionic buffer, 2(N-morpholino) ethane sulfonic acid (MES), contained a contaminant that inhibited a number of fungal NADP-dependent dehydrogenases. Enzymes that were particularly sensitive include 6-phosphogluconate dehydrogenases from Cryptococcus neoformans and Schizophyllum commune and glucose-6-phosphate dehydrogenase from Schizophyllum commune. A number of NADP-dependent dehydrogenases of animal origin were tested and all were completely insensitive to inhibition except for rat liver 6-phosphogluconate dehydrogenase, which was 10-fold less sensitive than the Cryptococcal enzyme. The pattern of inhibition in all cases was linear competitive versus NADP. The inhibitor has been purified and identified as an ethylenesulfonic acid oligomer. This inhibitor holds promise as a model compound for the development of a specific antifungal agent. PMID:8302365

  9. Interactions of APE1 with a redox inhibitor: Evidence for an alternate conformation of the enzyme

    PubMed Central

    Su, Dian; Delaplane, Sarah; Luo, Meihua; Rempel, Don L.; Vu, Bich; Kelley, Mark R.; Gross, Michael L.; Georgiadis, Millie M.

    2010-01-01

    Apurinic/apyrimidinic endonuclease (APE1) is an essential base excision repair protein that also functions as a reduction/oxidation (redox) factor in mammals. Through a thiol-based mechanism, APE1 reduces a number of important transcription factors including AP-1, p53, NF-κB, and HIF-1α. What is known about the mechanism to date is that the buried Cys residues 65 and 93 are critical for APE1’s redox activity. To further detail the redox mechanism, we developed a chemical footprinting/mass spectrometric assay using N-ethylmaleimide (NEM), an irreversible Cys modifier, to characterize the interaction of the redox inhibitor, E3330, with APE1. When incubated with E3330, two NEM-modified products were observed, one with 2 and a second with 7 added NEMs; this latter product corresponds to a fully modified APE1. In a similar control reaction without E3330, only the +2NEM product was observed in which the two solvent accessible Cys residues, C99 and C138, were modified by NEM. Through hydrogen-deuterium amide exchange with analysis by mass spectrometry, we found that the +7NEM modified species incorporates approximately 40 more deuterium atoms than the native protein, which exchanges nearly identically as the +2NEM product, suggesting that APE1 can be trapped in a partially unfolded state. E3330 was also found to increase disulfide bond formation involving redox critical Cys residues in APE1 as assessed by LC-MS/MS, suggesting a basis for its inhibitory effects on APE1’s redox activity. Collectively, our results suggest that APE1 adopts a partially unfolded state, which we propose is the redox active form of the enzyme. PMID:21117647

  10. Angiotensin-Receptor Blocker, Angiotensin-Converting Enzyme Inhibitor, and Risks of Atrial Fibrillation

    PubMed Central

    Hsieh, Yu-Cheng; Hung, Chen-Ying; Li, Cheng-Hung; Liao, Ying-Chieh; Huang, Jin-Long; Lin, Ching-Heng; Wu, Tsu-Juey

    2016-01-01

    Abstract Both angiotensin-receptor blockers (ARB) and angiotensin-converting enzyme inhibitors (ACEI) have protective effects against atrial fibrillation (AF). The differences between ARB and ACEI in their effects on the primary prevention of AF remain unclear. This study compared ARB and ACEI in combined antihypertensive medications for reducing the risk of AF in patients with hypertension, and determined which was better for AF prevention in a nationwide cohort study. Patients aged ≥55 years and with a history of hypertension were identified from Taiwan National Health Insurance Research Database. Medical records of 25,075 patients were obtained, and included 6205 who used ARB, 8034 who used ACEI, and 10,836 nonusers (no ARB or ACEI) in their antihypertensive regimen. Cox regression models were applied to estimate the hazard ratio (HR) for new-onset AF. During an average of 7.7 years’ follow-up, 1619 patients developed new-onset AF. Both ARB (adjusted HR: 0.51, 95% CI 0.44–0.58, P < 0.001) and ACEI (adjusted HR: 0.53, 95% CI 0.47–0.59, P < 0.001) reduced the risk of AF compared to nonusers. Subgroup analysis showed that ARB and ACEI were equally effective in preventing new-onset AF regardless of age, gender, the presence of heart failure, diabetes, and vascular disease, except for those with prior stroke or transient ischemic attack (TIA). ARB prevents new-onset AF better than ACEI in patients with a history of stroke or TIA (log-rank P = 0.012). Both ARB and ACEI reduce new-onset AF in patients with hypertension. ARB prevents AF better than ACEI in patients with a history of prior stroke or TIA. PMID:27196491

  11. Angiotensin-Converting Enzyme Inhibitors and Active Tuberculosis: A Population-Based Study.

    PubMed

    Wu, Jiunn-Yih; Lee, Meng-Tse Gabriel; Lee, Si-Huei; Lee, Shih-Hao; Tsai, Yi-Wen; Hsu, Shou-Chien; Chang, Shy-Shin; Lee, Chien-Chang

    2016-05-01

    Numerous epidemiological data suggest that the use of angiotensin-converting enzyme inhibitors (ACEis) can improve the clinical outcomes of pneumonia. Tuberculosis (TB) is an airborne bacteria like pneumonia, and we aimed to find out whether the use of ACEis can decrease the risk of active TB.We conducted a nested case-control analysis by using a 1 million longitudinally followed cohort, from Taiwan national health insurance research database. The rate ratios (RRs) for TB were estimated by conditional logistic regression, and adjusted using a TB-specific disease risk score (DRS) with 71 TB-related covariates.From January, 1997 to December, 2011, a total of 75,536 users of ACEis, and 7720 cases of new active TB were identified. Current use (DRS adjusted RR, 0.87 [95% CI, 0.78-0.97]), but not recent and past use of ACEis, was associated with a decrease in risk of active TB. Interestingly, it was found that chronic use (>90 days) of ACEis was associated with a further decrease in the risk of TB (aRR, 0.74, [95% CI, 0.66-0.83]). There was also a duration response effect, correlating decrease in TB risk with longer duration of ACEis use. The decrease in TB risk was also consistent across all patient subgroups (age, sex, heart failure, cerebrovascular diseases, myocardial infraction, renal diseases, and diabetes) and patients receiving other cardiovascular medicine.In this large population-based study, we found that subjects with recent and chronic use of ACEis were associated with decrease in TB risk. PMID:27175655

  12. Effect of the Angiotensin I Converting Enzyme Inhibitor, MK-421, on Experimentally Induced Drinking

    NASA Technical Reports Server (NTRS)

    Fregley, Melvin J.; Fater, Dennis C.; Greenleaf, John E.

    1982-01-01

    MK-421, the ethyl ester maleate salt of N-(S)-1-(ethoxycarbonyl)-3-phenyl-propyl- Ala-L-Pro, is an angiotensin I converting enzyme inhibitor. An initial objective was to determine whether MK-421, administered at 0, 2.5, 5.0, 10.0, 20.0 and 40.0 mg/kg, ip to 96 female rats 15 min prior to administration of the beta-adrenergic agonist, isoproterenol (25 microgram/kg, ip), would inhibit the drinking induced by isoproterenol during 2 h after its administration. The water intake induced by isoproterenol was inhibited significantly by 2.5 mg MK-421/kg. When a similar experiment was performed using Angiotensin I (AI) (200 microgram/kg, ip) as the dipsogenic agent, MK-421 (5 mg/kg, ip), administered 15 min prior to AI, inhibited significantly both the dipsogenic and the diuretic effect of AI. However, administration of angiotensin II (AII, 200 microgram/kg, ip) 15 min after MK-421 (5mg/kg) was accompanied by a water intake that did not differ from AII alone. The drink induced by ip administration of 1.0 m NaCl solution (1% of body wt, ip) was not inhibited by administration of MK-421 (5 mg/kg) 15 min prior to allowing access to water while the drink induced by a 24 h dehydration was partially inhibited. Thus, the drinks induced by administraition of either isoproterenol or AI are dependent on formation of AII. That induced by dehydration is partially dependent, while that induced by hypertonic siilinc is independent of the formation of AII.

  13. From Enzyme to Whole Blood: Sequential Screening Procedure for Identification and Evaluation of p38 MAPK Inhibitors.

    PubMed

    Bauer, Silke M; Kubiak, Jakub M; Rothbauer, Ulrich; Laufer, Stefan

    2016-01-01

    p38 mitogen-activated protein kinase (MAPK) is a pivotal enzyme in the biosynthesis of pro-inflammatory cytokines like IL-1 and TNF. Therefore, the success of anti-cytokine therapy for treatment of inflammatory processes qualified p38-MAPK as a solid target in drug research concerning chronic inflammatory diseases including infectious vascular, neurobiological, and autoimmune disorders. However, the discovery of new kinase inhibitors is limited by the need for a high biological activity combined with restricted activity to the target enzyme or pathway interaction. As a consequence, no p38 MAPK inhibitor has been introduced to the market so far, although several p38 inhibitors have proceeded into clinical trials. The development of novel inhibitor types and optimization of already known structural classes of MAPK inhibitors require appropriate testing systems reaching across these crucial parameters. As a new approach, we describe the sequential arrangement of three testing systems custom-tailored to the requirements of drug discovery programs with focus on p38 inhibition. Integrated analysis of the obtained results enables a concerted step-by-step selection of tested molecules in order to screen a compound library for the most suitable inhibitor. First, evaluation of the inhibitor's activity on the isolated p38 MAPK enzyme via an ELISA assay gives a first idea about the inhibitory potency of the molecule. Moreover, structure-activity relationships can be elucidated when comparing molecules within inhibitor series. Second, screening in living cells via a p38 substrate-specific MK2-EGFP translocation assay supplies further information about efficacy, but provides also a first notion concerning selectivity and toxicity. Third, efficacy is evaluated more specifically in vivo in LPS-stimulated human whole blood with regard to in vivo parameters, e.g., pharmacokinetic characteristics like plasma protein binding and cellular permeability. These three testing systems

  14. Combined Rational Design and a High Throughput Screening Platform for Identifying Chemical Inhibitors of a Ras-activating Enzyme*

    PubMed Central

    Evelyn, Chris R.; Biesiada, Jacek; Duan, Xin; Tang, Hong; Shang, Xun; Papoian, Ruben; Seibel, William L.; Nelson, Sandra; Meller, Jaroslaw; Zheng, Yi

    2015-01-01

    The Ras family small GTPases regulate multiple cellular processes, including cell growth, survival, movement, and gene expression, and are intimately involved in cancer pathogenesis. Activation of these small GTPases is catalyzed by a special class of enzymes, termed guanine nucleotide exchange factors (GEFs). Herein, we developed a small molecule screening platform for identifying lead hits targeting a Ras GEF enzyme, SOS1. We employed an ensemble structure-based virtual screening approach in combination with a multiple tier high throughput experimental screen utilizing two complementary fluorescent guanine nucleotide exchange assays to identify small molecule inhibitors of GEF catalytic activity toward Ras. From a library of 350,000 compounds, we selected a set of 418 candidate compounds predicted to disrupt the GEF-Ras interaction, of which dual wavelength GDP dissociation and GTP-loading experimental screening identified two chemically distinct small molecule inhibitors. Subsequent biochemical validations indicate that they are capable of dose-dependently inhibiting GEF catalytic activity, binding to SOS1 with micromolar affinity, and disrupting GEF-Ras interaction. Mutagenesis studies in conjunction with structure-activity relationship studies mapped both compounds to different sites in the catalytic pocket, and both inhibited Ras signaling in cells. The unique screening platform established here for targeting Ras GEF enzymes could be broadly useful for identifying lead inhibitors for a variety of small GTPase-activating GEF reactions. PMID:25825487

  15. The hepatoprotective cytochrome P-450 enzyme inhibitor isolated from the Nigerian medicinal plant Cochlospermum planchonii is a zinc salt.

    PubMed

    Aliyu, R; Okoye, Z S; Shier, W T

    1995-10-01

    Aqueous extracts of Cochlospermum planchonii Hook.f. (Cochlospermaceae) rhizomes are used by native medical practitioners in northern Nigeria to treat jaundice. An extract prepared by a laboratory adaptation of their method was hepatoprotective in carbon tetrachloride-treated rats (CCl4), and it inhibited cytochrome P-450 enzymes, which constitutes a plausible hepatoprotective mechanism. A crystalline inhibitor (0.3% of dry weight of rhizomes) was isolated using inhibition of two rat cytochrome P-450 enzymes, aminopyrine-N-demethylase and aniline hydroxylase, as bioassays to guide fractionation by solvent partitioning, polyamdie column chromatography, preparative thin layer chromatography and fractional crystallization. The inhibitor was identified as zinc formate by inductively coupled plasma atomic emission spectroscopy, nuclear magnetic resonance spectroscopy and comparison with synthetic material by power X-ray diffraction crystallography. Synthetic and plant-derived zinc formate were equally effective as inhibitors of cytochrome P-450 enzymes and as hepatoprotective agents in carbon tetrachloride-treated rats. Cochlospermum planchonii rhizomes contain unusually high levels of manganese and zinc, although much higher levels have been observed in plants considered to be hyperaccumulators of these metals. PMID:8583799

  16. Continuous flow immobilized enzyme reactor-tandem mass spectrometry for screening of AChE inhibitors in complex mixtures.

    PubMed

    Forsberg, Erica M; Green, James R A; Brennan, John D

    2011-07-01

    A method is described for identifying bioactive compounds in complex mixtures based on the use of capillary-scale monolithic enzyme-reactor columns for rapid screening of enzyme activity. A two-channel nanoLC system was used to continuously infuse substrate coupled with automated injections of substrate/small molecule mixtures, optionally containing the chromogenic Ellman reagent, through sol-gel derived acetylcholinesterase (AChE) doped monolithic columns. This is the first report of AChE encapsulated in monolithic silica for use as an immobilized enzyme reactor (IMER), and the first use of such IMERs for mixture screening. AChE IMER columns were optimized to allow rapid functional screening of compound mixtures based on changes in the product absorbance or the ratio of mass spectrometric peaks for product and substrate ions in the eluent. The assay had robust performance and produced a Z' factor of 0.77 in the presence of 2% (v/v) DMSO. A series of 52 mixtures consisting of 1040 compounds from the Canadian Compound Collection of bioactives was screened and two known inhibitors, physostigmine and 9-aminoacridine, were identified from active mixtures by manual deconvolution. The activity of the compounds was confirmed using the enzyme reactor format, which allowed determination of both IC(50) and K(I) values. Screening results were found to correlate well with a recently published fluorescence-based microarray screening assay for AChE inhibitors. PMID:21591743

  17. Indirect enzyme-antibody sandwich enzyme-linked immunosorbent assay for quantification of TAXI and XIP type xylanase inhibitors in wheat and other cereals.

    PubMed

    Beaugrand, Johnny; Gebruers, Kurt; Ververken, Cedric; Fierens, Ellen; Dornez, Emmie; Goddeeris, Bruno M; Delcour, Jan A; Courtin, Christophe M

    2007-09-19

    To quantify Triticum aestivum xylanase inhibitor (TAXI) and xylanase inhibiting protein (XIP) type proteins in cereals in general and wheat ( T. aestivum) in particular, a robust enzyme-linked immunosorbent assay (ELISA) using an uncommon enzyme-antibody sandwich format was developed. Bacillus subtilis glycoside hydrolase family (GH) 11 and Aspergillus oryzae GH 10 xylanases were selected for coating ELISA plate wells to capture TAXI and XIP, respectively, prior to probing with antibodies. The detection threshold of the developed ELISA was much lower than that of the currently used xylanase inhibitor assay and the recently described Western blot approach. Because of its broad dynamic range (TAXI, 30-600 ng/mL, and XIP, 3-60 ng/mL), one proper standard extract dilution can be used for analyzing different wheat varieties, whereas for the currently used colorimetric assay, often different dilutions need to be analyzed. The TAXI ELISA for wheat was successfully adapted for barley ( Hordeum vulgare) and could also be used for other cereals. PMID:17715986

  18. Molecular modeling study of binding to the catalytic site of PDE4 enzymes by a novel class of inhibitors

    NASA Astrophysics Data System (ADS)

    Lawrenz, Morgan E.; Salter, E. A.; Wierzbicki, Andrzej; Thompson, W. J.

    Cyclic nucleotide phosphodiesterases (PDEs) comprise a superfamily of enzymes that hydrolyze the second messengers adenosine and guanosine 3',5'-cyclic monophosphate (cAMP and cGMP) to their noncyclic nucleotides (5'-AMP and 5'-GMP). Selective inhibitors of all 11 gene families of PDEs are being sought based on the different biochemical properties of the different isoforms, including their substrate specificities. The PDE4 gene family consists of cAMP-specific isoforms; selective PDE4 inhibitors such as rolipram have been developed, and related agents are used clinically as anti-inflammatory agents for asthma and COPD. The known crystal structures of PDE4 bound with rolipram and IBMX have allowed us to define plausible binding orientations for a novel class of benzylpyridazinone-based PDE4 inhibitors represented by EMD 94360 and EMD 95832 that are structurally distinct from rolipram. Molecular mechanics modeling with autodocking is used to explore energetically favorable binding orientations within the PDE4 catalytic site. We present two putative orientations for EMD 94360/95832 inhibitor binding. Our estimated interaction energies for rolipram, IBMX, EMD 94360, and EMD 95832 are consistent with the experimental data for their IC50 values. Key binding residues and interactions in these orientations are identified and compared with known binding motifs proposed for rolipram. The experimentally observed improved strength of inhibition exhibited by this novel class of PDE4 inhibitors is explained by the molecular modeling reported here.

  19. ACEE composite structures technology

    NASA Technical Reports Server (NTRS)

    Klotzsche, M. (Compiler)

    1984-01-01

    The NASA Aircraft Energy Efficiency (ACEE) Composite Primary Aircraft Structures Program has made significant progress in the development of technology for advanced composites in commercial aircraft. Commercial airframe manufacturers have demonstrated technology readiness and cost effectiveness of advanced composites for secondary and medium primary components and have initiated a concerted program to develop the data base required for efficient application to safety-of-flight wing and fuselage structures. Oral presentations were compiled into five papers. Topics addressed include: damage tolerance and failsafe testing of composite vertical stabilizer; optimization of composite multi-row bolted joints; large wing joint demonstation components; and joints and cutouts in fuselage structure.

  20. An evaluation of the effect of an angiotensin-converting enzyme inhibitor on the growth rate of small abdominal aortic aneurysms: a randomised placebo-controlled trial (AARDVARK).

    PubMed Central

    Kiru, Gaia; Bicknell, Colin; Falaschetti, Emanuela; Powell, Janet; Poulter, Neil

    2016-01-01

    BACKGROUND Although data are inconsistent, angiotensin-converting enzyme inhibitors (ACE-Is) have been associated with a reduced incidence of abdominal aortic aneurysm (AAA) rupture in analysis of administrative databases. OBJECTIVES (1) To investigate whether or not the ACE-I perindopril (Coversyl arginine, Servier) reduces small AAA growth rate and (2) to evaluate blood pressure (BP)-independent effects of perindopril on small AAA growth and to compare the repeatability of measurement of internal and external aneurysm diameters. DESIGN A three-arm, multicentre, single-blind, randomised placebo-controlled trial. SETTING Fourteen hospitals in England. PARTICIPANTS Men or women aged ≥ 55 years with an AAA of 3.0-5.4 cm in diameter by internal or external measurement according to ultrasonography and who met the trial eligibility criteria. INTERVENTIONS Patients were randomised to receive 10 mg of perindopril arginine daily, 5 mg of the calcium channel blocker amlodipine daily or placebo daily. MAIN OUTCOME MEASURES The primary outcome was AAA diameter growth using external measurements in the longitudinal plane, which in-trial studies suggested was the preferred measure. Secondary outcome measures included AAA rupture, AAA repair, modelling of the time taken for the AAA to reach the threshold for intervention (5.5 cm) or referral for surgery, tolerance of study medication (measured by compliance, adverse events and quality of life) and a comparison of the repeatability of measures of internal and external AAA diameter. Patients were followed up every 3-6 months over 2 years. RESULTS In total, 227 patients were recruited and randomised into the three groups, which were generally well matched at baseline. Multilevel modelling was used to determine the maximum likelihood estimates for AAA diameter growth. No significant differences in the estimates of annual growth were apparent [1.68 (standard error 0.02) mm, 1.77 (0.02) mm and 1.81 (0.02) mm in the

  1. ACE2 Decreases Formation and Severity of Angiotensin II-induced Abdominal Aortic Aneurysms

    PubMed Central

    Thatcher, Sean E.; Zhang, Xuan; Howatt, Deborah A.; Yiannikouris, Frederique; Gurley, Susan B.; Ennis, Terri; Curci, John A.; Daugherty, Alan; Cassis, Lisa A.

    2014-01-01

    Objective Angiotensin converting enzyme 2 (ACE2) cleaves angiotensin II (AngII) to form angiotensin-(1-7) (Ang-(1-7)), which generally opposes effects of AngII. AngII infusion into hypercholesterolemic male mice induces formation of abdominal aortic aneurysms (AAAs). This study tests the hypothesis that deficiency of ACE2 promotes AngII-induced AAAs, while ACE2 activation suppresses aneurysm formation. Approach and Results ACE2 protein was detectable by immunostaining in mice and human AAAs. Whole body deficiency of ACE2 significantly increased aortic lumen diameters and external diameters of suprarenal aortas from AngII-infused mice. Conversely, ACE2 deficiency in bone marrow-derived cells had no effect on AngII-induced AAAs. In contrast to AngII-induced AAAs, ACE2 deficiency had no significant effect on external aortic diameters of elastase-induced AAAs. Since ACE2 deficiency promoted AAA formation in AngII-infused mice, we determined if ACE2 activation suppressed AAAs. ACE2 activation by administration of diminazine aceturate (DIZE, 30 mg/kg/day) to Ldlr−/− mice increased kidney ACE2 mRNA abundance and activity and elevated plasma Ang-(1-7) concentrations. Unexpectedly, administration of DIZE significantly reduced total sera cholesterol and VLDL-cholesterol concentrations. Notably, DIZE significantly decreased aortic lumen diameters and aortic external diameters of AngII-infused mice resulting in a marked reduction in AAA incidence (from 73 to 29%). None of these effects of DIZE were observed in the Ace2−/y mice. Conclusions These results demonstrate that ACE2 exerts a modulatory role in AngII-induced AAA formation, and that therapeutic stimulation of ACE2 could be a benefit to reduce AAA expansion and rupture in patients with an activated renin-angiotensin system. PMID:25301841

  2. A preference-based free-energy parameterization of enzyme-inhibitor binding. Applications to HIV-1-protease inhibitor design.

    PubMed Central

    Wallqvist, A.; Jernigan, R. L.; Covell, D. G.

    1995-01-01

    The interface between protein receptor-ligand complexes has been studied with respect to their binary interatomic interactions. Crystal structure data have been used to catalogue surfaces buried by atoms from each member of a bound complex and determine a statistical preference for pairs of amino-acid atoms. A simple free energy model of the receptor-ligand system is constructed from these atom-atom preferences and used to assess the energetic importance of interfacial interactions. The free energy approximation of binding strength in this model has a reliability of about +/- 1.5 kcal/mol, despite limited knowledge of the unbound states. The main utility of such a scheme lies in the identification of important stabilizing atomic interactions across the receptor-ligand interface. Thus, apart from an overall hydrophobic attraction (Young L, Jernigan RL, Covell DG, 1994, Protein Sci 3:717-729), a rich variety of specific interactions is observed. An analysis of 10 HIV-1 protease inhibitor complexes is presented that reveals a common binding motif comprised of energetically important contacts with a rather limited set of atoms. Design improvements to existing HIV-1 protease inhibitors are explored based on a detailed analysis of this binding motif. PMID:8528086

  3. Effects of ACE2 deficiency on physical performance and physiological adaptations of cardiac and skeletal muscle to exercise.

    PubMed

    Motta-Santos, Daisy; Dos Santos, Robson Augusto Souza; Oliveira, Marilene; Qadri, Fatimunnisa; Poglitsch, Marko; Mosienko, Valentina; Kappes Becker, Lenice; Campagnole-Santos, Maria Jose; M Penninger, Joseph; Alenina, Natalia; Bader, Michael

    2016-07-01

    The renin-angiotensin system (RAS) is related to physiological adaptations induced by exercise. Angiotensin-converting enzyme (ACE) 2 is a major regulator of the RAS in tissues, as it metabolizes angiotensin (Ang) II to Ang-(1-7). The aim of this study was to determine the effects of ACE2 deficiency on physical performance and physiological adaptations induced by voluntary running. Physical performance, body composition and plasma angiotensin levels, as well as tissue morphology and gene expression of RAS components in the left ventricle (LV) and skeletal muscle (gastrocnemius), were evaluated in ACE2-deficient (ACE2(-/y)) and wild-type (ACE2(+/y)) mice after 6 weeks of voluntary wheel running. ACE2(-/y) mice run less than ACE2(+/y) mice (19±4.7 vs. 26±12.6 revolutions per day × 100, P<0.01). The ACE2(+/y) group presented a lower fat mass (15±1.1%) and higher muscle mass (76.6±1.6%) after 6 weeks of voluntary running compared with the sedentary control group (fat mass: 18.3±2.1%; muscle mass: 72.7±2.2). However, no change in body composition was observed in ACE2(-/y) mice after exercise. Heart and skeletal muscle hypertrophy was observed only in trained ACE2(+/y) mice. Besides a small decrease in Ang I in ACE2(-/y) mice, plasma levels of angiotensin peptides remained unchanged by exercise or ACE2 deficiency. In the LV of trained animals, AT2 gene expression was higher in ACE2(+/y) compared with ACE2(-/y) mice. ACE2 deficiency leads to an increase in AT1 gene expression in skeletal muscle. ACE expression in soleus was increased in all exercised groups. ACE2 deficiency affects physical performance and impairs cardiac and skeletal muscle adaptations to exercise. PMID:27053009

  4. National Survey of ACE Programs.

    ERIC Educational Resources Information Center

    Constantino, Ernesto A.

