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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 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

  4. Tissue and plasma angiotensin converting enzyme and the response to ACE inhibitor drugs.

    PubMed Central

    MacFadyen, R J; Lees, K R; Reid, J L

    1991-01-01

    1. There is a body of circumstantial and direct evidence supporting the existence and functional importance of a tissue based RAS at a variety of sites. 2. The relation between circulatory and tissue based systems is complex. The relative importance of the two in determining haemodynamic effects is unknown. 3. Despite the wide range of ACE inhibitors already available, it remains unclear whether there are genuine differences related to tissue specificity. 4. Pathological states such as chronic cardiac failure need to be explored with regard to the contribution of tissue based ACE activities in generating acute and chronic haemodynamic responses to ACE inhibitors. 5. The role of tissue vs plasma ACE activity may be clarified by study of the relation between drug concentration and haemodynamic effect, provided that the temporal dissociation is examined and linked to circulating and tissue based changes in ACE activity, angiotensin peptides and sympathetic hormones. PMID:1849731

  5. Congenital renal tubular dysplasia and skull ossification defects similar to teratogenic effects of angiotensin converting enzyme (ACE) inhibitors.

    PubMed Central

    Kumar, D; Moss, G; Primhak, R; Coombs, R

    1997-01-01

    An apparently autosomal recessive syndrome of congenital renal tubular dysplasia and skull ossification defects is described in five infants from two separate, consanguineous, Pakistani Muslim kindreds. The clinical, pathological, and radiological features are similar to the phenotype associated with fetal exposure to angiotensin converting enzyme (ACE) inhibitors: intrauterine growth retardation, skull ossification defects, and fetal/ neonatal anuric renal failure associated with renal tubular dysplasia. There was no fetal exposure to ACE inhibitors in the affected infants. Phenotypic similarities between these familial cases and those associated with ACE inhibition suggest an abnormality of the "renin-angiotensin-aldosterone" system (RAS). It is postulated that the molecular pathology in this uncommon autosomal recessive proximal renal tubular dysgenesis could be related to mutations of the gene systems governing the RAS. Images PMID:9222960

  6. 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.

  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. Interactions of angiotensin-converting enzyme, kinins and nitric oxide in circulation and the beneficial effects of ACE inhibitors in cardiovascular diseases.

    PubMed

    Magen, E; Viskoper, R J

    2000-12-01

    Renin-angiotensin-aldosterone systems play a critical role in the development and progression of cardiovascular diseases, and inhibitors of angiotensin-converting enzyme have proven effective for the treatment of these diseases. Since angiotensin II receptor antagonists can inhibit the effects of angiotensin II via ACE-independent pathways, e.g., chymase, they were considered to be more effective than ACEIs. On the other hand, ACE inhibitors can increase bradykinin, and thus, nitric oxide, which may cause potent cardioprotection, inhibition of smooth muscle proliferation and attenuation of inflammation mechanisms. It appears that angiotensin II receptor antagonists and ACEIs may mediate cardioprotection in different ways. This is the rationale to explore the possibility of a combined administration of both drugs for the treatment of chronic heart failure and other cardiovascular pathology. In this review we try to analyze the role of ACE, kinins and chymase inhibition in the pathophysiology and treatment of cardiovascular diseases.

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

    PubMed

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

    1999-12-15

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

  10. 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

  11. ACE Inhibitor in the treatment of cutaneous and lymphatic sarcoidosis.

    PubMed

    Kaura, Vinod; Kaura, Samantha H; Kaura, Claire S

    2007-01-01

    Angiotensin-converting enzyme is used as a marker for sarcoid activity. We describe a case of remission of cutaneous and lymphatic sarcoidosis in a patient treated with an ACE inhibitor for congestive heart failure and hypertension; the remission has continued over 4 years of follow-up. Because this is a report of only one case, there is a possibility of sampling error. Whether the patient's remission in this case was a serendipitous spontaneous remission that happened to occur during ACE inhibitor therapy or whether ACE inhibitor therapy can play a role in the treatment of sarcoidosis needs to be determined in a large clinical trial.

  12. Individualised therapy of angiotensin converting enzyme (ACE) inhibitors in stable coronary artery disease: overview of the primary results of the PERindopril GENEtic association (PERGENE) study.

    PubMed

    Brugts, J J; de Maat, M P M; Danser, A H J; Boersma, E; Simoons, M L

    2012-01-01

    In patients with stable coronary artery disease (CAD) without overt heart failure, ACE inhibitors are among the most commonly used drugs as these agents have been proven effective in reducing the risk of cardiovascular events. Considerable individual variations in the blood pressure response to ACE inhibitors are observed and as such heterogeneity in clinical treatment effect would be likely as well. Assessing the consistency of treatment benefit is essential for the rational and cost-effective prescription of ACE inhibitors. Information on heterogeneities in treatment effect between subgroups of patients could be used to develop an evidence-based guidance for the installation of ACE-inhibitor therapy. Obviously, therapy should only be applied in those patients who most likely will benefit. Attempts to develop such treatment guidance by using clinical characteristics have been unsuccessful. No heterogeneity in risk reduction by ACE inhibitors has been observed in relation to relevant clinical characteristics. A new approach to such 'guided-therapy' could be to integrate more patient-specific characteristics such as the patients' genetic information. If proven feasible, pharmacogenetic profiling could optimise patients' benefit of treatment and reduce unnecessary treatment of patients. Cardiovascular pharmacogenetic research of ACE inhibitors in coronary artery disease patients is in a formative stage and studies are limited. The PERGENE study is a large pharmacogenetic substudy of the EUROPA trial, aimed to assess the achievability of pharmacogenetic profiling. We provide an overview of the main results of the PERGENE study in terms of the genetic determinants of treatment benefit and blood pressure response. The main results of the PERGENE study show a pharmacogenetic profile related to the treatment benefit of perindopril identifying responders and non-responders to treatment. PMID:21688035

  13. Cutaneous allergy to insulin: could statins and ACE inhibitors play a role? A case report.

    PubMed

    Pitrola, D; MacIver, C; Mallipedhi, A; Udiawar, M; Price, D E; Stephens, J W

    2014-04-01

    Insulin allergy is rare. Both statins and angiotensin converting enzyme (ACE) inhibitors may cause local urticarial skin reactions and have been implicated to precipitate local reactions to insulin. We describe a case of a localised urticarial allergic reaction related to insulin use in a patient co-prescribed an ACE inhibitor and statin. PMID:24534533

  14. Fosinopril and zofenopril, two angiotensin-converting enzyme (ACE) inhibitors, potentiate the anticonvulsant activity of antiepileptic drugs against audiogenic seizures in DBA/2 mice.

    PubMed

    Sarro, Giovambattista De; Paola, Eugenio Donato Di; Gratteri, Santo; Gareri, Pietro; Rispoli, Vincenzo; Siniscalchi, Antonio; Tripepi, Giovanni; Gallelli, Luca; Citraro, Rita; Russo, Emilio

    2012-03-01

    The renin-angiotensin system (RAS) exists in the brain and it may be involved in pathogenesis of neurological and psychiatric disorders including seizures. The aim of the present research was to evaluate the effects of some angiotensin-converting enzyme inhibitors (ACEi; captopril, enalapril, fosinopril and zofenopril), commonly used as antihypertensive agents, in the DBA/2 mice animal model of generalized tonic-clonic seizures. Furthermore, the co-administration of these compounds with some antiepileptic drugs (AEDs; carbamazepine, diazepam, felbamate, gabapentin, lamotrigine, phenobarbital, phenytoin, topiramate and valproate) was studied in order to identify possible positive interactions in the same model. All ACEi were able to decrease the severity of audiogenic seizures with the exception of enalapril up to the dose of 100mg/kg, the rank order of activity was as follows: fosinopril>zofenopril>captopril. The co-administration of ineffective doses of all ACE inhibitors with AEDs, generally increased the potency of the latter. Fosinopril was the most active in potentiating the activity of AEDs and the combination of ACEi with lamotrigine and valproate was the most favorable, whereas, the co-administrations with diazepam and phenobarbital seemed to be neutral. The increase in potency was generally associated with an enhancement of motor impairment, however, the therapeutic index of combined treatment of AEDs with ACEi was predominantly more favorable than control. ACEi administration did not influence plasma and brain concentrations of the AEDs studied excluding pharmacokinetic interactions and concluding that it is of pharmacodynamic nature. In conclusion, fosinopril, zofenopril, enalapril and captopril showed an additive anticonvulsant effect when co-administered with some AEDs, most notably carbamazepine, felbamate, lamotrigine, topiramate and valproate, implicating a possible therapeutic relevance of such drug combinations.

  15. Human intestine luminal ACE2 and amino acid transporter expression increased by ACE-inhibitors.

    PubMed

    Vuille-dit-Bille, Raphael N; Camargo, Simone M; Emmenegger, Luca; Sasse, Tom; Kummer, Eva; Jando, Julia; Hamie, Qeumars M; Meier, Chantal F; Hunziker, Schirin; Forras-Kaufmann, Zsofia; Kuyumcu, Sena; Fox, Mark; Schwizer, Werner; Fried, Michael; Lindenmeyer, Maja; Götze, Oliver; Verrey, François

    2015-04-01

    Sodium-dependent neutral amino acid transporter B(0)AT1 (SLC6A19) and imino acid (proline) transporter SIT1 (SLC6A20) are expressed at the luminal membrane of small intestine enterocytes and proximal tubule kidney cells where they exert key functions for amino acid (re)absorption as documented by their role in Hartnup disorder and iminoglycinuria, respectively. Expression of B(0)AT1 was shown in rodent intestine to depend on the presence of the carboxypeptidase angiotensin-converting enzyme 2 (ACE2). This enzyme belongs to the renin-angiotensin system and its expression is induced by treatment with ACE-inhibitors (ACEIs) or angiotensin II AT1 receptor blockers (ARBs) in many rodent tissues. We show here in the Xenopus laevis oocyte expression system that human ACE2 also functionally interacts with SIT1. To investigate in human intestine the potential effect of ACEIs or ARBs on ACE2, we analysed intestinal biopsies taken during routine gastroduodenoscopy and ileocolonoscopy from 46 patients of which 9 were under ACEI and 13 ARB treatment. Analysis of transcript expression by real-time PCR and of proteins by immunofluorescence showed a co-localization of SIT1 and B(0)AT1 with ACE2 in the brush-border membrane of human small intestine enterocytes and a distinct axial expression pattern of the tested gene products along the intestine. Patients treated with ACEIs displayed in comparison with untreated controls increased intestinal mRNA levels of ACE2, peptide transporter PEPT1 (SLC15A1) and AA transporters B(0)AT1 and PAT1 (SLC36A1). This study unravels in human intestine the localization and distribution of intestinal transporters involved in amino acid absorption and suggests that ACEIs impact on their expression.

  16. 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

  17. Evaluation of angiotensin-converting enzyme (ACE), its homologue ACE2 and neprilysin in angiotensin peptide metabolism

    PubMed Central

    2004-01-01

    In the RAS (renin–angiotensin system), Ang I (angiotensin I) is cleaved by ACE (angiotensin-converting enzyme) to form Ang II (angiotensin II), which has effects on blood pressure, fluid and electrolyte homoeostasis. We have examined the kinetics of angiotensin peptide cleavage by full-length human ACE, the separate N- and C-domains of ACE, the homologue of ACE, ACE2, and NEP (neprilysin). The activity of the enzyme preparations was determined by active-site titrations using competitive tight-binding inhibitors and fluorogenic substrates. Ang I was effectively cleaved by NEP to Ang (1–7) (kcat/Km of 6.2×105 M−1·s−1), but was a poor substrate for ACE2 (kcat/Km of 3.3×104 M−1·s−1). Ang (1–9) was a better substrate for NEP than ACE (kcat/Km of 3.7×105 M−1·s−1 compared with kcat/Km of 6.8×104 M−1·s−1). Ang II was cleaved efficiently by ACE2 to Ang (1–7) (kcat/Km of 2.2×106 M−1·s−1) and was cleaved by NEP (kcat/Km of 2.2×105 M−1·s−1) to several degradation products. In contrast with a previous report, Ang (1–7), like Ang I and Ang (1–9), was cleaved with a similar efficiency by both the N- and C-domains of ACE (kcat/Km of 3.6×105 M−1·s−1 compared with kcat/Km of 3.3×105 M−1·s−1). The two active sites of ACE exhibited negative co-operativity when either Ang I or Ang (1–7) was the substrate. In addition, a range of ACE inhibitors failed to inhibit ACE2. These kinetic data highlight that the flux of peptides through the RAS is complex, with the levels of ACE, ACE2 and NEP dictating whether vasoconstriction or vasodilation will predominate. PMID:15283675

  18. Affinity purification of angiotensin converting enzyme inhibitory peptides using immobilized ACE.

    PubMed

    Megías, Cristina; Pedroche, Justo; Yust, María del Mar; Alaiz, Manuel; Girón-Calle, Julio; Millan, Francisco; Vioque, Javier

    2006-09-20

    A lung extract rich in angiotensin converting enzyme (ACE) and pure ACE were immobilized by reaction with the activated support 4 BCL glyoxyl-agarose. These immobilized ACE derivatives were used for purification of ACE inhibitory peptides by affinity chromatography. The immobilized lung extract was used to purify inhibitory peptides from sunflower and rapeseed protein hydrolysates that had been obtained by treatment of protein isolates with alcalase. The ACE binding peptides that were retained by the derivatives were specifically released by treatment with the ACE inhibitor captopril and further purified by reverse-phase C18 HPLC chromatography. Inhibitory peptides with IC50 50 and 150 times lower than those of the original sunflower and rapeseed hydrolysates, respectively, were obtained. The derivative prepared using pure ACE was used for purification of ACE inhibitory peptides from the same type of sunflower protein hydrolysate. ACE binding peptides were released from the ACE-agarose derivatives by treatment with 1 M NaCl and had an IC50 a little higher than those obtained using immobilized extract and elution with captopril. Affinity chromatography facilitated the purification of ACE inhibitory peptides and potentially other bioactive peptides present in food proteins.

  19. Evaluation of renal function in elderly heart failure patients on ACE inhibitors

    PubMed Central

    Jolobe, O

    1999-01-01

    A total of 187 heart failure patients aged 65-92 years, with pretreatment serum creatinine levels below 200 µmol/l, were monitored for more than 12 months on angiotensin-converting enzyme (ACE) inhibitor therapy. Optimal ACE inhibitor dosage was found in 27% of patients, while a significant deterioration in renal function, characterised by >20% increase in serum creatinine to >200 µmol/l, occurred in 25 patients. This was most closely attributable to ACE inhibitor treatment per se (implying co-existence of bilateral renal artery stenosis) in only four cases, including one in whom renal deterioration was reproducible on inadvertent rechallenge. In the other 21, renal deterioration was attributable to diuretic-related blood volume depletion (two cases), nonsteroidal anti-inflammatory drugs (two cases), obstructive uropathy (two cases), preterminal renal shutdown (two cases), and the interaction between diuretic and ACE inhibitor dosage (including long-acting vs short-acting drugs) (13 cases). This study could serve as the basis for future comparisons of ACE-inhibitor-related renal deterioration when the entry requirement is optimal ACE inhibitor dosage.


Keywords: heart failure; elderly patients; angiotensin-converting enzyme inhibitors; renal deterioration PMID:10533630

  20. A prospective study of frequency and characteristics of cough during ACE inhibitor treatment.

    PubMed

    Sato, Atsuhisa; Fukuda, Seiichi

    2015-01-01

    Angiotensin converting enzyme (ACE) inhibitors are reportedly effective, and positively indicated in patients with chronic heart failure with decreased contractility, after myocardial infarction, after cerebrovascular disorders, and in those with chronic kidney disease. However, the biggest challenge to continuous use of ACE inhibitors is the adverse reaction of cough. Accordingly, in the present study, we investigated the present state and characteristics of ACE inhibitor-induced cough in patients with essential hypertension currently being treated with an ACE inhibitor for an average of 18 months, who could be regularly checked for cough. Subjects in this study were 176 patients overall (mean age 67 ± 11 years old), 90 men and 86 women. The adverse reaction of cough was observed in 20% of patients, and more frequently in women than in men. However, in 26 of the patients with cough, the cough either resolved naturally or completely disappeared while the treatment continued, after which patients could continue taking the medication. Specifically, ACE inhibitor treatment was eventually discontinued due to cough in 5.1% of patients. Cough occurred less frequently with concomitant calcium antagonists or diuretics than with ACE inhibitor monotherapy. Cough as an adverse reaction occurred at a low frequency when medication was taken at bedtime. We considered a number of measures to counteract cough, then in addition to starting the ACE inhibitor treatment as early as possible, it is important to devise ways for the ACE inhibitor treatment to be continued for as long as possible, through the adept use of these measures.

  1. Statins, ACE inhibitors and ARBs in cardiovascular disease.

    PubMed

    Montecucco, Fabrizio; Mach, François

    2009-06-01

    Atherosclerotic cardiovascular disease (CVD) is the main cause of death in developed and developing countries. It is well accepted that several diseases - including hypertension, dyslipidemia and diabetes mellitus - increase CVD. More recently also chronic inflammatory diseases, such as rheumatoid arthritis, have been shown to accelerate CVD. This association further supports a responsible role for inflammatory processes in all stages of CVD pathophysiology. Clinically, CVD ranges through different acute and chronic syndromes with ischemic symptoms in distal tissues, including heart, cerebral region or peripheral arteries. Several treatments for reducing CVD are under investigation. In this review we focus on statins, angiotensin-converting-enzyme (ACE) inhibitors, and angiotensin-II receptor blockers (ARBs), updating therapeutic evidence from the last clinical trials with particular relevance to diabetic patients. PMID:19520311

  2. Antihypertensive treatment in renal transplant patients--is there a role for ACE inhibitors?

    PubMed

    Hausberg, M; Kosch, M; Hohage, H; Suwelack, B; Barenbrock, M; Kisters, K; Rahn, K H

    2001-01-01

    During the past two decades great progress was achieved with regards to short-term kidney graft survival. However, long-term graft survival did not improve similarly. Many factors contribute to chronic graft nephropathy eventually resulting in late graft loss, among these arterial hypertension is of major importance. In patients with chronic renal disease of diabetic and non-diabetic origin, angiotensin converting enzyme inhibitors have been convincingly shown to slow the progression of renal failure. The achieved nephroprotection correlates with the reduction of proteinuria by ACE inhibitor treatment. Also in renal transplant patients, ACE inhibitors have been shown unequivocally to reduce urinary protein excretion. The prevention of hyperfiltration, particular in the context of a reduced number of functional nephrons in patients with chronic graft nephropathy, could be important to prolong graft survival after renal transplantation. Moreover, ACE inhibitors may exert beneficial effects on immunologic processes contributing to chronic graft nephropathy. Many studies published in the last decade show convincingly that ACE inhibitors are safe and effective for the treatment of hypertension in renal allograft recipients. However, no data exist so far showing that ACE inhibitors are superior to other antihypertensive drugs in renal transplant patients and that they prolong graft survival. Studies investigating this issue are warranted. Apart from effects on the graft, ACE inhibitors may improve alterations of the cardiovascular system generally observed in renal transplant patients, such as structural alterations of large arteries, left ventricular hypertrophy, disturbed mechanical vessel wall properties and endothelial dysfunction. Therefore, angiotensin converting enzyme inhibitors could reduce cardiovascular morbidity and mortality in kidney transplant patients.

  3. Tailored therapy of ACE inhibitors in stable coronary artery disease: pharmacogenetic profiling of treatment benefit.

    PubMed

    Brugts, Jasper J; Boersma, Eric; Simoons, Maarten L

    2010-08-01

    Angiotensin-converting enzyme (ACE) inhibitors are among the most commonly used drugs in stable coronary artery disease as these agents have been proven to be effective for reducing the risk of cardiovascular morbidity and mortality. As with other drugs, individual variation in treatment benefit is likely. Such heterogeneity could be used to target ACE-inhibitor therapy to those patients most likely to benefit from treatment. However, prior attempts to target ACE-inhibitor therapy to those patients who are most likely to benefit of such prophylactic treatment in secondary prevention using clinical characteristics or the level of baseline risk appeared not to be useful. A new approach of 'tailored therapy' could be to integrate more patient-specific characteristics, such as the genetic information of patients. Pharmacogenetic research of ACE inhibitors in coronary artery disease patients is at a formative stage, and studies are limited. The Perindopril Genetic association (PERGENE) study is a large pharmacogenetic substudy of the randomized placebo-controlled European trial On Reduction of Cardiac Events with Perindopril in Patients with Stable Coronary Artery disease (EUROPA) trial, aimed to assess the feasibility of pharmacogenetic profiling of ACE-inhibitor therapy by perindopril. This article summarizes the recent findings of the PERGENE study and pharmacogenetic research of the treatment benefit of perindopril in stable coronary artery disease. PMID:20712529

  4. New Perspectives in the Renin-Angiotensin-Aldosterone System (RAAS) II: Albumin Suppresses Angiotensin Converting Enzyme (ACE) Activity in Human

    PubMed Central

    Fagyas, Miklós; Úri, Katalin; Siket, Ivetta M.; Fülöp, Gábor Á.; Csató, Viktória; Daragó, Andrea; Boczán, Judit; Bányai, Emese; Szentkirályi, István Elek; Maros, Tamás Miklós; Szerafin, Tamás; Édes, István; Papp, Zoltán; Tóth, Attila

    2014-01-01

    About 8% of the adult population is taking angiotensin-converting enzyme (ACE) inhibitors to treat cardiovascular disease including hypertension, myocardial infarction and heart failure. These drugs decrease mortality by up to one-fifth in these patients. We and others have reported previously that endogenous inhibitory substances suppress serum ACE activity, in vivo, similarly to the ACE inhibitor drugs. Here we have made an effort to identify this endogenous ACE inhibitor substance. ACE was crosslinked with interacting proteins in human sera. The crosslinked products were immunoprecipitated and subjected to Western blot. One of the crosslinked products was recognized by both anti-ACE and anti-HSA (human serum albumin) antibodies. Direct ACE-HSA interaction was confirmed by binding assays using purified ACE and HSA. HSA inhibited human purified (circulating) and human recombinant ACE with potencies (IC50) of 5.7±0.7 and 9.5±1.1 mg/mL, respectively. Effects of HSA on the tissue bound native ACE were tested on human saphenous vein samples. Angiotensin I evoked vasoconstriction was inhibited by HSA in this vascular tissue (maximal force with HSA: 6.14±1.34 mN, without HSA: 13.54±2.63 mN), while HSA was without effects on angiotensin II mediated constrictions (maximal force with HSA: 18.73±2.17 mN, without HSA: 19.22±3.50 mN). The main finding of this study is that HSA was identified as a potent physiological inhibitor of the ACE. The enzymatic activity of ACE appears to be almost completely suppressed by HSA when it is present in its physiological concentration. These data suggest that angiotensin I conversion is limited by low physiological ACE activities, in vivo. PMID:24691203

  5. SY 12-2 ACE INHIBITORS AND ARBS: SIMILARITIES AND DIFFERENCES IN CV RISK REDUCTION.

    PubMed

    Danser, Alexander

    2016-09-01

    Blockade of the renin-angiotensin-aldosterone system (RAAS) can be accomplished at the level of the angiotensin-generating enzymes renin and angiotensin-converting enzyme (ACE; using renin inhibitors or ACE inhibitors), the type 1 angiotensin II (AT1) receptor or mineralocorticoid receptor (MR; using angiotensin receptor blockers [ARBs] or MR blockers) and/or renin release (using beta-blockers). Several of these drugs are often combined-for example in heart failure-but such approaches may ultimately lead to RAAS annihilation with adverse consequences such as hypotension, renal dysfunction and hyperkalaemia. The biochemical consequences of each type of blockade are different. For instance, ACE inhibitors will lower angiotensin II, thus no longer allowing stimulation of both AT1 and type 2 angiotensin II (AT2) receptors, while ARBs raise angiotensin II, allowing selective stimulation of the unoccupied AT2 receptor. This might be of particular importance in women, in whom the protective AT2 receptor pathway is believed to be upregulated. Multiple clinical trials have compared the various types of RAAS blockers and/or their combination. This talk will summarize the current evidence with regard to similarities and differences between ACE inhibitors and ARBs, also considering their side-effect profile, dose and combination with other RAAS blockers. PMID:27643121

  6. 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

  7. Does the use of ACE inhibitors or angiotensin receptor blockers affect bone loss in older men?

    PubMed Central

    Leung, J.; Zhang, Y. F.; Bauer, D.; Ensrud, K. E.; Barrett-Connor, E.; Leung, P. C.

    2013-01-01

    Summary In a prospective cohort study of 5,995 older American men (MrOS), users of angiotensin-converting enzyme (ACE) inhibitors had a small but significant increase in bone loss at the hip over 4 years after adjustment for confounders. Use of angiotensin II AT1 receptor blockers (ARB) was not significantly associated with bone loss. Introduction Experimental evidence suggests that angiotensin II promotes bone loss by its effects on osteoblasts. It is therefore plausible that ACE inhibitor and ARB may reduce rates of bone loss. The objective of this study is to examine the independent effects of ACE inhibitor and ARB on bone loss in older men. Methods Out of 5,995 American men (87.2%) aged ≥65 years, 5,229 were followed up for an average of 4.6 years in a prospective six-center cohort study—The Osteoporotic Fractures in Men Study (MrOS). Bone mineral densities (BMD) at total hip, femoral neck, and trochanter were measured by Hologic densitometer (QDR 4500) at baseline and year 4. Results Out of 3,494 eligible subjects with complete data, 1,166 and 433 subjects reported use of ACE inhibitors and ARBs, respectively. When compared with nonusers, continuous use of ACE inhibitors was associated with a small (0.004 g/cm2) but significant increase in the average rate of BMD loss at total hip and trochanter over 4 years after adjustment for confounders. Use of ARB was not significantly associated with bone loss. Conclusion Use of ACE inhibitors but not ARB may marginally increase bone loss in older men. PMID:22080379

  8. 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

  9. 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.

  10. 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... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  11. 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... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  12. 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... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  13. 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... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  14. 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... Test Systems § 862.1090 Angiotensin converting enzyme (A.C.E.) test system. (a) Identification. An angiotensin converting enzyme (A.C.E.) test system is a device intended to measure the activity of...

  15. Angiotensin converting enzyme inhibitors produced by Streptomyces chromofuscus. Discovery, taxonomy and fermentation.

    PubMed

    Nakatsukasa, W M; Wilgus, R M; Thomas, D N; Mertz, F P; Boeck, L D

    1985-08-01

    Culture A58365.1, NRRL 15098, identified as a new strain of Streptomyces chromofuscus, was found to produce two novel angiotensin converting enzyme (ACE) inhibitors, A58365A and A58365B. Fermentation medium studies afforded an increase in ACE inhibitor titers from less than 1 microgram/ml to greater than 20 micrograms/ml. Proline was the obligatory supplement for ACE inhibitor biosynthesis.

  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. What is the impact of the ACE gene insertion/deletion (I/D) polymorphism on the clinical effectiveness and adverse events of ACE inhibitors? – Protocol of a systematic review

    PubMed Central

    Scharplatz, M; Puhan, MA; Steurer, J; Bachmann, LM

    2004-01-01

    Background The Angiotensin Converting Enzyme (ACE) insertion/deletion (I/D) polymorphism has received much attention in pharmacogenetic research because observed variations in response to ACE inhibitors might be associated with this polymorphism. Pharmacogenetic testing raises the hope to individualise ACE inhibitor therapy in order to optimise its effectiveness and to reduce adverse effects for genetically different subgroups. However, the extent of its effect modification in patients treated with ACE inhibitors remains inconclusive. Therefore our objective is to quantify the effect modification of the insertion/deletion polymorphism of the angiotensin converting enzyme gene on any surrogate and clinically relevant parameters in patients with cardiovascular diseases, diabetes, renal transplantation and/or renal failure. Methods Systematic Review. We will perform literature searches in six electronic databases to identify randomised controlled trials comparing the effectiveness and occurrence of adverse events of ACE inhibitor therapy against placebo or any active treatment stratified by the I/D gene polymorphism. In addition, authors of trials, experts in pharmacogenetics and pharmaceutical companies will be contacted for further published or unpublished data. Hand searching will be accomplished by reviewing the reference lists of all included studies. The methodological quality of included papers will be assessed. Data analyses will be performed in clinically and methodologically cogent subgroups. The results of the quantitative assessment will be pooled statistically where appropriate to produce an estimate of the differences in the effect of ACE inhibitors observed between the three ACE genotypes. Discussion This protocol describes a strategy to quantify the effect modification of the ACE polymorphism on ACE inhibitors in relevant clinical domains using meta-epidemiological research methods. The results may provide evidence for the usefulness of pharmacogenetic

  18. Shedding of the germinal angiotensin I-converting enzyme (gACE) involves a serine protease and is activated by epididymal fluid.

    PubMed

    Thimon, Véronique; Métayer, Sonia; Belghazi, Maya; Dacheux, Françoise; Dacheux, Jean-Louis; Gatti, Jean-Luc

    2005-11-01

    The present report describes how the soluble germinal angiotensin I-converting enzyme (gACE) appears in the epididymal fluid, where it has been identified in some laboratory rodents and domestic ungulates. We showed that this gACE results from an active proteolytic process that releases the enzyme's extracellular domain from sperm in a precise spatiotemporal location during epididymal transit and that this process involves serine protease activity. Using polyclonal antibodies against the C-terminal intracellular sequence of ACE, a fragment of approximately 10 kDa was detected on the sperm extract only in the epididymal region, where the gACE release occurs. The fluid enzyme was purified, and the cleavage site was determined by mass spectrometry to be between Arg622 and Leu623 of the mature sheep gACE sequence (equivalent to Arg627 and Arg1203 of the human mature gACE and somatic ACE sequences, respectively). Thereafter, the C-terminal Arg was removed, leaving Ala621 as a C-terminal. Using an in vitro assay, gACE cleavage from sperm was strongly increased by the presence of epididymal fluid from the release zone, and this increase was inhibited specifically by the serine protease-inhibitor AEBSF but not by para-aminobenzamidine. None of the other inhibitors tested, such as metallo- or cystein-protease inhibitors, had a similar effect on release. It was also found that this process did not involve changes in gACE phosphorylation. PMID:15987822

  19. 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.

  20. Pathological Ace2-to-Ace enzyme switch in the stressed heart is transcriptionally controlled by the endothelial Brg1-FoxM1 complex.

    PubMed

    Yang, Jin; Feng, Xuhui; Zhou, Qiong; Cheng, Wei; Shang, Ching; Han, Pei; Lin, Chiou-Hong; Chen, Huei-Sheng Vincent; Quertermous, Thomas; Chang, Ching-Pin

    2016-09-20

    Genes encoding angiotensin-converting enzymes (Ace and Ace2) are essential for heart function regulation. Cardiac stress enhances Ace, but suppresses Ace2, expression in the heart, leading to a net production of angiotensin II that promotes cardiac hypertrophy and fibrosis. The regulatory mechanism that underlies the Ace2-to-Ace pathological switch, however, is unknown. Here we report that the Brahma-related gene-1 (Brg1) chromatin remodeler and forkhead box M1 (FoxM1) transcription factor cooperate within cardiac (coronary) endothelial cells of pathologically stressed hearts to trigger the Ace2-to-Ace enzyme switch, angiotensin I-to-II conversion, and cardiac hypertrophy. In mice, cardiac stress activates the expression of Brg1 and FoxM1 in endothelial cells. Once activated, Brg1 and FoxM1 form a protein complex on Ace and Ace2 promoters to concurrently activate Ace and repress Ace2, tipping the balance to Ace2 expression with enhanced angiotensin II production, leading to cardiac hypertrophy and fibrosis. Disruption of endothelial Brg1 or FoxM1 or chemical inhibition of FoxM1 abolishes the stress-induced Ace2-to-Ace switch and protects the heart from pathological hypertrophy. In human hypertrophic hearts, BRG1 and FOXM1 expression is also activated in endothelial cells; their expression levels correlate strongly with the ACE/ACE2 ratio, suggesting a conserved mechanism. Our studies demonstrate a molecular interaction of Brg1 and FoxM1 and an endothelial mechanism of modulating Ace/Ace2 ratio for heart failure therapy.

  1. Pathological Ace2-to-Ace enzyme switch in the stressed heart is transcriptionally controlled by the endothelial Brg1-FoxM1 complex.

    PubMed

    Yang, Jin; Feng, Xuhui; Zhou, Qiong; Cheng, Wei; Shang, Ching; Han, Pei; Lin, Chiou-Hong; Chen, Huei-Sheng Vincent; Quertermous, Thomas; Chang, Ching-Pin

    2016-09-20

    Genes encoding angiotensin-converting enzymes (Ace and Ace2) are essential for heart function regulation. Cardiac stress enhances Ace, but suppresses Ace2, expression in the heart, leading to a net production of angiotensin II that promotes cardiac hypertrophy and fibrosis. The regulatory mechanism that underlies the Ace2-to-Ace pathological switch, however, is unknown. Here we report that the Brahma-related gene-1 (Brg1) chromatin remodeler and forkhead box M1 (FoxM1) transcription factor cooperate within cardiac (coronary) endothelial cells of pathologically stressed hearts to trigger the Ace2-to-Ace enzyme switch, angiotensin I-to-II conversion, and cardiac hypertrophy. In mice, cardiac stress activates the expression of Brg1 and FoxM1 in endothelial cells. Once activated, Brg1 and FoxM1 form a protein complex on Ace and Ace2 promoters to concurrently activate Ace and repress Ace2, tipping the balance to Ace2 expression with enhanced angiotensin II production, leading to cardiac hypertrophy and fibrosis. Disruption of endothelial Brg1 or FoxM1 or chemical inhibition of FoxM1 abolishes the stress-induced Ace2-to-Ace switch and protects the heart from pathological hypertrophy. In human hypertrophic hearts, BRG1 and FOXM1 expression is also activated in endothelial cells; their expression levels correlate strongly with the ACE/ACE2 ratio, suggesting a conserved mechanism. Our studies demonstrate a molecular interaction of Brg1 and FoxM1 and an endothelial mechanism of modulating Ace/Ace2 ratio for heart failure therapy. PMID:27601681

  2. 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

  3. Visual hallucinations related to angiotensin-converting enzyme inhibitor use: case reports and review.

    PubMed

    Doane, John; Stults, Barry

    2013-04-01

    Four patients experienced visual hallucinations that appear to have been precipitated by lisinopril. Other cases of visual hallucinations have been reported with other angiotensin-converting enzyme (ACE) inhibitors. Older patients, particularly those with a history of either dementia or mild cognitive impairment, may be at higher risk. Hallucinations resolved within 1 to 30 days after cessation of ACE inhibitors. Development of visual hallucinations after initiation of ACE inhibitors should prompt discontinuation of therapy. Visual hallucinations have been reported in one case involving an ARB. Visual hallucinations have not been associated with direct renin inhibitors. Consideration should be given to use of alternative, unrelated antihypertensive drug classes.

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

    PubMed Central

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

    2013-01-01

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

  5. Taking ACE inhibitors during pregnancy. Is it safe?

    PubMed Central

    Ratnapalan, Savithiri; Koren, Gideon

    2002-01-01

    QUESTION: A pregnant patient is taking enalapril for primary hypertension. How safe are angiotension-converting enzyme inhibitors (ACEI) during pregnancy? ANSWER: Evidence of whether ACEIs cause problems during the first trimester of pregnancy is reassuring. There is evidence that they cause severe renal and other problems during the second and third trimesters, however. These drugs should be avoided during pregnancy. PMID:12113190

  6. Potentially lethal ACE-inhibitor-induced angioedema in a child.

    PubMed

    Bukhari, Esraa; Safdar, Osama Y; Shalaby, Mohammed; AlSharif, Shafiqa Mj; Alsufiany, Khoulod; Kari, Jameela A

    2015-06-01

    We report a case of a 9-year-old female with known end-stage kidney disease who presented with sudden onset tongue swelling. A diagnosis of angiotensin-converting enzyme inhibitor-induced angioedema related to bradykinin accumulation was made. Her symptoms resolved shortly after discontinuation of captopril. Early diagnosis can save patients from severe upper airway obstruction.

  7. 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

  8. 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

  9. 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

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

    2014-08-13

    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.

  10. 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.

  11. Secoisolariciresinol Diglucoside (SDG) Isolated from Flaxseed, an Alternative to ACE Inhibitors in the Treatment of Hypertension.