    In 1987-88, a national survey was conducted to determine the adult/continuing education (ACE) policies and practices of large, urban community colleges. Questionnaires were mailed to ACE deans at 74 colleges, requesting information about program characteristics, funding sources, personnel, curriculum review, and marketing and publicity. Study…

  5. Flow-through enzyme immobilized amperometric detector for the rapid screening of acetylcholinesterase inhibitors by flow injection analysis.

    PubMed

    Vandeput, Marie; Parsajoo, Cobra; Vanheuverzwijn, Jérôme; Patris, Stéphanie; Yardim, Yavuz; le Jeune, Alexandre; Sarakbi, Ahmad; Mertens, Dominique; Kauffmann, Jean-Michel

    2015-01-01

    A commercially available thin-layer flow-through amperometric detector, with the sensing block customized in an original design, was applied to the screening of drug compounds known as acetylcholinesterase (AChE) inhibitors. AChE from electric eel was covalently immobilized onto a cysteamine modified gold disk adjacent to a silver disk working electrode. On-line studies were performed by flow injection analysis (FIA) in PBS buffer pH 7.4. Seven commercially available AChE inhibitors used in the medical field, namely neostigmine, eserine, tacrine, donepezil, rivastigmine, pyridostigmine and galantamine as well as two natural compounds, quercetin and berberine, were investigated. The same trend of inhibitory potency as described in the literature was observed. Of particular interest and in addition to the determination of the IC50 values, this flow-through system allowed the study of both, the stability of the enzyme-inhibitor complex and the kinetic of the enzyme activity recovery. PMID:25459923

  6. Monoterpenes as inhibitors of digestive enzymes and counter-adaptations in a specialist avian herbivore.

    PubMed

    Kohl, Kevin D; Pitman, Elizabeth; Robb, Brecken C; Connelly, John W; Dearing, M Denise; Forbey, Jennifer Sorensen

    2015-05-01

    Many plants produce plant secondary metabolites (PSM) that inhibit digestive enzymes of herbivores, thus limiting nutrient availability. In response, some specialist herbivores have evolved digestive enzymes that are resistant to inhibition. Monoterpenes, a class of PSMs, have not been investigated with respect to the interference of specific digestive enzymes, nor have such interactions been studied in avian herbivores. We investigated this interaction in the Greater Sage-Grouse (Phasianidae: Centrocercus urophasianus), which specializes on monoterpene-rich sagebrush species (Artemisia spp.). We first measured the monoterpene concentrations in gut contents of free-ranging sage-grouse. Next, we compared the ability of seven individual monoterpenes present in sagebrush to inhibit a protein-digesting enzyme, aminopeptidase-N. We also measured the inhibitory effects of PSM extracts from two sagebrush species. Inhibition of aminopeptidase-N in sage-grouse was compared to inhibition in chickens (Gallus gallus). We predicted that sage-grouse enzymes would retain higher activity when incubated with isolated monoterpenes or sagebrush extracts than chicken enzymes. We detected unchanged monoterpenes in the gut contents of free-ranging sage-grouse. We found that three isolated oxygenated monoterpenes (borneol, camphor, and 1,8-cineole) inhibited digestive enzymes of both bird species. Camphor and 1,8-cineole inhibited enzymes from chickens more than from sage-grouse. Extracts from both species of sagebrush had similar inhibition of chicken enzymes, but did not inhibit sage-grouse enzymes. These results suggest that specific monoterpenes may limit the protein digestibility of plant material by avian herbivores. Further, this work presents additional evidence that adaptations of digestive enzymes to plant defensive compounds may be a trait of specialist herbivores. PMID:25652583

  7. Intrarenal alterations of the angiotensin-converting enzyme type 2/angiotensin 1-7 complex of the renin-angiotensin system do not alter the course of malignant hypertension in Cyp1a1-Ren-2 transgenic rats.

    PubMed

    Husková, Zuzana; Kopkan, Libor; Červenková, Lenka; Doleželová, Šárka; Vaňourková, Zdeňka; Škaroupková, Petra; Nishiyama, Akira; Kompanowska-Jezierska, Elzbieta; Sadowski, Janusz; Kramer, Herbert J; Červenka, Luděk

    2016-04-01

    The role of the intrarenal renin-angiotensin system (RAS) in the pathophysiology of malignant hypertension is not fully understood. Accumulating evidence indicates that the recently discovered vasodilator axis of the RAS, angiotensin-converting enzyme (ACE) type 2 (ACE2)/angiotensin 1-7 (ANG 1-7), constitutes an endogenous system counterbalancing the hypertensiogenic axis, ACE/angiotensin II (ANG II)/AT1 receptor. This study aimed to evaluate the role of the intrarenal vasodilator RAS axis in the pathophysiology of ANG II-dependent malignant hypertension in Cyp1a1-Ren-2 transgenic rats. ANG II-dependent malignant hypertension was induced by 13 days' dietary administration of indole-3-carbinol (I3C), a natural xenobiotic that activates the mouse renin gene in Cyp1a1-Ren-2 transgenic rats. It was hypothesized that pharmacologically-induced inhibition of the ACE2/ANG 1-7 complex should aggravate, and activation of this axis should attenuate, the course of ANG II-dependent malignant hypertension. Blood pressure (BP) was monitored by radiotelemetry. ACE2 inhibitor (DX 600, 0.2 μg/day) and ACE2 activator (DIZE, 1 mg/day) were administrated via osmotic minipumps. Even though ACE2 inhibitor significantly decreased and ACE2 activator increased intrarenal ANG 1-7 concentrations, the course of BP, as well as of albuminuria, cardiac hypertrophy and renal glomerular damage, were not altered. It was shown that intrarenal alterations in the ACE2/ANG 1-7 complex did not significantly modify the course of malignant hypertension in I3C-induced Cyp1a1-Ren-2 transgenic rats. Thus, in our experimental setting alterations of this intrarenal vasodilator complex of the RAS do not significantly modify the form of malignant hypertension that clearly depends on the inappropriately increased activity of the ACE/ANG II/AT1 receptor axis. PMID:26833491

  8. Design, synthesis, and antihypertensive activity of curcumin-inspired compounds via ACE inhibition and vasodilation, along with a bioavailability study for possible benefit in cardiovascular diseases.

    PubMed

    Zhuang, Xiao-Dong; Liao, Li-Zhen; Dong, Xiao-Bian; Hu, Xun; Guo, Yue; Du, Zhi-Min; Liao, Xin-Xue; Wang, Li-Chun

    2016-01-01

    This study describes the synthesis of a novel series of curcumin-inspired compounds via a facile synthetic route. The structures of these derivatives were ascertained using various spectroscopic and analytic techniques. The pharmacological effects of the target analogs were assessed by assaying their inhibition of angiotensin-converting enzyme (ACE). All of the synthesized derivatives exhibited considerable inhibition of ACE, with half-maximal inhibitory concentrations ranging from 1.23 to 120.32 μM. In a docking analysis with testicular ACE (tACE), the most promising inhibitor (4j) was efficiently accommodated in the deep cleft of the protein cavity, making close interatomic contacts with Glu162, His353, and Ala356, comparable with lisinopril. Compounds 4i, 4j, 4k, and 4l were further selected for determination of their vasodilator activity (cardiac output and stroke volume) on isolated rat hearts using the Langendorff technique. The bioavailability of compound 4j was determined in experimental mice. PMID:26792980

  9. Design, synthesis, and antihypertensive activity of curcumin-inspired compounds via ACE inhibition and vasodilation, along with a bioavailability study for possible benefit in cardiovascular diseases

    PubMed Central

    Zhuang, Xiao-dong; Liao, Li-zhen; Dong, Xiao-bian; Hu, Xun; Guo, Yue; Du, Zhi-min; Liao, Xin-xue; Wang, Li-chun

    2016-01-01

    This study describes the synthesis of a novel series of curcumin-inspired compounds via a facile synthetic route. The structures of these derivatives were ascertained using various spectroscopic and analytic techniques. The pharmacological effects of the target analogs were assessed by assaying their inhibition of angiotensin-converting enzyme (ACE). All of the synthesized derivatives exhibited considerable inhibition of ACE, with half-maximal inhibitory concentrations ranging from 1.23 to 120.32 μM. In a docking analysis with testicular ACE (tACE), the most promising inhibitor (4j) was efficiently accommodated in the deep cleft of the protein cavity, making close interatomic contacts with Glu162, His353, and Ala356, comparable with lisinopril. Compounds 4i, 4j, 4k, and 4l were further selected for determination of their vasodilator activity (cardiac output and stroke volume) on isolated rat hearts using the Langendorff technique. The bioavailability of compound 4j was determined in experimental mice. PMID:26792980

  10. The intrinsic dynamics of enzymes plays a dominant role in determining the structural changes induced upon inhibitor binding.

    PubMed

    Bakan, Ahmet; Bahar, Ivet

    2009-08-25

    The conformational flexibility of target proteins continues to be a major challenge in accurate modeling of protein-inhibitor interactions. A fundamental issue, yet to be clarified, is whether the observed conformational changes are controlled by the protein or induced by the inhibitor. Although the concept of induced fit has been widely adopted for describing the structural changes that accompany ligand binding, there is growing evidence in support of the dominance of proteins' intrinsic dynamics which has been evolutionarily optimized to accommodate its functional interactions. The wealth of structural data for target proteins in the presence of different ligands now permits us to make a critical assessment of the balance between these two effects in selecting the bound forms. We focused on three widely studied drug targets, HIV-1 reverse transcriptase, p38 MAP kinase, and cyclin-dependent kinase 2. A total of 292 structures determined for these enzymes in the presence of different inhibitors and unbound form permitted us to perform an extensive comparative analysis of the conformational space accessed upon ligand binding, and its relation to the intrinsic dynamics before ligand binding as predicted by elastic network model analysis. Our results show that the ligand selects the conformer that best matches its structural and dynamic properties among the conformers intrinsically accessible to the protein in the unliganded form. The results suggest that simple but robust rules encoded in the protein structure play a dominant role in predefining the mechanisms of ligand binding, which may be advantageously exploited in designing inhibitors. PMID:19706521

  11. The discovery of novel tartrate-based TNF-[alpha] converting enzyme (TACE) inhibitors

    SciTech Connect

    Rosner, Kristin E.; Guo, Zhuyan; Orth, Peter; Shipps, Jr., Gerald W.; Belanger, David B.; Chan, Tin Yau; Curran, Patrick J.; Dai, Chaoyang; Deng, Yongqi; Girijavallabhan, Vinay M.; Hong, Liwu; Lavey, Brian J.; Lee, Joe F.; Li, Dansu; Liu, Zhidan; Popovici-Muller, Janeta; Ting, Pauline C.; Vaccaro, Henry; Wang, Li; Wang, Tong; Yu, W.; Zhou, G.; Niu, X.; Sun, J.; Kozlowski, J.A.; Lundell, D.J.; Madison, V.; McKittrick, B.; Piwinski, J.J.; Shih, N.Y.; Siddiqui, M. Arshad; Strickland, Corey O.

    2010-09-17

    A novel series of TNF-{alpha} convertase (TACE) inhibitors which are non-hydroxamate have been discovered. These compounds are bis-amides of L-tartaric acid (tartrate) and coordinate to the active site zinc in a tridentate manner. They are selective for TACE over other MMP's. We report the first X-ray crystal structure for a tartrate-based TACE inhibitor.

  12. The ACE2/Ang-(1-7)/Mas Axis Regulates the Development of Pancreatic Endocrine Cells in Mouse Embryos

    PubMed Central

    Wang, Lin; Liang, Juan; Leung, Po Sing

    2015-01-01

    Angiotensin-converting enzyme 2 (ACE2), its product Angiotensin-(1-7) [Ang-(1-7)], and Ang-(1-7) receptor Mas, have been shown to regulate organogenesis during embryonic development in various species. However, it is not known whether a local ACE2/Ang-(1-7)/Mas axis is present in the fetal pancreas. It is hypothesized that there is a local ACE2/Ang-(1-7)/Mas axis in the embryonic pancreas in mice that is involved in regulating islet cell development. To address this issue, the endogenous expression profile of axis constituents in embryonic mouse pancreata was examined. Involvement of the ACE2 axis in the regulation of pancreatic development was also examined. The present experiments showed in an in vivo animal model that endogenous expression levels of ACE2 and the Mas receptor were upregulated in mouse pancreata in late embryogenesis, peaking on embryonic day E16.5, when it reached 3 folds compared to that seen at E12.5. Consistently, endogenous expression of Ang-(1-7) also peaked at E16.5. Treatment with the ACE2 inhibitor DX600 did not alter islet development. However, prenatal treatment with A779, a Mas receptor antagonist, reduced the β-cell to α-cell ratio in neonatal islets, impaired islet insulin secretory function, and impaired the pups’ glucose tolerance. In ex vivo pancreas explant cultures, A779 again decreased the β-cell to α-cell ratio, apparently through its effects on β-cell proliferation (reduced proliferation shown with Ki67 staining), and also decreased Insulin and Ngn3 mRNA expression. Furthermore, treatment of explant cultures with Ang-(1-7) increased mRNA levels of Insulin and pancreatic progenitor marker Ngn3, as well as Nox4, the ROS generation enzyme; these stimulatory effects were attenuated by co-treatment with A779, suggesting that Ang-(1-7), via Mas receptor signaling, may promote differentiation of pancreatic progenitors into insulin-producing cells via modulation of reactive oxygen species. These data together suggest that a

  13. Prevention of lethal graft vs Host disease following bone marrow transplantation (pretreatment of the inoculum with purine metabolic enzyme inhibitors)

    SciTech Connect

    Kennedy, D.W.

    1983-01-01

    A correlation between lymphocyte function and enzymes of the purine metabolic pathway has been shown. Abnormal levels of three of these enzymes - adenosine deaminase (ADA), 5'-nucleotidase (5'-NT), and purine nucleoside phosphorylase (PNP) - have been associated with defective lymphoid functions. Selective inhibition of one or more of these enzymes may result in elimination of specific lymphocyte populations from a bone marrow (BM) graft and thus prevent graft-vs-host disease (GVHD). To test this hypothesis, BM and spleen cells were pretreated with inhibitors of ADA or PNP before transplant to histoincompatible recipients. Germfree (GF) mice approximately 11 weeks of age were lethally X-irradiated with 1000 Rads. At 24 hours post irradiation the mice received 5 x 10/sup 6/ BM cells and 5 x 10/sup 6/ BM cells and 5 x 10/sup 6/ spleen cells i.v. from syngeneic donors or allogeneic donors. Prior to injection the mice were divided into 5 groups: (1) the inoculum was treated with a final concentration of 10 ..mu..M deoxycoformycin (dCF), and ADA inhibitor, and 100 ..mu..M deoxyadenosine (dAdo); (2) the inoculum was treated with a final concentration of 100 ..mu..M 8-aminoguanosine (8AGuo), an inhibitor of PNP, and 100 ..mu..M 2'-deoxyguanosine (2'dGuo); (3) allogenic controls; (4) syngeneic controls; and (5) radiation controls. In vitro experiments utilizing human peripheral blood and bone marrow demonstrated a severe immunosuppressive effect by the combination of 2'dCF and dAdo which was quick acting and not easily washed away. Treatment with 8A Guo + 2'dGuo also was immunosuppressive, but not as effective as the dCF and dAdo treatment. Both groups of drugs deserve further investigation for possible clinical application to BM transplantation.

  14. Effect of Enzyme Inhibitors on Terpene Trilactones Biosynthesis and Gene Expression Profiling in Ginkgo biloba Cultured Cells.

    PubMed

    Chen, Lijia; Tong, Hui; Wang, Mingxuan; Zhu, Jianhua; Zi, Jiachen; Song, Liyan; Yu, Rongmin

    2015-12-01

    The biosynthetic pathway of terpene trilactones of Ginkgo biloba is unclear. In this present study, suspension cultured cells of G. biloba were used to explore the regulation of the mevalonic acid (MVA) and methylerythritol 4-phosphate (MEP) pathways in response to specific enzyme inhibitors (lovastatin and clomazone). The results showed that the biosynthesis of bilobalide was more highly correlated with the MVA pathway, and the biosynthesis of ginkgolides was more highly correlated with the MEP pathway. Meanwhile, according to the results, it could be speculated that bilobalide might be a product of ginkgolide metabolism. PMID:26882658

  15. Kinetic Study of the Effect of Histidines 240 and 164 on TEM-149 Enzyme Probed by β-Lactam Inhibitors

    PubMed Central

    Mancini, Alisia; Celenza, Giuseppe; Bottoni, Carlo; Bellio, Pierangelo; Sabatini, Alessia; Di Pietro, Letizia; Brisdelli, Fabrizia; Segatore, Bernardetta; Amicosante, Gianfranco

    2014-01-01

    In the present study, we performed a detailed kinetic analysis of the enzymes TEM-149, TEM-149H240, and TEM-149H164-H240 versus a large panel of inhibitors/inactivators, including penicillins, penems, carbapenems, monobactams, cephamycin, and carbacephem. These compounds behaved as poor substrates versus TEM-149, TEM-149H240, and TEM-149H164-H240 β-lactamases, and the Ki (inhibition constant), K (dissociation constant of the Henri-Michaelis complex), k+2 and k+3 (first-order acylation and deacylation constants, respectively), and k+2/K values were calculated. PMID:25092695

  16. Therapeutic effect of human umbilical cord mesenchymal stem cells modified by angiotensin-converting enzyme 2 gene on bleomycin-induced lung fibrosis injury.

    PubMed

    Min, Fang; Gao, Fengying; Li, Qian; Liu, Zhenwei

    2015-04-01

    The aim of the present study was to evaluate the therapeutic effects of human umbilical cord mesenchymal stem cells (uMSCs) in the presence of angiotensin‑converting enzyme 2 gene (ACE2; ACE2‑uMSCs) on bleomycin (BLM)‑induced lung injury and pulmonary fibrosis in mice. A total of 100 male C57BL/6 mice were divided at random into five groups (n=20) as follows: Control group, BLM group, ACE2 group, uMSC group and ACE2‑uMSC group. At 7, 14 and 28 days post‑treatment, the following parameters were evaluated in lung tissue: Oxidation indexes [malondialedehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and oxidized glutathione (GSSG)]; fibrosis factors [tumor necrosis factor (TNF)‑α, interferon (IFN)‑γ and transforming growth factor (TGF)‑β]; inflammatory cytokines [Interleukin (IL)‑1, IL‑2, IL‑6 and IL‑10]; ACE2 gene expression; hydroxyproline and collagen type 1 messenger RNA (mRNA) concentration; as well as matrix metalloproteinase (MMPs; 2 and 9) and tissue inhibitor of metalloproteinase (TIMP)1‑4 expression. ACE2‑uMSC injection following bleomycin pretreatment significantly alleviated lung injury in mice. In addition, treatment with ACE2‑uMSCs demonstrated a stronger therapeutic effect than ACE2‑ or uMSC treatment alone, indicated by decreased expression of MDA, GSSG, TNF‑α, IFN‑γ, TGF‑β, IL‑1, IL‑2, IL‑6, collagen type 1 mRNA, MMPs and TIMPs as well as hydroxyproline concentration, and upregulation of SOD, GSH and ACE2 and IL‑10. In conclusion, the results of the present study demonstrated that ACE2 and uMSCs had a synergistic therapeutic effect on bleomycin‑induced acute lung injury. PMID:25435005

  17. Screening for selective inhibitors of xanthine oxidase from Flos Chrysanthemum using ultrafiltration LC-MS combined with enzyme channel blocking.

    PubMed

    Song, Hui-Peng; Zhang, Hui; Fu, Yu; Mo, Hua-yan; Zhang, Mu; Chen, Jun; Li, Ping

    2014-06-15

    In this study, a new method based on ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS) combined with enzyme channel blocking (ECB) was developed to discover bioactive components from herbal medicines. Xanthine oxidase (XOD), a critical enzyme for treating gout, was employed as the target protein for screening. By comparing chromatographic profiles of the compounds binding to XOD before and after the ECB experiment, the selective ligands could be distinguished from the non-selective binders. In this experiment, febuxostat bound to the channel entering into the active site of the enzyme and prevented potential ligands from binding. Finally, four compounds, namely, luteolin-7-O-glucoside, apigenin-7-O-glucoside, luteolin and apigenin were screened and identified as the candidate XOD inhibitors based on the ultrafiltration chromatogram of Flos Chrysanthemum, a famous traditional Chinese medicine used in many prescriptions for gout treatment. To verify the compounds screened further, a microplate method was applied to evaluate their enzyme inhibitory activities. The IC50 values of the above 4 compounds were 23.61, 38.80, 1.54 and 1.96μM, respectively. The structure-function relationship was also estimated according to the in vitro assay. The results were in favor of the hypothesis that the Flos Chrysanthemum extract might be used for gout treatment by inhibiting XOD. PMID:24861872

  18. 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. PMID:26862777

  19. [Proteolytic enzymes and trypsin inhibitors of higher plants under stress conditions].