    PubMed

    Prasad, Kailash

    2013-12-01

    Secoisolariciresionol diglucoside (SDG) is a plant lignan isolated from flaxseed and is phytoestrogen. SDG is a potent and long-acting hypotensive agent. Plant phytoestrogens have inhibitory effects on angiotensin-converting enzyme (ACE). The hypotensive effects of SDG, a phytoestrogen, may be mediated through inhibition of ACE. The objective of this study was to investigate if SDG-induced hypotension is mediated through inhibition of ACE. The Sprague Dawley male rats were anesthetized and trachea was cannulated. The right jugular vein was cannulated to administer the drug and the carotid artery was cannulated to record arterial pressures using PIOEZ-1 miniature model transducer (Becton, Dickinson and Company, Franklin Lakes, NJ) and Beckman dynograph (Beckman Instruments, Inc., Schiller Park, IL). The effects of angiotensin I (0.2 µg/kg, intravenously [IV]) in the absence and presence of SDG (10 mg/kg, IV), and SDG alone on systolic, diastolic, and mean arterial pressures were measured before and after 15, 30, and 60 minutes of drug administration. SDG decreased the systolic, diastolic, and mean arterial pressure by 37, 47, and 43%, respectively, at 15 minutes and 18.8, 21.2, and 20.3%, respectively, at 60 minutes. Angiotensin I increased the arterial pressure. SDG decreased angiotensin I-induced rise in the systolic, diastolic, and mean arterial pressures by 60, 58, and 51%, respectively, at 15 minutes and 48, 46, and 30%, respectively, at 60 minutes. The data suggest that SDG reduced the angiotensin I-induced rise in the arterial pressures and hence SDG is a potent ACE inhibitor.

  12. Potentially lethal ACE-inhibitor-induced angioedema in a child

    PubMed Central

    Bukhari, Esraa; Safdar, Osama Y; Shalaby, Mohammed; AlSharif, Shafiqa MJ; Alsufiany, Khoulod; Kari, Jameela A

    2015-01-01

    Key Clinical Message We report a case of a 9-year-old female with known end-stage kidney disease who presented with sudden onset tongue swelling. A diagnosis of angiotensin-converting enzyme inhibitor-induced angioedema related to bradykinin accumulation was made. Her symptoms resolved shortly after discontinuation of captopril. Early diagnosis can save patients from severe upper airway obstruction. PMID:26185642

  13. ACE inhibitors could be therapeutic for antisocial personality disorder.

    PubMed

    Hobgood, Donna K

    2013-11-01

    Antisocial personality traits are an important topic for research. The societal cost of these behaviors encourages efforts at a better understanding of central nervous system causes. Catecholamine genes are being studied to facilitate this understanding, and some tentative findings are being reached about several of these genes. It seems that many genes play a role to produce antisocial behaviors so complexity of elucidating each gene is obvious. One conclusion that could be drawn from the current research findings is that DA2 like receptors (DRD2, DRD3, DRD4) with alleles that decrease neurotransmission are facilitatory of antisocial behaviors. DA2 like receptors cause neuronal firing to inhibit many peripheral functions through adenylyl cyclase inhibition. When these receptors are less active by genetically decreased density, lower affinity, or by low dopamine levels as final common pathways then inhibition is released and a state of disinhibition can be said to describe this state. Peripheral metabolism is increased and behavioral activation is noted. Renin is disinhibited in this setting thus allowing sympathetic nervous system activation. The fight or flight behaviors thus produced, in the extreme, would be the setting of antisocial behavior. Research validates this hypothesis. Understanding this final common pathway toward antisocial behavior should lead to better treatment for individuals with this pattern of behavior before they have caused harm to themselves and others. ACE inhibitors are well tolerated drugs used in the treatment of hypertension and heart failure and would also treat antisocial behavior disorders.

  14. Angiotensin-converting enzyme inhibitors: measurement of relative inhibitory potency and serum drug levels by radioinhibitor binding displacement assay

    SciTech Connect

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

    1987-06-01

    Radioinhibitor binding displacement, a new method for the measurement of angiotensin-converting enzyme (ACE) competitive inhibitors, has been used to assess the relative potency of nine synthetic ACE inhibitors. MK351A, tyrosyl derivative of enalaprilic acid was iodinated with /sup 125/I and used as the radioligand. (/sup 125/I)MK351A bound to human serum ACE in a concentration-dependent manner. It was displaced in a concentration-dependent manner by all ACE inhibitors tested. Fifty percent displacement of bound (/sup 125/I)MK351A (DD50) for each ACE inhibitor correlated well with inhibitor potency ID50, estimated using an ACE enzymatic activity assay using Hip-His-Leu as substrate (r = 0.96, p less than 0.001; n = 9). The radioinhibitor binding displacement assay was used to measure serum concentration of enalaprilic acid (MK422) in human serum samples. Drug concentration estimated by radioinhibitor binding displacement assay correlated closely (r = 0.96, p less than 0.001; n = 22) with the drug concentration measured by a specific radioimmunoassay. The radioinhibitor binding displacement technique using (/sup 125/I)MK351A as the ligand for human serum ACE has general application to all competitive ACE inhibitors, allowing comparison of in vitro ACE inhibitor potencies and estimation of serum ACE inhibitor concentrations.

  15. 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.

  16. 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.

  17. 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.

  18. [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

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

    PubMed

    Mercier, Kelly; Smith, Holly; Biederman, Jason

    2014-12-01

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

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

    PubMed

    Mercier, Kelly; Smith, Holly; Biederman, Jason

    2014-12-01

    Angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy in hypertensive diabetic patients with macroalbuminuria, microalbuminuria, or normoalbuminuria has been repeatedly shown to improve cardiovascular mortality and reduce the decline in glomerular filtration rate. Renin-angiotensin-aldosterone system (RAAS) blockade in normotensive diabetic patients with normoalbuminuria or microalbuminuria cannot be advocated at present. Dual RAAS inhibition with ACE inhibitors plus ARBs or ACE inhibitors plus direct renin inhibitors has failed to improve cardiovascular or renal outcomes but has predisposed patients to serious adverse events. PMID:25439533

  1. Genetic influences of angiotensin-converting enzyme inhibitor response: an opportunity for personalizing therapy?

    PubMed

    Brugts, Jasper J; Simoons, Maarten L

    2012-08-01

    The angiotensin-converting enzyme (ACE) inhibitors are a cornerstone drug therapy in the current treatment of patients with hypertension, stable coronary artery disease and heart failure. Individualizing therapy of ACE inhibitors with clinical risk factors in low-risk patients with stable coronary artery disease is not feasible. The concept of pharmacogenetics, by studying patient factors more individually, offers a first glimpse in the quest for the 'holy grail' of personalized medicine. As such, genetic targets in the direct pharmacodynamic pathway of ACE inhibitors, the renin-angiotensin-aldosterone system, is a plausible candidate for such an approach. In the past few decades, results of pharmacogenetic studies were scarce and inconsistent. However, recently the first reports of larger pharmacogenetic studies are now confirming that the 'pharmacogenetic approach' might be feasible in the future. The current review focuses on the recent developments in pharmacogenetic research in response to ACE inhibitors in patients with stable coronary artery disease. PMID:23030290

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

    PubMed

    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.

  3. Angiotensin-converting enzyme inhibition studies by natural leech inhibitors by capillary electrophoresis and competition assay.

    PubMed

    Deloffre, Laurence; Sautiere, Pierre-Eric; Huybrechts, Roger; Hens, Korneel; Vieau, Didier; Salzet, Michel

    2004-06-01

    A protocol to follow the processing of angiotensin I into angiotensin II by rabbit angiotensin-converting enzyme (ACE) and its inhibition by a novel natural antagonist, the leech osmoregulator factor (LORF) using capillary zonal electrophoresis is described. The experiment was carried out using the Beckman PACE system and steps were taken to determine (a) the migration profiles of angiotensin and its yielded peptides, (b) the minimal amount of angiotensin II detected, (c) the use of different electrolytes and (d) the concentration of inhibitor. We demonstrated that LORF (IPEPYVWD), a neuropeptide previously found in leech brain, is able to inhibit rabbit ACE with an IC(50) of 19.8 micro m. Interestingly, its cleavage product, IPEP exhibits an IC(50) of 11.5 micro m. A competition assay using p-benzoylglycylglycylglycine and insect ACE established that LORF and IPEP fragments are natural inhibitors for invertebrate ACE. Fifty-four percent of insect ACE activity is inhibited with 50 micro m IPEP and 35% inhibition with LORF (25 mm). Extending the peptide at both N- and C-terminus (GWEIPEPYVWDES) and the cleavage of IPEP in IP abolished the inhibitory activity of both peptides. Immunocytochemical data obtained with antisera raised against LORF and leech ACE showed a colocalization between the enzyme and its inhibitor in the same neurons. These results showed that capillary zonal electrophoresis is a useful technique for following enzymatic processes with small amounts of products and constitutes the first evidence of a natural ACE inhibitor in invertebrates.

  4. 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.

  5. Angiotensin converting enzyme inhibitors and the reduced risk of Alzheimer's disease in the absence of apolipoprotein E4 allele.

    PubMed

    Qiu, Wei Qiao; Mwamburi, Mkaya; Besser, Lilah M; Zhu, Haihao; Li, Huajie; Wallack, Max; Phillips, Leslie; Qiao, Liyan; Budson, Andrew E; Stern, Robert; Kowall, Neil

    2013-01-01

    Our cross-sectional study showed that the interaction between apolipoprotein E4 (ApoE4) and angiotensin converting enzyme (ACE) inhibitors was associated with Alzheimer's disease (AD). The aim of this longitudinal study was to differentiate whether ACE inhibitors accelerate or reduce the risk of AD in the context of ApoE alleles. Using the longitudinal data from the National Alzheimer's Coordinating Center (NACC) with ApoE genotyping and documentation of ACE inhibitors use, we found that in the absence of ApoE4, subjects who had been taking central ACE inhibitor use (χ2 test: 21% versus 27%, p = 0.0002) or peripheral ACE inhibitor use (χ2 test: 13% versus 27%, p < 0.0001) had lower incidence of AD compared with those who had not been taking an ACE inhibitor. In contrast, in the presence of ApoE4, there was no such association between ACE inhibitor use and the risk of AD. After adjusting for the confounders, central ACE inhibitor use (OR = 0.68, 95% CI = 0.55, 0.83, p = 0.0002) or peripheral ACE inhibitor use (OR = 0.33, 95% CI = 0.33, 0.68, p < 0.0001) still remained inversely associated with a risk of developing AD in ApoE4 non-carriers. In conclusion, ACE inhibitors, especially peripherally acting ones, were associated with a reduced risk of AD in the absence of ApoE4, but had no such effect in those carrying the ApoE4 allele. A double-blind clinical trial should be considered to determine the effect of ACE inhibitors on prevention of AD in the context of ApoE genotype.

  6. Therapeutic substitution post-patent expiry: the cases of ACE inhibitors and proton pump inhibitors.

    PubMed

    Vandoros, Sotiris

    2014-05-01

    This paper examines whether there is a switch in total (originator and generic) consumption after generic entry from molecules that face generic competition towards other molecules of the same class, which are still in-patent. Data from six European countries for the time period 1991 to 2006 are used to study the cases of angiotensin-converting enzyme inhibitors and proton pump inhibitors. Empirical evidence shows that patent expiry of captopril and enalapril led to a switch in total (off-patent originator and generic) consumption towards other in-patent angiotensin-converting enzyme inhibitors, whereas patent expiry of omeprazole led to a switch in consumption towards other proton pump inhibitors. This phenomenon makes generic policies ineffective and results in an increase in pharmaceutical expenditure due to the absence of generic alternatives in the market of in-patent molecules.

  7. 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

  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. 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

  11. 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

  12. Model Development and Use of ACE Inhibitors for Preclinical Mitigation of Radiation-Induced Injury to Multiple Organs

    PubMed Central

    Medhora, Meetha; Gao, Feng; Wu, Qingping; Molthen, Robert C.; Jacobs, Elizabeth R.; Moulder, John E.; Fish, Brian L.

    2014-01-01

    The NIH/NIAID initiated a countermeasure program to develop mitigators for radiation-induced injuries from a radiological attack or nuclear accident. We have previously characterized and demonstrated mitigation of single organ injuries, such as radiation pneumonitis, pulmonary fibrosis or nephropathy by angiotensin converting enzyme (ACE) inhibitors. Our current work extends this research to examine the potential for mitigating multiple organ dysfunctions occurring in the same irradiated rats. Using total body irradiation (TBI) followed by bone marrow transplant, we tested four doses of X radiation (11, 11.25, 11.5 and 12 Gy) to develop lethal late effects. We identified three of these doses (11, 11.25 and 11.5 Gy TBI) that were lethal to all irradiated rats by 160 days to test mitigation by ACE inhibitors of injury to the lungs and kidneys. In this study we tested three ACE inhibitors at doses: captopril (88 and 176 mg/m2/day), enalapril (18, 24 and 36 mg/m2/day) and fosinopril (60 mg/m2/day) for mitigation. Our primary end point was survival or criteria for euthanization of morbid animals. Secondary end points included breathing intervals, other assays for lung structure and function and blood urea nitrogen (BUN) to assess renal damage. We found that captopril at 176 mg/m2/day increased survival after 11 or 11.5 Gy TBI. Enalapril at 18–36 mg/m2/day improved survival at all three doses (TBI). Fosinopril at 60 mg/m2/day enhanced survival at a dose of 11 Gy, although no improvement was observed for pneumonitis. These results demonstrate the use of a single countermeasure to mitigate the lethal late effects in the same animal after TBI. PMID:25361399

  13. ACE and platelet aggregation inhibitors from Tamarix hohenackeri Bunge (host plant of Herba Cistanches) growing in Xinjiang

    PubMed Central

    Xing, Yachao; Liao, Jing; Tang, Yingzhan; Zhang, Peng; Tan, Chengyu; Ni, Hui; Wu, Xueqin; Li, Ning; Jia, Xiaoguang

    2014-01-01

    Background: Tamarix hohenackeri Bunge is a salt cedar that grows widespread in the desert mountains in Xinjiang. T. hohenackeri has not been investigated earlier, although there are many reports of phytochemical work on other Tamarix species. Materials and Methods: To find out natural angiotensin-converting enzyme (ACE) inhibitor and platelet aggregation inhibitors, the bioactive extract (ethyl acetate [EtOAc] fraction) from the dried aerial parts of T. hohenackeri were investigated. The active fraction was purified by repeated column chromatography, including silica gel, Sephadex LH-20 column, medium-pressure liquid chromatography (MPLC) (polyamide column) and high-performance liquid chromatography (HPLC). The isolated major constituents were tested for their anti-platelet aggregation activity. Results: Bioassay-directed separation of the EtOAc fraction of the 70% ethanol extract from the air-dried aerial parts of T. hohenackeri led to the isolation of a new triterpenoid lactone (1), together with 13 known compounds (2-14). It was the first time to focus on screening bioactive constituents for this plant. The chemical structures were established on the basis of spectral data (ESI-MS and NMR). The results showed that the flavonoid compounds (7 and 8) and phenolic compounds (9, 10, 11, and 14) were potential ACE inhibitors. And the flavonoid compounds (5 and 7) showed significant anti-platelet aggregation activities. Conclusion: On the basis of the chemical and biological data, the material basis of ACE inhibitory activity for the active part was the phenolic constituents. However, the flavonoid compounds were responsible for the anti-platelet aggregation. The primary structure and activity relationship were also discussed respectively. PMID:24914275

  14. 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

  15. 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

  16. Angiotensin-converting enzyme (ACE) genotypes and disability in hospitalized older patients.

    PubMed

    Seripa, Davide; Paroni, Giulia; Matera, Maria G; Gravina, Carolina; Scarcelli, Carlo; Corritore, Michele; D'Ambrosio, Luigi P; Urbano, Maria; D'Onofrio, Grazia; Copetti, Massimiliano; Kehoe, Patrick G; Panza, Francesco; Pilotto, Alberto

    2011-09-01

    The association between angiotensin-converting enzyme (ACE) genotypes and functional decline in older adults remains controversial. To assess if ACE gene variations influences functional abilities at older age, the present study explored the association between the common ACE insertion/deletion (I/D) polymorphism and disability measured with activities of daily living (ADL) in hospitalized older patients. We analyzed the frequency of the ACE genotypes (I/I, I/D, and D/D) in a population of 2,128 hospitalized older patients divided according to presence or absence of ADL disability. Logistic regression analysis adjusted for possible confounding factors, identified an association between the I/I genotype with ADL disability (OR=1.54, 95% CI 1.04-2.29). This association was significant in men (OR=2.01, 95% CI 1.07-3.78), but not in women (OR=1.36, 95% CI 0.82-2.25). These results suggested a possible role of the ACE polymorphism as a genetic marker for ADL disability in hospitalized older patients.

  17. Molecular dynamics simulation and molecular docking studies of Angiotensin converting enzyme with inhibitor lisinopril and amyloid Beta Peptide.

    PubMed

    Jalkute, Chidambar Balbhim; Barage, Sagar Hindurao; Dhanavade, Maruti Jayram; Sonawane, Kailas Dasharath

    2013-06-01

    Angiotensin converting enzyme (ACE) cleaves amyloid beta peptide. So far this cleavage mechanism has not been studied in detail at atomic level. Keeping this view in mind, we performed molecular dynamics simulation of crystal structure complex of testis truncated version of ACE (tACE) and its inhibitor lisinopril along with Zn(2+) to understand the dynamic behavior of active site residues of tACE. Root mean square deviation results revealed the stability of tACE throughout simulation. The residues Ala 354, Glu 376, Asp 377, Glu 384, His 513, Tyr 520 and Tyr 523 of tACE stabilized lisinopril by hydrogen bonding interactions. Using this information in subsequent part of study, molecular docking of tACE crystal structure with Aβ-peptide has been made to investigate the interactions of Aβ-peptide with enzyme tACE. The residues Asp 7 and Ser 8 of Aβ-peptide were found in close contact with Glu 384 of tACE along with Zn(2+). This study has demonstrated that the residue Glu 384 of tACE might play key role in the degradation of Aβ-peptide by cleaving peptide bond between Asp 7 and Ser 8 residues. Molecular basis generated by this attempt could provide valuable information towards designing of new therapies to control Aβ concentration in Alzheimer's patient.

  18. 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.

  19. 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.

  20. Angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism in Mexican populations.

    PubMed

    Vargas-Alarcón, Gilberto; Hernández-Pacheco, Guadalupe; Rodríguez-Pérez, José Manuel; Pérez-Hernández, Nonanzit; Pavón, Zinnia; Fragoso, José Manuel; Juarez-Cedillo, Teresa; Villarreal-Garza, Cynthia; Granados, Julio

    2003-12-01

    The angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism was determined in 211 Mexican healthy individuals belonging to different Mexican ethnic groups (98 Mestizos, 64 Teenek, and 49 Nahuas). ACE polymorphism differed among Mexicans with a high frequency of the D allele and the D/D genotype in Mexican Mestizos. The D/D genotype was absent in Teenek and present in only one Nahua individual (2.0%). When comparisons were made, we observed that Caucasian, African, and Asian populations presented the highest frequencies of the D allele, whereas Amerindian (Teenek and Pima) and Australian Aboriginals showed the highest frequencies of the I allele. The distribution of I/D genotype was heterogeneous in all populations: Australian Aboriginals presented the lowest frequency (4.9%), whereas Nahuas presented the highest (73.4%). The present study shows the frequencies of a polymorphism not analyzed previously in Mexican populations and establishes that this polymorphism distinguishes the Amerindian populations of other groups. On the other hand, since ACE alleles have been associated with genetic susceptibility to developing cardiovascular diseases and hypertension, knowledge of the distribution of these alleles could help to define the true significance of ACE polymorphism as a genetic susceptibility marker in the Amerindian populations.

  1. 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

  2. Effects of angiotensin converting enzyme inhibitors in hypertensive patients with aortic valve stenosis: a drug withdrawal study

    PubMed Central

    Jiménez-Candil, J; Bermejo, J; Yotti, R; Cortina, C; Moreno, M; Cantalapiedra, J L; García-Fernández, M A

    2005-01-01

    Objective: To determine the effects of angiotensin converting enzyme (ACE) inhibitors in hypertensive patients with aortic valve stenosis (AS). Design: Observational, drug withdrawal, single blinded study, with randomisation of the order of tests. Setting: Hypertension and asymptomatic AS. Patients and interventions: 20 patients (aged 73 (9) years, valve area 0.7 (0.3) cm2, left ventricular ejection fraction ⩾ 45%) were enrolled. Each patient underwent two sets of tests (with and without taking the drug), each of which included clinical evaluation, Doppler echocardiogram, and symptom limited exercise echocardiography. Main outcome measures: Functional and haemodynamic variables while taking and not taking ACE inhibitors. Results: Drug intervention induced no change in patients’ subjective functional class. While taking ACE inhibitors, patients had a lower systolic blood pressure (140 (18) mm Hg with ACE inhibitors v 159 (12) mm Hg without ACE inhibitors, p  =  0.02), a higher mean pressure gradient (34 (15) mm Hg v 28 (18) mm Hg, p  =  0.037), and a higher left ventricular stroke work loss (19 (6)% v 14 (10)%, p  =  0.009). Other baseline functional and haemodynamic parameters were unmodified. Five patients had an abnormal blood pressure response during one of the exercise tests (two patients while taking the drug and three patients while not taking the drug). When taking ACE inhibitors, patients had a higher stroke volume at peak stress (59 (11) ml v 54 (25) ml, p  =  0.046). All other stress variables remained constant. Conclusions: In AS, the afterload relief caused by ACE inhibitors is blunted by a parallel increase in the pressure gradient. However, ACE inhibitors favourably affect stress haemodynamic function in most hypertensive patients with AS and should not be discontinued. PMID:16162624

  3. A review of the preclinical cardiovascular pharmacology of cilazapril, a new angiotensin converting enzyme inhibitor.

    PubMed

    Waterfall, J F

    1989-01-01

    1. Cilazapril is the monoethyl ester prodrug form of the di-acid cilazaprilat, a new angiotensin converting enzyme (ACE) inhibitor. Cilazaprilat has an IC50 of 1.9 nM as an inhibitor of rabbit lung ACE in vitro making it one of the most potent ACE inhibitors currently available. Studies on a wide range of other enzymes show that the inhibition is highly specific. 2. An oral dose of 0.1 mg kg-1 cilazapril evoked the same maximum degree of plasma ACE inhibition (approximately 76%) in the rat as 0.25 mg kg-1 enalapril. Cilazapril (0.25 mg kg-1 p.o.) inhibited plasma ACE by greater than 95%. The rate of recovery of ACE activity was slower with cilazapril (5-6% h-1) than with enalapril (10% h-1). 3. In anaesthetised rats cilazaprilat was equipotent with ramiprilat and slightly more potent (1.5x) than enalaprilat as an inhibitor of the angiotensin I pressor response. 4. Following oral administration to conscious rats and intravenous administration to anaesthetised dogs, cilazapril was 2-4.5x more potent than enalapril as an ACE inhibitor. 5. In cats cilazapril (0.1 and 0.3 mg kg-1 p.o.) dose dependently decreased plasma ACE activity and the angiotensin pressor response. Peak effects occurred at 2 h after dosing and plasma ACE inhibition was maintained at greater than or equal to 50% for up to 18 h. Mean arterial pressure was also decreased dose dependently with a peak effect at 3-4 h. 6. Daily oral dosing of cilazapril (30 mg kg-1 p.o.) to spontaneously hypertensive rats evoked a progressive and prolonged (24 h) antihypertensive response with a maximum decrease in systolic blood pressure of 110 mm Hg. 7. Cilazapril (10 mg kg-1 p.o. twice daily for 3.5 days) progressively decreased blood pressure in volume depleted renal hypertensive dogs. The maximum fall in systolic pressure was 39 +/- 6 mm Hg. 8. Haemodynamic studies in open chest anaesthetised dogs showed that the hypotensive response to intravenous cilazapril was accompanied by a reduction in total peripheral

  4. 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: ...

  5. Binding of the angiotensin-converting enzyme inhibitor, RACX-65, to trout gills

    SciTech Connect

    Olson, K.R.; Evan, A.P.; Ryan, J.W.

    1986-03-01

    Galardy et al. have shown that in rainbow trout, Salmo gairdneri, nearly all of the angiotensin converting enzyme (ACE) activity is found in the gills. In the present study, binding and localization of the angiotensin-converting enzyme inhibitor N-(1(S)-carboxanili-dopropyl)-L-Ala-L-Pro (RAC-X-65) to trout gill was examined in homogenized gill tissues, an isolated perfused gill and by autoradiography. RAC-X-65 inhibited gill ACE as effectively as it inhibits human ACE; the apparent Ki for gill homogenates fell over 15 min from 3 x 10/sup -9/M to 5.5 x 10/sup -10/M. In the arterioarterial pathway (supplying the systematic circulation) of the perfused gill, /sup 3/H-RAC-X-65 extraction (compared to the inert volume maker, /sup 14/C-sucrose) decreased from 72.2 +/- 4.5% after 6 min perfusion to 54.7 +/- 6.8% (14 min) and 38.4 +/- 9.0% after 20 min (N = 6). By 40 min, extraction was less then 10% indicating saturation of ACE binding sites. Relatively little extraction was observed in the gill arteriovenous pathway. Autoradiography of gills perfused with /sup 3/H-RAC-X-65 demonstrated that the pillar cells are the major site of /sup 3/H accumulation and, therefore, probably contain most of the ACE activity.

  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. Membrane-associated zinc peptidase families: comparing ACE and ACE2.

    PubMed

    Guy, J L; Lambert, D W; Warner, F J; Hooper, N M; Turner, A J

    2005-08-01

    In contrast to the relatively ubiquitous angiotensin-converting enzyme (ACE), expression of the mammalian ACE homologue, ACE2, was initially described in the heart, kidney and testis. ACE2 is a type I integral membrane protein with its active site domain exposed to the extracellular surface of endothelial cells and the renal tubular epithelium. Here ACE2 is poised to metabolise circulating peptides which may include angiotensin II, a potent vasoconstrictor and the product of angiotensin I cleavage by ACE. To this end, ACE2 may counterbalance the effects of ACE within the renin-angiotensin system (RAS). Indeed, ACE2 has been implicated in the regulation of heart and renal function where it is proposed to control the levels of angiotensin II relative to its hypotensive metabolite, angiotensin-(1-7). The recent solution of the structure of ACE2, and ACE, has provided new insight into the substrate and inhibitor profiles of these two key regulators of the RAS. As the complexity of this crucial pathway is unravelled, there is a growing interest in the therapeutic potential of agents that modulate the activity of ACE2.

  8. Lysozyme and bilirubin bind to ACE and regulate its conformation and shedding

    PubMed Central

    Danilov, Sergei M.; Lünsdorf, Heinrich; Akinbi, Henry T.; Nesterovitch, Andrew B.; Epshtein, Yuliya; Letsiou, Eleftheria; Kryukova, Olga V.; Piegeler, Tobias; Golukhova, Elena Z.; Schwartz, David E.; Dull, Randal O.; Minshall, Richard D.; Kost, Olga A.; Garcia, Joe G. N.

    2016-01-01

    Angiotensin I-converting enzyme (ACE) hydrolyzes numerous peptides and is a critical participant in blood pressure regulation and vascular remodeling. Elevated tissue ACE levels are associated with increased risk for cardiovascular and respiratory disorders. Blood ACE concentrations are determined by proteolytic cleavage of ACE from the endothelial cell surface, a process that remains incompletely understood. In this study, we identified a novel ACE gene mutation (Arg532Trp substitution in the N domain of somatic ACE) that increases blood ACE activity 7-fold and interrogated the mechanism by which this mutation significantly increases blood ACE levels. We hypothesized that this ACE mutation disrupts the binding site for blood components which may stabilize ACE conformation and diminish ACE shedding. We identified the ACE-binding protein in the blood as lysozyme and also a Low Molecular Weight (LMW) ACE effector, bilirubin, which act in concert to regulate ACE conformation and thereby influence ACE shedding. These results provide mechanistic insight into the elevated blood level of ACE observed in patients on ACE inhibitor therapy and elevated blood lysozyme and ACE levels in sarcoidosis patients. PMID:27734897

  9. 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

  10. Differential systemic and regional hemodynamic profiles of four angiotensin-I converting-enzyme inhibitors in the rat.

    PubMed

    Richer, C; Doussau, M P; Giudicelli, J F

    1989-12-01

    Angiotensin-converting enzyme (ACE) inhibitors decrease blood pressure by reducing systemic vascular resistance. That the peripheral vasodilating properties of ACE inhibitors might not be homogeneously distributed in all vascular beds and might differ from one drug to another has been investigated in the normotensive rat by the pulsed Doppler technique using the active components of four different ACE inhibitors: captopril, enalapril, perindopril, and ramipril. Systemic (cardiac output and blood pressure) and regional (kidney, mesentery, hindquarter) hemodynamic responses to saline or to cumulative bolus injections (0.01-1 mg/kg) of captopril, enalaprilat, perindoprilat, or ramiprilat were continuously monitored. The effects of successive bolus injections (0.3-300 ng/kg) of angiotensinII were also investigated. The four ACE inhibitors produced an almost complete blockade of plasma angiotensin-II converting-enzyme activity (83%, 100%, 100%, and 100%, respectively), induced dose-dependent decreases in mean blood pressure, did not significantly affect cardiac output, and reduced total peripheral and mesenteric vascular resistances to the same extent. Hindlimb vascular resistance was identically decreased, but to a lower extent than total peripheral resistance by enalaprilat, perindoprilat, and ramiprilat, whereas it was increased by captopril at low doses only. Renal resistance was markedly decreased by the four drugs, and especially by captopril. The decreasing rank order for ACE-inhibitor-induced vasodilation is exactly the same (renal greater than total peripheral = mesenteric greater than hindlimb vascular resistances) as that of angiotensin-H-induced regional vasoconstriction, indicating that the vasodilator properties of ACE inhibitors are mainly due to angiotensin-II vasomotor tone suppression. None of the investigated compounds significantly affected mesenteric and hindlimb blood flows, except captopril, which lowered the latter significantly

  11. Angiotensin I-converting enzyme inhibitor peptides derived from the endostatin-containing NC1 fragment of human collagen XVIII.

    PubMed

    Farias, Shirley L; Sabatini, Regiane A; Sampaio, Tatiana C; Hirata, Izaura Y; Cezari, Maria Helena S; Juliano, Maria A; Sturrock, Edward D; Carmona, Adriana K; Juliano, Luiz

    2006-05-01

    Extracellular matrix and soluble plasma proteins generate peptides that regulate biological activities such as cell growth, differentiation and migration. Bradykinin, a peptide released from kininogen by kallikreins, stimulates vasodilatation and endothelial cell proliferation. Various classes of substances can potentiate these biological actions of bradykinin. Among them, the best studied are bradykinin potentiating peptides (BPPs) derived from snake venom, which can also strongly inhibit angiotensin I-converting enzyme (ACE) activity. We identified and synthesized sequences resembling BPPs in the vicinity of potential proteolytic cleavage sites in the collagen XVIII molecule, close to endostatin. These peptides were screened as inhibitors of human recombinant wild-type ACE containing two intact functional domains; two full-length ACE mutants containing only a functional C- or N-domain catalytic site; and human testicular ACE, a natural form of the enzyme that only contains the C-domain. The BPP-like peptides inhibited ACE in the micromolar range and interacted preferentially with the C-domain. The proteolytic activity involved in the release of BPP-like peptides was studied in human serum and human umbilical-vein endothelial cells. The presence of enzymes able to release these peptides in blood led us to speculate on a physiological mechanism for the control of ACE activities.

  12. Identification of new polymorphisms of the angiotensin I-converting enzyme (ACE) gene, and study of their relationship to plasma ACE levels by two-QTL segregation-linkage analysis

    SciTech Connect

    Villard, E.; Soubrier, F.; Tiret, L.; Rakotovao, R. Cambien, F.; Visvikis, S.

    1996-06-01

    Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage disequilibrium (LD) with the ACE insertion/deletion (I/D) polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D polymorphism. These polymorphisms could be divided into two groups: five polymorphisms in the 5{prime} region and three in the coding sequence and the 3{prime} UTR. Within each group, polymorphisms were in nearly complete association, whereas polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D polymorphism, all polymorphisms of the 5{prime} group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D polymorphism itself or the newly characterized 4656(CT){sub 2/3} polymorphism. The second QTL would have a frequency of {approximately}.20, which is incompatible with any of the yet-identified polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants. 30 refs., 1 fig., 6 tabs.

  13. Efficacy and Safety of Complete RAAS Blockade with ALISKIREN in Patients with Refractory Proteinuria Who were already on Combined ACE Inhibitor, ARB, and Aldosterone Antagonist

    PubMed Central

    Sreelatha, M

    2016-01-01

    Introduction Proteinuria is always associated with intrinsic kidney disese and is a strong predictor of later development of End Stage Renal Disease (ESRD). As Renin Angiotensin Aldosterone System (RAAS) has a role in mediating proteinuria, inhibitors of this system are renoprotective and patients with refractory proteinuria are put on a combination of these agents. The routinely employed triple blockade of RAAS with Angiotensin Converting Enzyme (ACE) inhibitor, ARB and Aldosterone antagonist has many limitations. Addition of Aliskiren to this combination suppresses the RAAS at the earliest stage and can offset many of these limitations. Aim This study was conducted to assess the safety and efficacy of complete RAAS blockade by the addition of Aliskiren in those patients with refractory proteinuria who were already on triple blockade with ACE inhibitor, ARB and Aldosterone antagonist. Settings This study was conducted in Nephrology Department, Calicut Medical College. Materials and Methods A total of 36 patients with refractory proteinuria who were already on ACE inhibitor, ARB and Aldosterone antagonist were divided in to two groups A and B. Group A received Aliskiren in addition to the above combination whereas group B continued the same treatment for 12 weeks. Efficacy of the treatment was assessed by recording 24hr urine protein and safety by S.Creatinine, S.Potassium every 2 weeks of the treatment period. Statistical Analysis Statistical analysis of the lab values was done using SPSS software. Unpaired t-test, Paired t-test and Chi-square test were done for data analysis. Results Statistical analysis revealed that addition of Aliskiren to the combination therapy with ACE inhibitor+ ARB+ Aldosterone antagonist offers no advantage. But mean reduction in proteinuria was more with Group A than Group B. There is no statistically significant change in S.Creatinine and S.Potassium at the end of treatment. Conclusion As proteinuria is a strong risk factor for

  14. Angiotensin-converting enzyme 2 (ACE2) mediates influenza H7N9 virus-induced acute lung injury.

    PubMed

    Yang, Penghui; Gu, Hongjing; Zhao, Zhongpeng; Wang, Wei; Cao, Bin; Lai, Chengcai; Yang, Xiaolan; Zhang, LiangYan; Duan, Yueqiang; Zhang, Shaogeng; Chen, Weiwen; Zhen, Wenbo; Cai, Maosheng; Penninger, Josef M; Jiang, Chengyu; Wang, Xiliang

    2014-11-13

    Since March 2013, the emergence of an avian-origin influenza A (H7N9) virus has raised concern in China. Although most infections resulted in respiratory illness, some severe cases resulted in acute respiratory distress syndrome (ARDS), which is a severe form of acute lung injury (ALI) that further contributes to morbidity. To date, no effective drugs that improve the clinical outcome of influenza A (H7N9) virus-infected patients have been identified. Angiotensin-converting enzyme (ACE) and ACE2 are involved in several pathologies such as cardiovascular functions, renal disease, and acute lung injury. In the current study, we report that ACE2 could mediate the severe acute lung injury induced by influenza A (H7N9) virus infection in an experimental mouse model. Moreover, ACE2 deficiency worsened the disease pathogenesis markedly, mainly by targeting the angiotensin II type 1 receptor (AT1). The current findings demonstrate that ACE2 plays a critical role in influenza A (H7N9) virus-induced acute lung injury, and suggest that might be a useful potential therapeutic target for future influenza A (H7N9) outbreaks.