    PubMed

    Domash, V I; Sharpio, T P; Zabreĭko, S A; Sosnovskaia, T F

    2008-01-01

    The response of the components of a protease-inhibitor system of legume and cereal crops to stress factors was studied. It was found that salinization, heavy metal ions, and phytopathogenic flora inhibit the activity of neutral, acidic, and alkaline proteases at early stages of seed germination, the degree of the inhibition of the endoprotease activity being dependent on the index of tolerance of legume and cereal crops. It was shown that, in response to unfavorable conditions, accumulation of trypsin inhibitors occurs, which is accompanied by the appearance of new protein components, as indicated by electrophoresis. The results confirm the presumption that serine protease inhibitors are involved in the response of plants to stress factors. PMID:18672684

  20. Metabolic effects of inhibitors of two enzymes of the branched-chain amino acid pathway in Salmonella typhimurium.

    PubMed Central

    Epelbaum, S; Chipman, D M; Barak, Z

    1996-01-01

    The metabolic effects of inhibitors of two enzymes in the pathway for biosynthesis of branched-chain amino acids were examined in Salmonella typhimurium mutant strain TV105, expressing a single isozyme of acetohydroxy acid synthase (AHAS), AHAS isozyme II. One inhibitor was the sulfonylurea herbicide sulfometuron methyl (SMM), which inhibits this isozyme and AHAS of other organisms, and the other was N-isopropyl oxalylhydroxamate (IpOHA), which inhibits ketol-acid reductoisomerase (KARI). The effects of the inhibitors on growth, levels of several enzymes of the pathway, and levels of intermediates of the pathway were measured. The intracellular concentration of the AHAS substrate 2-ketobutyrate increased on addition of SMM, but a lack of correlation between increased ketobutyrate and growth inhibition suggests that the former is not the immediate cause of the latter. The levels of the keto acid precursor of valine, but not of the precursor of isoleucine, were drastically decreased by SMM, and valine, but not isoleucine, partially overcame SMM inhibition. This apparent stronger effect of SMM on the flux into the valine arm, as opposed to the isoleucine arm, of the branched-chain amino acid pathway is explained by the kinetics of the AHAS reaction, as well as by the different roles of pyruvate, ketobutyrate, and the valine precursor in metabolism. The organization of the pathway thus potentiates the inhibitory effect of SMM. IpOHA has strong initial effects at lower concentrations than does SMM and leads to increases both in the acetohydroxy acid substrates of KARI and, surprisingly, in ketobutyrate. Valine completely protected strain TV105 from IpOHA at the MIC. A number of explanations for this effect can be ruled out, so that some unknown arrangement of the enzymes involved must be suggested. IpOHA led to initial cessation of growth, with partial recovery after a time whose duration increased with the inhibitor concentration. The recovery is apparently due to

  1. Metabolic effects of inhibitors of two enzymes of the branched-chain amino acid pathway in Salmonella typhimurium.

    PubMed

    Epelbaum, S; Chipman, D M; Barak, Z

    1996-02-01

    The metabolic effects of inhibitors of two enzymes in the pathway for biosynthesis of branched-chain amino acids were examined in Salmonella typhimurium mutant strain TV105, expressing a single isozyme of acetohydroxy acid synthase (AHAS), AHAS isozyme II. One inhibitor was the sulfonylurea herbicide sulfometuron methyl (SMM), which inhibits this isozyme and AHAS of other organisms, and the other was N-isopropyl oxalylhydroxamate (IpOHA), which inhibits ketol-acid reductoisomerase (KARI). The effects of the inhibitors on growth, levels of several enzymes of the pathway, and levels of intermediates of the pathway were measured. The intracellular concentration of the AHAS substrate 2-ketobutyrate increased on addition of SMM, but a lack of correlation between increased ketobutyrate and growth inhibition suggests that the former is not the immediate cause of the latter. The levels of the keto acid precursor of valine, but not of the precursor of isoleucine, were drastically decreased by SMM, and valine, but not isoleucine, partially overcame SMM inhibition. This apparent stronger effect of SMM on the flux into the valine arm, as opposed to the isoleucine arm, of the branched-chain amino acid pathway is explained by the kinetics of the AHAS reaction, as well as by the different roles of pyruvate, ketobutyrate, and the valine precursor in metabolism. The organization of the pathway thus potentiates the inhibitory effect of SMM. IpOHA has strong initial effects at lower concentrations than does SMM and leads to increases both in the acetohydroxy acid substrates of KARI and, surprisingly, in ketobutyrate. Valine completely protected strain TV105 from IpOHA at the MIC. A number of explanations for this effect can be ruled out, so that some unknown arrangement of the enzymes involved must be suggested. IpOHA led to initial cessation of growth, with partial recovery after a time whose duration increased with the inhibitor concentration. The recovery is apparently due to

  2. Twenty years of the MEROPS database of proteolytic enzymes, their substrates and inhibitors.

    PubMed

    Rawlings, Neil D; Barrett, Alan J; Finn, Robert

    2016-01-01

    The MEROPS database (http://merops.sanger.ac.uk) is an integrated source of information about peptidases, their substrates and inhibitors, which are of great relevance to biology, medicine and biotechnology. The hierarchical classification of the database is as follows: homologous sets of sequences are grouped into a protein species; protein species are grouped into a family; families are grouped into clans. There is a type example for each protein species (known as a 'holotype'), family and clan, and each protein species, family and clan has its own unique identifier. Pages to show the involvement of peptidases and peptidase inhibitors in biological pathways have been created. Each page shows the peptidases and peptidase inhibitors involved in the pathway, along with the known substrate cleavages and peptidase-inhibitor interactions, and a link to the KEGG database of biological pathways. Links have also been established with the IUPHAR Guide to Pharmacology. A new service has been set up to allow the submission of identified substrate cleavages so that conservation of the cleavage site can be assessed. This should help establish whether or not a cleavage site is physiologically relevant on the basis that such a cleavage site is likely to be conserved. PMID:26527717

  3. Discovery of Novel Nonactive Site Inhibitors of the Prothrombinase Enzyme Complex.

    PubMed

    Kapoor, Karan; McGill, Nicole; Peterson, Cynthia B; Meyers, Harold V; Blackburn, Michael N; Baudry, Jerome

    2016-03-28

    The risk of serious bleeding is a major liability of anticoagulant drugs that are active-site competitive inhibitors targeting the Factor Xa (FXa) prothrombin (PT) binding site. The present work identifies several new classes of small molecule anticoagulants that can act as nonactive site inhibitors of the prothrombinase (PTase) complex composed of FXa and Factor Va (FVa). These new classes of anticoagulants were identified, using a novel agnostic computational approach to identify previously unrecognized binding pockets at the FXa-FVa interface. From about three million docking calculations of 281,128 compounds in a conformational ensemble of FXa heavy chains identified by molecular dynamics (MD) simulations, 97 compounds and their structural analogues were selected for experimental validation, through a series of inhibition assays. The compound selection was based on their predicted binding affinities to FXa and their ability to successfully bind to multiple protein conformations while showing selectivity for particular binding sites at the FXa/FVa interface. From these, thirty-one (31) compounds were experimentally identified as nonactive site inhibitors. Concentration-based assays further identified 10 compounds represented by four small-molecule families of inhibitors that achieve dose-independent partial inhibition of PTase activity in a nonactive site-dependent and self-limiting mechanism. Several compounds were identified for their ability to bind to protein conformations only seen during MD, highlighting the importance of accounting for protein flexibility in structure-based drug discovery approaches. PMID:26848511

  4. Three low molecular weight cysteine proteinase inhibitors of human seminal fluid: purification and enzyme kinetic properties.

    PubMed

    Yadav, Vikash Kumar; Chhikara, Nirmal; Gill, Kamaldeep; Dey, Sharmistha; Singh, Sarman; Yadav, Savita

    2013-08-01

    The cystatins form a superfamily of structurally related proteins with highly conserved structural folds. They are all potent, reversible, competitive inhibitors of cysteine proteinases (CPs). Proteins from this group present differences in proteinase inhibition despite their high level of structural similarities. In this study, three cysteine proteinase inhibitors (CPIs) of low molecular weight were isolated from human seminal fluid (HSF) by affinity chromatography on carboxymethyl (CM)-papain-Sepharose column, purified using various chromatographic procedures and checked for purity on sodium-dodecyl PAGE (SDS-PAGE). Matrix-assisted laser desorption-ionization-time-of flight-mass spectrometry (MALDI-TOF-MS) identified these proteins as cystatin 9, cystatin SN, and SAP-1 (an N-terminal truncated form of cystatin S). All three CPIs suppressed the activity of papain potentially and showed remarkable heat stability. Interestingly SAP-1 also inhibits the activity of trypsin, chymotrypsin, pepsin, and PSA (prostate specific antigen) and acts as a cross-class protease inhibitor in in vitro studies. Using Surface Plasmon Resonance, we have also observed that SAP-1 shows a significant binding with all these proteases. These studies suggest that SAP-1 is a cross-class inhibitor that may regulate activity of various classes of proteases within the reproductive systems. To our knowledge, this is the first report about purification of CPIs from HSF; the identification of such proteins could provide better insights into the physiological processes and offer intimation for further research. PMID:23619703

  5. Is angiotensin-converting enzyme inhibitors/angiotensin receptor blockers therapy protective against prostate cancer?

    PubMed Central

    Mao, Yeqing; Xu, Xin; Wang, Xiao; Zheng, Xiangyi; Xie, Liping

    2016-01-01

    Emerging evidence suggests that renin-angiotensin system (RAS) may act as a molecular and therapeutic target for treating site-specific cancers, including prostate cancer. However, previous observational studies regarding the association between RAS inhibitors and prostate cancer risk have reported inconsistent results. We examined this association by performing a systematic review and meta-analysis. A total of 20,267 patients from nine cohort studies were enrolled. Compared with non-users of RAS inhibitors, individuals using RAS inhibitors had a reduced risk of prostate cancer (RR 0.92, 95 % CI 0.87-0.98), without statistically significant heterogeneity among studies (P = 0.118 for heterogeneity, I2 = 37.6 %). In addition, when subgroup analyses by study quality and number of cases, more statistically significant associations were observed in studies of high quality (RR 0.93, 95 % CI 0.88-0.97) and large sample size (RR 0.94, 95 % CI 0.91-0.98). There was no evidence of significant publication bias with Begg's test (P = 0.602) or with Egger's test (P = 0.350). Overall, this study indicates that use of RAS inhibitors may be associated with a decreased risk of prostate cancer. Large-scale well designed studies are needed to further explore this association. PMID:26760503

  6. An Allosteric Inhibitor of the Human Cdc34 Ubiquitin-Conjugating Enzyme

    SciTech Connect

    Ceccarelli, Derek F.; Tang, Xiaojing; Pelletier, Benoit; Orlicky, Stephen; Xie, Weilin; Plantevin, Veronique; Neculai, Dante; Chou, Yang-Chieh; Ogunjimi, Abiodun; Al-Hakim, Abdallah; Varelas, Xaralabos; Koszela, Joanna; Wasney, Gregory A.; Vedadi, Masoud; Dhe-Paganon, Sirano; Cox, Sarah; Xu, Shuichan; Lopez-Girona, Antonia; Mercurio, Frank; Wrana, Jeff; Durocher, Daniel; Meloche, Sylvain; Webb, David R.; Tyers, Mike; Sicheri, Frank

    2011-09-06

    In the ubiquitin-proteasome system (UPS), E2 enzymes mediate the conjugation of ubiquitin to substrates and thereby control protein stability and interactions. The E2 enzyme hCdc34 catalyzes the ubiquitination of hundreds of proteins in conjunction with the cullin-RING (CRL) superfamily of E3 enzymes. We identified a small molecule termed CC0651 that selectively inhibits hCdc34. Structure determination revealed that CC0651 inserts into a cryptic binding pocket on hCdc34 distant from the catalytic site, causing subtle but wholesale displacement of E2 secondary structural elements. CC0651 analogs inhibited proliferation of human cancer cell lines and caused accumulation of the SCF{sup Skp2} substrate p27{sup Kip1}. CC0651 does not affect hCdc34 interactions with E1 or E3 enzymes or the formation of the ubiquitin thioester but instead interferes with the discharge of ubiquitin to acceptor lysine residues. E2 enzymes are thus susceptible to noncatalytic site inhibition and may represent a viable class of drug target in the UPS.

  7. Identification of CYP2C19 inhibitors from phytochemicals using the recombinant human enzyme model.

    PubMed

    Kong, L M; Xu, S Y; Hu, H H; Zhou, H; Jiang, H D; Yu, L S; Zeng, S

    2014-05-01

    The aim of the present study was to develop the recombinant insect cell-expressed protein as an in vitro model for inhibitors screening for human cytochrome P450 2C19 (CYP2C19), and to use the model to investigate the inhibition effect of three phytochemicals on CYP2C19 in vitro. Omeprazole was applied as the probe substrate. The estimated inhibitory constant (K(i)) of ticlopidine and fluvoxamine were 0.64 +/- 0.025 microM and 0.29 +/- 0.090 microM, respectively. After co-incubation with ticlopidine or fluvoxamine, the mean omeprazole Michaelis-Menten constant (K(m)) increased from 4.99 +/- 0.22 microM to 16.25 +/- 1.22 microM or 19.20 +/- 1.73 microM, respectively, while omeprazole's mean V(max) did not vary much. Both ticlopidine and fluvoxamine were competitive inhibitors of CYP2C19. The IC50 of three phytochemicals, isoalantolactone, curcumol and schisandrin A was determined as 38.91 microM, 121.0 microM and 86.41 microM, and the K(i) as 5.02 +/- 1.04 microM, 35.84 +/- 8.95 microM, and 4.46 +/- 0.017 microM, respectively. The in vitro model for inhibitor screening established using recombinant CYP2C19 could be used to assess the inhibition potential of drug candidates. Isoalantolactone and schisandrin A are potent inhibitors of CYP2C19, while curcumol is a moderate potent inhibitor of CYP2C19. PMID:24855828

  8. Silencing of the polyamine catabolic key enzyme SSAT prevents CDK inhibitor-induced apoptosis in Caco-2 colon cancer cells.

    PubMed

    Çoker, A; Arısan, E D; Palavan-Ünsal, N

    2012-04-01

    Roscovitine and purvalanol are purine derivative cyclin-dependent kinase (CDK) inhibitors that induce apoptosis in various types of cancer cells. However, their impact on the apoptotic cell death mechanism requires further elucidation. Natural polyamines putrescine, spermidine and spermine play essential roles in the regulation of cell growth and proliferation. Increased levels of polyamines in cells are considered to be involved in cancer progression. Intracellular polyamine levels are under the control of several catabolic enzymes, such as spermidine/spermine-N-acetyl transferase (SSAT), acetylpolyamine oxidase (APAO) and spermine oxidase (SMO), which could be altered by several therapeutic drugs. However, the possible role of polyamines in drug-induced apoptosis has yet to be clarified. In the present study, our aim was to determine the modulation of the polyamine catabolic pathway related to CDK inhibitor-induced apoptosis in Caco-2 cells. We found that roscovitine and purvalanol (each 20 µM) induced apoptosis by activating caspase-9 and -3, and inhibiting the mitochondrial membrane potential in Caco-2 cells. CDK inhibitors decreased the intracellular putrescine and spermine levels without affecting spermidine levels. Although both roscovitine and purvalanol induced SSAT expression, they did not exert a significant effect on the APAO expression profile. SSAT transient silencing prevented roscovitine-induced apoptosis compared to parental cells. Thus, we concluded that roscovitine and purvalanol significantly induce apoptosis in Caco-2 cells by modulating the polyamine catabolism, and that SSAT could be an important target in evaluating the potential role of polyamines in apoptotic cell death. PMID:22294330

  9. Potent and Selective α-Ketoheterocycle-Based Inhibitors of the Anandamide and Oleamide Catabolizing Enzyme, Fatty Acid Amide Hydrolase

    PubMed Central

    Romero, F. Anthony; Du, Wu; Hwang, Inkyu; Rayl, Thomas J.; Kimball, F. Scott; Leung, Donmienne; Hoover, Heather S.; Apodaca, Richard L.; Breitenbucher, J. Guy; Cravatt, Benjamin F.; Boger, Dale L.

    2008-01-01

    A study of the structure–activity relationships (SAR) of 2f (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the 5-position of the oxazole. Examination of a series of substituted benzene derivatives (12–14) revealed that the optimal position for substitution was the meta-position with selected members approaching or exceeding the potency of 2f. Concurrent with these studies, the effect of substitution on the pyridine ring of 2f was also examined. A series of small, non-aromatic C5-substituents was also explored and revealed that the Ki follows a well-defined correlation with the Hammett σp constant (ρ = 3.01, R2 = 0.91) in which electron-withdrawing substituents enhance potency leading to inhibitors with Ki’s as low as 400 pM (20n). Proteomic-wide screening of the inhibitors revealed that most are exquisitely selective for FAAH over all other mammalian proteases reversing the 100-fold preference of 20a (C5 substituent = H) for the enzyme TGH. PMID:17279740

  10. Heterocyclic derivatives of 3-substituted-1,1,1-trifluoro-2-propanones as inhibitors of esterolytic enzymes.

    PubMed

    Székács, A; Halarnkar, P P; Olmstead, M M; Prag, K A; Hammock, B D

    1990-01-01

    A series of (alkylthio)trifluoropropanones containing a heterocyclic moiety was synthesized. The compounds were tested for in vitro inhibition of four hydrolytic enzymes including insect juvenile hormone esterase (JHE), eel acetylcholinesterase (AChE), yeast lipase (LP), and bovine alpha-chymotrypsin. The I50 values ranged from 10(-3) to 10(-7) M. 3-(2-Pyridylthio)-1,1,1-trifluoro-2-propanone was found to be the most potent inhibitor as compared to the other tested heterocyclic analogues with an I50 value of 98 nM against JHE from the fifth-instar larvae of Trichoplusia ni. Results from X-ray crystallography showed that the compound exists in a tetrahedral gem-diol form stabilized by an intramolecular hydrogen bond in the solid state. X-ray crystallography of a less potent inhibitor, 3-(4-pyridylthio)-1,1,1-trifluoro-2- propanone, showed that it also exists in the hydrated form, but it lacks an intramolecular hydrogen bond. These results provide indirect support that trifluoromethyl ketones are transition-state mimic inhibitors of esterases, and the bearing of the results on the transition-state mimic theory is discussed. The I50 values against AChE were in the micromolar range. Compounds containing a imidazolyl, triazolyl, and pyrimidyl moiety showed the highest inhibition of this enzyme. Differential selectivity of inhibition was associated with the bond distances between the nitrogen and the carbonyl group as in the natural substrate, when measured in the molecules in their minimal energy conformations. Inhibition of LP was moderate to weak, when compared to JHE and AChE. None of the tested compounds showed significant inhibition of alpha-chymotrypsin.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2133080

  11. Discovery of Desketoraloxifene Analogues as Inhibitors of Mammalian, Pseudomonas aeruginosa, and NAPE Phospholipase D Enzymes

    PubMed Central

    2015-01-01

    Phospholipase D (PLD) hydrolyses cellular lipids to produce the important lipid second messenger phosphatidic acid. A PLD enzyme expressed by Pseudomonas aeruginosa (PldA) has been shown to be important in bacterial infection, and NAPE-PLD has emerged as being key in the synthesis of endocannabinoids. In order to better understand the biology and therapeutic potential of these less explored PLD enzymes, small molecule tools are required. Selective estrogen receptor modulators (SERMs) have been previously shown to inhibit mammalian PLD (PLD1 and PLD2). By targeted screening of a library of SERM analogues, additional parallel synthesis, and evaluation in multiple PLD assays, we discovered a novel desketoraloxifene-based scaffold that inhibited not only the two mammalian PLDs but also structurally divergent PldA and NAPE-PLD. This finding represents an important first step toward the development of small molecules possessing universal inhibition of divergent PLD enzymes to advance the field. PMID:25384256

  12. Synthetic peptides derived from the prosegments of proprotein convertase 1/3 and furin are potent inhibitors of both enzymes.

    PubMed Central

    Basak, Ajoy; Lazure, Claude

    2003-01-01

    Proprotein convertases (PCs) are Ca(2+)-dependent serine proteases of the subtilisin/kexin family which are known specifically to cleave propeptide and proprotein substrates at the C-terminal of R-X-(K/R)-R/ to generate the relevant biologically active peptides. PCs are initially synthesized as enzymically inactive proenzyme forms where the prosegments play an important inhibitory role to the respective enzymes. Here we investigated whether synthetic peptides derived from the pro-region could also represent specific and potent inhibitors. Based upon sequence alignment, secondary structure analysis and hydrophilicity plot, a number of peptides ranging from 8 to 33 residues were selected. These included segments encompassing residues 55-62, 50-62, 39-62, 50-83, 55-83, 64-83 and 74-83 in the pro-mouse PC1/3 sequence and residues 54-62, 48-62 and 39-62 of the pro-human furin sequence. All peptides were prepared by solid-phase FastMoc chemistry, purified by reversed-phase HPLC and characterized by MS and amino acid analysis. These peptides were tested in vitro for inhibitory activity towards recombinant mouse PC1/3 and human furin. Progress-curve and end-time kinetic analysis demonstrated that a number of these peptides, particularly those containing both the primary and the secondary processing sites, displayed strong inhibition of both enzymes with inhibition constants (K (i)) in the high nanomolar range. Unlike the whole propeptide, these small synthetic peptide inhibitors exhibited either true competitive or mixed competitive inhibition, depending on the sequence. Our data revealed further the critical role of the last two basic amino acid residues (e.g. Lys(82)-Arg(83) for the mouse PC1/3 sequence) of the prodomain in imparting a strong anti-convertase activity. The study also establishes the inhibitory potential of certain regions contained within the prosegment of the two convertases. PMID:12662153

  13. Inhibitors

    MedlinePlus

    ... Community Counts Blood Safety Inhibitors Articles & Key Findings Free Materials Videos Starting the Conversation Playing it Safe A Look at Hemophilia Joint Range of Motion My Story Links to Other Websites ...

  14. Cognitive enhancing effect of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers on learning and memory

    PubMed Central

    Nade, V. S.; Kawale, L. A.; Valte, K. D.; Shendye, N. V.

    2015-01-01

    Objective: The present study was designed to investigate cognitive enhancing property of angiotensin-converting enzymes inhibitors (ACEI) and angiotensin receptor blockers (ARBs) in rats. Materials and Methods: The elevated plus maze (EPM), passive avoidance test (PAT), and water maze test (WMT) were used to assess cognitive enhancing activity in young and aged rats. Ramipril (10 mg/kg, p.o.), perindopril (10 mg/kg, i.p), losartan (20 mg/kg, i.p), and valsartan (20 mg/kg, p.o) were administered to assess their effect on learning and memory. Scopolamine (1 mg/kg, i.p) was used to impair cognitive function. Piracetam (200 mg/kg, i.p) was used as reference drug. Results: All the treatments significantly attenuated amnesia induced by aging and scopolamine. In EPM, aged and scopolamine-treated rats showed an increase in transfer latency (TL) whereas, ACEI and ARBs showed a significant decrease in TL. Treatment with ACEI and ARBs significantly increased step down latencies and decreased latency to reach the platform in target quadrant in young, aged and scopolamine-treated animals in PAT and WMT, respectively. The treatments inhibited acetylcholinesterase (AChE) enzyme in the brain. Similarly, all the treatments attenuated scopolamine-induced lipid peroxidation and normalize antioxidant enzymes. Conclusion: The results suggest that the cognitive enhancing effect of ACEI and ARBs may be due to inhibition of AChE or by regulation of antioxidant system or increase in formation of angiotensin IV. PMID:26069362

  15. Small molecule inhibitors of disulfide bond formation by the bacterial DsbA-DsbB dual enzyme system.

    PubMed

    Halili, Maria A; Bachu, Prabhakar; Lindahl, Fredrik; Bechara, Chérine; Mohanty, Biswaranjan; Reid, Robert C; Scanlon, Martin J; Robinson, Carol V; Fairlie, David P; Martin, Jennifer L

    2015-04-17

    The DsbA:DsbB redox machinery catalyzes disulfide bond formation in secreted proteins and is required for bacterial virulence factor assembly. Both enzymes have been identified as targets for antivirulence drugs. Here, we report synthetic analogues of ubiquinone (dimedone derivatives) that inhibit disulfide bond formation (IC50∼1 μM) catalyzed by E. coli DsbA:DsbB. The mechanism involves covalent modification of a single free cysteine leaving other cysteines unmodified. A vinylogous anhydride in each inhibitor is cleaved by the thiol, which becomes covalently modified to a thioester by a propionyl substituent. Cysteines and lysines on DsbA and DsbB and a nonredox enzyme were modified in a manner that implies some specificity. Moreover, human thioredoxin was not inhibited under the same conditions that inhibited EcDsbA. This proof of concept work uses small molecules that target specific cysteines to validate the DsbA and DsbB dual enzyme system as a viable and potentially druggable antivirulence target. PMID:25603425

  16. ACE-I Inhibitory Activity from Phaseolus lunatus and Phaseolus vulgaris Peptide Fractions Obtained by Ultrafiltration.

    PubMed

    Betancur-Ancona, David; Dávila-Ortiz, Gloria; Chel-Guerrero, Luis Antonio; Torruco-Uco, Juan Gabriel

    2015-11-01

    The involvement of angiotensin-I-converting enzyme (ACE-I) as one of the mechanisms controlling blood pressure is being studied to find alternative means of control of hypertension on human beings. On the market there are synthetic drugs that can control it, but these can cause undesirable health side effects. In this work was assessed the fractionation by ultrafiltration of the Lima bean (Phaseolus lunatus) and Jamapa bean (Phaseolus vulgaris), protein hydrolysates obtained with Alcalase(®) and Flavourzyme(®) on ACE-I inhibitory activity. Four membranes of different molecular cutoffs (10, 5, 3, and 1 kDa) were used. Fractions that had a higher inhibitory activity in both legumes were denominated as E (<1 kDa) with IC50 of 30.3 and 51.8 μg/mL values for the P. lunatus with Alcalase and Flavourzyme, respectively, and for the Phaseolus vulgaris with Alcalase and Flavourzyme with about 63.8 and 65.8 μg/mL values, respectively. The amino acid composition of these fractions showed residues in essential amino acids, which make a good source of energy and amino acids. On the other hand, the presence of hydrophobic amino acids such as V and P is a determining factor in the ACE-I inhibitor effect. The results suggest the possibility of obtaining and utilizing these peptide fractions in the development and innovation of a functional product that helps with treatment and/or prevention of hypertension. PMID:26061663

  17. Toward the design of mutation-resistant enzyme inhibitors: Further evaluation of the substrate envelope hypothesis

    PubMed Central

    Kairys, Visvaldas; Gilson, Michael K.; Lather, Viney; Schiffer, Celia A.; Fernandes, Miguel X.