  15. 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

  16. 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

  17. Renal hemodynamics in hypertensive renal allograft recipients: effects of calcium antagonists and ACE inhibitors.

    PubMed

    Grekas, D; Dioudis, C; Kalevrosoglou, I; Alivanis, P; Derveniotis, V; Tourkantonis, A

    1996-06-01

    Hypertension present in more than 50% of successfully renal transplanted patients and its prevalence has slightly increased since the introduction of cyclosporine A. Twenty patients, 9 women and 11 men aged from 30 to 58 years, with stable cadaveric renal allograft function and moderate to severe hypertension, were included in the study. Renal artery graft stenosis causing hypertension were excluded. All patients were given triple drug immunosuppressive treatment with methylprednisolone, azathioprine and cyclosporine A (CsA) and their hypertension was treated with a nifedipine dose of 20 mg twice daily. To evaluate the effect of ACE inhibitors on renal hemodynamics and hypertension, a 4 mg/daily dose of perindopril was added to the above regimen for two months. Effective renal plasma flow (ERPF) decreased from 208 +/- 54 to 168 +/- 61 ml/min and renal vascular resistance (RVR) increased from 75 +/- 12 to 88 +/- 17 mm Hg/ml/min (P < 0.05 and P < 0.01, respectively). Mean blood pressure was significantly (P < 0.001) reduced by the combination of both agents in comparison to the blood pressure control by monotherapy with nifedipine. It is suggested that the combination of both antihypertensive agents was more effective than monotherapy with nifedipine in controlling blood pressure, but less favorable on the renal hemodynamic response in hypertensive renal transplant patients who were maintained on CsA.

  18. Yeasts from Colombian Kumis as source of peptides with Angiotensin I converting enzyme (ACE) inhibitory activity in milk.

    PubMed

    Chaves-López, Clemencia; Tofalo, Rosanna; Serio, Annalisa; Paparella, Antonello; Sacchetti, Giampiero; Suzzi, Giovanna

    2012-09-17

    This study investigated the possibility of using yeast strains in fermented milks to obtain products with high Angiotensin I-converting enzyme (ACE) inhibitory activity and low bitter taste. Ninety-three yeast strains isolated from Colombian Kumis in different geographic regions were molecularly identified, and their milk fermentation performances were determined. Molecular identification evidenced that Galactomyces geotrichum, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis, were the dominant species. Eighteen out of 93 strains produced fermented milk with ACE-inhibitory (ACEI) activity values ranging from 8.69 to 88.19%. Digestion of fermented milk samples by pepsin and pancreatin demonstrated an increase in ACEI activity, with C. lusitaniae KL4A as the best producer of ACEI peptides. Moreover, sensory analysis of the products containing the major ACE-inhibitory activity pointed out that P. kudriavzevii KL84A and Kluyveromyces marxianus KL26A could be selected as potential adjunct starter cultures in Kumis, since they made a considerable contribution to the ACE inhibitory activity and produced fermented milk without bitter taste. In this study we observed that Colombian Kumis can be an excellent vehicle for the isolation of yeasts with a potential to enhance bioactive peptides produced during milk fermentation. PMID:22938834

  19. Angiotensin I converting enzyme (ACE) inhibitory activity of hetero-chitooligosaccharides prepared from partially different deacetylated chitosans.

    PubMed

    Park, Pyo-Jam; Je, Jae-Young; Kim, Se-Kwon

    2003-08-13

    Angiotensin I converting enzyme (ACE) inhibitory activity of hetero-chitooligosaccharides (hetero-COSs) prepared from partially different deacetylated chitosans was investigated. Partially deacetylated chitosans, 90, 75, and 50% deacetylated chitosan, were prepared from crab chitin by N-deacetylation with 40% sodium hydroxide solution for durations. In addition, nine kinds of hetero-COSs with relatively high molecular masses (5000-10 000 Da; 90-HMWCOSs, 75-HMWCOSs, and 50-HMWCOSs), medium molecular masses (1000-5000 Da; 90-MMWCOSs, 75-MMWCOSs, and 50-MMWCOSs), and low molecular masses (below 1000 Da; 90-LMWCOSs, 75-LMWCOSs, and 50-LMWCOSs) were prepared using an ultrafiltration membrane bioreactor system. ACE inhibitory activity of hetero-COSs was dependent on the degree of deacetylation of chitosans. 50-MMWCOSs that are COSs hydrolyzed from 50% deacetylated chitosan, the relatively lowest degree of deacetylation, exhibited the highest ACE inhibitory activity, and the IC(50) value was 1.22 +/- 0.13 mg/mL. In addition, the ACE inhibition pattern of the 50-MMWCOSs was investigated by Lineweaver-Burk plots, and the inhibition pattern was found to be competitive.

  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. 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

  3. 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

  4. Advances in algal drug research with emphasis on enzyme inhibitors.

    PubMed

    Rengasamy, Kannan R R; Kulkarni, Manoj G; Stirk, Wendy A; Van Staden, Johannes

    2014-12-01

    Enzyme inhibitors are now included in all kinds of drugs essential to treat most of the human diseases including communicable, metabolic, cardiovascular, neurological diseases and cancer. Numerous marine algae have been reported to be a potential source of novel enzyme inhibitors with various pharmaceutical values. Thus, the purpose of this review is to brief the enzyme inhibitors from marine algae of therapeutic potential to treat common diseases. As per our knowledge this is the first review for the potential enzyme inhibitors from marine origin. This review contains 86 algal enzyme inhibitors reported during 1989-2013 and commercial enzyme inhibitors available in the market. Compounds in the review are grouped according to the disease conditions in which they are involved; diabetes, obesity, dementia, inflammation, melanogenesis, AIDS, hypertension and other viral diseases. The structure-activity relationship of most of the compounds are also discussed. In addition, the drug likeness properties of algal inhibitors were evaluated using Lipinski's 'Rule of Five'. PMID:25195189

  5. Angiotensin converting enzyme inhibitors mitigate collagen synthesis induced by a single dose of radiation to the whole thorax.

    PubMed

    Kma, Lakhan; Gao, Feng; Fish, Brian L; Moulder, John E; Jacobs, Elizabeth R; Medhora, Meetha

    2012-01-01

    Our long-term goal is to use angiotensin converting enzyme (ACE) inhibitors to mitigate the increase in lung collagen synthesis that is induced by irradiation to the lung, which could result from accidental exposure or radiological terrorism. Rats (WAG/RijCmcr) were given a single dose of 13 Gy (dose rate of 1.43 Gy/min) of X-irradiation to the thorax. Three structurally-different ACE inhibitors, captopril, enalapril and fosinopril were provided in drinking water beginning 1 week after irradiation. Rats that survived acute pneumonitis (at 6-12 weeks) were evaluated monthly for synthesis of lung collagen. Other endpoints included breathing rate, wet to dry lung weight ratio, and analysis of lung structure. Treatment with captopril (145-207 mg/m(2)/day) or enalapril (19-28 mg/m(2)/day), but not fosinopril (19-28 mg/m(2)/day), decreased morbidity from acute pneumonitis. Lung collagen in the surviving irradiated rats was increased over that of controls by 7 months after irradiation. This increase in collagen synthesis was not observed in rats treated with any of the three ACE inhibitors. Analysis of the lung morphology at 7 months supports the efficacy of ACE inhibitors against radiation-induced fibrosis. The effectiveness of fosinopril against fibrosis, but not against acute pneumonitis, suggests that pulmonary fibrosis may not be a simple consequence of injury during acute pneumonitis. In summary, three structurally-different ACE inhibitors mitigate the increase in collagen synthesis 7 months following irradiation of the whole thorax and do so, even when therapy is started one week after irradiation. PMID:22302041

  6. Radiation-induced endothelial dysfunction and fibrosis in rat lung: modification by the angiotensin converting enzyme inhibitor CL242817

    SciTech Connect

    Ward, W.F.; Molteni, A.; Ts'ao, C.H.

    1989-02-01

    The purpose of this study was to evaluate the angiotensin converting enzyme (ACE) inhibitor CL242817 as a modifier of radiation-induced pulmonary endothelial dysfunction and pulmonary fibrosis in rats sacrificed 2 months after a single dose of 60Co gamma rays (0-30 Gy) to the right hemithorax. CL242817 was administered in the feed continuously after irradiation at a regimen of 60 mg/kg/day. Pulmonary endothelial function was monitored by lung ACE activity, plasminogen activator (PLA) activity, and prostacyclin (PGI2) and thromboxane (TXA2) production. Pulmonary fibrosis was evaluated by lung hydroxyproline (HP) content. Lung ACE and PLA activities decreased with increasing radiation dose, and cotreatment with CL242817 significantly ameliorated both responses. CL242817 dose-reduction factors (DRF) were 1.3-1.5 for ACE and PLA activity. Lung PGI2 and TXA2 production increased with increasing radiation dose, and CL242817 almost completely prevented both radiation responses. The slope of the radiation dose-response curves in the CL242817-treated rats was essentially zero, precluding calculation of DRF values for PGI2 and TXA2 production. Lung HP content also increased with increasing radiation dose, and CL242817 significantly attenuated this response (DRF = 1.5). These data suggest that the ability of ACE inhibitors to ameliorate radiation-induced pulmonary endothelial dysfunction is not unique to captopril, rather it is a therapeutic action shared by other members of this class of compounds. These data also provide the first evidence that ACE inhibitors exhibit antifibrotic activity in irradiated rat lung.

  7. Effects of centrally acting ACE inhibitors on the rate of cognitive decline in dementia

    PubMed Central

    Gao, Yang; O'Caoimh, Rónán; Healy, Liam; Kerins, David M; Eustace, Joseph; Guyatt, Gordon; Sammon, David; Molloy, D William

    2013-01-01

    Objectives There is growing evidence that antihypertensive agents, particularly centrally acting ACE inhibitors (CACE-Is), which cross the blood–brain barrier, are associated with a reduced rate of cognitive decline. Given this, we compared the rates of cognitive decline in clinic patients with dementia receiving CACE-Is (CACE-I) with those not currently treated with CACE-Is (NoCACE-I), and with those who started CACE-Is, during their first 6 months of treatment (NewCACE-I). Design Observational case–control study. Setting 2 university hospital memory clinics. Participants 817 patients diagnosed with Alzheimer's disease, vascular or mixed dementia. Of these, 361 with valid cognitive scores were included for analysis, 85 CACE-I and 276 NoCACE-I. Measurements Patients were included if the baseline and end-point (standardised at 6 months apart) Standardised Mini-Mental State Examination (SMMSE) or Quick Mild Cognitive Impairment (Qmci) scores were available. Patients with comorbid depression or other dementia subtypes were excluded. The average 6-month rates of change in scores were compared between CACE-I, NoCACE-I and NewCACE-I patients. Results When the rate of decline was compared between groups, there was a significant difference in the median, 6-month rate of decline in Qmci scores between CACE-I (1.8 points) and NoCACE-I (2.1 points) patients (p=0.049), with similar, non-significant changes in SMMSE. Median SMMSE scores improved by 1.2 points in the first 6 months of CACE treatment (NewCACE-I), compared to a 0.8 point decline for the CACE-I (p=0.003) group and a 1 point decline for the NoCACE-I (p=0.001) group over the same period. Multivariate analysis, controlling for baseline characteristics, showed significant differences in the rates of decline, in SMMSE, between the three groups, p=0.002. Conclusions Cognitive scores may improve in the first 6 months after CACE-I treatment and use of CACE-Is is associated with a reduced rate of cognitive

  8. [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

  9. No contribution of angiotensin-converting enzyme (ACE) gene variants to severe obesity: a model for comprehensive case/control and quantitative cladistic analysis of ACE in human diseases.

    PubMed

    Bell, Christopher G; Meyre, David; Petretto, Enrico; Levy-Marchal, Claire; Hercberg, Serge; Charles, Marie Aline; Boyle, Cliona; Weill, Jacques; Tauber, Maïte; Mein, Charles A; Aitman, Timothy J; Froguel, Philippe; Walley, Andrew J

    2007-03-01

    Candidate gene analyses are often inconclusive owing to genetic or phenotypic heterogeneity, low statistical power, selection of nonfunctional SNPs, and inadequate statistical analysis of the genetic architecture. Angiotensin-converting enzyme (ACE) is involved in adipocyte growth and function and the ACE-processed angiotensin II inhibits adipocyte differentiation. Associations between body mass index (BMI) and ACE polymorphisms have been reported in general populations, but the contribution to severe obesity of this gene, which is located under an obesity genome-scan linkage peak on 17q23, is unknown. ACE is one of the most studied genes and markers responsible for variation in circulating ACE enzyme levels have been extensively characterised. Eight of these variants were genotyped in 1054 severely obese cases and 918 nonobese controls, as well as 116 nuclear families from the genome scan (n=447), enabling the known clades to be inferred. Qualitative analysis of individual single-nucleotide polymorphisms (SNPs), haplotypes, clades, and diploclades demonstrated no significant associations (P<0.05) after minimal correction for multiple testing. Quantitative analysis of clades and diploclades for BMI, waist-to-hip ratio, or ZBMI in children were also not significant. This rigorous, large-scale study of common, well-defined, severe polygenic obesity provides strong evidence that functionally relevant sequence variation in ACE, whether it is defined at the level of SNPs, haplotypes, or clades, is not associated with severe obesity in French Caucasians. Such a study design exemplifies the strategy needed to clearly define the contribution of the ACE gene to the plethora of complex genetic diseases where weak associations have been previously reported.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. [Advances on enzymes and enzyme inhibitors research based on microfluidic devices].

    PubMed

    Hou, Feng-Hua; Ye, Jian-Qing; Chen, Zuan-Guang; Cheng, Zhi-Yi

    2010-06-01

    With the continuous development in microfluidic fabrication technology, microfluidic analysis has evolved from a concept to one of research frontiers in last twenty years. The research of enzymes and enzyme inhibitors based on microfluidic devices has also made great progress. Microfluidic technology improved greatly the analytical performance of the research of enzymes and enzyme inhibitors by reducing the consumption of reagents, decreasing the analysis time, and developing automation. This review focuses on the development and classification of enzymes and enzyme inhibitors research based on microfluidic devices.

  16. 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

  17. Angiotensin I-converting enzyme inhibitors potentiate bradykinin's inotropic effects independently of blocking its inactivation.

    PubMed

    Minshall, R D; Erdös, E G; Vogel, S M

    1997-08-01

    The positive inotropic effects of bradykinin (BK) and 2 analogs resistant to angiotensin I-converting enzyme (ACE) were potentiated on isolated guinea pig atrial preparations by enalaprilat. The stable BK analogs, dextran-BK and [Hyp3-Tyr(Me)8]-BK, were as active as BK. Pretreatment for 5 min with enalaprilat augmented the maximal positive inotropic effect of [Hyp3-Tyr(Me)8]-BK 2.8-fold, from 19% to 53% and that of BK from 28% to 42% over baseline; inotropic responses to dextran-BK (1 microM) were similarly increased. The activity of atrial ACE, a zinc-requiring enzyme, was completely inhibited by 8-hydroxyquinoline-5-sulfonic acid (QSA, 10 mM), which raised the maximal inotropic effect of BK to 39% above baseline. This value rose to 67% when in addition to QSA, 1 microM enalaprilat was added; enalaprilat thus, potentiated the effects of BK independently of enzyme inhibition. The positive inotropic effects to BK and its analogs decline with time in the presence of these agonists. After 10 min of exposure, the response to 1 microM [Hyp3-Tyr(Me)8]-BK decreased to about half, and after 20 min, to 0. Enalaprilat, when present in the tissue bath, prevented the decline in inotropy; even after tachyphylaxis occurred, it reversed this decrease in activity when added. The effects of 1 microM [Hyp3-Tyr(Me)8]-BK, in the absence or presence of enalaprilat, were abolished by the BK B2 receptor antagonist icatibant (0.75 microM). The results indicate that ACE inhibitors, by potentiating the BK effects and blocking BK B2-receptor desensitization, may contribute to the beneficial cardiac effects of BK independently of blocking its inactivation.

  18. Atrial overexpression of angiotensin-converting enzyme 2 improves the canine rapid atrial pacing-induced structural and electrical remodeling. Fan, ACE2 improves atrial substrate remodeling.

    PubMed

    Fan, Jinqi; Zou, Lili; Cui, Kun; Woo, Kamsang; Du, Huaan; Chen, Shaojie; Ling, Zhiyu; Zhang, Quanjun; Zhang, Bo; Lan, Xianbin; Su, Li; Zrenner, Bernhard; Yin, Yuehui

    2015-01-01

    The purpose of this study was to investigate whether atrial overexpression of angiotensin-converting enzyme 2 (ACE2) by homogeneous transmural atrial gene transfer can reverse atrial remodeling and its mechanisms in a canine atrial-pacing model. Twenty-eight mongrel dogs were randomly divided into four groups: Sham-operated, AF-control, gene therapy with adenovirus-enhanced green fluorescent protein (Ad-EGFP) and gene therapy with Ad-ACE2 (Ad-ACE2) (n = 7 per subgroup). AF was induced in all dogs except the Sham-operated group by rapid atrial pacing at 450 beats/min for 2 weeks. Ad-EGFP and Ad-ACE2 group then received epicardial gene painting. Three weeks after gene transfer, all animals except the Sham group underwent rapid atrial pacing for another 3 weeks and then invasive electrophysiological, histological and molecular studies. The Ad-ACE2 group showed an increased ACE2 and Angiotensin-(1-7) expression, and decreased Angiotensin II expression in comparison with Ad-EGFP and AF-control group. ACE2 overexpression attenuated rapid atrial pacing-induced increase in activated extracellular signal-regulated kinases and mitogen-activated protein kinases (MAPKs) levels, and decrease in MAPK phosphatase 1(MKP-1) level, resulting in attenuation of atrial fibrosis collagen protein markers and transforming growth factor-β1. Additionally, ACE2 overexpression also modulated the tachypacing-induced up-regulation of connexin 40, down-regulation of connexin 43 and Kv4.2, and significantly decreased the inducibility and duration of AF. ACE2 overexpression could shift the renin-angiotensin system balance towards the protective axis, attenuate cardiac fibrosis remodeling associated with up-regulation of MKP-1 and reduction of MAPKs activities, modulate tachypacing-induced ion channels and connexin remodeling, and subsequently reduce the inducibility and duration of AF.