    2010-01-01

    Previous studies have shown the usefulness of the substrate envelope concept in the analysis and prediction of drug resistance profiles for HIV protease mutants. This study tests its applicability to several other therapeutic targets: Abl kinase, chitinase, thymidylate synthase, dihydrofolate reductase, and neuraminidase. For the targets where many (≥6) mutation data are available to compute the average mutation sensitivity of inhibitors, the total volume of an inhibitor molecule that projects outside the substrate envelope Vout, is found to correlate with average mutation sensitivity. Analysis of a locally computed volume suggests that the same correlation would hold for the other targets if more extensive mutation data sets were available. It is concluded that the substrate envelope concept offers a promising and easily implemented computational tool for the design of drugs that will tend to resist mutations. Software implementing these calculations is provided with the supplemental material. PMID:19703025

  18. Toward the design of mutation-resistant enzyme inhibitors: further evaluation of the substrate envelope hypothesis.

    PubMed

    Kairys, Visvaldas; Gilson, Michael K; Lather, Viney; Schiffer, Celia A; Fernandes, Miguel X

    2009-09-01

    Previous studies have shown the usefulness of the substrate envelope concept in the analysis and prediction of drug resistance profiles for human immunodeficiency virus protease mutants. This study tests its applicability to several other therapeutic targets: Abl kinase, chitinase, thymidylate synthase, dihydrofolate reductase, and neuraminidase. For the targets where many (> or =6) mutation data are available to compute the average mutation sensitivity of inhibitors, the total volume of an inhibitor molecule that projects outside the substrate envelope V(out), is found to correlate with average mutation sensitivity. Analysis of a locally computed volume suggests that the same correlation would hold for the other targets, if more extensive mutation data sets were available. It is concluded that the substrate envelope concept offers a promising and easily implemented computational tool for the design of drugs that will tend to resist mutations. Software implementing these calculations is provided with the 'Supporting Information'. PMID:19703025

  19. Metallocene-based inhibitors of cancer-associated carbonic anhydrase enzymes IX and XII.

    PubMed

    Salmon, Adam J; Williams, Michael L; Wu, Quoc K; Morizzi, Julia; Gregg, Daniel; Charman, Susan A; Vullo, Daniela; Supuran, Claudiu T; Poulsen, Sally-Ann

    2012-06-14

    In this study, 20 metallocene-based compounds comprising extensive structural diversity were synthesized and evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. These compounds proved moderate to good CA inhibitors in vitro, with several compounds displaying selectivity for cancer-associated isozymes CA IX and CA XII compared to off-target CA I and CA II. Compound 6 was the most potent ferrocene-based inhibitor with K(i)s of 5.9 and 6.8 nM at CA IX and XII, respectively. A selection of key drug-like parameters comprising Log P, Log D, solubility, and in vitro metabolic stability and permeability were measured for two of the ferrocene-based compounds, regioisomers 1 and 5. Compounds 1 and 5 were found to have characteristics consistent with lipophilic compounds, however, our findings show that the lipophilicity of the ferrocene moiety is not well modeled by replacement with either a naphthyl or a phenyl moiety in software prediction tools. PMID:22540953

  20. Angiotensin I Converting Enzyme Inhibitory Peptides Obtained after In Vitro Hydrolysis of Pea (Pisum sativum var. Bajka) Globulins

    PubMed Central

    Baraniak, Barbara

    2014-01-01

    Pea seeds represent a valuable source of active compounds that may positively influence health. In this study, the pea globulins were digested in vitro under gastrointestinal condition and potentially bioaccessible angiotensin I converting enzyme (ACE) inhibitory peptides were identified. The degree of hydrolysis after pepsin, 14.42%, and pancreatin, 30.65%, were noted. The peptides with the highest ACE inhibitory properties were separated using ion exchange chromatography on DEAE-cellulose. Thirteen peptides fractions were obtained but only four showed potential antihypertensive properties. The highest inhibitory activity was determined for the fraction F8 (IC50 = 0.0014 mg/mL). This fraction was separated on Sephadex G10 and two peptide fractions were obtained. The peptides fraction (B) with the highest ACE inhibitory activity (IC50 = 0.073 mg/mL) was identified by ESI-MS/MS. The sequences of ACE inhibitory peptides were GGSGNY, DLKLP, GSSDNR, MRDLK, and HNTPSR. Based on Lineweaver-Burk plots for the fraction B, the kinetic parameters as Km, Vmax, and Ki and mode of inhibition were determined. This fraction belongs to uncompetitive inhibitor of ACE activity. The seeds of pea are the source of precursor protein, which releases the ACE inhibitory peptides as a result of enzymatic hydrolysis. PMID:25250321

  1. Identification of Angiotensin I-Converting Enzyme Inhibitory Peptides Derived from Enzymatic Hydrolysates of Razor Clam Sinonovacula constricta

    PubMed Central

    Li, Yun; Sadiq, Faizan A.; Fu, Li; Zhu, Hui; Zhong, Minghua; Sohail, Muhammad

    2016-01-01

    Angiotensin I-converting enzyme (ACE) inhibitory activity of razor clam hydrolysates produced using five proteases, namely, pepsin, trypsin, alcalase, flavourzyme and proteases from Actinomucor elegans T3 was investigated. Flavourzyme hydrolysate showed the highest level of degree of hydrolysis (DH) (45.87%) followed by A. elegans T3 proteases hydrolysate (37.84%) and alcalase (30.55%). The A. elegans T3 proteases was observed to be more effective in generating small peptides with ACE-inhibitory activity. The 3 kDa membrane permeate of A. elegans T3 proteases hydrolysate showed the highest ACE-inhibitory activity with an IC50 of 0.79 mg/mL. After chromatographic separation by Sephadex G-15 gel filtration and reverse phase-high performance liquid chromatography, the potent fraction was subjected to MALDI/TOF-TOF MS/MS for identification. A novel ACE-inhibitory peptide (VQY) was identified exhibiting an IC50 of 9.8 μM. The inhibitory kinetics investigation by Lineweaver-Burk plots demonstrated that the peptide acts as a competitive ACE inhibitor. The razor clam hydrolysate obtained by A. elegans T3 proteases could serve as a source of functional peptides with ACE-inhibitory activity for physiological benefits. PMID:27271639

  2. Identification of Angiotensin I-Converting Enzyme Inhibitory Peptides Derived from Enzymatic Hydrolysates of Razor Clam Sinonovacula constricta.

    PubMed

    Li, Yun; Sadiq, Faizan A; Fu, Li; Zhu, Hui; Zhong, Minghua; Sohail, Muhammad

    2016-01-01

    Angiotensin I-converting enzyme (ACE) inhibitory activity of razor clam hydrolysates produced using five proteases, namely, pepsin, trypsin, alcalase, flavourzyme and proteases from Actinomucor elegans T3 was investigated. Flavourzyme hydrolysate showed the highest level of degree of hydrolysis (DH) (45.87%) followed by A. elegans T3 proteases hydrolysate (37.84%) and alcalase (30.55%). The A. elegans T3 proteases was observed to be more effective in generating small peptides with ACE-inhibitory activity. The 3 kDa membrane permeate of A. elegans T3 proteases hydrolysate showed the highest ACE-inhibitory activity with an IC50 of 0.79 mg/mL. After chromatographic separation by Sephadex G-15 gel filtration and reverse phase-high performance liquid chromatography, the potent fraction was subjected to MALDI/TOF-TOF MS/MS for identification. A novel ACE-inhibitory peptide (VQY) was identified exhibiting an IC50 of 9.8 μM. The inhibitory kinetics investigation by Lineweaver-Burk plots demonstrated that the peptide acts as a competitive ACE inhibitor. The razor clam hydrolysate obtained by A. elegans T3 proteases could serve as a source of functional peptides with ACE-inhibitory activity for physiological benefits. PMID:27271639

  3. Alpha2-plasmin inhibitor and alpha2-macroglobulin-plasmin complexes in plasma. Quantitation by an enzyme-linked differential antibody immunosorbent assay.

    PubMed Central

    Harpel, P C

    1981-01-01

    An enzyme-linked differential antibody immunosorbent assay has been developed for the quantification of alpha2-plasmin inhibitor-plasmin and alpha2-macroglobulin-plasmin complexes. In this method the inhibitor-plasmin complex is bound to a surface by an inhibitor-specific antibody, and the plasmin bound to the inhibitor is quantified by a second antibody, rabbit antiplasminogen F(ab')2, labeled with alkaline phosphatase. The hydrolysis of p-nitrophenyl phosphate by the alkaline phosphatase is expressed in femtomoles of plasminogen per milliliter, by reference to a standard plasminogen curve. Inhibitor-enzyme complexes were generated in plasma by the addition of plasmin or of urokinase. The concentration of plasmin added was well below the plasma concentration of alpha2-plasmin inhibitor (1 microM) or of alpha2-macroglobulin (3.5 microM), so that neither inhibitor would be fully saturated with enzyme. Under these conditions increasing amounts of plasmin generated an increase in both alpha2-plasmin inhibitor-plasmin and alpha2-macroglobulin-plasmin complexes. Varying amounts of plasmin were incubated with each of the purified inhibitors in the concentration found in plasma, and the complexes. Varying amounts of plasmin were incubated with each of the purified inhibitors in the concentration found in plasma, and the complexes that formed were quantified by immunoassay. These studies made it possible to quantify the distribution of plasmin between the two inhibitors in plasmin or urokinase-treated plasma. In plasmin-treated plasma, 10% or less of the plasmin bound to both inhibitors was in complex with alpha2-macroglobulin. In contrast, between 19 and 51% of the plasmin generated in urokinase-activated plasma was bound to alpha2-macroglobulin. Thus, major changes in the distribution of plasma were observed, according to whether plasmin was added to plasma or whether plasminogen was activated endogenously. The pattern of inhibitor plasmin complexes generated in vivo by

  4. Screening of inhibitors of glycogen synthase kinase-3β from traditional Chinese medicines using enzyme-immobilized magnetic beads combined with high-performance liquid chromatography.

    PubMed

    Li, Yunfang; Xu, Jia; Chen, Yu; Mei, Zhinan; Xiao, Yuxiu

    2015-12-18

    Glycogen synthase kinase-3β (GSK-3β) was immobilized on magnetic beads (MBs) by affinity method for the first time. The enzyme-immobilized MBs were coupled with high-performance liquid chromatography-ultraviolet (HPLC-UV) technique to establish a cost-effective and reliable method for screening of inhibitors of GSK-3β. A peptide substrate of GSK-3β containing a tyrosine residue was employed since it can be sensitively detected by UV detector at 214nm. The substrate and its phosphorylated product were separated by baseline within 10min. The enzyme activity was determined by the quantification of peak area of the product. Parameters including enzyme immobilization, enzyme reaction and the performance of immobilized-enzyme were investigated. The immobilized enzyme can be reused for 10 times and remain stable for 4 days at 4°C. The inhibitory activities of extracts of 15 traditional Chinese medicines (TCMs) were screened. As a result, three of them including Euonymus fortunei, Amygdalus communis and Garcinia xanthochymus were found possessing high inhibitory activities (inhibition rate >90%). From G. xanthochymus, a new inhibitor of GSK-3β, fukugetin, was discovered with an IC50 value of 3.18±0.07μM. Enzyme kinetics and molecular docking experiments further revealed the inhibitory mechanism, indicating fukugetin was a non-ATP competitive inhibitor interacting with the phosphate recognizing substrate binding site of GSK-3β. PMID:26610618

  5. Identifying GSK-3β kinase inhibitors of Alzheimer's disease: Virtual screening, enzyme, and cell assays.

    PubMed

    Lin, Chih-Hsin; Hsieh, Yu-Shao; Wu, Yih-Ru; Hsu, Chia-Jen; Chen, Hsuan-Chiang; Huang, Wun-Han; Chang, Kuo-Hsuan; Hsieh-Li, Hsiu Mei; Su, Ming-Tsan; Sun, Ying-Chieh; Lee, Guan-Chiun; Lee-Chen, Guey-Jen

    2016-06-30

    Glycogen synthase kinase 3β (GSK-3β) is widely known as a critical target protein for treating Alzheimer's disease (AD). We utilized virtual screening to search databases for compounds with the potential to be used in drugs targeting GSK-3β kinase, and kinase as well as cell assays to investigate top-scored, selected compounds. Virtual screening of >1.1 million compounds in the ZINC and in-house databases was conducted using an optimized computational protocol in the docking program GOLD. Of the top-ranked compounds, 16 underwent a luminescent kinase assay and a cell assay using HEK293 cells expressing DsRed-tagged ΔK280 in the repeat domain of tau (tauRD). The compounds VB-003 (a potent GSK-3β inhibitor) and VB-008 (AM404, an anandamide transport inhibitor), with determined IC50 values of 0.25 and 5.4μM, respectively, were identified as reducing tau aggregation. Both compounds increased expression of phospho-GSK-3β (Ser9) and reduced endogenous tau phosphorylation at the sites of Ser202, Thr231, and Ser396. In the ∆K280 tauRD-DsRed SH-SY5Y cells, VB-008, but not VB-003, enhanced HSPB1 and GRP78 expression, increased ∆K280 tauRD-DsRed solubility, and promoted neurite outgrowth. Thus VB-008 performed best to the end of the present study. The identified compound VB-008 may guide the identification and synthesis of potential inhibitors analogous to this compound. PMID:27094783

  6. Molecular Characterization of an rsmD-Like rRNA Methyltransferase from the Wolbachia Endosymbiont of Brugia malayi and Antifilarial Activity of Specific Inhibitors of the Enzyme

    PubMed Central

    Rana, Ajay Kumar; Chandra, Sharat; Siddiqi, Mohammad Imran

    2013-01-01

    The endosymbiotic organism Wolbachia is an attractive antifilarial drug target. Here we report on the cloning and expression of an rsmD-like rRNA methyltransferase from the Wolbachia endosymbiont of Brugia malayi, its molecular properties, and assays for specific inhibitors. The gene was found to be expressed in all the major life stages of B. malayi. The purified enzyme expressed in Escherichia coli was found to be in monomer form in its native state. The activities of the specific inhibitors (heteroaryl compounds) against the enzyme were tested with B. malayi adult and microfilariae for 7 days in vitro at various concentrations, and NSC-659390 proved to be the most potent compound (50% inhibitory concentration [IC50], 0.32 μM), followed by NSC-658343 (IC50, 4.13 μM) and NSC-657589 (IC50, 7.5 μM). On intraperitoneal administration at 5 mg/kg of body weight for 7 days to adult jirds into which B. malayi had been transplanted intraperitoneally, all the compounds killed a significant proportion of the implanted worms. A very similar result was observed in infected mastomys when inhibitors were administered. Docking studies of enzyme and inhibitors and an in vitro tryptophan quenching experiment were also performed to understand the binding mode and affinity. The specific inhibitors of the enzyme showed a higher affinity for the catalytic site of the enzyme than the nonspecific inhibitors and were found to be potent enough to kill the worm (both adults and microfilariae) in vitro as well as in vivo in a matter of days at micromolar concentrations. The findings suggest that these compounds be evaluated against other pathogens possessing a methyltransferase with a DPPY motif and warrant the design and synthesis of more such inhibitors. PMID:23733469

  7. Transition-state inhibitors of purine salvage and other prospective enzyme targets in malaria

    PubMed Central

    Ducati, Rodrigo G.; Namanja-Magliano, Hilda A.; Schramm, Vern L.

    2013-01-01

    Malaria is a leading cause of human death within the tropics. The gradual generation of drug resistance imposes an urgent need for the development of new and selective antimalarial agents. Kinetic isotope effects coupled to computational chemistry have provided the relevant details on geometry and charge of enzymatic transition states to facilitate the design of transition-state analogs. These features have been reproduced into chemically stable mimics through synthetic chemistry, generating inhibitors with dissociation constants in the pico- to femto-molar range. Transition-state analogs are expected to contribute to the control of malaria. PMID:23859211

  8. Polyphenols as enzyme inhibitors in different degraded peat soils: Implication for microbial metabolism in rewetted peatlands

    NASA Astrophysics Data System (ADS)

    Zak, Dominik; Roth, Cyril; Gelbrecht, Jörg; Fenner, Nathalie; Reuter, Hendrik

    2015-04-01

    Recently, more than 30,000 ha of drained minerotrophic peatlands (= fens) in NE Germany were rewetted to restore their ecological functions. Due to an extended drainage history, a re-establishment of their original state is not expected in the short-term. Elevated concentrations of dissolved organic carbon, ammonium and phosphate have been measured in the soil porewater of the upper degraded peat layers of rewetted fens at levels of one to three orders higher than the values in pristine systems; an indicator of increased microbial activity in the upper degraded soil layers. On the other hand there is evidence that the substrate availability within the degraded peat layer is lowered since the organic matter has formerly been subject to intense decomposition over the decades of drainage and intense agricultural use of the areas. Previously however, it was suggested that inhibition of hydrolytic enzymes by polyphenolic substances is suspended during aeration of peat soils mainly due to the decomposition of the inhibiting polyphenols by oxidising enzymes such as phenol oxidase. Accordingly we hypothesised a lack of enzyme inhibiting polyphenols in degraded peat soils of rewetted fens compared to less decomposed peat of more natural fens. We collected both peat samples at the soil surface (0-20 cm) and fresh roots of dominating vascular plants and mosses (as peat parent material) from five formerly drained rewetted sites and five more natural sites of NE Germany and NW Poland. Less decomposed peat and living roots were used to obtain an internal standard for polyphenol analysis and to run enzyme inhibition tests. For all samples we determined the total phenolic contents and in addition we distinguished between the contents of hydrolysable and condensed tannic substances. From a methodical perspective the advantage of internal standards compared to the commercially available standards cyanidin chloride and tannic acid became apparent. Quantification with cyanidin or

  9. Effects of nabumetone, celecoxib, and ibuprofen on blood pressure control in hypertensive patients on angiotensin converting enzyme inhibitors.

    PubMed

    Palmer, Robert; Weiss, Robert; Zusman, Randall M; Haig, Ann; Flavin, Susan; MacDonald, Brian

    2003-02-01

    Nonsteroidal anti-inflammatory drugs interfere with certain antihypertensive therapies. In a double-blind study, 385 hypertensive patients stabilized on an angiotensin converting enzyme inhibitor were treated with nabumetone, celecoxib, ibuprofen, or placebo for 4 weeks. Ibuprofen caused significantly greater increases in systolic (P < .001) and diastolic (P < .01) blood pressures (BPs) compared to placebo, but not nabumetone or celecoxib. The proportion of patients with systolic BP increases of clinical concern at end point was significantly higher (P < .001) for the ibuprofen group (16.7%; 15 of 90), but not for the nabumetone group (5.5%; 5 of 91) or the celecoxib group (4.6%; 4 of 87) compared to the placebo group (1.1%; 1 of 91). PMID:12559680

  10. Aliskiren – an alternative to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in the therapy of arterial hypertension

    PubMed Central

    Hoffmann, Karolina; Bryl, Wiesław; Minczykowski, Andrzej

    2013-01-01

    There has been enormous progress in antihypertensive therapy over the last few decades. However, the management of arterial hypertension is still insufficient and more efforts are needed to improve both non-pharmacological and pharmacological treatment of this widely prevalent disease. Renin-angiotensin-aldosterone system (RAAS) inhibition is crucial both for blood pressure (BP) control and for prevention of organ damage or its development in patients with hypertension. Angiotensin-converting enzyme inhibitors and/or sartans block RAAS incompletely. Aliskiren is one of the novel drugs that has been introduced to antihypertensive therapy recently. Up to now no trial has confirmed that aliskiren is efficacious in reducing cardiovascular events. Double RAAS blockade with aliskiren was not always safe. This review article presents the current view on the place of aliskiren in the therapy of arterial hypertension. PMID:25276171

  11. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in women of childbearing age: risks versus benefits.

    PubMed

    Pucci, Mark; Sarween, Nadia; Knox, Ellen; Lipkin, Graham; Martin, Una

    2015-03-01

    Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are effective and widely used antihypertensive drugs. Exposure to these agents is known to be harmful to the fetus in the second and third trimesters of pregnancy. Concerns have also been raised about the risk of congenital malformations if ACEIs or ARBs are taken during the first trimester of pregnancy. The evidence to date, however, is conflicting and observed malformations may be due to confounders such as undiagnosed diabetes or maternal obesity, other antihypertensive medications or the hypertension itself. Nonetheless, in women who become pregnant while taking an ACEI or ARB, the drug should be stopped as soon as possible. In women with chronic kidney disease and proteinuria, it may be appropriate to continue taking an ACEI or ARB until the pregnancy is confirmed because of the significant benefit to their kidney function and the lower fertility rate in these patients. PMID:25612630

  12. An Unusual Case of Angiotensin-Converting-Enzyme Inhibitor-Related Penile Angioedema with Evolution to the Oropharynx

    PubMed Central

    Wagner, Jonathan G.; Bench, Elias M.; Plantmason, Lee

    2015-01-01

    A 52-year-old African American male with a long history of poorly controlled hypertension presented to the emergency department (ED) with two days of genital edema and pain. During ED work-up, the patient developed sudden onset of non-pitting, non-pruritic, and non-urticarial upper lip edema. Review of his antihypertensive medication list revealed that he normally took benazepril, highly suggestive of a diagnosis of angiotensin-converting-enzyme inhibitor-related angioedema (ACEI-RA). We present the first reported case of penile ACEI-RA that progressed to involve the oropharynx. The ED management of the condition and some of the newer treatment options available for ACEI-RA is also briefly discussed. PMID:26759679

  13. A luminescent beta-cyclodextrin-based Ru(phen)3 complex as DNA compactor, enzyme inhibitor, and translocation tracer.

    PubMed

    Liu, Yu; Chen, Yong; Duan, Zhong-Yu; Feng, Xi-Zeng; Hou, Sen; Wang, Chen; Wang, Rui

    2007-11-01

    A beta-cyclodextrin-based Ru(phen)(3) complex (1) has been synthesized and exhibits good luminescent behavior. Atomic force microscopic and scanning electron microscopic studies show that 1 can induce the aggregation of originally circular DNA to toroidal or spherical shapes. The morphology of these DNA aggregates changes following a pathway of naked circular DNA --> toroid with gaps --> solid toroid --> spherical aggregate, depending on the different 1/DNA (w/w) ratios, and their average diameters vary from the nanometer to micrometer scale. Owing to its capability of inducing the aggregation of DNA, 1 can be used as an inhibitor for DNA topoisomerase and DNA cleavage enzymes. Further studies by means of fluorescence microscopy indicate that 1 can also efficiently trace the translocation of DNA into 293T cells (the human embryonic kidney cell line). These observations consequently establish 1 as not only a potential DNA carrier but also a fluorescent DNA probe. PMID:19206682

  14. Aliskiren - an alternative to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in the therapy of arterial hypertension.

    PubMed

    Zaporowska-Stachowiak, Iwona; Hoffmann, Karolina; Bryl, Wiesław; Minczykowski, Andrzej

    2014-08-29

    There has been enormous progress in antihypertensive therapy over the last few decades. However, the management of arterial hypertension is still insufficient and more efforts are needed to improve both non-pharmacological and pharmacological treatment of this widely prevalent disease. Renin-angiotensin-aldosterone system (RAAS) inhibition is crucial both for blood pressure (BP) control and for prevention of organ damage or its development in patients with hypertension. Angiotensin-converting enzyme inhibitors and/or sartans block RAAS incompletely. Aliskiren is one of the novel drugs that has been introduced to antihypertensive therapy recently. Up to now no trial has confirmed that aliskiren is efficacious in reducing cardiovascular events. Double RAAS blockade with aliskiren was not always safe. This review article presents the current view on the place of aliskiren in the therapy of arterial hypertension. PMID:25276171

  15. Pyrithione-based ruthenium complexes as inhibitors of aldo-keto reductase 1C enzymes and anticancer agents.

    PubMed

    Kljun, Jakob; Anko, Maja; Traven, Katja; Sinreih, Maša; Pavlič, Renata; Peršič, Špela; Ude, Žiga; Codina, Elisa Esteve; Stojan, Jure; Lanišnik Rižner, Tea; Turel, Iztok

    2016-08-01

    Four ruthenium complexes of clinically used zinc ionophore pyrithione and its oxygen analog 2-hydroxypyridine N-oxide were prepared and evaluated as inhibitors of enzymes of the aldo-keto reductase subfamily 1C (AKR1C). A kinetic study assisted with docking simulations showed a mixed type of inhibition consisting of a fast reversible and a slow irreversible step in the case of both organometallic compounds 1A and 1B. Both compounds also showed a remarkable selectivity towards AKR1C1 and AKR1C3 which are targets for breast cancer drug design. The organoruthenium complex of ligand pyrithione as well as pyrithione itself also displayed toxicity on the hormone-dependent MCF-7 breast cancer cell line with EC50 values in the low micromolar range. PMID:27357845

  16. Adenosine kinase inhibitors. 1. Synthesis, enzyme inhibition, and antiseizure activity of 5-iodotubercidin analogues.

    PubMed

    Ugarkar, B G; DaRe, J M; Kopcho, J J; Browne, C E; Schanzer, J M; Wiesner, J B; Erion, M D

    2000-07-27

    Adenosine receptor agonists produce a wide variety of therapeutically useful pharmacologies. However, to date they have failed to undergo successful clinical development due to dose-limiting side effects. Adenosine kinase inhibitors (AKIs) represent an alternative strategy, since AKIs may raise local adenosine levels in a more site- and event-specific manner and thereby elicit the desired pharmacology with a greater therapeutic window. Starting with 5-iodotubercidin (IC50 = 0.026 microM) and 5'-amino-5'-deoxyadenosine (IC50 = 0.17 microM) as lead inhibitors of the isolated human AK, a variety of pyrrolo[2,3-d]pyrimidine nucleoside analogues were designed and prepared by coupling 5-substituted-4-chloropyrrolo[2,3-d]pyrimidine bases with ribose analogues using the sodium salt-mediated glycosylation procedure. 5'-Amino-5'-deoxy analogues of 5-bromo- and 5-iodotubercidins were found to be the most potent AKIs reported to date (IC50S < 0.001 microM). Several potent AKIs were shown to exhibit anticonvulsant activity in the rat maximal electric shock (MES) induced seizure assay. PMID:10956196

  17. Identification of new SUMO activating enzyme 1 inhibitors using virtual screening and scaffold hopping.

    PubMed

    Kumar, Ashutosh; Ito, Akihiro; Hirohama, Mikako; Yoshida, Minoru; Zhang, Kam Y J

    2016-02-15

    Sumoylation involves the enzymatic conjugation of small ubiquitin-like modifier (SUMO) protein to their substrate proteins. Sumoylation is not only crucial for maintaining normal cellular physiology but also implicated in the development of several diseases including cancer. SUMO E1, the first protein in sumoylation pathway is of particular significance due to its confirmed role in tumorogenesis. However, notwithstanding its role as potential drug target, only a few small molecule inhibitors of SUMO E1 have been identified. Here, we report the identification of pyrazole and thiazole urea containing compounds as inhibitors of SUMO E1. We have utilized 3D-shape matching, electrostatic potential similarity evaluations and molecular docking to scaffold hop from previously known aryl urea scaffold with SUMO E1 activity to thiazole and pyrazole urea based scaffolds. These two classes of compounds were found to have moderate SUMO E1 inhibitory activity and can be used as starting points for the development of highly potent lead compounds against cancer. PMID:26810265

  18. Selective inhibitors of a PAF biosynthetic enzyme lysophosphatidylcholine acyltransferase 2[S

    PubMed Central

    Tarui, Megumi; Shindou, Hideo; Kumagai, Kazuo; Morimoto, Ryo; Harayama, Takeshi; Hashidate, Tomomi; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Nagase, Takahide; Shimizu, Takao

    2014-01-01

    Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid mediator. In response to extracellular stimuli, PAF is rapidly biosynthesized by lyso-PAF acetyltransferase (lyso-PAFAT). Previously, we identified two types of lyso-PAFATs: lysophosphatidylcholine acyltransferase (LPCAT)1, mostly expressed in the lungs where it produces PAF and dipalmitoyl-phosphatidylcholine essential for respiration, and LPCAT2, which biosynthesizes PAF and phosphatidylcholine (PC) in the inflammatory cells. Under inflammatory conditions, LPCAT2, but not LPCAT1, is activated and upregulated to produce PAF. Thus, it is important to develop inhibitors specific for LPCAT2 in order to ameliorate PAF-related inflammatory diseases. Here, we report the first identification of LPCAT2-specific inhibitors, N-phenylmaleimide derivatives, selected from a 174,000-compound library using fluorescence-based high-throughput screening followed by the evaluation of the effects on LPCAT1 and LPCAT2 activities, cell viability, and cellular PAF production. Selected compounds competed with acetyl-CoA for the inhibition of LPCAT2 lyso-PAFAT activity and suppressed PAF biosynthesis in mouse peritoneal macrophages stimulated with a calcium ionophore. These compounds had low inhibitory effects on LPCAT1 activity, indicating that adverse effects on respiratory functions may be avoided. The identified compounds and their derivatives will contribute to the development of novel drugs for PAF-related diseases and facilitate the analysis of LPCAT2 functions in phospholipid metabolism in vivo. PMID:24850807

  19. Perioperative management of patients treated with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers: a quality improvement audit.