  19. ACE inhibition can improve orthostatic proteinuria associated with nutcracker syndrome.

    PubMed

    Ha, Tae-Sun; Lee, Eun-Ju

    2006-11-01

    Left renal vein entrapment syndrome (nutcracker syndrome) was documented by magnetic resonance angiography (MRA) as a cause of orthostatic proteinuria in a 14-year-old girl female adolescent. Because of continuous proteinuria we performed a left renal biopsy which showed moderate mesangial hypercellularity. Her overt orthostatic proteinuria disappeared after a treatment of angiotensin-converting enzyme (ACE) inhibition. Nutcracker syndrome remains a rare but important cause of elevated protein excretion, which can induce mesangial changes and be improved by ACE inhibitor treatment.

  20. 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

  1. 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

  2. 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

  3. 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.

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

    PubMed Central

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

    2013-01-01

    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 (Ki=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-domainselective inhibition and assists in the design of novel N-selective ACE inhibitors that could be employed in treatment of fibrosis disorders. PMID:24015848

  5. 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.

  6. Calcium channel blockers, angiotensin receptor blockers, and angiotensin-converting enzyme inhibitors: Effectiveness in combination with diuretics or β-blockers for treating hypertension

    PubMed Central

    Bisognano, John D; McLaughlin, Trent; Roberts, Craig S; Tang, Simon SK

    2007-01-01

    This retrospective database analysis compared the effectiveness of dihydropyridine calcium channel blockers (DHPs), angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs) added to diuretics or β-blockers. Adults with hypertension treated with diuretic or β-blocker monotherapy between 1998 and 2001 were identified from a large US electronic medical records database of primary care practices. Patients were required to have a baseline blood pressure (BP) ≥140/90 mmHg (≥130/80 mmHg for diabetes mellitus) and recorded BP measurements within 6 months before and 1–12 months following index date. Patients were matched 1:1:1 by propensity score to correct for differences in baseline characteristics. 1875 patients met study criteria and 660 (220 in each cohort) were matched based on propensity scores. Matched cohorts had no significant differences in baseline characteristics. Mean changes in systolic/diastolic BP were −17.5/−8.8, −15.7/−6.3, and −13.0/−8.0 mmHg with DHPs, ACE inhibitors, and ARBs, respectively. Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High BP 6/7 goal attainment for each regimen was 47.3%, 40.0%, and 32.2%, respectively. DHPs, ACE inhibitors, and ARBs improved BP when added to patients’ β-blocker or diuretic therapy. The greatest benefits were observed with DHPs, followed by ACE inhibitors, then ARBs. PMID:18078009

  7. 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

  8. Investigation of potential inhibitors of chorismate-utilizing enzymes.

    PubMed

    Švarcová, Markéta; Krátký, Martin; Vinšova, Jarmila

    2015-01-01

    Chorismate-utilizing enzymes (CUE) such as chorismate mutase, anthranilate synthase, chorismate pyruvate-lyase, 4-amino-4-deoxychorismate synthase, isochorismate synthase and salicylate synthase are responsible for converting chorismate into various products necessary for the survival of bacteria. The absence of these enzymes in humans and their importance in the virulence and survival of bacteria make them suitable targets for potential antimicrobial compounds. Furthermore, the CUE have significant structural homology and similar catalytic mechanisms, enabling the strategy of affecting multiple enzymes with one single inhibitor. This review follows up the investigation of mechanisms of CUE-catalysed reactions and the concurrent development of CUE inhibitors. Many active compounds were found amongst the structures mimicking the transition state of chorismate during the reaction. Most recently, high nanomolar and low micromolar inhibitors against isochorismate-pyruvate lyase were identified, which were also effective against chorismate mutase and salicylate synthase and belong to the most active inhibitors reported up to date.

  9. 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

  10. Debate: angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers--a gap in evidence-based medicine.

    PubMed

    Ball, Stephen G; White, William B

    2003-05-22

    In this article, 2 leading physicians debate the strength of outcome data on the efficacy of angiotensin-converting enzyme (ACE) inhibitors versus angiotensin II receptor blockers (ARBs) for reducing the incidence of cardiovascular, cerebrovascular, and renovascular events. Dr. Stephen G. Ball notes that the efficacy of ACE inhibitors for reducing the risk for myocardial infarction independent of their effects on blood pressure is controversial. In the Heart Outcomes Prevention Evaluation (HOPE) study, ramipril treatment in high-risk patients was associated with a 20% reduction in the risk for myocardial infarction; mean reduction in blood pressure was 3 mm Hg for systolic blood pressure and 1 mm Hg for diastolic blood pressure. The HOPE investigators propose that the 20% reduction was much greater than would be expected based on the observed blood pressure reduction. However, a meta-regression analysis of blood pressure reduction in >20 antihypertensive therapy outcome trials found that the reduction in myocardial infarction risk with ramipril observed in HOPE was consistent with the modest blood pressure reduction seen with that agent. Nevertheless, there are convincing data for prevention of myocardial infarction with ACE inhibitors in patients with heart failure, including those with heart failure after myocardial infarction, as well as supportive evidence from studies in patients with diabetes mellitus and concomitant hypertension. On the other hand, Dr. William B. White takes the position that ARBs are well-tolerated antihypertensive agents that specifically antagonize the angiotensin II type 1 (AT(1)) receptor and provide a more complete block of the pathologic effects of angiotensin II-which are mediated via the AT(1) receptor-than ACE inhibitors. The Evaluation of Losartan in the Elderly (ELITE) II study and the Valsartan Heart Failure Trial (ValHeFT) suggest that ARBs reduce the risk for mortality in patients with congestive heart failure. The Losartan

  11. Debate: angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers--a gap in evidence-based medicine.

    PubMed

    Ball, Stephen G; White, William B

    2003-05-22

    In this article, 2 leading physicians debate the strength of outcome data on the efficacy of angiotensin-converting enzyme (ACE) inhibitors versus angiotensin II receptor blockers (ARBs) for reducing the incidence of cardiovascular, cerebrovascular, and renovascular events. Dr. Stephen G. Ball notes that the efficacy of ACE inhibitors for reducing the risk for myocardial infarction independent of their effects on blood pressure is controversial. In the Heart Outcomes Prevention Evaluation (HOPE) study, ramipril treatment in high-risk patients was associated with a 20% reduction in the risk for myocardial infarction; mean reduction in blood pressure was 3 mm Hg for systolic blood pressure and 1 mm Hg for diastolic blood pressure. The HOPE investigators propose that the 20% reduction was much greater than would be expected based on the observed blood pressure reduction. However, a meta-regression analysis of blood pressure reduction in >20 antihypertensive therapy outcome trials found that the reduction in myocardial infarction risk with ramipril observed in HOPE was consistent with the modest blood pressure reduction seen with that agent. Nevertheless, there are convincing data for prevention of myocardial infarction with ACE inhibitors in patients with heart failure, including those with heart failure after myocardial infarction, as well as supportive evidence from studies in patients with diabetes mellitus and concomitant hypertension. On the other hand, Dr. William B. White takes the position that ARBs are well-tolerated antihypertensive agents that specifically antagonize the angiotensin II type 1 (AT(1)) receptor and provide a more complete block of the pathologic effects of angiotensin II-which are mediated via the AT(1) receptor-than ACE inhibitors. The Evaluation of Losartan in the Elderly (ELITE) II study and the Valsartan Heart Failure Trial (ValHeFT) suggest that ARBs reduce the risk for mortality in patients with congestive heart failure. The Losartan

  12. 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

  13. Mixed inhibitors of angiotensin-converting enzyme (EC 3.4.15.1) and enkephalinase (EC 3.4.24.11): rational design, properties, and potential cardiovascular applications of glycopril and alatriopril.

    PubMed Central

    Gros, C; Noël, N; Souque, A; Schwartz, J C; Danvy, D; Plaquevent, J C; Duhamel, L; Duhamel, P; Lecomte, J M; Bralet, J

    1991-01-01

    Angiotensin-converting enzyme (ACE) and enkephalinase, two cell surface metallopeptidases, are responsible for angiotensin II formation and atrial natriuretic factor (ANF) degradation, respectively, and thereby play a critical role in the metabolism of hormonal peptides exerting essentially opposite actions in cardiovascular regulations. To affect simultaneously both hormonal systems by a single molecular structure, we have designed glycoprilat and alatrioprilat [(S)-N-[3-(3,4-methylene-dioxyphenyl)-2-(mercaptomethyl)-1-oxoprop yl] glycine and -alanine, respectively]. In vitro the two compounds inhibit both ACE and enkephalinase activities with similar, nanomolar potencies, and in vivo, glycopril and alatriopril, the corresponding diester prodrugs, occupy the two enzyme molecules in lung at similar low dosages (0.2-0.5 mg/kg of body weight, per os). The high potency of these compounds is attributable to interaction of the methylenedioxy group with the S1 subsite of ACE and of the aromatic ring with the S1' subsite of enkephalinase. In rodents, low doses of these mixed inhibitors exert typical actions of ACE inhibitors--i.e., prevention of angiotensin I-induced hypertension--as well as of enkephalinase inhibitors--i.e., protection from 125I-ANF degradation or enhancement of diuresis and natriuresis following acute extracellular volume expansion. In view of the known counterbalanced physiological actions of the two hormonal peptides, whose metabolism is controlled by ACE and enkephalinase, mixed inhibitors of the two peptidases show promise for the treatment of various cardiovascular and salt-retention disorders. PMID:1851998

  14. 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

  15. The angiotensin-converting enzyme inhibitor captopril inhibits poly(ADP-ribose)polymerase activation and exerts beneficial effects in an ovine model of burn and smoke injury

    PubMed Central

    Asmussen, Sven; Bartha, Eva; Olah, Gabor; Sbrana, Elena; Rehberg, Sebastian W.; Yamamoto, Yusuke; Enkhbaatar, Perenlei; Hawkins, Hal K.; Ito, Hiroshi; Cox, Robert A.; Traber, Lillian D.; Traber, Daniel L.; Szabo, Csaba

    2011-01-01

    We investigated the effect of the angiotensin converting enzyme (ACE) inhibitor captopril in a clinically relevant ovine model of smoke and burn injury, with special reference to oxidative stress, activation of poly(ADP-ribose) polymerase in the lung and in circulating leukocytes. Female, adult sheep (28–40 kg) were divided into 3 groups. After tracheostomy and under deep anesthesia both vehicle-control (n=5) and captopril (20 mg/kg/d, iv., starting 0.5 hour before the injury) treated (n=5) groups were subjected to 2×20%, third degree burn injury and were insufflated with 48 breaths of cotton smoke. A sham group not receiving burn/smoke was also studied (n=5). Animals were mechanically ventilated and fluid resuscitated for 24 h in the awake state. Burn and smoke injury resulted in an upregulation of ACE in the lung, evidenced by immunohistochemical determination and Western blotting. Burn and smoke injury resulted in pulmonary dysfunction, as well as systemic hemodynamic alterations. Captopril treatment of burn and smoke animals improved PaO2/FiO2 ratio and pulmonary shunt fraction and reduced the degree of lung edema. There was a marked increase in PAR levels in circulating leukocytes after burn/smoke injury, which was significantly decreased by captopril. The pulmonary level of ACE and the elevated pulmonary levels of TGF-β in response to burn and smoke injury were significantly decreased by captopril treatment. Our results suggest that the ACE inhibitor captopril exerts beneficial effects on the pulmonary function in burn/smoke injury. The effects of the ACE inhibitor may be related to the prevention of ROS-induced PARP over-activation. ACE inhibition may also exert additional beneficial effects by inhibiting the expression of the pro-fibrotic mediator TGF-β. PMID:21701415

  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.

  17. Inhibitors of the peptidoglycan biosynthesis enzymes MurA-F.

    PubMed

    Hrast, Martina; Sosič, Izidor; Sink, Roman; Gobec, Stanislav

    2014-08-01

    The widespread emergence of resistant bacterial strains is becoming a serious threat to public health. This thus signifies the need for the development of new antibacterial agents with novel mechanisms of action. Continuous efforts in the design of novel antibacterials remain one of the biggest challenges in drug development. In this respect, the Mur enzymes, MurA-F, that are involved in the formation of UDP-N-acetylmuramyl-pentapeptide can be genuinely considered as promising antibacterial targets. This review provides an in-depth insight into the recent developments in the field of inhibitors of the MurA-F enzymes. Special attention is also given to compounds that act as multiple inhibitors of two, three or more of the Mur enzymes. Moreover, the reasons for the lack of preclinically successful inhibitors and the challenges to overcome these hurdles in the next years are also debated.

  18. Inhibitors of nucleotidyltransferase superfamily enzymes suppress herpes simplex virus replication.

    PubMed

    Tavis, John E; Wang, Hong; Tollefson, Ann E; Ying, Baoling; Korom, Maria; Cheng, Xiaohong; Cao, Feng; Davis, Katie L; Wold, William S M; Morrison, Lynda A

    2014-12-01

    Herpesviruses are large double-stranded DNA viruses that cause serious human diseases. Herpesvirus DNA replication depends on multiple processes typically catalyzed by nucleotidyltransferase superfamily (NTS) enzymes. Therefore, we investigated whether inhibitors of NTS enzymes would suppress replication of herpes simplex virus 1 (HSV-1) and HSV-2. Eight of 42 NTS inhibitors suppressed HSV-1 and/or HSV-2 replication by >10-fold at 5 μM, with suppression at 50 μM reaching ∼1 million-fold. Five compounds in two chemical families inhibited HSV replication in Vero and human foreskin fibroblast cells as well as the approved drug acyclovir did. The compounds had 50% effective concentration values as low as 0.22 μM with negligible cytotoxicity in the assays employed. The inhibitors suppressed accumulation of viral genomes and infectious particles and blocked events in the viral replication cycle before and during viral DNA replication. Acyclovir-resistant mutants of HSV-1 and HSV-2 remained highly sensitive to the NTS inhibitors. Five of six NTS inhibitors of the HSVs also blocked replication of another herpesvirus pathogen, human cytomegalovirus. Therefore, NTS enzyme inhibitors are promising candidates for new herpesvirus treatments that may have broad efficacy against members of the herpesvirus family.

  19. 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

  20. 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

  1. 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

  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. 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.

  4. Effect of angiotensin-converting enzyme (ACE) gene polymorphism on progression of renal disease and the influence of ACE inhibition in IDDM patients: findings from the EUCLID Randomized Controlled Trial. EURODIAB Controlled Trial of Lisinopril in IDDM.

    PubMed

    Penno, G; Chaturvedi, N; Talmud, P J; Cotroneo, P; Manto, A; Nannipieri, M; Luong, L A; Fuller, J H

    1998-09-01

    We examined whether the ACE gene insertion/deletion (I/D) polymorphism modulates renal disease progression in IDDM and how ACE inhibitors influence this relationship. The EURODIAB Controlled Trial of Lisinopril in IDDM is a multicenter randomized placebo-controlled trial in 530 nonhypertensive, mainly normoalbuminuric IDDM patients aged 20-59 years. Albumin excretion rate (AER) was measured every 6 months for 2 years. Genotype distribution was 15% II, 58% ID, and 27% DD. Between genotypes, there were no differences in baseline characteristics or in changes in blood pressure and glycemic control throughout the trial. There was a significant interaction between the II and DD genotype groups and treatment on change in AER (P = 0.05). Patients with the II genotype showed the fastest rate of AER progression on placebo but had an enhanced response to lisinopril. AER at 2 years (adjusted for baseline AER) was 51.3% lower on lisinopril than placebo in the II genotype patients (95% CI, 15.7 to 71.8; P = 0.01), 14.8% in the ID group (-7.8 to 32.7; P = 0.2), and 7.7% in the DD group (-36.6 to 37.6; P = 0.7). Absolute differences in AER between placebo and lisinopril at 2 years were 8.1, 1.7, and 0.8 microg/min in the II, ID, and DD groups, respectively. The significant beneficial effect of lisinopril on AER in the II group persisted when adjusted for center, blood pressure, and glycemic control, and also for diastolic blood pressure at 1 month into the study. Progression from normoalbuminuria to microalbuminuria (lisinopril versus placebo) was 0.27 (0.03-2.26; P = 0.2) in the II group, and 1.30 (0.33-5.17; P = 0.7) in the DD group (P = 0.6 for interaction). Knowledge of ACE genotype may be of value in determining the likely impact of ACE inhibitor treatment.

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

    PubMed

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

    2015-07-01

    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

  6. 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.

  7. The appropriate dose of angiotensin‐converting‐enzyme inhibitors or angiotensin receptor blockers in patients with dilated cardiomyopathy. The higher, the better?

    PubMed Central

    Konishi, Masaaki; von Haehling, Stephan

    2015-01-01

    Abstract Heart failure is a major public issue, and dilated cardiomyopathy (DCM) is one of the common etiologies of heart failure. DCM is generally progressive, and some patients with DCM need heart transplant despite optimal medical and mechanical therapy. Current guidelines recommend inhibitors of renin–angiotensin–aldosterone system, namely angiotensin‐converting‐enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB), and mineralocorticoid receptor antagonist as well as beta‐blockers for the medical treatment of heart failure with reduced ejection fraction, including DCM. Furthermore, because they have beneficial effects on the outcome of heart failure in a dose‐related fashion, they should be titrated to the target dose. In clinical practice, the underuse and under‐dose of these agents matter; however, the efficacy and safety of supramaximal dose of ACE inhibitor or ARB have never been investigated in the patients with DCM. In this issue of ESC Heart Failure, it is demonstrated that benazepril or valsartan at supramaximal dose improved left ventricular function and reduced cardiovascular events compared with each drug at low dose, respectively. In this editorial, the current evidence concerning the use of ACE inhibitor or ARB in patients with HF and future prospective will be discussed.

  8. 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

  9. The implications of angiotensin-converting enzymes and their modulators in neurodegenerative disorders: current and future perspectives.