    PubMed

    Vijay, A; Grover, A; Coulson, T G; Myles, P S

    2016-05-01

    Previous studies have shown that patients continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers on the day of surgery are more likely to have significant intraoperative hypotension, higher rates of postoperative acute kidney injury, and lower incidences of postoperative atrial fibrillation. However, many of these studies were prone to bias and confounding, and questions remain over the validity of these outcomes. This observational, before-and-after quality improvement audit aimed to assess the effect of withholding these medications on the morning of surgery. We recruited 323 participants, with 83 (26%) having their preoperative angiotensin-converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB) withheld on the day of surgery. There were only very small Spearman rank-order correlations between time since last dose of these medications (rho -0.12, P=0.057) and intraoperative and recovery room intravenous fluid administration (rho -0.11, P=0.042). There was no statistically significant difference between the continued or withheld groups in vasopressor (metaraminol use 3.5 [1.5-8.3] mg versus 3.5 [1.5-8.5] mg, P=0.67) or intravenous fluid administration (1000 ml [800-1500] ml versus 1000 [800-1500] ml, P=0.096), nor rates of postoperative acute kidney injury (13% vs 18%, P=0.25) or atrial fibrillation (15% versus 18%, P=0.71). This audit found no significant differences in measured outcomes between the continued or withheld ACEi/ARB groups. This finding should be interpreted with caution due to the possibility of confounding and an insufficient sample size. However, as the finding is in contrast to many previous studies, future prospective randomised clinical trials are required to answer this important question. PMID:27246933

  20. Structure based virtual screening to identify inhibitors against MurE Enzyme of Mycobacterium tuberculosis using AutoDock Vina

    PubMed Central

    Singh, Shilpi; Bajpai, Urmi; Lynn, Andrew Michael

    2014-01-01

    The Mur E enzyme of Mur pathway of Mycobacterium tuberculosis is an attractive drug target as it is unique to bacteria and is absent in mammalian cells. The virtual screening of large libraries of drug like molecules against a protein target is a common strategy used to identify novel inhibitors. However, the method has a large number of pitfalls, with large variations in accuracy caused in part by inaccurate protocols, use of improper standards and libraries, and system dependencies such as the potential for nonspecific docking from large active-site cavities. The screening of drug-like small molecules from diversity sets can, however, be used to short-list potential fragments as building blocks to generate leads with improved specificity. We describe a protocol to implement this strategy, which involves an analysis of the active site and known inhibitors to identify orthospecific determinants, virtual screening of a drug-like diversity library to identify potential drug primitives, and inspection of the potential docked fragments for both binding potential and toxicity. The protocol is implemented on the M.tb Mur E protein which has a large active site with poor enrichment of known positives and a set of drug-like molecules that meets this criteria is presented for further analysis. Abbreviations MTB - Mycobacterium tuberculosis, NCI - National Cancer Institute, PDB - Protein Databank. PMID:25512687

  1. Antidepressant-like effects of the xanthine oxidase enzyme inhibitor allopurinol in rats. A comparison with fluoxetine.

    PubMed

    Gürbüz Özgür, Börte; Aksu, Hatice; Birincioğlu, Mustafa; Dost, Turhan

    2015-11-01

    Allopurinol is a xanthine oxidase enzyme inhibitor that is widely used for the treatment of hyperuricemia and gout. The activity of tryptophan 2,3-dioxygenase, which metabolizes tryptophan (TRP), is decreased by xanthine oxidase inhibitors, causing TRP levels in the body to be increased. Increases in TRP levels in the brain might have antidepressant effects. The purpose of this study is to evaluate the antidepressant effects of allopurinol compared to those of fluoxetine, which is a proven antidepressant. Thirty-two Wistar albino male rats were divided into four groups (control, 10mg/kg fluoxetine, 50mg/kg allopurinol, 50mg/kg allopurinol+10 mg/kg fluoxetine; n=8 per group), and forced swimming tests were performed before and after 14days of drug administration. Serotonin, 5-hydroxyindolacetic acid and uric acid levels were measured in blood samples after the final treatment. When allopurinol and fluoxetine were administered separately, a decrease in the duration of immobility and an increased duration of swimming were observed in the forced swimming test. The results showed similar antidepressant efficacies between allopurinol and fluoxetine. However, we found no statistically significant difference in the antidepressant effect of the combined therapy versus single drug therapy. PMID:26409178

  2. The evaluation of inhibitive effectiveness of the tumour necrosis factor-α converting enzyme selective inhibitors by HPLC.

    PubMed

    Zhao, Yunbin; Yu, Jin; Gu, Jiuling; Huang, Wei

    2011-04-01

    A novel high-performance liquid chromatography (HPLC) method based on the internal standard method was established for assaying the tumour necrosis factor-α converting enzyme (TACE) activity and matrix metalloprotease-9 (MMP-9) activity, and was used to evaluate the inhibitive effectiveness of inhibitors to TACE and MMP-9. In the assay method for TACE and MMP-9, peptides labelled with the ultraviolet group-Dpa were used as substrates. Alanine-Dpa was synthesised and was used as the internal standard for quantitative analysis. After the peptide substrates were hydrolysed by TACE (MMP-9) for 15 min (25 min) at 37 °C, the amount of remaining substrates were determined by reversed-phased HPLC with UV detection at 353 nm. The relative peak area of the substrate was linearly dependent on the substrate concentration. This method was then applied to determine the 50% inhibitory concentration (IC₅₀) of GM6001 and inhibitor A for both TACE and MMP-9. PMID:21406033

  3. Alternative Roles of STAT3 and MAPK Signaling Pathways in the MMPs Activation and Progression of Lung Injury Induced by Cigarette Smoke Exposure in ACE2 Knockout Mice.

    PubMed

    Hung, Yi-Han; Hsieh, Wen-Yeh; Hsieh, Jih-Sheng; Liu, Fon-Chang; Tsai, Chin-Hung; Lu, Li-Che; Huang, Chen-Yi; Wu, Chien-Liang; Lin, Chih-Sheng

    2016-01-01

    Inflammation-mediated abnormalities in the renin-angiotensin system (RAS) and expression of matrix metalloproteinases (MMPs) are implicated in the pathogenesis of lung injury. Angiotensin converting enzyme II (ACE2), an angiotensin converting enzyme (ACE) homologue that displays antagonist effects on ACE/angiotensin II (Ang II) axis, could also play a protective role against lung diseases. However, the relationship between ACE2 and MMPs activation in lung injury is still largely unclear. The purpose of this study is to investigate whether MMPs activity could be affected by ACE2 and which ACE2 derived signaling pathways could be also involved via using a mouse model with lung injury induced by cigarette smoke (CS) exposure for 1 to 3 weeks. Wild-type (WT; C57BL/6) and ACE2 KO mice (ACE2(-/-)) were utilized to study CS-induced lung injury. Increases in the resting respiratory rate (RRR), pulmonary immunokines, leukocyte infiltration and bronchial hyperplasia were observed in the CS-exposed mice. Compared to WT mice, more serious physiopathological changes were found in ACE2(-/-) mice in the first week of CS exposure. CS exposure increased pulmonary ACE and ACE2 activities in WT mice, and significantly increased ACE in ACE2(-/-) mice. Furthermore, the activity of pulmonary MMPs was decreased in CS-exposed WT mice, whereas this activity was increased in ACE2(-/-) mice. CS exposure increased the pulmonary p-p38, p-JNK and p-ERK1/2 level in all mice. In ACE2(-/-) mice, a significant increase p-STAT3 signaling was detected; however, no effect was observed on the p-STAT3 level in WT mice. Our results support the hypothesis that ACE2 deficiency influences MMPs activation and STAT3 phosphorylation signaling to promote more pulmonary inflammation in the development of lung injury. PMID:27019629

  4. Alternative Roles of STAT3 and MAPK Signaling Pathways in the MMPs Activation and Progression of Lung Injury Induced by Cigarette Smoke Exposure in ACE2 Knockout Mice

    PubMed Central

    Hung, Yi-Han; Hsieh, Wen-Yeh; Hsieh, Jih-Sheng; Liu, Fon-Chang; Tsai, Chin-Hung; Lu, Li-Che; Huang, Chen-Yi; Wu, Chien-Liang; Lin, Chih-Sheng

    2016-01-01

    Inflammation-mediated abnormalities in the renin-angiotensin system (RAS) and expression of matrix metalloproteinases (MMPs) are implicated in the pathogenesis of lung injury. Angiotensin converting enzyme II (ACE2), an angiotensin converting enzyme (ACE) homologue that displays antagonist effects on ACE/angiotensin II (Ang II) axis, could also play a protective role against lung diseases. However, the relationship between ACE2 and MMPs activation in lung injury is still largely unclear. The purpose of this study is to investigate whether MMPs activity could be affected by ACE2 and which ACE2 derived signaling pathways could be also involved via using a mouse model with lung injury induced by cigarette smoke (CS) exposure for 1 to 3 weeks. Wild-type (WT; C57BL/6) and ACE2 KO mice (ACE2-/-) were utilized to study CS-induced lung injury. Increases in the resting respiratory rate (RRR), pulmonary immunokines, leukocyte infiltration and bronchial hyperplasia were observed in the CS-exposed mice. Compared to WT mice, more serious physiopathological changes were found in ACE2-/- mice in the first week of CS exposure. CS exposure increased pulmonary ACE and ACE2 activities in WT mice, and significantly increased ACE in ACE2-/- mice. Furthermore, the activity of pulmonary MMPs was decreased in CS-exposed WT mice, whereas this activity was increased in ACE2-/- mice. CS exposure increased the pulmonary p-p38, p-JNK and p-ERK1/2 level in all mice. In ACE2-/- mice, a significant increase p-STAT3 signaling was detected; however, no effect was observed on the p-STAT3 level in WT mice. Our results support the hypothesis that ACE2 deficiency influences MMPs activation and STAT3 phosphorylation signaling to promote more pulmonary inflammation in the development of lung injury. PMID:27019629

  5. Mutational analysis of target enzyme recognition of the beta-trefoil fold barley alpha-amylase/subtilisin inhibitor.

    PubMed

    Bønsager, Birgit C; Nielsen, Peter K; Abou Hachem, Maher; Fukuda, Kenji; Praetorius-Ibba, Mette; Svensson, Birte

    2005-04-15

    The barley alpha-amylase/subtilisin inhibitor (BASI) inhibits alpha-amylase 2 (AMY2) with subnanomolar affinity. The contribution of selected side chains of BASI to this high affinity is discerned in this study, and binding to other targets is investigated. Seven BASI residues along the AMY2-BASI interface and four residues in the putative protease-binding loop on the opposite side of the inhibitor were mutated. A total of 15 variants were compared with the wild type by monitoring the alpha-amylase and protease inhibitory activities using Blue Starch and azoalbumin, respectively, and the kinetics of binding to target enzymes by surface plasmon resonance. Generally, the mutations had little effect on k(on), whereas the k(off) values were increased up to 67-fold. The effects on the inhibitory activity, however, were far more pronounced, and the K(i) values of some mutants on the AMY2-binding side increased 2-3 orders of magnitude, whereas mutations on the other side of the inhibitor had virtually no effect. The mutants K140L, D150N, and E168T lost inhibitory activity, revealing the pivotal role of charge interactions for BASI activity on AMY2. A fully hydrated Ca(2+) at the AMY2-BASI interface mediates contacts to the catalytic residues of AMY2. Mutations involving residues contacting the solvent ligands of this Ca(2+) had weaker affinity for AMY2 and reduced sensitivity to the Ca(2+) modulation of the affinity. These results suggest that the Ca(2+) and its solvation sphere are integral components of the AMY2-BASI complex, thus illuminating a novel mode of inhibition and a novel role for calcium in relation to glycoside hydrolases. PMID:15657043

  6. Cytotoxic gold(I) N-heterocyclic carbene complexes with phosphane ligands as potent enzyme inhibitors.

    PubMed

    Rubbiani, Riccardo; Salassa, Luca; de Almeida, Andreia; Casini, Angela; Ott, Ingo

    2014-06-01

    Organometallic gold complexes with N-heterocyclic carbene (NHC) ligands have been demonstrating promising properties as novel anticancer agents. Gold(I) NHC complexes containing different phosphanes as secondary ligands were shown to trigger strong cytotoxic effects in cancer cells, and their effective uptake into the cells was quantified by atomic absorption spectroscopy. Moreover, the new compounds strongly inhibited the activity of the seleno-enzyme thioredoxin reductase (TrxR) and of the zinc-finger enzyme poly(ADP-ribose) polymerase 1 (PARP-1). In the case of TrxR inhibition, their activity depended clearly on the size of the alkyl/aryl residues of phosphorus atoms. Density functional theory (DFT) calculations showed that the Au-P bond of the triphenylphosphane complex [Au(I) (NHC)(PPh3 )]I had a lower bond dissociation energy compared to trialkylphosphane complexes [Au(I) (NHC)(PR3 )]I, indicating a higher kinetic reactivity of this particular compound. In fact, [Au(I) (NHC)(PPh3 )]I triggered an enhanced inhibitory activity against PARP-1. PMID:24677779

  7. Antioxidant Enzyme Inhibitor Role of Phosphine Metal Complexes in Lung and Leukemia Cell Lines

    PubMed Central

    Keleş, Tuğba; Serindağ, Osman

    2014-01-01

    Phosphine metal complexes have been recently evaluated in the field of cancer therapy. In this research, the cytotoxic effects of some metal phosphines {[PdCl2((CH2OH)2PCH2)2NCH3] (C1), [RuCl2(((CH2OH)2PCH2)2NCH3)2] (C2), [PtCl2((Ph2PCH2)2NCH3)(timin)2] (C3)} on K562 (human myelogenous leukemia cell line) and A549 (adenocarcinomic human alveolar basal epithelial cells) cells were investigated using the MTT test. C1 and C2 are water-soluble metal complexes, which may have some advantages in in vitro and in vivo studies. The effects of the above-mentioned metal complexes on thioredoxin reductase (TrxR) (EC: 1.8.1.9), glutathione peroxidase (GPx) (EC: 1.11.1.9), and catalase (Cat) (EC: 1.11.1.6) enzymes were also tested. The results of this research showed that all three metal complexes indicated dose-dependent cytotoxicity on A549 and K562 cell lines and that the complexes inhibited different percentages of the TrxR, GPx, and Cat enzymes of these tumor cells. PMID:25610346

  8. ACE to Ulysses Coherences

    NASA Astrophysics Data System (ADS)

    Thomson, D. J.; Maclennan, C. G.; Lanzerotti, L. J.

    2006-12-01

    The EPAM charged particle instrument on ACE is the backup for the HISCALE instrument on Ulysses making the two ideally suited for spatial coherence studies over large heliosphere distances. Fluxes of low-energy ( ~50 - 200 keV) electrons are detected in eight spatial sectors on both spacecraft. A spherical harmonic description of the particle flux as a function of time using only the l=0 and l=1 degree coefficients describes most of the observed flux. Here we concentrate on the three l=1 coefficients for the 60--100 kev electrons.Between the two spacecraft these result in nine coherence estimates that are all typically moderately coherent, but the fact that the different coefficients at each spacecraft are also coherent with each other makes interpretation difficult. To avoid this difficulty we estimated the canonical coherences between the two groups of three series. This, in effect, chooses an optimum coordinate system at each spacecraft and for each frequency and estimates the coherence in this frame. Using one--minute data, we find that the canonical coherences are generally larger at high frequencies (3 mHz and above) than they are at low frequencies. This appears to be generally true and does not depend particularly on time, range, etc. However, if the data segment is chosen too long, say > 30 days with 1--minute sampling, the coherence at high frequencies drops. This may be because the spatial and temporal features of the mode are confounded, or possibly because the solar modes p--modes are known to change frequency with solar activity, so do not appear coherent on long blocks.The coherences are not smooth functions of frequency, but have a bimodal distribution particularly in the 100 μHz to 5 mHz range. Classifying the data at frequencies where the canonical coherences are high in terms of apparent polarization and orientation, we note two major families of modes that appear to be organized by the Parker spiral. The magnetic field data on the two

  9. Angiotensin-Converting-Enzyme Inhibition in Stable Coronary Artery Disease

    PubMed Central

    2008-01-01

    BACKGROUND Angiotensin-converting-enzyme (ACE) inhibitors are effective in reducing the risk of heart failure, myocardial infarction, and death from cardiovascular causes in patients with left ventricular systolic dysfunction or heart failure. ACE inhibitors have also been shown to reduce atherosclerotic complications in patients who have vascular disease without heart failure. METHODS In the Prevention of Events with Angiotensin Converting Enzyme Inhibition (PEACE) Trial, we tested the hypothesis that patients with stable coronary artery disease and normal or slightly reduced left ventricular function derive therapeutic benefit from the addition of ACE inhibitors to modern conventional therapy. The trial was a double-blind, placebo-controlled study in which 8290 patients were randomly assigned to receive either trandolapril at a target dose of 4 mg per day (4158 patients) or matching placebo (4132 patients). RESULTS The mean (±SD) age of the patients was 64±8 years, the mean blood pressure 133±17/78±10 mm Hg, and the mean left ventricular ejection fraction 58±9 percent. The patients received intensive treatment, with 72 percent having previously undergone coronary revascularization and 70 percent receiving lipid-lowering drugs. The incidence of the primary end point — death from cardiovascular causes, myocardial infarction, or coronary revascularization — was 21.9 percent in the trandolapril group, as compared with 22.5 percent in the placebo group (hazard ratio in the trandolapril group, 0.96; 95 percent confidence interval, 0.88 to 1.06; P=0.43) over a median follow-up period of 4.8 years. CONCLUSIONS In patients with stable coronary heart disease and preserved left ventricular function who are receiving “current standard” therapy and in whom the rate of cardiovascular events is lower than in previous trials of ACE inhibitors in patients with vascular disease, there is no evidence that the addition of an ACE inhibitor provides further benefit in

  10. Human γ-Glutamyl Transpeptidase 1: STRUCTURES OF THE FREE ENZYME, INHIBITOR-BOUND TETRAHEDRAL TRANSITION STATES, AND GLUTAMATE-BOUND ENZYME REVEAL NOVEL MOVEMENT WITHIN THE ACTIVE SITE DURING CATALYSIS.

    PubMed

    Terzyan, Simon S; Burgett, Anthony W G; Heroux, Annie; Smith, Clyde A; Mooers, Blaine H M; Hanigan, Marie H

    2015-07-10

    γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within the active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. These data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use. PMID:26013825

  11. Improved mortality of the Formosan subterranean termite by fungi, when amended with cuticle-degrading enzymes or eicosanoid biosynthesis inhibitors.

    PubMed

    Wright, Maureen S; Lax, Alan R

    2016-01-01

    Formosan subterranean termites (FST) were exposed to strains of Beauveria pseudobassiana (Bpb) and Isaria fumosorosea (Ifr) to determine virulence of the fungi. Once lethality was determined, sublethal doses of Bpb were combined with enzymes capable of degrading the insect cuticle to measure the potential to enhance fungal infection. Bpb applied to FST in combination with proteinases and a chitinase caused increased mortality over the fungus alone. Mortality was enhanced when Ifr was applied to FST in combination with a chitinase isolated from Serratia marcesans. A lipase isolated from Pseudomonas cepacia, when combined with Ifr, also resulted in greater mortality than all control treatments. FST were also exposed to the eicosanoid biosynthesis inhibitors (EBIs) dexamethasone (DEX), ibuprofen (IBU), and ibuprofen sodium salt (IBUNA), in combination with Ifr. Combining Ifr with IBUNA caused significantly increased mortality on days 6, 7, and 9. Cuticle-degrading enzymes and EBIs may have potential to enhance the pathogenic effect of a fungal control agent against the Formosan subterranean termite. PMID:26122366

  12. Broad 4-Hydroxyphenylpyruvate Dioxygenase Inhibitor Herbicide Tolerance in Soybean with an Optimized Enzyme and Expression Cassette[W][OPEN

    PubMed Central

    Siehl, Daniel L.; Tao, Yumin; Albert, Henrik; Dong, Yuxia; Heckert, Matthew; Madrigal, Alfredo; Lincoln-Cabatu, Brishette; Lu, Jian; Fenwick, Tamara; Bermudez, Ericka; Sandoval, Marian; Horn, Caroline; Green, Jerry M.; Hale, Theresa; Pagano, Peggy; Clark, Jenna; Udranszky, Ingrid A.; Rizzo, Nancy; Bourett, Timothy; Howard, Richard J.; Johnson, David H.; Vogt, Mark; Akinsola, Goke; Castle, Linda A.

    2014-01-01

    With an optimized expression cassette consisting of the soybean (Glycine max) native promoter modified for enhanced expression driving a chimeric gene coding for the soybean native amino-terminal 86 amino acids fused to an insensitive shuffled variant of maize (Zea mays) 4-hydroxyphenylpyruvate dioxygenase (HPPD), we achieved field tolerance in transgenic soybean plants to the HPPD-inhibiting herbicides mesotrione, isoxaflutole, and tembotrione. Directed evolution of maize HPPD was accomplished by progressively incorporating amino acids from naturally occurring diversity and novel substitutions identified by saturation mutagenesis, combined at random through shuffling. Localization of heterologously expressed HPPD mimicked that of the native enzyme, which was shown to be dually targeted to chloroplasts and the cytosol. Analysis of the native soybean HPPD gene revealed two transcription start sites, leading to transcripts encoding two HPPD polypeptides. The N-terminal region of the longer encoded peptide directs proteins to the chloroplast, while the short form remains in the cytosol. In contrast, maize HPPD was found almost exclusively in chloroplasts. Evolved HPPD enzymes showed insensitivity to five inhibitor herbicides. In 2013 field trials, transgenic soybean events made with optimized promoter and HPPD variant expression cassettes were tested with three herbicides and showed tolerance to four times the labeled rates of mesotrione and isoxaflutole and two times the labeled rates of tembotrione. PMID:25192697

  13. ACE2 overexpression inhibits acquired platinum resistance-induced tumor angiogenesis in NSCLC.

    PubMed

    Cheng, Qijian; Zhou, Ling; Zhou, Jianping; Wan, Huanying; Li, Qingyun; Feng, Yun

    2016-09-01

    Angiotensin II (AngII) is a multifunctional bioactive peptide in the renin-angiotensin system (RAS). Angiotensin-converting enzyme 2 (ACE2) is a newly identified component of RAS. We previously reported that ACE2 overexpression may inhibit cell growth and vascular endothelial growth factor (VEGF) production in vitro and in vivo. In the present study, we investigated the effect of ACE2 on tumor-associated angiogen-esis after the development of acquired platinum resistance in non-small cell lung cancer (NSCLC). Four NSCLC cell lines, A549, LLC, A549-DDP and LLC-DDP, were used in vitro, while A549 and A549-DDP cells were used in vivo. A549-DDP and LLC-DDP cells were newly established at our institution as acquired platinum-resistant sublines by culturing the former parent cells in cisplatin (CDDP)-containing conditioned medium for 6 months. These platinum-resistant cells showed significantly higher angiotensin II type 1 receptor (AT1R), ACE and VEGF production and lower ACE2 expression than their corresponding parent cells. We showed that ACE2 overexpression inhibited the production of VEGF in vitro and in vivo compared to their corresponding parent cells. We also found that ACE2 overexpression reduced the expression of AT1R and ACE. Additionally, we confirmed that ACE2 overexpres-sion inhibited cell growth and VEGF production while simultaneously suppressing ACE and AT1R expression in human lung cancer xenografts. Our findings indicate that ACE2 overexpression may potentially suppress angiogenesis in NSCLC after the development of acquired platinum resistance. PMID:27460845

  14. EquiNox2: A new method to measure NADPH oxidase activity and to study effect of inhibitors and their interactions with the enzyme.

    PubMed

    Derochette, Sandrine; Serteyn, Didier; Mouithys-Mickalad, Ange; Ceusters, Justine; Deby-Dupont, Ginette; Neven, Philippe; Franck, Thierry

    2015-11-01

    Excessive neutrophil stimulation and reactive oxygen species (ROS) production are involved in numerous human or horse pathologies. The modulation of the neutrophil NADPH oxidase (NOX) has a great therapeutic potential since this enzyme produces superoxide anion whose most of the other ROS derive. The measurement of NOX activity by cell-free systems is often used to test potential inhibitors of the enzyme. A major drawback of this technique is the possible interferences between inhibitors and the probe, ferricytochrome c, used to measure the activity. We designed the "EquiNox2", a new pharmacological tool, to determine the direct interaction of potential inhibitors with equine phagocytic NOX and their effect on the enzyme activity or assembly. This method consists in binding the membrane fractions of neutrophils containing flavocytochrome b558 or the entire complex, reconstituted in vitro from membrane and cytosolic fractions of PMNs, onto the wells of a microplate followed by incubation with potential inhibitors or drugs. After incubation, the excess of the drug is simply eliminated or washed prior measuring the activity of the reconstituted complex. This latter step avoid the risk of interference between the inhibitor and the revelation solution and can distinguish if inhibitors, strongly bound or not, could interfere with the assembly of the enzymatic complex or with its activity. The EquiNox2 was validated using diphenyliodonium chloride and Gp91ds-tat, two well-known inhibitors largely described for human NADPH oxidase. The present technique was used to study and understand better the effect of curcumin and its water-soluble derivative, NDS27, on the assembly and activity of NOX. We demonstrated that curcumin and NDS27 can strongly bind to the enzyme and prevents its assembly making these molecules good candidates for the treatment of horse or human pathologies implying an excessive activation of neutrophils. PMID:26452955

  15. Angiotensin-converting enzyme inhibitory effects by plant phenolic compounds: a study of structure activity relationships.

    PubMed

    Al Shukor, Nadin; Van Camp, John; Gonzales, Gerard Bryan; Staljanssens, Dorien; Struijs, Karin; Zotti, Moises J; Raes, Katleen; Smagghe, Guy

    2013-12-01

    In this study, 22 phenolic compounds were investigated to inhibit the angiotensin-converting enzyme (ACE). Tannic acid showed the highest activity (IC50 = 230 μM). The IC50 values obtained for phenolic acids and flavonoids ranged between 0.41 and 9.3 mM. QSAR analysis confirmed that the numbers of hydroxyl groups on the benzene ring play an important role for activity of phenolic compounds and that substitution of hydroxyl groups by methoxy groups decreased activity. Docking studies indicated that phenolic acids and flavonoids inhibit ACE via interaction with the zinc ion and this interaction is stabilized by other interactions with amino acids in the active site. Other compounds, such as resveratrol and pyrogallol, may inhibit ACE via interactions with amino acids at the active site, thereby blocking the catalytic activity of ACE. These structure-function relationships are useful for designing new ACE inhibitors and potential blood-pressure-lowering compounds based on phenolic compounds. PMID:24219111

  16. Amino sugars: new inhibitors of zeaxanthin epoxidase, a violaxanthin cycle enzyme.

    PubMed

    Latowski, Dariusz; Banaś, Agnieszka Katarzyna; Strzałka, Kazimierz; Gabryś, Halina

    2007-03-01

    The effect of three sugars and their amino derivatives on violaxanthin cycle enzymes activity was investigated in duckweed (Lemna trisulca), a model water-plant. No effect of sugars and amino sugars on violaxanthin de-epoxidase was observed independent of incubation time; however, epoxidation of zeaxanthin to violaxanthin was inhibited. The minimum amino sugar concentrations causing maximum inhibition of zeaxanthin epoxidation have been estimated. Amino sugars but not sugars caused more than a 50% inhibition of zeaxanthin epoxidation in duckweed after a 24h incubation when applied at a concentration of 0.5%. Incubation with amino sugars under a 6d photoperiod enhanced the inhibitory effect. Zeaxanthin epoxidation was completely inhibited under such conditions, whereas only a minor inhibitory effect was observed in sugar treated plants. The strong amino sugar inhibition of zeaxanthin epoxidase activity represents additional evidence for the creation of an unstable carotenoid carbocation in the molecular mechanism of epoxidation. PMID:17074410

  17. ACE expression in monocytes is induced by cytokines, phorbol ester and steroid

    SciTech Connect

    Lazarus, D.; Lanzillo, J.; Fanburg, B. )

    1991-03-15

    Angiotensin converting enzyme (ACE) levels are elevated in the serum and peripheral blood monocytes (PBM) of patients with granulomatous diseases. However, the role of ACE in (Mo) physiology and the regulation of the inflammatory response is not well understood. Since Mo can be stimulated to form giant cells using phorbol esters, glucocorticoids or certain inflammatory cytokines, the authors examined production of ACE protein by normal PBM, a Mo-like cell line, THP-1, and a macrophage-like cell line, U937 following stimulation with these agents. Using a sensitive ELISA assay, they found that in U937 cells, expression of ACE protein increased by 3.4 fold with dexamethasone, 3.7. fold with phorbol 12-myristate acetate (PMA), and 5.8 fold with the two agents combined. The cytokines IL-4 and GM-CSF substantially increased ACE expression, by 7.6 and 7.7 fold respectively, with maximal effect at 0.01 U/ml, while IFN-{gamma} and TNF-{alpha} had little effect. Similar results were found with PBM and THP-1 cells. The combination of dexamethasone and PMA also induced homotypic cluster formation in PBM, suggesting a correlation between cell adhesion and ACE production. The authors conclude that ACE expression in monocytes and macrophages is stimulated by low concentration of glucocorticoids and certain inflammatory cytokines. ACE may participate in the initiation and propagation of granulomatous inflammatory processes.

  18. Iatrogenic angioedema associated with ACEi, sitagliptin, and deficiency of 3 enzymes catabolizing bradykinin.

    PubMed

    Beaudouin, E; Defendi, F; Picaud, J; Drouet, C; Ponard, D; Moneret-Vautrin, D A

    2014-05-01

    New concepts of idiopathic and iatrogenic angioedema underline the role of bradykinin, and the importance of catabolizing enzymes. A case is described of Angiotensin converting enzyme inhibitor (ACEi) and sitagliptin induced angioedema, where AO attacks decreased after the withdrawal of lisinopril but resolved only after the withdrawal of sitagliptin, an inhibitor of dipeptylpeptidase IV. ACE, aminopeptidase P and carboxypeptidase N were decreased down to 17%, 42%, 64% of median references values, and remained low one year after the interruption of these drugs: 56%, 28% and 50%, respectively. The combined deficiency of APP and CPN might enhance the inhibiting effect of the DPP IV inhibitor. The fact that this triple deficiency remained latent before and after the treatment indicates that searching for latent enzyme deficiencies should be carried out when there is intention to treat with a combination of drugs interfering with the bradykinin metabolism. PMID:24853572

  19. Haplotypes extending across ACE are associated with Alzheimer's disease.

    PubMed

    Kehoe, Patrick G; Katzov, Hagit; Feuk, Lars; Bennet, Anna M; Johansson, Boo; Wiman, Björn; de Faire, Ulf; Cairns, Nigel J; Wilcock, Gordon K; Brookes, Anthony J; Blennow, Kaj; Prince, Jonathan A

    2003-04-15

    Numerous genes have been implicated in Alzheimer's disease (AD), but, with the exception of a demonstrated association with the epsilon 4 allele of APOE, findings have not been consistently replicated across populations. One of the most widely studied is the gene for angiotensin I converting enzyme (ACE ). A meta-analysis of published data on a common Alu indel polymorphism in ACE was performed which indicated highly significant association of the insertion allele with AD (OR 1.30; 95% CI 1.19 - 1.41; P=4 x 10(-8)). To further explore the influence of ACE on AD, several single-nucleotide polymorphisms (SNPs) were genotyped in five independent populations represented by over 3100 individuals. Analyses based upon single markers and haplotypes revealed strong evidence of association in case-control models and also in a model examining the influence of variation in ACE upon cerebrospinal fluid levels of amyloid beta42 peptide (Abeta42). The most significant evidence for association with AD was found for an SNP, A-262T, located in the ACE promoter (OR 1.64; 95% CI 1.33 -1.94; P=2 x 10(-5)). Estimates of population attributable risk for the common allele of this SNP suggest that it, or an allele in tight linkage disequilibrium (LD) with it, may contribute to as much as 35% of AD in the general population. Results support a model whereby decreased ACE activity may influence AD susceptibility by a mechanism involving beta-amyloid metabolism. PMID:12668609

  20. Essential residues in angiotensin converting enzyme: Modification with 1-fluoro-2,4-dinitrobenzene

    SciTech Connect

    Bunning, P.; Kleemann, S.G.; Riordan, J.F. )

    1990-11-01

    The peptidase and esterase activities of rabbit pulmonary angiotensin converting enzyme (ACE) are rapidly abolished on reaction with 1-fluoro-2,4-dinitrobenzene (Dnp-F). Inactivation follows first-order kinetics with respect to the reagent and is accompanied by stoichiometric incorporation of 3,5-({sup 3}H)Dnp, indicating that the effect is due to a specific modification of the enzyme. Thin-layer chromatography of an acid hydrolysate of the modifed enzyme indicates that most of the radioactive label is present as O-Dnp-tyrosine (65 to >95{percent}) and the rest at N{epsilon}-Dnp-lysine. The pH dependence of the reaction is consistent with modification of either tyrosine or lysine. The presence of a competitive inhibitor effectively protects the enzyme against inactivation by Dnp-F. Acetylation of ACE with N-acetylimidazole also protects the enzyme against modification with Dnp-F. The results indicate the presence of catalytically essential tyrosine and lysine residues at the active site of ACE.

  1. Radiosensitization of Human Colorectal Cancer Cells by MLN4924: An Inhibitor of NEDD8-Activating Enzyme.

    PubMed

    Wan, Juefeng; Zhu, Ji; Li, Guichao; Zhang, Zhen

    2016-08-01

    Colorectal cancer is the third most frequently diagnosed cancer and the combination of radiation with capecitabine has been shown to achieve only 15% to 25% of pathologic complete response. This study aimed to investigate the effect of MLN4924, a potent small molecule inhibitor of SKP1-Cullin-F-box proteins E3 ubiquitin ligases, as a novel radiosensitizing agent in colorectal cancer cells. Indeed, we found that MLN4924 effectively sensitized colorectal cancer cells to radiation with a sensitivity-enhancement ratio of 1.61 for HT-29 cells and 1.35 for HCT-116 cells. Mechanistically, MLN4924 significantly enhanced radiation-induced G2/M arrest, apoptosis, and DNA damage response through accumulation of p27. Knockdown of p27 via small interfering RNA partially inhibited MLN4924-induced radiosensitization, indicating a causal role played by p27. Our study suggested that MLN4924 could be further developed as a novel radiosensitizing agent against colorectal cancer. PMID:26082455

  2. New metabolically stabilized analogues of lysophosphatidic acid: agonists, antagonists and enzyme inhibitors.

    PubMed

    Prestwich, G D; Xu, Y; Qian, L; Gajewiak, J; Jiang, G

    2005-12-01

    Lysophosphatidic acid (LPA) is a metabolically labile natural phospholipid with a bewildering array of physiological effects. We describe herein a variety of long-lived receptor-specific agonists and antagonists for LPA receptors. Several LPA and PA (phosphatidic acid) analogues also inhibit LPP (lipid phosphate phosphatase). The sn-1 or sn-2 hydroxy groups have been replaced by fluorine, difluoromethyl, difluoroethyl, O-methyl or O-hydroxyethoxy groups to give non-migrating LPA analogues that resist acyltransferases. Alkyl ether replacement of acyl esters produced lipase and acyltransferase-resistant analogues. Replacement of the bridging oxygen in the monophosphate by an alpha-monofluoromethylene-, alpha-bromomethylene- or alpha,alpha-difluoromethylenephosphonate gave phosphatase-resistant analogues. Phosphorothioate analogues with O-acyl and O-alkyl chains are potent, long-lived agonists for LPA1 and LPA3 receptors. Most recently, we have (i) prepared stabilized O-alkyl analogues of lysobisphosphatidic acid, (ii) explored the structure-activity relationship of stabilized cyclic LPA analogues and (iii) synthesized neutral head group trifluoromethylsulphonamide analogues of LPA. Through collaborative studies, we have collected data for these stabilized analogues as selective LPA receptor (ant)agonists, LPP inhibitors, TREK (transmembrane calcium channel) K+ channel agonists, activators of the nuclear transcription factor PPAR-gamma (peroxisome-proliferator-activated receptor-gamma), promoters of cell motility and survival, and radioprotectants for human B-cells. PMID:16246118

  3. ACE2: Angiotensin II/Angiotensin-(1-7) balance in cardiorenal injury

    PubMed Central

    Varagic, Jasmina; Ahmad, Sarfaraz; Nagata, Sayaka; Ferrario, Carlos M.

    2014-01-01

    Our current recognition of the renin-angiotensin system is more convoluted than originally thought due to the discovery of multiple novel enzymes, peptides, and receptors inherent to this interactive biochemical cascade. Over the last decade angiotensin converting enzyme 2 (ACE2) has emerged as a key player in the pathophysiology of hypertension and cardiovascular and renal disease due to its pivotal role in metabolizing vasoconstrictive/hypertrophic/proliferative angiotensin II into favorable angiotensin-(1-7). This review addresses a considerable advancement in research on the role of tissue ACE2 in development and progression of hypertension and cardiorenal injury. We also summarize the results from recent clinical and experimental studies suggesting that serum or urine soluble ACE2 may serve as a novel biomarker or independent risk factor relevant for diagnosis and prognosis of cardiorenal disease. Recent proceedings on novel therapeutic approaches to enhance ACE2/angiotensin-(1-7) axis are also reviewed. PMID:24510672

  4. Oral Delivery of ACE2/Ang-(1–7) Bioencapsulated in Plant Cells Protects against Experimental Uveitis and Autoimmune Uveoretinitis

    PubMed Central

    Shil, Pollob K; Kwon, Kwang-Chul; Zhu, Ping; Verma, Amrisha; Daniell, Henry; Li, Qiuhong

    2014-01-01

    Hyperactivity of the renin-angiotensin system (RAS) resulting in elevated Angiotensin II (Ang II) contributes to all stages of inflammatory responses including ocular inflammation. The discovery of angiotensin-converting enzyme 2 (ACE2) has established a protective axis of RAS involving ACE2/Ang-(1–7)/Mas that counteracts the proinflammatory and hypertrophic effects of the deleterious ACE/AngII/AT1R axis. Here we investigated the hypothesis that enhancing the systemic and local activity of the protective axis of the RAS by oral delivery of ACE2 and Ang-(1–7) bioencapsulated in plant cells would confer protection against ocular inflammation. Both ACE2 and Ang-(1–7), fused with the non-toxic cholera toxin subunit B (CTB) were expressed in plant chloroplasts. Increased levels of ACE2 and Ang-(1–7) were observed in circulation and retina after oral administration of CTB-ACE2 and Ang-(1–7) expressing plant cells. Oral feeding of mice with bioencapsulated ACE2/Ang-(1–7) significantly reduced endotoxin-induced uveitis (EIU) in mice. Treatment with bioencapsulated ACE2/Ang-(1–7) also dramatically decreased cellular infiltration, retinal vasculitis, damage and folding in experimental autoimmune uveoretinitis (EAU). Thus, enhancing the protective axis of RAS by oral delivery of ACE2/Ang-(1–7) bioencapsulated in plant cells provide an innovative, highly efficient and cost-effective therapeutic strategy for ocular inflammatory diseases. PMID:25228068

  5. Fast gradient high performance liquid chromatography method with UV detection for simultaneous determination of seven angiotensin converting enzyme inhibitors together with hydrochlorothiazide in pharmaceutical dosage forms and spiked human plasma and urine.

    PubMed

    Elsebaei, Fawzi; Zhu, Yan

    2011-07-15

    The development of a reversed phase liquid chromatographic method for the simultaneous determination of seven angiotensin converting enzyme (ACE) inhibitors; five drugs namely benazepril HCl (BZL), enalapril maleate (ENL), fosinopril sodium (FSP), lisinopril (LSP) and ramipril (RMP) and two metabolites captopril disulfide (CPD) and enalaprilat (ENT) together with hydrochlorothiazide (HCT) is described. The method can serve as a substitute for many published papers for the analysis of the targeted compounds with or without hydrochloothiazide in pharmaceutical formulations as well as in spiked human plasma and urine samples. The method utilizes a simple gradient procedure for the separation in a 11 min run time using acetonitrile aqueous ammonia buffer (pH 9) solution and an Extend RP-C18 (25 μm particle size, 4.6 mm×250 mm, Agilent) HPLC column. The effluent was monitored on a UV detector at 215 nm. The effect of pH, solvent strength and analysis time on the peak shape and quantification were carefully studied in order to optimize the method. Adopting the proposed procedure, the analytes produce well-shaped peaks with good linear relationship over the investigated concentration ranges. The limits of detection (LOD) and limits of quantification (LOQ) from standard drug solutions lie in the range of 17-64 and 56-212 ng mL(-1), respectively. Correlation coefficient values (r) higher than 0.997 were obtained for all the studied drugs in spiked human plasma and urine samples. The intra-day and inter-day precision of the method was evaluated with relative standard deviation values being satisfactory for their purposed analysis. The method was validated with respect to specificity, recovery, accuracy, precision and linearity. PMID:21645680

  6. Analysis of novel angiotensin-I-converting enzyme inhibitory peptides from protease-hydrolyzed marine shrimp Acetes chinensis.

    PubMed

    Hai-Lun, He; Xiu-Lan, Chen; Cai-Yun, Sun; Yu-Zhong, Zhang; Bai-Cheng, Zhou

    2006-11-01

    Acetes chinensis is an underutilized shrimp species thriving in the Bo Hai Gulf of China. In a previous study, we had used the protease from Bacillus sp. SM98011 to digest this kind of shrimp and found that the oligopeptide-enriched hydrolysate possessed antioxidant activity and high angiotensin I-converting enzyme (ACE) inhibitory activity with an IC50 value of 0.97 mg/ml. In this paper, by ultrafiltration, gel permeation chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC), five peptides with high ACE inhibitory activity were purified from the shrimp hydrolysates and their sequences were identified by amino acid composition analysis and molecular weight (MW) analysis. Three of them, FCVLRP (a), IFVPAF (f) and KPPETV (j), were novel ACE inhibitory peptides. Their IC50 values were 12.3 microM, 3.4 microM and 24.1 microM, respectively, and their recoveries were 30 mg/100 g (solid basis of shrimp), 19 mg/100 g and 33 mg/100 g, respectively. Lineweaver-Burk plots for the three novel peptides showed that they are all competitive inhibitors. To test the ACE inhibitory activity of peptide a, f, j after they were digested by digestive enzymes in vivo, 12 derived peptides from FCVLRP and IFVPAF were synthesized based on their amino acid sequences and the cleavage sites of digestive enzymes. No digestive enzyme cleavage site was found in KPPETV. The IC50 values of the derived peptides were determined and the result showed that except for VPAF, FC and FCVL, the ACE inhibitory activity of the other nine derived peptides did not significantly change when compared with their original peptides. Surprisingly, five peptides had lower IC50 values than their original peptides, particularly for RP (IC50 value = 0.39 microM), which is about 30 times lower than its original peptide and almost the lowest IC50 value for ACE inhibitory peptides reported. Therefore, the novel peptides identified from A. chinensis hydrolysates probably still maintain a high ACE

  7. Effect of chronic treatment with the vasopeptidase inhibitor AVE 7688 and ramipril on endothelial function in atherogenic diet rabbits.

    PubMed

    Weckler, Nadine; Leitzbach, Daniela; Kalinowski, Leszek; Malinski, Tadeusz; Busch, Andreas E; Linz, Wolfgang; Kalinowski, Ludmila

    2003-09-01

    Cardiovascular disease is the major cause of death in Western nations, although improved possibilities regarding diagnosis and therapy now exist. Endothelial dysfunction is triggered by cardiovascular risk factors such as hypercholesterolaemia, hypertension, adiposity and smoking, contributing to the common endpoint of atherosclerosis. This study examined the pharmacological effects of angiotensin-converting enzyme (ACE) and combined ACE-neutral endopeptidase (NEP) (vasopeptidase) inhibitors on endothelial dysfunction in the model of hyperlipidaemic rabbits. The focus of the study was to assess endothelial function after treatment with the ACE-NEP inhibitor AVE 7688 (30 mg/kg/day) in comparison to the ACE inhibitor (ACE-I) ramipril (1 mg/kg/day). Different parameters, such as endothelial function, blood pressure (BP), expansion of plaques, endothelial nitric oxide (NO) and superoxide (O2-) release and plasma levels of various lipidaemic parameters were analysed. Control groups consisted of one group fed only with normal diet, one group fed only with atherogenic diet and the direct control group fed with varied diets (six weeks atherogenic diet followed by 12 weeks normal diet). Since for the treatment of atherosclerosis, a change in feeding is absolutely necessary, in the present study, at the start of the treatments with AVE 7688 and ramipril, the rabbits food was changed to a normal diet. At the end of the study, mean arterial blood pressure (MAP) was measured in the anaesthetised animals. The values in standard, atherogenic and varied diet-fed rabbits were around 73 2 mmHg. Angiotensin I (Ang I) given intravenous (i.v.) induced a strong increase in MAP of about 20%. In both the treated groups Ang I-induced BP increase was inhibited. In contrast, i.v. bradykinin led to a strong reduction in MAP in both the treated groups of around 50%. Six weeks feeding with an atherogenic diet in the rabbits induced an enduring endothelial dysfunction despite the food

  8. Iminosugar inhibitors of carbohydrate-active enzymes that underpin cereal grain germination and endosperm metabolism.

    PubMed

    Andriotis, Vasilios M E; Rejzek, Martin; Rugen, Michael D; Svensson, Birte; Smith, Alison M; Field, Robert A

    2016-02-01

    Starch is a major energy store in plants. It provides most of the calories in the human diet and, as a bulk commodity, it is used across broad industry sectors. Starch synthesis and degradation are not fully understood, owing to challenging biochemistry at the liquid/solid interface and relatively limited knowledge about the nature and control of starch degradation in plants. Increased societal and commercial demand for enhanced yield and quality in starch crops requires a better understanding of starch metabolism as a whole. Here we review recent advances in understanding the roles of carbohydrate-active enzymes in starch degradation in cereal grains through complementary chemical and molecular genetics. These approaches have allowed us to start dissecting aspects of starch degradation and the interplay with cell-wall polysaccharide hydrolysis during germination. With a view to improving and diversifying the properties and uses of cereal grains, it is possible that starch degradation may be amenable to manipulation through genetic or chemical intervention at the level of cell wall metabolism, rather than simply in the starch degradation pathway per se. PMID:26862201

  9. Iminosugar inhibitors of carbohydrate-active enzymes that underpin cereal grain germination and endosperm metabolism

    PubMed Central

    Andriotis, Vasilios M. E.; Rejzek, Martin; Rugen, Michael D.; Svensson, Birte; Smith, Alison M.; Field, Robert A.