    PubMed

    Kaur, Parneet; Muthuraman, Arunachalam; Kaur, Manjinder

    2015-04-15

    Angiotensin converting enzyme (ACE) is a dipeptidyl peptidase transmembrane bound enzyme. Generally, ACE inhibitors are used for the cardiovascular disorders. ACE inhibitors are primary agents for the management of hypertension, so these cannot be avoided for further use. The present Review focuses on the implications of angiotensin converting enzyme inhibitors in neurodegenerative disorders such as dementia, Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, stroke, and diabetic neuropathy. ACE inhibitors such as ramipril, captopril, perindopril, quinapril, lisinopril, enalapril, and trandolapril have been documented to ameliorate the above neurodegenerative disorders. Neurodegeneration occurs not only by angiotensin II, but also by other endogenous factors, such as the formation of free radicals, amyloid beta, immune reactions, and activation of calcium dependent enzymes. ACE inhibitors interact with the above cellular mechanisms. Thus, these may act as a promising factor for future medicine for neurological disorders beyond the cardiovascular actions. Central acting ACE inhibitors can be useful in the future for the management of neuropathic pain due to following actions: (i) ACE-2 converts angiotensinogen to angiotensin(1-7) (hepatapeptide) which produces neuroprotective action; (ii) ACE inhibitors downregulate kinin B1 receptors in the peripheral nervous system which is responsible for neuropathic pain. However, more extensive research is required in the field of neuropathic pain for the utilization of ACE inhibitors in human.

  10. Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Hypertensive Effect of Protein Hydrolysate from Actinopyga lecanora (Sea Cucumber) in Rats

    PubMed Central

    Sadegh Vishkaei, Mahdokht; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

    2016-01-01

    Food protein hydrolysates are known to exhibit angiotensin converting enzyme (ACE) inhibitory properties and can be used as a novel functional food for prevention of hypertension. This study evaluated the ACE inhibitory potentials of Actinopyga lecanora proteolysate (ALP) in vivo. The pre-fed rats with ALP at various doses (200, 400, 800 mg/kg body weight) exhibited a significant (p ≤ 0.05) suppression effect after inducing hypertension. To determine the optimum effective dose that will produce maximal reduction in blood pressure, ALP at three doses was fed to the rats after inducing hypertension. The results showed that the 800 mg/kg body weight dose significantly reduced blood pressure without noticeable negative physiological effect. In addition, there were no observable changes in the rats’ heart rate after oral administration of the ALP. It was concluded that Actinopyga lecanora proteolysate could potentially be used for the development of functional foods and nutraceuticals for prevention and treatment of hypertension. PMID:27706040

  11. Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.

    PubMed

    Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

    2011-04-01

    Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion.

  12. 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

  13. An inhibitor of a deubiquitinating enzyme regulates ubiquitin homeostasis.

    PubMed

    Kimura, Yoko; Yashiroda, Hideki; Kudo, Tai; Koitabashi, Sumiko; Murata, Shigeo; Kakizuka, Akira; Tanaka, Keiji

    2009-05-01

    The dynamic and reversible process of ubiquitin modification controls various cellular activities. Ubiquitin exists as monomers, unanchored chains, or protein-conjugated forms, but the regulation of these interconversions remains largely unknown. Here, we identified a protein designated Rfu1 (regulator of free ubiquitin chains 1), which regulates intracellular concentrations of monomeric ubiquitins and free ubiquitin chains in Saccharomyces cerevisiae. Rfu1 functions as an inhibitor of Doa4, a deubiquitinating enzyme. Rapid loss of free ubiquitin chains upon heat shock, a condition in which more proteins require ubiquitin conjugation, was mediated in part by Doa4 and Rfu1. Thus, regulation of ubiquitin homeostasis is controlled by a balance between a deubiquitinating enzyme and its inhibitor. We propose that free ubiquitin chains function as a ubiquitin reservoir that allows maintenance of monomeric ubiquitins at adequate levels under normal conditions and rapid supply for substrate conjugation under stress conditions. PMID:19410548

  14. 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

  15. Single-molecule enzyme kinetics in the presence of inhibitors.

    PubMed

    Saha, Soma; Sinha, Antara; Dua, Arti

    2012-07-28

    Recent studies in single-molecule enzyme kinetics reveal that the turnover statistics of a single enzyme is governed by the waiting time distribution that decays as mono-exponential at low substrate concentration and multi-exponential at high substrate concentration. The multi-exponentiality arises due to protein conformational fluctuations, which act on the time scale longer than or comparable to the catalytic reaction step, thereby inducing temporal fluctuations in the catalytic rate resulting in dynamic disorder. In this work, we study the turnover statistics of a single enzyme in the presence of inhibitors to show that the multi-exponentiality in the waiting time distribution can arise even when protein conformational fluctuations do not influence the catalytic rate. From the Michaelis-Menten mechanism of inhibited enzymes, we derive exact expressions for the waiting time distribution for competitive, uncompetitive, and mixed inhibitions to quantitatively show that the presence of inhibitors can induce dynamic disorder in all three modes of inhibitions resulting in temporal fluctuations in the reaction rate. In the presence of inhibitors, dynamic disorder arises due to transitions between active and inhibited states of enzymes, which occur on time scale longer than or comparable to the catalytic step. In this limit, the randomness parameter (dimensionless variance) is greater than unity indicating the presence of dynamic disorder in all three modes of inhibitions. In the opposite limit, when the time scale of the catalytic step is longer than the time scale of transitions between active and inhibited enzymatic states, the randomness parameter is unity, implying no dynamic disorder in the reaction pathway.

  16. Simulated digestion of proanthocyanidins in grape skin and seed extracts and the effects of digestion on the angiotensin I-converting enzyme (ACE) inhibitory activity.

    PubMed

    Fernández, Katherina; Labra, Javiera

    2013-08-15

    This study investigated the effect of in vitro gastrointestinal digestion on the stability and composition of flavan-3-ols from red grape skin and seed extracts (raw and purified, which are high in proanthocyanidins (PAs)). In addition, the effects of digestion on the angiotensin I-converting enzyme (ACE) inhibitory activities of these extracts were evaluated. The extracts were digested with a mixture of pepsin-HCl for 2 h, followed by a 2 h incubation with pancreatin and bile salts including a cellulose dialysis tubing (molecular weight cut-off 12 kDa) at 37°C with shaking in the dark and under N2. Under gastric conditions, the mean degree of polymerisation (mDP) of seed extracts, raw (mDP≈6, p<0.05), and purified (mDP≈10, p<0.05) was stable. The mDP of the raw skin extracts increased from 19 to 25 towards the end of the digestion. The PAs were significantly degraded (up to 80%) during the pancreatic digestion, yielding low-molecular-weight compounds that diffused into the serum-available fraction (mDP≈2). The overall mass transfer coefficient (K) of the seed extracts was 10(-7) m(2)/s. After simulated gastrointestinal digestion, over 80% of ACE inhibition by raw seed and skin extracts was preserved. However, the purified seed and skin extracts lost their ability to inhibit ACE after intestinal digestion.

  17. 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

  18. Bioguided isolation of angiotensin-converting enzyme inhibitors from the seeds of Plantago asiatica L.

    PubMed

    Geng, Fang; Yang, Li; Chou, Guixin; Wang, Zhengtao

    2010-07-01

    Ethanolic extract of the seeds of Plantago asiatica L. showed significant inhibitory activity of angiotensin-converting enzyme (ACE) determined by monitoring the transformation from a substrate hippuryl-histidyl-leucine (HHL) to the product hippuric acid (HA) in vitro using an UPLC-MS method. The bioguided fractionation of the extract resulted in the isolation of four ACE inhibitory active phenylpropanoid glycosides acteoside, isoacteoside, plantainoside D, and plantamajoside with IC(50) values of 2.69 mM, 2.46 mM, 2.17 mM, and 2.47 mM, respectively. Their structures were elucidated through the analysis of NMR, UV, IR and MS data. Our study is the first demonstration that Plantago asiatica L. and its major constituents have ACE inhibitory activity in vitro. It is assumed that the identified compounds contribute to the angiotensin-converting enzyme-inhibitory activity of the extract.

  19. [The specific enzyme inhibitors for potential therapeutic use].

    PubMed

    Bretner, Maria

    2015-01-01

    Therapy for hepatitis C virus (HCV) initially consisted on administering ribavirin - having a broad spectrum of action - and pegylated interferon, and was only effective in 40-50% of patients. Appropriate was to find effective inhibitors of viral replication e.g. by inhibition of a viral enzyme, NTPase/helicase required in the process of translation and RNA replication of the HCV. We developed methods of synthesis of many compounds belonging to different groups - derivatives of nucleosides, benzotriazole, benzimidazole, tropolone and epirubicine. Some of the derivatives inhibit HCV helicase activity at low concentrations and reduces replication of the viral RNA in subgenomic replicon system. In the process of HCV replication casein kinase CK2 plays an important role. It regulates the level of phosphorylation of HCV protein NS5A, which affects the production of infectious virions of HCV. Effective and selective inhibitors of kinase CK2 could be of use in the treatment of HCV in combination with other drugs. CK2 kinase phosphorylates approximately 300 proteins that affect the growth, differentiation, proliferation or apoptosis. Elevated CK2 kinase activity has been observed in several types of cancer and other diseases, therefore, inhibitors of this enzyme are potential therapeutic importance, particularly for anti-cancer treatment. Research carried out in collaboration with prof. Shugar led to the synthesis of one of the most selective inhibitors of this enzyme which is 4,5,6,7-tetrabromo-1H-benzotriazole, used for the study of the role of kinase CK2 in a number of metabolic processes in tumor cells.

  20. 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

  1. 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

  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 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

  3. 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

  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. Angiotensin-Converting Enzyme 2 (ACE2) Activator Diminazene Aceturate Ameliorates Endotoxin-Induced Uveitis in Mice

    PubMed Central

    Qiu, Yiguo; Shil, Pollob Kumar; Zhu, Ping; Yang, Hongxia; Verma, Amrisha; Lei, Bo; Li, Qiuhong

    2014-01-01

    Purpose. Uveitis is a common cause of vision loss. The renin angiotensin system (RAS), which plays a vital role in cardiovascular system, is a potent mediator of inflammation and has been implicated in the pathogenesis of uveitis. A newly identified axis of RAS, ACE2/Ang-(1-7)/Mas, has emerged as a novel target because it counteracts the deleterious effect of angiotensin II. The purpose of this study was to investigate the effect of endogenous ACE2 activation in preventing endotoxin-induced uveitis (EIU) in mice. Methods. ACE2 activator diminazene aceturate (DIZE) was administered both systemically and locally. For systemic administration, female BALB/c mice received intraperitoneal injection of DIZE (60 mg/kg body weight [BW]) for 2 days prior to lipopolysaccharide (LPS) intravitreal injection (125 ng) to induce uveitis. For local study, DIZE was given at 0.5, 0.1, and 0 mg/mL as eyedrops six times per day for 2 days before LPS injection. The anterior segment of the mice was examined at 12, 24, 48, and 72 hours after LPS injection, and clinical scores were determined at the same time. Morphology and infiltrating inflammatory cells were evaluated after 24 hours. The mRNA levels of inflammatory cytokines were analyzed by real-time RT-PCR. ACE2 activity was determined using a self-quenching fluorescent substrate. Results. At 24 hours, the clinical score of mice treated with DIZE systemically was significantly lower (mean, ∼1.75) than the saline vehicle group (mean, ∼4) (P < 0.001). Histological examination showed 63.4% reduction of infiltrating inflammatory cells in the anterior segment and 57.4% reduction in the posterior segment of DIZE-treated eyes. The number of CD45+ inflammatory cells in the vitreous of the DIZE-treated group was decreased (43.3%) compared to the vehicle group (P < 0.01). The mRNA levels of inflammatory cytokines were significantly reduced in the DIZE-treated group (P < 0.01, P < 0.001). The number of infiltrating inflammatory cells was

  6. 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

  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. 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

  9. Boronic acid-based enzyme inhibitors: a review of recent progress.

    PubMed

    Fu, H; Fang, H; Sun, Jie; Wang, H; Liu, A; Sun, J; Wu, Z

    2014-01-01

    Since Bortezomib was approved by US FDA as the first drug to treat multiple myeloma, various boronic acid compounds have been developed as enzyme inhibitors. This paper reviewed the progress of boronic acid-based inhibitors against enzymes including proteasome, serine protease, HDACs and other enzymes in the past decade.

  10. 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…

  11. 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

  12. 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)

  13. 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

  14. [Arteriosclerosis obliterans. Treatment with angiotensin-converting enzyme inhibitors].

    PubMed

    Orea, A; Valdés, R; Niebla, L; Rivas, R; Camacho, B

    1990-01-01

    We compare the effects of two of the main angiotensin convertase enzyme inhibitors, captopril and enalapril, aiming to evaluate their effects in the arterial circulation performance, micro-circulation, and changes in regional blood flow, assuming their property of lowering the angiotensin II blood levels, a very strong peripheral vasoconstrictor. We studied 22 patients: all of them with hypertension and/or skin ulcerations, dropping out those who had venous. They were evaluated periodically, clinically and with photoelectric plethysmography of lower extremities. To interpret the traces we designed an ideogram which gathered the plethysmographic behavior before and after the treatment. Nearly 80% showed considerable improvement in pain, functional capacity and plethysmographic traces patterns. healing of the ulcerations was achieved in all case. We propose some hypothesis to explain the good effect that we have observed.

  15. Organometallics as Structural Scaffolds for Enzyme Inhibitor Design

    NASA Astrophysics Data System (ADS)

    Mulcahy, Seann P.; Meggers, Eric

    Substitutionally inert metal-containing compounds provide new opportunities as structurally diverse and unique scaffolds for the design of protein binders. This review cites progress in this area by highlighting the use of metal complexes, including truly organometallic compounds, as inhibitors for enzymes of biological interest, such as esterases, proteases, and protein kinases. A common theme in all discussed examples is the use of the metal center as an anchor for the 3D display of organic ligands. While the metal center does not engage in any direct contacts to protein residues, it is the structural orientation of the ligands into previously unaccessible architectures that make metal complexes emerging candidates for bioactive agents with unique properties.

  16. 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.

  17. Angiotensin converting enzymes from human urine of mild hypertensive untreated patients resemble the N-terminal fragment of human angiotensin I-converting enzyme.

    PubMed

    Casarini, D E; Plavinik, F L; Zanella, M T; Marson, O; Krieger, J E; Hirata, I Y; Stella, R C

    2001-01-01

    Angiotensin I-converting enzyme (ACE) activity was analyzed in human urine collected from mild hypertensive untreated patients. DEAE-cellulose chromatography using linear gradient elution revealed two forms of angiotensin I-converting enzyme, eluted in the conductivity of 0.75 and 1.25 mS. The fractions of each conductivity were pooled and submitted to direct gel filtration in an AcA-34 column, and the apparent molecular weights of urinary ACEs were estimated as 90 kDa (for ACE eluted in 0.75 mS) and 65 kDa (for ACE eluted in 1.25 mS). Both enzymes have a K(i) of the order of 10(-7) M for the specific inhibitors studied, and are able to hydrolyze luteinizing hormone-releasing hormone and N-acetyl-Ser-Asp-Lys-Pro as described for N-domain ACE. By Western blot analysis, both peaks were recognized by ACE-specific antibody Y4, confirming the molecular weight already described. A plate precipitation assay using monoclonal antibodies to the N-domain of ACE showed that both forms of ACE binds with all monoclonal antibodies to the active N-domain ACE, suggesting that these forms of human urine ACEs resemble the N-fragment of ACE. The HP2 ACE (65 kDa) is similar to low molecular weight (LMW) ACE from normal subjects, and the HP2 ACE (90 kDa) is different from high molecular weight (190 kDa) and LMW (65 kDa) normal ACEs. The 90 kDa ACE could have an important role in development of hypertension. It will be fundamental to elucidate the molecular mechanism responsible for the genesis of this isoform.

  18. 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

  19. 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.

  20. The angiotensin converting enzyme inhibitor, captopril, prevents the hyperactivity and impulsivity of neurokinin-1 receptor gene 'knockout' mice: sex differences and implications for the treatment of attention deficit hyperactivity disorder.

    PubMed

    Porter, Ashley J; Pillidge, Katharine; Grabowska, Ewelina M; Stanford, S Clare

    2015-04-01

    Mice lacking functional neurokinin-1 receptors (NK1R-/-) display behavioural abnormalities resembling attention deficit hyperactivity disorder (ADHD): locomotor hyperactivity, impulsivity and inattentiveness. The preferred ligand for NK1R, substance P, is metabolised by angiotensin converting enzyme (ACE), which forms part of the brain renin angiotensin system (BRAS). In view of evidence that the BRAS modulates locomotor activity and cognitive performance, we tested the effects of drugs that target the BRAS on these behaviours in NK1R-/- and wildtype mice. We first tested the effects of the ACE inhibitor, captopril, on locomotor activity. Because there are well-established sex differences in both ADHD and ACE activity, we compared the effects of captopril in both male and female mice. Locomotor hyperactivity was evident in male NK1R-/- mice, only, and this was abolished by treatment with captopril. By contrast, male wildtypes and females of both genotypes were unaffected by ACE inhibition. We then investigated the effects of angiotensin AT1 (losartan) and AT2 (PD 123319) receptor antagonists on the locomotor activity of male NK1R-/- and wildtype mice. Both antagonists increased the locomotor activity of NK1R-/- mice, but neither affected the wildtypes. Finally, we tested the effects of captopril on the performance of male NK1R-/- and wildtype mice in the 5-choice serial reaction-time task (5-CSRTT) and found that ACE inhibition prevented the impulsivity of NK1R-/- mice. These results indicate that certain behaviours, disrupted in ADHD, are influenced by an interaction between the BRAS and NK1R, and suggest that ACE inhibitors could provide a novel treatment for this disorder.

  1. 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

  2. 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

  3. 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.

  4. Simplified assays of lipolysis enzymes for drug discovery and specificity assessment of known inhibitors.

    PubMed

    Iglesias, Jose; Lamontagne, Julien; Erb, Heidi; Gezzar, Sari; Zhao, Shangang; Joly, Erik; Truong, Vouy Linh; Skorey, Kathryn; Crane, Sheldon; Madiraju, S R Murthy; Prentki, Marc

    2016-01-01

    Lipids are used as cellular building blocks and condensed energy stores and also act as signaling molecules. The glycerolipid/ fatty acid cycle, encompassing lipolysis and lipogenesis, generates many lipid signals. Reliable procedures are not available for measuring activities of several lipolytic enzymes for the purposes of drug screening, and this resulted in questionable selectivity of various known lipase inhibitors. We now describe simple assays for lipolytic enzymes, including adipose triglyceride lipase (ATGL), hormone sensitive lipase (HSL), sn-1-diacylglycerol lipase (DAGL), monoacylglycerol lipase, α/β-hydrolase domain 6, and carboxylesterase 1 (CES1) using recombinant human and mouse enzymes either in cell extracts or using purified enzymes. We observed that many of the reported inhibitors lack specificity. Thus, Cay10499 (HSL inhibitor) and RHC20867 (DAGL inhibitor) also inhibit other lipases. Marked differences in the inhibitor sensitivities of human ATGL and HSL compared with the corresponding mouse enzymes was noticed. Thus, ATGListatin inhibited mouse ATGL but not human ATGL, and the HSL inhibitors WWL11 and Compound 13f were effective against mouse enzyme but much less potent against human enzyme. Many of these lipase inhibitors also inhibited human CES1. Results describe reliable assays for measuring lipase activities that are amenable for drug screening and also caution about the specificity of the many earlier described lipase inhibitors.