    2016-01-01

    Starch is a major energy store in plants. It provides most of the calories in the human diet and, as a bulk commodity, it is used across broad industry sectors. Starch synthesis and degradation are not fully understood, owing to challenging biochemistry at the liquid/solid interface and relatively limited knowledge about the nature and control of starch degradation in plants. Increased societal and commercial demand for enhanced yield and quality in starch crops requires a better understanding of starch metabolism as a whole. Here we review recent advances in understanding the roles of carbohydrate-active enzymes in starch degradation in cereal grains through complementary chemical and molecular genetics. These approaches have allowed us to start dissecting aspects of starch degradation and the interplay with cell-wall polysaccharide hydrolysis during germination. With a view to improving and diversifying the properties and uses of cereal grains, it is possible that starch degradation may be amenable to manipulation through genetic or chemical intervention at the level of cell wall metabolism, rather than simply in the starch degradation pathway per se. PMID:26862201

  10. Characterization of a secretase activity which releases angiotensin-converting enzyme from the membrane.

    PubMed Central

    Oppong, S Y; Hooper, N M

    1993-01-01

    Angiotensin-converting enzyme (ACE; EC 3.4.1.15.1) exists in both membrane-bound and soluble forms. Phase separation in Triton X-114 and a competitive e.l.i.s.a. have been employed to characterize the activity which post-translationally converts the amphipathic, membrane-bound form of ACE in pig kidney microvilli into a hydrophilic, soluble form. This secretase activity was enriched to a similar extent as other microvillar membrane proteins, was tightly membrane-associated, being resistant to extensive washing of the microvillar membranes with 0.5 M NaCl, and displayed a pH optimum of 8.4. The ACE secretase was not affected by inhibitors of serine-, thiol- or aspartic-proteases, nor by reducing agents or alpha 2-macroglobulin. The metal chelators, EDTA and 1,10-phenanthroline, inhibited the secretase activity, with, in the case of EDTA, an inhibitor concentration of 2.5 mM causing 50% inhibition. In contrast, EGTA inhibited the secretase by a maximum of 15% at a concentration of 10 mM. The inhibition of EDTA was reactivated substantially (83%) by Mg2+ ions, and partially (34% and 29%) by Zn2+ and Mn2+ ions respectively. This EDTA-sensitive secretase activity was also present in microsomal membranes prepared from pig lung and testis, and from human lung and placenta, but was absent from human kidney and human and pig intestinal brush-border membranes. The form of ACE released from the microvillar membrane by the secretase co-migrated on SDS/PAGE with ACE purified from pig plasma, thus the action and location of the secretase would be consistent with it possibly having a role in the post-translational proteolytic cleavage of membrane-bound ACE to generate the soluble form found in blood, amniotic fluid, seminal plasma and other body fluids. Images Figure 4 PMID:8389141

  11. Preclinical assessment of Orteronel(®), a CYP17A1 enzyme inhibitor in rats.

    PubMed

    Zainuddin, Mohd; Vinod, A B; Gurav, Sandip Dhondiram; Police, Anitha; Kumar, Avinash; Mithra, Chandan; Dewang, Purushottam; Kethiri, Raghava Reddy; Mullangi, Ramesh

    2016-02-01

    Orteronel (TAK-700) is a novel and selective inhibitor of CYP17A1, which is expressed in testicular, adrenal and prostate tumor tissues. Orteronel is currently in Phase-III clinical development for metastatic castration-resistant prostate patients. The objective of the study is to assess the permeability, metabolic stability (in various preclinical and human liver microsomes), identify the major CYPs involved in the metabolism of Orteronel. We have also studied the pharmacokinetics and excretion of Orteronel in Sprague-Dawley rats. Orteronel was found to be stable in various liver microsomes tested. The half-life (t ½) of Orteronel with intravenous (i.v.) route was found to be 1.65 ± 0.22 h. The clearance and volume of distribution by i.v. route for Orteronel were found to be 27.5 ± 3.09 mL/min/kg and 3.94 ± 0.85 L/kg, respectively. The absorption of Orteronel was rapid, with maximum concentrations of drug in plasma of 614 ± 76.4, 1,764 ± 166, 4,652 ± 300 and 17,518 ± 3,178 ng/mL attained at 0.38, 0.75, 0.50 and 0.83 h, respectively, after oral administration of Orteronel at 5, 10, 30 and 100 mg/kg as a suspension. In the dose proportional oral pharmacokinetic study, the mean t ½ by oral route was found to be ~3.5 h and bioavailability ranged between 69 and 89 %. The primary route of elimination for Orteronel is urine. PMID:25297456

  12. Characterization of human liver enzymes involved in the biotransformation of boceprevir, a hepatitis C virus protease inhibitor.

    PubMed

    Ghosal, Anima; Yuan, Yuan; Tong, Wei; Su, Ai-Duen; Gu, Chunyan; Chowdhury, Swapan K; Kishnani, Narendra S; Alton, Kevin B

    2011-03-01

    Boceprevir (SCH 503034), a protease inhibitor, is under clinical development for the treatment of human hepatitis C virus infections. In human liver microsomes, formation of oxidative metabolites after incubations with [(14)C]boceprevir was catalyzed by CYP3A4 and CYP3A5. In addition, the highest turnover was observed in recombinant CYP3A4 and CYP3A5. After a single radiolabeled dose to human, boceprevir was subjected to two distinct pathways, namely cytochrome P450-mediated oxidation and ketone reduction. Therefore, attempts were made to identify the enzymes responsible for the formation of carbonyl-reduced metabolites. Human liver S9 and cytosol converted ∼ 28 and ∼ 68% of boceprevir to M28, respectively, in the presence of an NADPH-generating system. Screening of boceprevir with recombinant human aldo-keto reductases (AKRs) revealed that AKR1C2 and AKR1C3 exhibited catalytic activity with respect to the formation of M+2 metabolites (M28 and M31). The formation of M28 was inhibited by 100 μM flufenamic acid (80.3%), 200 μM mefenamic acid (83.7%), and 100 μM phenolphthalein (86.1%), known inhibitors of AKRs, suggesting its formation through carbonyl reduction pathway. Formation of M28 was also inhibited by 100 μM diazepam (75.1%), 1 mM ibuprofen (70%), and 200 μM diflunisal (89.4%). These data demonstrated that CYP3A4 and CYP3A5 are primarily responsible for the formation of oxidative metabolites and the formation of M28 and M31, the keto-reduced metabolites, are most likely mediated by AKR1C2 and AKR1C3. Because the biotransformation and clearance of boceprevir involves two different enzymatic pathways, boceprevir is less likely to be a victim of significant drug-drug interaction with concomitant medication affecting either of these pathways. PMID:21123164

  13. Angiotensin-converting enzymes modulate aphid-plant interactions.

    PubMed

    Wang, Wei; Luo, Lan; Lu, Hong; Chen, Shaoliang; Kang, Le; Cui, Feng

    2015-01-01

    Angiotensin-converting enzymes (ACEs) are key components of the renin-angiotensin system in mammals. However, the function of ACE homologs in insect saliva is unclear. Aphids presumably deliver effector proteins via saliva into plant cells to maintain a compatible insect-plant interaction. In this study, we showed that ACE modulates aphid-plant interactions by affecting feeding behavior and survival of aphids on host plants. Three ACE genes were identified from the pea aphid Acyrthosiphon pisum genome. ACE1 and ACE2 were highly expressed in the salivary glands and are predicted to function as secretory proteins. The ACE2 transcript level decreased in aphids fed on artificial diet compared with aphids fed on Vicia faba. The knockdown of the expression of each ACE by RNAi failed to affect aphid survival. When ACE1 and ACE2 were simultaneously knocked down, aphid feeding was enhanced. Aphids required less time to find the phloem sap and showed longer passive ingestion. However, the simultaneous knockdown of ACE1 and ACE2 resulted in a higher mortality rate than the control group when aphids were fed on plants. These results indicated that ACE1 and ACE2 function together to modulate A. pisum feeding and survival on plants. PMID:25744345

  14. Angiotensin-converting enzymes modulate aphid–plant interactions

    PubMed Central

    Wang, Wei; Luo, Lan; Lu, Hong; Chen, Shaoliang; Kang, Le; Cui, Feng

    2015-01-01

    Angiotensin-converting enzymes (ACEs) are key components of the renin–angiotensin system in mammals. However, the function of ACE homologs in insect saliva is unclear. Aphids presumably deliver effector proteins via saliva into plant cells to maintain a compatible insect–plant interaction. In this study, we showed that ACE modulates aphid–plant interactions by affecting feeding behavior and survival of aphids on host plants. Three ACE genes were identified from the pea aphid Acyrthosiphon pisum genome. ACE1 and ACE2 were highly expressed in the salivary glands and are predicted to function as secretory proteins. The ACE2 transcript level decreased in aphids fed on artificial diet compared with aphids fed on Vicia faba. The knockdown of the expression of each ACE by RNAi failed to affect aphid survival. When ACE1 and ACE2 were simultaneously knocked down, aphid feeding was enhanced. Aphids required less time to find the phloem sap and showed longer passive ingestion. However, the simultaneous knockdown of ACE1 and ACE2 resulted in a higher mortality rate than the control group when aphids were fed on plants. These results indicated that ACE1 and ACE2 function together to modulate A. pisum feeding and survival on plants. PMID:25744345

  15. Predictors of angiotensin-converting enzyme inhibitor-induced reduction of urinary albumin excretion in nondiabetic patients.

    PubMed

    van de Wal, Ruud M A; Gansevoort, Ron T; van der Harst, Pim; Boomsma, Frans; Thijs Plokker, H W; van Veldhuisen, Dirk J; de Jong, Paul E; van Gilst, Wiek H; Voors, Adriaan A

    2006-11-01

    Urinary albumin excretion is a predictor for cardiovascular mortality and morbidity. We investigated which parameters determine baseline urinary albumin excretion in nondiabetic subjects, without renal disease. In addition, we evaluated the parameters that predict the albuminuria-lowering efficacy of an angiotensin-converting enzyme inhibitor. In this substudy of the Prevention of Renal and Vascular Endstage Disease Intervention Trial, 384 microalbuminuric patients were included. Patient and biochemical characteristics were obtained at baseline and after 3 months of double-blinded, randomized treatment (fosinopril 20 mg or placebo). Mean age was 51.1+/-11.5 years, and 65.6% were male. Median urinary albumin excretion was 22.2 mg per 24 hours. At baseline, mean arterial pressure (beta(standardized)=0.161; P=0.006), urinary sodium excretion (beta(standardized)=0.154; P=0.011), and estimated renal function were independently associated with albumin excretion. In these predominantly normotensive to prehypertensive subjects, fosinopril reduced albumin excretion by 18.5% versus a 6.1% increase on placebo after 3 months (P<0.001). Fosinopril use and blood pressure reduction independently predicted the change in urinary albumin excretion. Baseline urinary albumin excretion independently predicted the antialbuminuric effect of fosinopril (beta(standardized)=-0.303; P<0.001). In conclusion, at baseline, sodium intake and blood pressure were positively associated with urinary albumin excretion. Fosinopril reduced albuminuria more than might be expected from its blood pressure-lowering effect alone, and this effect was more outspoken in subjects with higher baseline albumin excretion. Based on our data, we hypothesize that angiotensin-converting enzyme inhibition may result in superior cardiovascular protection when compared with other blood pressure-lowering agents in subjects with higher baseline levels of albuminuria. PMID:17000930

  16. ACE2 deficiency reduces β-cell mass and impairs β-cell proliferation in obese C57BL/6 mice.

    PubMed

    Shoemaker, Robin; Yiannikouris, Frederique; Thatcher, Sean; Cassis, Lisa

    2015-10-01

    Drugs that inhibit the renin-angiotensin system (RAS) decrease the onset of type 2 diabetes (T2D). Pancreatic islets express RAS components, including angiotensin-converting enzyme 2 (ACE2), which cleaves angiotensin II (Ang II) to angiotensin-(1-7) [Ang-(1-7)]. Overexpression of ACE2 in pancreas of diabetic mice improved glucose homeostasis. The purpose of this study was to determine if deficiency of endogenous ACE2 contributes to islet dysfunction and T2D. We hypothesized that ACE2 deficiency potentiates the decline in β-cell function and augments the development of diet-induced T2D. Male Ace2(+/y) or Ace2(-/y) mice were fed a low-fat (LF) or high-fat (HF) diet for 1 or 4 mo. A subset of 1-mo HF-fed mice were infused with Sal (Sal), losartan (Los), or Ang-(1-7). At 4 mo, while both genotypes of HF-fed mice developed a similar level of insulin resistance, adaptive hyperinsulinemia was reduced in Ace2(-/y) vs. Ace2(+/y) mice. Similarly, in vivo glucose-stimulated insulin secretion (GSIS) was reduced in 1-mo HF-fed Ace2(-/y) compared with Ace2(+/y) mice, resulting in augmented hyperglycemia. The average islet area was significantly smaller in both LF- and HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Additionally, β-cell mass and proliferation were reduced significantly in HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Neither infusion of Los nor Ang-(1-7) was able to correct impaired in vivo GSIS of HF-fed ACE2-deficient mice. These results demonstrate a critical role for endogenous ACE2 in the adaptive β-cell hyperinsulinemic response to HF feeding through regulation of β-cell proliferation and growth. PMID:26389599

  17. Developmental expression of ACE2 in the SHR kidney: a role in hypertension?

    PubMed

    Tikellis, C; Cooper, M E; Bialkowski, K; Johnston, C I; Burns, W C; Lew, R A; Smith, A I; Thomas, M C

    2006-07-01

    The abnormal development of the intrarenal renin-angiotensin system (RAS) is thought contribute to adult-onset hypertension in the spontaneously hypertensive rat (SHR). Angiotensin-converting enzyme 2 (ACE2) is a novel enzyme with complementary actions to that of ACE. Recent studies have shown that ACE2 expression is reduced in the adult SHR. However, its regulation in pre-hypertensive animals is unknown. In this study, we examine the developmental expression of ACE2 in the rodent kidney and its temporal expression, as it relates to the development of hypertension in the SHR model. Kidneys from SHR and normotensive Wistar Kyoto (WKY) rats (n=8-12/group) at birth, 6 weeks of age, and adulthood (80 days) were examined. Gene expression and activity of ACE2 were determined by real-time reverse transcription-polymerase chain reaction and quenched fluorescence assays, respectively. Renal expression was localized by in situ hybridization and immunohistochemistry. The expression and ACE2 activity are significantly increased in the SHR kidney at birth. With the onset of hypertension, the tubular expression of ACE2 falls in SHR compared to WKY and remains reduced in the adult SHR kidney. Glomerular expression is paradoxically increased in the SHR glomerulus. The overall developmental pattern of ACE2 expression in the SHR kidney is also modified, with declining expression over the course of renal development. The developmental pattern of ACE2 expression in the SHR kidney is altered before the onset of hypertension, consistent with the key role of the RAS in the pathogenesis of adult-onset hypertension. Further research is required to distinguish the contribution of these changes to the development and progression of hypertension in this model. PMID:16710353

  18. Exploring the Chemical Space around 8-Mercaptoguanine as a Route to New Inhibitors of the Folate Biosynthesis Enzyme HPPK

    PubMed Central

    Chhabra, Sandeep; Barlow, Nicholas; Dolezal, Olan; Hattarki, Meghan K.; Newman, Janet; Peat, Thomas S.; Graham, Bim; Swarbrick, James D.

    2013-01-01

    As the second essential enzyme of the folate biosynthetic pathway, the potential antimicrobial target, HPPK (6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase), catalyzes the Mg2+-dependant transfer of pyrophosphate from the cofactor (ATP) to the substrate, 6-hydroxymethyl-7,8-dihydropterin. Recently, we showed that 8-mercaptoguanine (8-MG) bound at the substrate site (KD ∼13 µM), inhibited the S. aureus enzyme (SaHPPK) (IC50 ∼ 41 µM), and determined the structure of the SaHPPK/8-MG complex. Here we present the synthesis of a series of guanine derivatives, together with their HPPK binding affinities, as determined by SPR and ITC analysis. The binding mode of the most potent was investigated using 2D NMR spectroscopy and X-ray crystallography. The results indicate, firstly, that the SH group of 8-MG makes a significant contribution to the free energy of binding. Secondly, direct N9 substitution, or tautomerization arising from N7 substitution in some cases, leads to a dramatic reduction in affinity due to loss of a critical N9-H···Val46 hydrogen bond, combined with the limited space available around the N9 position. The water-filled pocket under the N7 position is significantly more tolerant of substitution, with a hydroxyl ethyl 8-MG derivative attached to N7 (compound 21a) exhibiting an affinity for the apo enzyme comparable to the parent compound (KD ∼ 12 µM). In contrast to 8-MG, however, 21a displays competitive binding with the ATP cofactor, as judged by NMR and SPR analysis. The 1.85 Å X-ray structure of the SaHPPK/21a complex confirms that extension from the N7 position towards the Mg2+-binding site, which affords the only tractable route out from the pterin-binding pocket. Promising strategies for the creation of more potent binders might therefore include the introduction of groups capable of interacting with the Mg2+ centres or Mg2+ -binding residues, as well as the development of bitopic inhibitors featuring 8-MG linked to a moiety

  19. A comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced memory impairments in rats.

    PubMed

    Jawaid, Talha; Jahan, Shah; Kamal, Mehnaz

    2015-01-01

    The comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced neuroinflammation in albino Wistar rats was studied. Male albino rats were administered with scopolamine to induce memory impairment. The standard nootropic agent, piracetam (200 mg/kg b.w., [i.p.]), perindopril (0.1 mg/kg b.w., [i.p.]), enalapril (0.1 mg/kg b.w., [i.p.]), and ramipril (0.1 mg/kg b.w., [i.p.]) were administered in different group of animals for 5 days. On 5(th) day, scopolamine (1 mg/kg b.w., i.p.) was administered after 60 min of the last dose of test drug. Memory function was evaluated in Morris water maze (MWM) test and pole climbing test (PCT). Biochemical estimations like glutathione (GSH), malondialdehyde (MDA), and acetylcholinesterase activity in the brain were estimated after completion of behavior study. All three test groups shows improvement in learning and memory in comparison to control group. Perindopril treated group showed a more effective significant decrease in escape latency time and transfer latency time compared to enalapril and ramipril treated group on day 4 in MWM test and PCT, respectively. Perindopril shows a significant reduction in MDA level and acetylcholinesterase activity and a significant rise in GSH level compared to enalapril and ramipril. The finding of this study indicates that Perindopril is more effective in memory retention compared to enalapril and ramipril. PMID:26317078

  20. Cardiovascular risk reduction in hypertension: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers. Where are we up to?

    PubMed

    Sindone, A; Erlich, J; Lee, C; Newman, H; Suranyi, M; Roger, S D

    2016-03-01

    Previously, management of hypertension has concentrated on lowering elevated blood pressure. However, the target has shifted to reducing absolute cardiovascular (CV) risk. It is estimated that two in three Australian adults have three or more CV risk factors at the same time. Moderate reductions in several risk factors can, therefore, be more effective than major reductions in one. When managing hypertension, therapy should be focused on medications with the strongest evidence for CV event reduction, substituting alternatives only when a primary choice is not appropriate. Hypertension management guidelines categorise angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) interchangeably as first-line treatments in uncomplicated hypertension. These medications have different mechanisms of action and quite different evidence bases. They are not interchangeable and their prescription should be based on clinical evidence. Despite this, currently ARB prescriptions are increasing at a higher rate than those for ACEI and other antihypertensive classes. Evidence that ACEI therapy prevents CV events and death, in patients with coronary artery disease or multiple CV risk factors, emerged from the European trial on reduction of cardiac events with perindopril in stable coronary artery disease (EUROPA) and Heart Outcomes Prevention Evaluation (HOPE) trials respectively. The consistent benefit has been demonstrated in meta-analyses. The clinical trial data for ARB are less consistent, particularly regarding CV outcomes and mortality benefit. The evidence supports the use of ACEI (Class 1a) compared with ARB despite current prescribing trends. PMID:26968600

  1. Sleep-related movement disorder symptoms in SHR are attenuated by physical exercise and an angiotensin-converting enzyme inhibitor.

    PubMed

    Frank, Miriam Kannebley; de Mello, Marco Tulio; Lee, Kil Sun; Daubian-Nosé, Paulo; Tufik, Sergio; Esteves, Andrea Maculano

    2016-02-01

    The relationship between hypertension and sleep-related movement disorders has been hypothesized for humans, but the causes and mechanisms have not been elucidated. We investigated whether an alteration in blood pressure (BP) induced by physical exercise and/or an angiotensin-converting enzyme inhibitor (enalapril) could affect locomotor activity in spontaneously hypertensive rats, with emphasis on the dopaminergic system. We used SHR and normotensive Wistar rats distributed into 4 groups for each strain: control, physical exercise, enalapril and physical exercise+enalapril. Physical exercise was performed on a treadmill, and enalapril was administered by gavage, both for 8weeks. During this period, locomotor activity was evaluated in an open field test, and BP was evaluated by tail plethysmography. Dopaminergic receptors, dopamine transporter and tyrosine hydroxylase levels at the striatum were evaluated by Western blotting. The control group of spontaneously hypertensive rats showed higher BP, increased activity in the open field test and lower levels of D2 receptors and tyrosine hydroxylase compared with all other groups throughout the experimental period. In general, physical exercise and enalapril attenuated these alterations. This study suggested the existence of comorbidity between hypertension and sleep-related movement disorders in spontaneously hypertensive rats. Physical exercise and enalapril conferred protection for both hypertension and the observed behavioral changes. In addition, these treatments led to changes in dopaminergic signaling in the striatal region (i.e., D2 receptor, TH and DAT). PMID:26650246

  2. A comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced memory impairments in rats

    PubMed Central

    Jawaid, Talha; Jahan, Shah; Kamal, Mehnaz

    2015-01-01

    The comparative study of neuroprotective effect of angiotensin converting enzyme inhibitors against scopolamine-induced neuroinflammation in albino Wistar rats was studied. Male albino rats were administered with scopolamine to induce memory impairment. The standard nootropic agent, piracetam (200 mg/kg b.w., [i.p.]), perindopril (0.1 mg/kg b.w., [i.p.]), enalapril (0.1 mg/kg b.w., [i.p.]), and ramipril (0.1 mg/kg b.w., [i.p.]) were administered in different group of animals for 5 days. On 5th day, scopolamine (1 mg/kg b.w., i.p.) was administered after 60 min of the last dose of test drug. Memory function was evaluated in Morris water maze (MWM) test and pole climbing test (PCT). Biochemical estimations like glutathione (GSH), malondialdehyde (MDA), and acetylcholinesterase activity in the brain were estimated after completion of behavior study. All three test groups shows improvement in learning and memory in comparison to control group. Perindopril treated group showed a more effective significant decrease in escape latency time and transfer latency time compared to enalapril and ramipril treated group on day 4 in MWM test and PCT, respectively. Perindopril shows a significant reduction in MDA level and acetylcholinesterase activity and a significant rise in GSH level compared to enalapril and ramipril. The finding of this study indicates that Perindopril is more effective in memory retention compared to enalapril and ramipril. PMID:26317078

  3. Autodisplay of Human Hyaluronidase Hyal-1 on Escherichia coli and Identification of Plant-Derived Enzyme Inhibitors.

    PubMed

    Orlando, Zoya; Lengers, Isabelle; Melzig, Matthias F; Buschauer, Armin; Hensel, Andreas; Jose, Joachim

    2015-01-01

    Hyaluronan (HA) is the main component of the extracellular matrix (ECM). Depending on its chain size, it is generally accepted to exert diverse effects. High molecular weight HA is anti-angiogenic, immunosuppressive and anti-inflammatory, while lower fragments are angiogenic and inflammatory. Human hyaluronidase Hyal-1 (Hyal-1) is one of the main enzymes in the metabolism of HA. This makes Hyal-1 an interesting target. Not only for functional and mechanistic studies, but also for drug development. In this work, Hyal-1 was expressed on the surface of E. coli, by applying Autodisplay, to overcome formation of inactive "inclusion bodies". With the cells displaying Hyal-1 an activity assay was performed using "stains-all" dye. Subsequently, the inhibitory effects of four saponins and 14 plant extracts on the activity of surface displayed Hyal-1 were evaluated. The determined IC50 values were 177 µM for glycyrrhizic acid, 108 µM for gypsophila saponin 2, 371 µM for SA1657 and 296 µM for SA1641. Malvae sylvestris flos, Equiseti herba and Ononidis radix extracts showed IC50 values between 1.4 and 1.7 mg/mL. In summary, Autodisplay enabled the expression of functional human target protein Hyal-1 in E. coli and facilitated an accelerated testing of potential inhibitors. PMID:26343612

  4. Preparation of Antibodies and Development of an Enzyme-Linked Immunosorbent Assay for the Tyrosine Kinase Inhibitors Lapatinib and Nilotinib.

    PubMed

    Saita, Tetsuya; Yamamoto, Yuta; Shin, Masashi; Nakano, Yukitaka

    2015-01-01

    In this paper, we describe the production of the first specific antibodies against the tyrosine kinase inhibitors lapatinib and nilotinib. Anti-lapatinib antibody was obtained by immunizing rabbits with an antigen conjugated with bovine serum albumin using 3-chloro-4-((3-fluorobenzyl)oxy)aniline. Anti-nilotinib antibody was produced by immunizing mice with an antigen conjugated with bovine serum albumin using 2-(5-amino-2-methylanilino)-4-(3-pyridyl)pyrimidine. The generated antibodies were used to develop highly sensitive and specific enzyme-linked immunosorbent assays (ELISAs) for lapatinib and nilotinib in human serum. The assays were capable of detecting lapatinib and nilotinib at serum concentrations as low as 40 and 8 ng/mL, respectively. Using the two ELISAs, drugs levels were easily measured in the serum of rats after a single dose oral administration of lapatinib or nilotinib. The assays are therefore expected be valuable tools for therapeutic drug monitoring in the clinical setting and pharmacokinetic studies of lapatinib and nilotinib. PMID:26424026

  5. β-blockers and Angiotensin Converting Enzyme Inhibitors: Comparison of Effects on Aortic Growth in Pediatric Patients with Marfan Syndrome

    PubMed Central

    Phomakay, Venusa; Huett, Wilson G.; Gossett, Jeffrey M.; Tang, Xinyu; Bornemeier, Renee A.; Collins, R. Thomas

    2015-01-01

    Objectives Angiotensin converting enzyme inhibitors (ACEI) have been shown to decrease AGV in Marfan syndrome (MFS). We sought to compare the effect of β-blockers and ACEI on aortic growth velocity (AGV) in MFS. Study design We reviewed retrospectively all data from all patients with MFS seen at Arkansas Children’s Hospital between January 1, 1976 and January 1, 2013. Generalized least squares were used to evaluate AGV over time as a function of age, medication group, and the interaction between the two. A mixed model was used to compare AGV between medication groups as a function of age, medication group (none, β-blocker, ACEI), and the interaction between the two. Results A total of 67 patients with confirmed MFS were identified (34/67, 51% female). Mean age at first encounter was 13 ± 10 years, with mean follow-up of 7.6 ± 5.8 years. There were 839 patient encounters with a median of 10 (range 2–42) encounters per patient. AGV was nearly normal in the β-blocker group, and was less than either the ACEI or untreated groups. The AGV was higher than normal in ACEI and untreated groups (p<0.001 for both). Conclusions β-blocker therapy results in near-normalization of AGV in MFS. ACEI did not decrease AGV in a clinically significant manner. PMID:25109242

  6. A simpler sampling interface of venturi easy ambient sonic-spray ionization mass spectrometry for high-throughput screening enzyme inhibitors.

    PubMed

    Liu, Ning; Liu, Yang; Yang, YuHan; He, Lan; Ouyang, Jin

    2016-03-24

    High-throughput screening (HTS) is often required in enzyme inhibitor drugs screening. Mass spectrometry (MS) provides a powerful method for high-throughput screening enzyme inhibitors because its high speed, sensitivity and property of lable free. However, most of the MS methods need complicated sampling interface system. Overall throughput was limited by sample loading in these cases. In this study, we develop a simple interface which coupled droplet segmented system to a venturi easy ambient sonic-spray ionization mass spectrometer. It is fabricated by using a single capillary to act as both sampling probe and the emitter, which simplifies the construction, reduces the cost and shorten the sampling time. Samples sucked by venturi effect are segmented to nanoliter plugs by air, then the plugs can be detected by MS directly. This system eliminated the need for flow injection which was popular used in classic scheme. The new system is applied to screen angiotensin converting enzyme inhibitors. High-throughput was achieved in analyzing 96 samples at 1.6 s per sample. The plugs formation was at 0.5s per sample. Carry-over between samples was less than 5%, the peak height RSD was 2.92% (n = 15). Dose-response curves of 3 known inhibitors were also measured to validate its potential in drug discovery. The calculated IC50 agreed well with reported values. PMID:26944992

  7. Involvement of human plasma angiotensin I-converting enzyme in the degradation of the haemoregulatory peptide N-acetyl-seryl-aspartyl-lysyl-proline.

    PubMed Central

    Rieger, K J; Saez-Servent, N; Papet, M P; Wdzieczak-Bakala, J; Morgat, J L; Thierry, J; Voelter, W; Lenfant, M

    1993-01-01

    The degradation of N-Ac-Ser-Asp-Lys-Pro (AcSDKP), a negative regulator controlling the proliferation of the haematopoietic stem cell, by enzymes present in human plasma, has been investigated. Radiolabelled AcSD[4-3H]KP ([3H]AcSDKP, 1 mM) was completely metabolized in human plasma with a half-life of 80 min, leading exclusively to the formation of radiolabelled lysine. The cleavage of AcSDKP was insensitive to classical proteinase inhibitors including leupeptin, but sensitive to metalloprotease inhibitors. The degradation was completely blocked by specific inhibitors of angiotensin I-converting enzyme (ACE; kininase II; peptidyldipeptide hydrolase, EC 3.4.15.1), showing that the first step of the hydrolysis was indeed due to ACE. In dialysed plasma, the hydrolysis proceeded at only 17% of the maximal rate, whereas addition of 20 mM NaCl led to the recovery of the initial rate observed with normal plasma. Hydrolysis of AcSDKP by commercial rabbit lung ACE generated the C-terminal dipeptide Lys-Pro. Thus, ACE cleaves AcSDKP by a dipeptidyl carboxypeptidase activity. In fact the formation of Lys-Pro was observed when AcSDKP was incubated in human plasma in the presence of HgCl2. These results suggest that ACE is involved in the first limiting step of AcSDKP degradation in human plasma. The second step seems to be under the control of a leupeptin- and E-64-insensitive, HgCl2-sensitive plasmatic enzyme. PMID:8257427

  8. Tissue Specificity of Human Angiotensin I-Converting Enzyme

    PubMed Central

    Kryukova, Olga V.; Tikhomirova, Victoria E.; Golukhova, Elena Z.; Evdokimov, Valery V.; Kalantarov, Gavreel F.; Trakht, Ilya N.; Schwartz, David E.; Dull, Randal O.; Gusakov, Alexander V.; Uporov, Igor V.; Kost, Olga A.; Danilov, Sergei M.

    2015-01-01

    Background Angiotensin-converting enzyme (ACE), which metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling, as well as in reproductive functions, is expressed as a type-1 membrane glycoprotein on the surface of endothelial and epithelial cells. ACE also presents as a soluble form in biological fluids, among which seminal fluid being the richest in ACE content - 50-fold more than that in blood. Methods/Principal Findings We performed conformational fingerprinting of lung and seminal fluid ACEs using a set of monoclonal antibodies (mAbs) to 17 epitopes of human ACE and determined the effects of potential ACE-binding partners on mAbs binding to these two different ACEs. Patterns of mAbs binding to ACEs from lung and from seminal fluid dramatically differed, which reflects difference in the local conformations of these ACEs, likely due to different patterns of ACE glycosylation in the lung endothelial cells and epithelial cells of epididymis/prostate (source of seminal fluid ACE), confirmed by mass-spectrometry of ACEs tryptic digests. Conclusions Dramatic differences in the local conformations of seminal fluid and lung ACEs, as well as the effects of ACE-binding partners on mAbs binding to these ACEs, suggest different regulation of ACE functions and shedding from epithelial cells in epididymis and prostate and endothelial cells of lung capillaries. The differences in local conformation of ACE could be the base for the generation of mAbs distingushing tissue-specific ACEs. PMID:26600189

  9. Susceptibilities of human immunodeficiency virus type 1 enzyme and viral variants expressing multiple resistance-engendering amino acid substitutions to reserve transcriptase inhibitors.

    PubMed Central

    Byrnes, V W; Emini, E A; Schleif, W A; Condra, J H; Schneider, C L; Long, W J; Wolfgang, J A; Graham, D J; Gotlib, L; Schlabach, A J

    1994-01-01

    To evaluate the potential that multiply resistant human immunodeficiency virus type 1 variants may arise during combination nucleoside and nonnucleoside reverse transcriptase inhibitor therapy, we constructed a series of mutant reverse transcriptase enzymes and viruses that coexpressed various combinations of resistance-associated amino acid substitutions. Substitutions at residues 100 (Leu-->Ile) and 181 (Tyr-->Cys), which mediate resistance to the nonnucleosides, suppressed resistance to 3'-azido-3'-deoxythymidine (AZT) when coexpressed with AZT-specific substitutions. However, a number of viral variants that exhibited significantly reduced susceptibilities to both classes of inhibitors were constructed. PMID:7522428

  10. ACE2 Deficiency Worsens Epicardial Adipose Tissue Inflammation and Cardiac Dysfunction in Response to Diet-Induced Obesity.

    PubMed

    Patel, Vaibhav B; Mori, Jun; McLean, Brent A; Basu, Ratnadeep; Das, Subhash K; Ramprasath, Tharmarajan; Parajuli, Nirmal; Penninger, Josef M; Grant, Maria B; Lopaschuk, Gary D; Oudit, Gavin Y

    2016-01-01

    Obesity is increasing in prevalence and is strongly associated with metabolic and cardiovascular disorders. The renin-angiotensin system (RAS) has emerged as a key pathogenic mechanism for these disorders; angiotensin (Ang)-converting enzyme 2 (ACE2) negatively regulates RAS by metabolizing Ang II into Ang 1-7. We studied the role of ACE2 in obesity-mediated cardiac dysfunction. ACE2 null (ACE2KO) and wild-type (WT) mice were fed a high-fat diet (HFD) or a control diet and studied at 6 months of age. Loss of ACE2 resulted in decreased weight gain but increased glucose intolerance, epicardial adipose tissue (EAT) inflammation, and polarization of macrophages into a proinflammatory phenotype in response to HFD. Similarly, human EAT in patients with obesity and heart failure displayed a proinflammatory macrophage phenotype. Exacerbated EAT inflammation in ACE2KO-HFD mice was associated with decreased myocardial adiponectin, decreased phosphorylation of AMPK, increased cardiac steatosis and lipotoxicity, and myocardial insulin resistance, which worsened heart function. Ang 1-7 (24 µg/kg/h) administered to ACE2KO-HFD mice resulted in ameliorated EAT inflammation and reduced cardiac steatosis and lipotoxicity, resulting in normalization of heart failure. In conclusion, ACE2 plays a novel role in heart disease associated with obesity wherein ACE2 negatively regulates obesity-induced EAT inflammation and cardiac insulin resistance. PMID:26224885

  11. Advanced Collaborative Emissions Study (ACES)

    SciTech Connect

    Greenbaum, Daniel; Costantini, Maria; Van Erp, Annemoon; Shaikh, Rashid; Bailey, Brent; Tennant, Chris; Khalek, Imad; Mauderly, Joe; McDonald, Jacob; Zielinska, Barbara; Bemis, Jeffrey; Storey, John; Hallberg, Lance; Clark, Nigel

    2013-12-31

    The objective of the Advanced Collaborative Emissions Study (ACES) was to determine before widespread commercial deployment whether or not the new, energy-efficient, heavy duty diesel engines (2007 and 2010 EPA Emissions Standards Compliant) may generate anticipated toxic emissions that could adversely affect the environment and human health. ACES was planned to take place in three phases. In Phase 1, extensive emissions characterization of four production-intent prototype engine and control systems designed to meet 2007 standards for nitrogen oxides (NOx) and particulate matter (PM) was conducted at an existing emissions characterization facility: Southwest Research Institute (SwRI). One of the tested engines was selected (at random, after careful comparison of results) for health testing in Phase 3. In Phase 2, extensive emission characterization of three production-intent prototype engine and control systems meeting the 2010 standards (including more advanced NOx controls to meet the more stringent 2010 NOx standards) was conducted at the same test facility. In Phase 3, one engine/aftertreatment system selected from Phase 1 was further characterized during health effects studies (at an existing inhalation toxicology laboratory: Lovelace Respiratory Research Institute, [LRRI]) to form the basis of the ACES safety assessment. The Department of Energy (DOE) award provided funding for emissions characterization in Phases 1 and 2 as well as exposure characterization in Phase 3. The main health analyses in Phase 3 were funded separately and are not reported here.

  12. Prediction of novel and selective TNF-alpha converting enzyme (TACE) inhibitors and characterization of correlative molecular descriptors by machine learning approaches.

    PubMed

    Cong, Yong; Yang, Xue-Gang; Lv, Wei; Xue, Ying

    2009-10-01

    The inhibition of TNF-alpha converting enzyme (TACE) has been explored as a feasible therapy for the treatment of rheumatoid arthritis (RA) and Crohn's disease (CD). Recently, large numbers of novel and selective TACE inhibitors have been reported. It is desirable to develop machine learning (ML) models for identifying the inhibitors of TACE in the early drug design phase and test the prediction capabilities of these ML models. This work evaluated four ML methods, support vector machine (SVM), k-nearest neighbor (k-NN), back-propagation neural network (BPNN) and C4.5 decision tree (C4.5 DT), which were trained and tested by using a diverse set of 443 TACE inhibitors and 759 non-inhibitors. A well-established feature selection method, the recursive feature elimination (RFE) method, was used to select the most appropriate descriptors for classification from a large pool of descriptors, and two evaluation methods, 5-fold cross-validation and independent evaluation, were used to assess the performances of these developed models. In this study, all these ML models have already achieved promising prediction accuracies. By using the RFE method, the prediction accuracies are further improved. In k-NN, the model gives the best prediction for TACE inhibitors (98.32%), and the SVM bears the best prediction for non-inhibitors (99.51%). Both the k-NN and SVM model give the best overall prediction accuracy (98.45%). To the best of our knowledge, the SVM model developed in this work is the first one for the classification prediction of TACE inhibitors with a broad applicability domain. Our study suggests that ML methods, particularly SVM, are potentially useful for facilitating the discovery of TACE inhibitors and for exhibiting the molecular descriptors associated with TACE inhibitors. PMID:19729328

  13. Identification of the Major ACE-Inhibitory Peptides Produced by Enzymatic Hydrolysis of a Protein Concentrate from Cuttlefish Wastewater

    PubMed Central

    Rodríguez Amado, Isabel; Vázquez, José Antonio; González, Pilar; Esteban-Fernández, Diego; Carrera, Mónica; Piñeiro, Carmen

    2014-01-01

    The aim of this work was the purification and identification of the major angiotensin converting enzyme (ACE) inhibitory peptides produced by enzymatic hydrolysis of a protein concentrate recovered from a cuttlefish industrial manufacturing effluent. This process consisted on the ultrafiltration of cuttlefish softening wastewater, with a 10 kDa cut-off membrane, followed by the hydrolysis with alcalase of the retained fraction. Alcalase produced ACE inhibitors reaching the highest activity (IC50 = 76.8 ± 15.2 μg mL−1) after 8 h of proteolysis. Sequential ultrafiltration of the 8 h hydrolysate with molecular weight cut-off (MWCO) membranes of 10 and 1 kDa resulted in the increased activity of each permeate, with a final IC50 value of 58.4 ± 4.6 μg mL−1. Permeate containing peptides lower than 1 kDa was separated by reversed-phase high performance liquid chromatography (RP-HPLC). Four fractions (A–D) with potent ACE inhibitory activity were isolated and their main peptides identified using high performance liquid chromatography coupled to an electrospray ion trap Fourier transform ion cyclotron resonance-mass spectrometer (HPLC-ESI-IT-FTICR) followed by comparison with databases and de novo sequencing. The amino acid sequences of the identified peptides contained at least one hydrophobic and/or a proline together with positively charged residues in at least one of the three C-terminal positions. The IC50 values of the fractions ranged from 1.92 to 8.83 μg mL−1, however this study fails to identify which of these peptides are ultimately responsible for the potent antihypertensive activity of these fractions. PMID:24619242

  14. Pharmacogenetic Risk Stratification in Angiotensin-Converting Enzyme Inhibitor-Treated Patients with Congestive Heart Failure: A Retrospective Cohort Study

    PubMed Central

    Nelveg-Kristensen, Karl Emil; Busk Madsen, Majbritt; Torp-Pedersen, Christian; Køber, Lars; Egfjord, Martin; Berg Rasmussen, Henrik; Riis Hansen, Peter

    2015-01-01

    Background Evidence for pharmacogenetic risk stratification of angiotensin-converting enzyme inhibitor (ACEI) treatment is limited. Therefore, in a cohort of ACEI-treated patients with congestive heart failure (CHF), we investigated the predictive value of two pharmacogenetic scores that previously were found to predict ACEI efficacy in patients with ischemic heart disease and hypertension, respectively. Score A combined single nucleotide polymorphisms (SNPs) of the angiotensin II receptor type 1 gene (rs275651 and rs5182) and the bradykinin receptor B1 gene (rs12050217). Score B combined SNPs of the angiotensin-converting enzyme gene (rs4343) and ABO blood group genes (rs495828 and rs8176746). Methods Danish patients with CHF enrolled in the previously reported Echocardiography and Heart Outcome Study were included. Subjects were genotyped and categorized according to pharmacogenetic scores A and B of ≤1, 2 and ≥3 each, and followed for up to 10 years. Difference in cumulative incidences of cardiovascular death and all-cause death were assessed by the cumulative incidence estimator. Survival was modeled by Cox proportional hazard analyses. Results We included 667 patients, of whom 80% were treated with ACEIs. Differences in cumulative incidences of cardiovascular death (P = 0.346 and P = 0.486) and all-cause death (P = 0.515 and P = 0.486) were not significant for score A and B, respectively. There was no difference in risk of cardiovascular death or all-cause death between subjects with score A ≤1 vs. 2 (HR 1.03 [95% CI 0.79–1.34] and HR 1.11 [95% CI 0.88–1.42]), score A ≤1 vs. ≥3 (HR 0.80 [95% CI 0.59–1.08] and HR 0.91 [95% CI 0.70–1.20]), score B ≤1 vs. 2 (HR 1.02 [95% CI 0.78–1.32] and HR 0.98 [95% CI 0.77–1.24]), and score B ≤1 vs. ≥3 (HR 1.03 [95% CI 0.75–1.41] and HR 1.05 [95% CI 0.79–1.40]), respectively. Conclusions We found no association between either of the analyzed pharmacogenetic scores and fatal outcomes in ACEI

  15. Angiotensin-Receptor Blocker, Angiotensin-Converting Enzyme Inhibitor, and Risks of Atrial Fibrillation: A Nationwide Cohort Study.

    PubMed

    Hsieh, Yu-Cheng; Hung, Chen-Ying; Li, Cheng-Hung; Liao, Ying-Chieh; Huang, Jin-Long; Lin, Ching-Heng; Wu, Tsu-Juey

    2016-05-01

    Both angiotensin-receptor blockers (ARB) and angiotensin-converting enzyme inhibitors (ACEI) have protective effects against atrial fibrillation (AF). The differences between ARB and ACEI in their effects on the primary prevention of AF remain unclear. This study compared ARB and ACEI in combined antihypertensive medications for reducing the risk of AF in patients with hypertension, and determined which was better for AF prevention in a nationwide cohort study.Patients aged ≥55 years and with a history of hypertension were identified from Taiwan National Health Insurance Research Database. Medical records of 25,075 patients were obtained, and included 6205 who used ARB, 8034 who used ACEI, and 10,836 nonusers (no ARB or ACEI) in their antihypertensive regimen. Cox regression models were applied to estimate the hazard ratio (HR) for new-onset AF.During an average of 7.7 years' follow-up, 1619 patients developed new-onset AF. Both ARB (adjusted HR: 0.51, 95% CI 0.44-0.58, P < 0.001) and ACEI (adjusted HR: 0.53, 95% CI 0.47-0.59, P < 0.001) reduced the risk of AF compared to nonusers. Subgroup analysis showed that ARB and ACEI were equally effective in preventing new-onset AF regardless of age, gender, the presence of heart failure, diabetes, and vascular disease, except for those with prior stroke or transient ischemic attack (TIA). ARB prevents new-onset AF better than ACEI in patients with a history of stroke or TIA (log-rank P = 0.012).Both ARB and ACEI reduce new-onset AF in patients with hypertension. ARB prevents AF better than ACEI in patients with a history of prior stroke or TIA. PMID:27196491

  16. Impact of Angiotensin Converting Enzyme Inhibitor versus Angiotensin Receptor Blocker on Incidence of New-Onset Diabetes Mellitus in Asians

    PubMed Central

    Park, Ji Young; Choi, Byoung Geol; Choi, Se Yeon; Choi, Jae Woong; Ryu, Sung Kee; Lee, Se Jin; Kim, Seunghwan; Noh, Yung-Kyun; Akkala, Raghavender Goud; Li, Hu; Ali, Jabar; Kim, Ji Bak; Lee, Sunki; Na, Jin Oh; Choi, Cheol Ung; Lim, Hong Euy; Kim, Jin Won; Kim, Eung Ju; Park, Chang Gyu; Seo, Hong Seog; Oh, Dong Joo

    2016-01-01

    Purpose Angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) are associated with a decreased incidence of new-onset diabetes mellitus (NODM). The aim of this study was to compare the protective effect of ACEI versus ARBs on NODM in an Asian population. Materials and Methods We investigated a total of 2817 patients who did not have diabetes mellitus from January 2004 to September 2009. To adjust for potential confounders, a propensity score matched (PSM) analysis was performed using a logistic regression model. The primary end-point was the cumulative incidence of NODM, which was defined as having a fasting blood glucose ≥126 mg/dL or HbA1c ≥6.5%. Multivariable cox-regression analysis was performed to determine the impact of ACEI versus ARB on the incidence of NODM. Results Mean follow-up duration was 1839±1019 days in all groups before baseline adjustment and 1864±1034 days in the PSM group. After PSM (C-statistics=0.731), a total 1024 patients (ACEI group, n=512 and ARB group, n=512) were enrolled for analysis and baseline characteristics were well balanced. After PSM, the cumulative incidence of NODM at 3 years was lower in the ACEI group than the ARB group (2.1% vs. 5.0%, p=0.012). In multivariate analysis, ACEI vs. ARB was an independent predictor of the lower incidence for NODM (odd ratio 0.37, confidence interval 0.17-0.79, p=0.010). Conclusion In the present study, compared with ARB, chronic ACEI administration appeared to be associated with a lower incidence of NODM in a series of Asian cardiovascular patients. PMID:26632399

  17. Interactions of the hepatitis C virus protease inhibitor faldaprevir with cytochrome P450 enzymes: in vitro and in vivo correlation.

    PubMed

    Sabo, John P; Kort, Jens; Ballow, Charles; Kashuba, Angela D M; Haschke, Manuel; Battegay, Manuel; Girlich, Birgit; Ting, Naitee; Lang, Benjamin; Zhang, Wei; Cooper, Curtis; O'Brien, Drané; Seibert, Eleanore; Chan, Tom S; Tweedie, Donald; Li, Yongmei

    2015-04-01

    The potential inhibition of the major human cytochrome P450 (CYP) enzymes by faldaprevir was evaluated both in vitro and in clinical studies (healthy volunteers and hepatitis C virus [HCV] genotype 1-infected patients). In vitro studies indicated that faldaprevir inhibited CYP2B6, CYP2C9, and CYP3A, and was a weak-to-moderate inactivator of CYP3A4. Faldaprevir 240 mg twice daily in healthy volunteers demonstrated moderate inhibition of hepatic and intestinal CYP3A (oral midazolam: 2.96-fold increase in AUC(0-24 h)), weak inhibition of hepatic CYP3A (intravenous midazolam: 1.56-fold increase in AUC(0-24 h)), weak inhibition of CYP2C9 ([S]-warfarin: 1.29-fold increase in AUC(0-120 h)), and had no relevant effects on CYP1A2, CYP2B6, or CYP2D6. Faldaprevir 120 mg once daily in HCV-infected patients demonstrated weak inhibition of hepatic and intestinal CYP3A (oral midazolam: 1.52-fold increase in AUC(0-∞)), and had no relevant effects on CYP2C9 or CYP1A2. In vitro drug-drug interaction predictions based on inhibitor concentration ([I])/inhibition constant (Ki) ratios tended to overestimate clinical effects and a net-effect model provided a more accurate approach. These studies suggest that faldaprevir shows a dose-dependent inhibition of CYP3A and CYP2C9, and does not induce CYP isoforms. PMID:25449227

  18. Angiotensin-converting enzyme inhibitor-induced angioedema: a multicenter review and an algorithm for airway management.

    PubMed

    Chiu, A G; Newkirk, K A; Davidson, B J; Burningham, A R; Krowiak, E J; Deeb, Z E

    2001-09-01

    Angioedema is a nonpitting edema of which the presentation ranges from benign facial swelling to airway obstruction managed by intubation or tracheotomy. The presentation of this disease is reviewed, and a treatment algorithm based on initial signs and symptoms is proposed for proper airway management. We performed a retrospective review of 108 patients treated in 2 tertiary care centers in the Washington, DC, area over a 5-year period. Ninety-eight patients (90.7%) were African-American, and 81 (75%) were female. Seventy-four patients (68.5%) were taking angiotensin-converting enzyme inhibitors (ACEIs). A classification system was developed based on the location of the edema at initial presentation: 1) isolated facial swelling and oral cavity edema, excluding the floor of the mouth; 2) floor of mouth and/or oropharyngeal edema, and 3) oropharyngeal edema with glottic and/or supraglottic involvement. Fourteen patients (13%) needed airway intervention, 2 of whom underwent a cricothyrotomy after a failed intubation attempt. Eleven (78.6%) were taking ACEIs. The indication for each intubation was massive tongue and floor of mouth edema. The patients were extubated 48 to 72 hours later. No patient demonstrated symptom progression after medical treatment was initiated. Therapy included discontinuation of the ACEI or other inciting agent, a high-humidity face tent, an initial dose of intravenous antihistamines, and a continued course of intravenous steroids. Within 48 hours, most patients had a resolution of their edema. Only cases of significant tongue and oropharyngeal edema took longer than 48 hours to resolve. The ACEIs are a common cause of angioedema. Left untreated, angioedema may progress to involve the oropharynx and supraglottis, resulting in a life-threatening airway compromise. Marked floor of mouth and tongue edema are the indications for airway intervention. An algorithm based on the initial presentation is essential for proper airway and patient management

  19. Antihypertensive efficacy of the angiotensin receptor blocker azilsartan medoxomil compared with the angiotensin-converting enzyme inhibitor ramipril

    PubMed Central

    Bönner, G; Bakris, G L; Sica, D; Weber, M A; White, W B; Perez, A; Cao, C; Handley, A; Kupfer, S

    2013-01-01

    Drug therapy often fails to control hypertension. Azilsartan medoxomil (AZL-M) is a newly developed angiotensin II receptor blocker with high efficacy and good tolerability. This double-blind, controlled, randomised trial compared its antihypertensive efficacy and safety vs the angiotensin-converting enzyme inhibitor ramipril (RAM) in patients with clinic systolic blood pressure (SBP) 150–180 mm Hg. Patients were randomised (n=884) to 20 mg AZL-M or 2.5 mg RAM once daily for 2 weeks, then force-titrated to 40 or 80 mg AZL-M or 10 mg RAM for 22 weeks. The primary endpoint was change in trough, seated, clinic SBP. Mean patient age was 57±11 years, 52.4% were male, 99.5% were Caucasian. Mean baseline BP was 161.1±7.9/94.9±9.0 mm Hg. Clinic SBP decreased by 20.6±0.95 and 2