  5. 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.

  6. Dual inhibition of angiotensin-converting enzyme and neutral endopeptidase by the orally active inhibitor mixanpril: a potential therapeutic approach in hypertension.

    PubMed Central

    Fournié-Zaluski, M C; Gonzalez, W; Turcaud, S; Pham, I; Roques, B P; Michel, J B

    1994-01-01

    In the treatment of cardiovascular disease, it could be of therapeutic interest to associate the hypotensive effects due to the inhibition of angiotensin II formation with the diuretic and natriuretic responses induced by the protection of the endogenous atrial natriuretic peptide (ANP). Investigation of this hypothesis requires an orally active compound able to simultaneously inhibit angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP), which is involved in renal ANP metabolism. Such compounds have been rationally designed by taking into account the structural characteristics of the active site of both peptidases. Among them, RB 105, N-[(2S,3R)-2-mercaptomethyl-1-oxo-3-phenylbutyl]-(S)-alanine, inhibited NEP and ACE with Ki values of 1.7 +/- 0.3 nM and 4.2 +/- 0.5 nM, respectively. Intravenous infusion of RB 105 in conscious spontaneously hypertensive rats prevented the pressor response to exogenous angiotensin I and potentiated the natriuretic response to ANP. Infusion of RB 105, at 2.5, 5, 10, 25, and 50 mg/kg per hr decreased blood pressure dose-dependently in conscious catheterized spontaneously hypertensive rats and increased diuresis and natriuresis. Infusion of RB 105 as a bolus of 25 mg/kg followed by 25 mg/kg per hr similarly decreased blood pressure and increased natriuresis in three different models of hypertension (renovascular, deoxycorticosterone acetate-salt, and spontaneously hypertensive rats). Mixanpril, a lipophilic prodrug of RB 105 (ED50 values when given orally to mice, 0.7 mg/kg for NEP; 7 mg/kg for ACE), elicited dose-dependent hypotensive effects of long duration in spontaneously hypertensive rats after oral administration [-37 mmHg for 50 mg/kg twice a day (1 mmHg = 133 Pa) and is therefore the first dual NEP/ACE inhibitor potentially useful for clinical investigations. Images PMID:8171037

  7. Effects of angiotensin-converting enzyme inhibitor therapy on levels of inflammatory markers in response to exercise-induced stress: studies in the metabolic syndrome.

    PubMed

    Vaccari, Christopher S; Rahman, Syed T; Khan, Qamar A; Cheema, Faiz A; Khan, Bobby V

    2008-01-01

    The authors sought to determine whether the angiotensin-converting enzyme (ACE) inhibitor perindopril has beneficial effects on vascular markers of inflammation in patients with the metabolic syndrome when exposed to exercise-induced stress. Thirty patients with the metabolic syndrome were randomized to perindopril (4 mg/d) or placebo in a double-blind fashion for 4 weeks. Prior to treatment, the patients underwent an exercise treadmill study to a level of 8 metabolic equivalents. Circulating monocyte CD11b expression, levels of soluble interleukin 6 (sIL-6), and levels of vascular cell adhesion molecule-1 (VCAM-1) were measured. After the treatment period, exercise treadmill study and measurement of markers were repeated. Treatment with perindopril reduced sIL-6 levels at pre-exercise by 22% and at 1 and 30 minutes by 30% and 33%, respectively (P<.005). Levels of soluble VCAM-1 in perindopril-treated patients were reduced at pre-exercise by 25% and at 1 and 30 minutes by 31% and 37%, respectively. Treatment with perindopril reduced monocyte CD11b expression by 25%. In response to exercise-induced physical stress, the addition of an ACE inhibitor differentially regulates markers of inflammation, thereby providing potential vascular protection in the metabolic syndrome.

  8. Atrial fibrillation after radiofrequency ablation of atrial flutter: preventive effect of angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, and diuretics

    PubMed Central

    Anné, W; Willems, R; Van der Merwe, N; Van de Werf, F; Ector, H; Heidbüchel, H

    2004-01-01

    Objectives: To determine risk factors for the development of atrial fibrillation (AF) after atrial flutter (AFL) ablation; and to study the relation between AF development and periprocedural drug use. Methods: AFL ablation was performed in 196 patients. The relation between AF occurrence and clinical, echocardiographic, and procedural factors and periprocedural drug use was analysed retrospectively by a Cox proportional hazard method. Results: After a median follow up of 2.2 years, 114 patients (58%) developed at least one AF episode. Factors associated with AF development were the presence of preprocedural AF, a history of cardioversion, and the number of antiarrhythmic drugs used before the procedure. Use of angiotensin converting enzyme (ACE) inhibitors/angiotensin II receptor blockers and diuretics was significantly associated by univariate and multivariate analyses with less development of AF. Conclusions: A high proportion of patients develop AF after AFL ablation. The incidence of AF is related to pre-ablation AF and its persistence. ACE inhibitors/angiotensin II receptor blockers and diuretics seem to protect against AF. PMID:15310691

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Application of capillary enzyme micro-reactor in enzyme activity and inhibitors studies of glucose-6-phosphate dehydrogenase.

    PubMed

    Camara, Mohamed Amara; Tian, Miaomiao; Guo, Liping; Yang, Li

    2015-05-15

    In this study, we present an on-line measurement of enzyme activity and inhibition of Glucose-6-phosphate dehydrogenase (G6PDH) enzyme using capillary electrophoresis based immobilized enzyme micro-reactor (CE-based IMER). The IMER was prepared using a two-step protocol based on electrostatic assembly. The micro-reactor exhibited good stability and reproducibility for on-line assay of G6PDH enzyme. Both the activity as well as the inhibition of the G6PDH enzyme by six inhibitors, including three metals (Cu(2+), Pb(2+), Cd(2+)), vancomycin, urea and KMnO4, were investigated using on-line assay of the CE-based IMERs. The enzyme activity and inhibition kinetic constants were measured using the IMERs which were found to be consistent with those using traditional off-line enzyme assays. The kinetic mechanism of each inhibitor was also determined. The present study demonstrates the feasibility of using CE-based IMERs for rapid and efficient on-line assay of G6PDH, an important enzyme in the pentosephosphate pathway of human metabolism.

  1. 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

  2. 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

  3. Selective imidazoline agonist moxonidine plus the ACE inhibitor ramipril in hypertensive patients with impaired insulin sensitivity: partners in a successful MARRIAGE?

    PubMed

    Rayner, Brian

    2004-03-01

    Hypertension in combination with clinically overt diabetes mellitus is recognized as a particularly powerful combination of risk factors that greatly increases cardiovascular vulnerability. There is also evidence that presumed pre-diabetic conditions such as insulin resistance, hyperinsulinaemia and compensatory hyperglycaemia may amplify overall cardiovascular risk in patients with hypertension, especially when encountered as part of the condition known as metabolic syndrome X (Reaven's syndrome). The long-term benefits of antihypertensive therapy may be compromised if these drugs exert adverse effects on metabolic parameters such as insulin sensitivity, or if they promote a transition from pre-diabetes to overt diabetes. Class differences in the effects of antihypertensives on metabolic indices may therefore be an important consideration when choosing treatment for patients who exhibit these characteristics. Experience from clinical trials suggests that drugs that target the renin-angiotensin system may have metabolic advantages over drugs such as beta-blockers and diuretics, but this conclusion has not been proved definitively. Moxonidine, which selectively targets imidazoline type-1 receptors in the sympathetic vasomotor centres of the rostral-ventrolateral medulla, is an effective antihypertensive and has been reported to exert favourable metabolic effects in preclinical and clinical studies. The MARRIAGE study (Moxonidine And Ramipril Regarding Insulin And Glucose Evaluation) will extend these preliminary observations by comparing the effects of moxonidine and the ACE inhibitor ramipril--and the combination of both drugs--on metabolic and haemodynamic parameters in patients with hypertension and impaired fasting glycaemia. A description is provided of the design and conduct of MARRIAGE.

  4. Development of inhibitors as research tools for carbohydrate-processing enzymes.

    PubMed

    Gloster, Tracey M

    2012-10-01

    Carbohydrates, which are present in all domains of life, play important roles in a host of cellular processes. These ubiquitous biomolecules form highly diverse and often complex glycan structures without the aid of a template. The carbohydrate structures are regulated solely by the location and specificity of the enzymes responsible for their synthesis and degradation. These enzymes, glycosyltransferases and glycoside hydrolases, need to be functionally well characterized in order to investigate the structure and function of glycans. The use of enzyme inhibitors, which target a particular enzyme, can significantly aid this understanding, and may also provide insights into therapeutic applications. The present article describes some of the approaches used to design and develop enzyme inhibitors as tools for investigating carbohydrate-processing enzymes.

  5. 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

  6. Enzyme inhibitor studies reveal complex control of methyl-D-erythritol 4-phosphate (MEP) pathway enzyme expression in Catharanthus roseus.

    PubMed

    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.

  7. Assessment of the angiotensin-I-converting enzyme (ACE-I) inhibitory and antioxidant activities of hydrolysates of bovine brisket sarcoplasmic proteins produced by papain and characterisation of associated bioactive peptidic fractions.

    PubMed

    Di Bernardini, Roberta; Mullen, Anne Maria; Bolton, Declan; Kerry, Joseph; O'Neill, Eileen; Hayes, Maria

    2012-01-01

    The main objective was to investigate the angiotensin-I-converting enzyme (ACE-I) inhibitory and antioxidant activities of sarcoplasmic proteins isolated from the brisket muscle (Pectoralis profundus) of 3 (Bos taurus) cattle and hydrolysed with papain for 24 h at 37°C. Sarcoplasmic protein hydrolysates were ultra-filtered using molecular weight cut off (MWCO) membranes and 10-kDa and 3-kDa filtrates were obtained. The total sarcoplasmic protein extracts and the 3-kDa filtrates were tested for angiotensin I-converting enzyme inhibitory (ACE-I) activities. The total hydrolysates, 10-kDa and 3-kDa filtrates were also tested for their associated antioxidant activities using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay, the ferric ion reducing antioxidant power (FRAP) assay and the Fe(2+) metal chelating ability assay. The peptidic content of the total hydrolysates, the 10-kDa and the 3-kDa filtrates were analysed using an ORBITRAP mass spectrometer, and mass spectral data obtained were analysed using TurboSEQUEST. Eleven peptides were characterised from the total hydrolysates, fifteen from the 10-kDa filtrate fractions, whilst nine peptides were characterised from the 3-kDa filtrate fractions. Similarities between the amino acid sequences of the peptides identified in this study and previously identified antioxidant and ACE-I inhibitory peptides detailed in the BIOPEP database were outlined. PMID:21880436

  8. 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

  9. Pseudoaldosteronism due to the concurrent use of two herbal medicines containing glycyrrhizin: interaction of glycyrrhizin with angiotensin-converting enzyme inhibitor.

    PubMed

    Iida, Rinako; Otsuka, Yasushi; Matsumoto, Kei; Kuriyama, Satoru; Hosoya, Tatsuo

    2006-06-01

    A 77-year-old man with a history of hypertension and hyperuricemia was admitted to our hospital complaining of limb weakness, persistent constipation, and worsening hypertension. He had been taking a Chinese herbal remedy for allergic rhinitis for the past 10 years, together with an angiotensin-converting enzyme inhibitor (ACE-I; enalapril, 20 mg daily). After the dosage of enalapril had been reduced to 10 mg daily about 1(1/2) years before the current admission, he had developed persistent constipation. Therefore, he had started taking another traditional Chinese herbal remedy, a laxative, for the constipation, about 4 months prior to this hospitalization. Laboratory data on admission demonstrated marked metabolic alkalosis with severe hypokalemia associated with urinary wasting of potassium and chloride. A diagnosis of pseudoaldosteronism was made based upon his past history of exposure to various traditional Chinese medicines containing glycyrrhizin. Discontinuation of the Chinese remedies and supplementation of potassium successfully normalized the electrolyte imbalance and relieved all symptoms within a short time. The present case describes the occurrence of pseudoaldosteronism induced by a patient taking two traditional Chinese herbs, both containing glycyrrhizin, resulting in an overdose of this causative chemical agent. The development of pseudoaldosteronism appeared to be of particular interest with regard to the interaction of the renin-angiotensin-aldosterone (RAA) system with glycyrrhizin, in which an ACE-I retarded the development of pseudoaldosteronism.

  10. Novel concept of enzyme selective nicotinamide adenine dinucleotide (NAD)-modified inhibitors based on enzyme taxonomy from the diphosphate conformation of NAD.

    PubMed

    Fujii, Mikio; Kitagawa, Yasuyuki; Iida, Shui; Kato, Keisuke; Ono, Machiko

    2015-11-15

    The dihedral angle θ of the diphosphate part of NAD(P) were investigated to distinguish the differences in the binding-conformation of NAD(P) to enzymes and to create an enzyme taxonomy. Furthermore, new inhibitors with fixed dihedral angles showed that enzymes could recognize the differences in the dihedral angle θ. We suggest the taxonomy and the dihedral angle θ are important values for chemists to consider when designing inhibitors and drugs that target enzymes.

  11. 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...

  12. Inhibitors of plant invertases do not affect the structurally related enzymes of fructan metabolism.

    PubMed

    Kusch, Ute; Harms, Karsten; Rausch, Thomas; Greiner, Steffen

    2009-01-01

    Plant fructan active enzymes (FAZYs), including the enzymes involved in inulin metabolism, namely sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99), fructan:fructan 1-fructosyltransferase (1-FFT; EC 2.4.1.100) and fructan 1-exohydrolase (1-FEH; EC 3.2.1.153), are evolutionarily related to acid invertases (AIs), that is, plant cell wall invertase (CWI) and vacuolar invertase (VI). Acid invertases are post-translationally controlled by proteinaceous inhibitors. Whether FAZYs are subject to similar controls is not known. To probe their possible interactions with invertase inhibitors, we transiently expressed chicory (Cichorium intybus) FAZYs, as well as several previously characterized invertase inhibitors from nonfructan species, and the C. intybus cell wall/vacuolar inhibitor of fructosidase (CiC/VIF), a putative invertase inhibitor of a fructan-accumulating plant, in leaves of Nicotiana benthamiana. Leaf extracts containing recombinant, enzymatically active FAZYs were used to explore the interaction with invertase inhibitors. Neither heterologous inhibitors nor CiC/VIF affected FAZY activities. CiC/VIF was confirmed as an AI inhibitor with a stronger effect on CWI than on VI. Its expression in planta was developmentally regulated (high in taproots, and undetectable in leaves and flowers). In agreement with its target specificities, CiC/VIF was associated with the cell wall. It is concluded that subtle structural differences between AIs and FAZYs result in pronounced selectivity of inhibitor action.

  13. General pharmacology of the non-sulfhydryl angiotensin converting enzyme inhibitor N-[8-amino-1(S)-carboxyoctyl]-L-alanyl-L-proline.

    PubMed

    Shirota, M; Hayashi, M; Kajiwara, Y; Kitabatake, K; Uruno, T; Kubota, K

    1993-11-01

    The effects of N-[8-amino-1(S)-carboxyoctyl]-L-alanyl-L-proline (AB-47, CAS 120008-53-9), an orally active angiotensin converting enzyme inhibitor, on the central nervous, respiratory and cardiovascular, autonomic systems, isolated smooth muscles and other functions were investigated in various experimental animals. AB-47 had no effect on central nervous, autonomic systems and isolated smooth muscles. AB-47 (10 and 30 micrograms/kg i.v.) significantly lowered femoral blood pressure without affecting respiration and heart rate in anesthetized rats. However, AB-47 had no effect on the contractile tension of mammalian isolated atrium and aorta. AB-47 had no effect on gastrointestinal transit in mice. Very slight injury of gastric mucosa was observed 4 h after the oral administration of AB-47 in rats but AB-47 did not damage the small intestinal mucosa. AB-47 had no effect on the contraction of rat phrenic nerve-diaphragm preparation induced by electrical stimulation. AB-47 did not affect the incidence of acetic acid-induces writhings. AB-47 potentiated carrageenan-induced hind paw edema in rats. The potentiation of edema may be due to an accumulation of bradykinin induced by the inhibition of angiotensin converting enzyme (ACE), because ACE is the identical enzyme with kinase II. The pretreatment of AB-47 for 7 days (1, 3, 10 mg/kg/d p.o.) inhibited the cardiac hypertrophy induced by isoproterenol (isoprenaline). This result suggests that the renin-angiotensin-aldosterone system directly or indirectly participates in the cardiac hypertrophy induced by isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8292059

  14. Fabrication of enzyme-immobilized halloysite nanotubes for affinity enrichment of lipase inhibitors from complex mixtures.

    PubMed

    Wang, Haibo; Zhao, Xiaoping; Wang, Shufang; Tao, Shan; Ai, Ni; Wang, Yi

    2015-05-01

    Lipase is the key enzyme for catalyzing triglyceride hydrolysis in vivo, and lipase inhibitors have been used in the management of obesity. We present the first report on the use of lipase-adsorbed halloysite nanotubes as an efficient medium for the selective enrichment of lipase inhibitors from natural products. A simple and rapid approach was proposed to fabricate lipase-adsorbed nanotubes through electrostatic interaction. Results showed that more than 85% lipase was adsorbed into nanotubes in 90 min, and approximately 80% of the catalytic activity was maintained compared with free lipase. The specificity and reproducibility of the proposed approach were validated by screening a known lipase inhibitor (i.e., orlistat) from a mixture that contains active and inactive compounds. Moreover, we applied this approach with high performance liquid chromatography-mass spectrometry technique to screen lipase inhibitors from the Magnoliae cortex extract, a medicinal plant used for treating obesity. Two novel biphenyl-type natural lipase inhibitors magnotriol A and magnaldehyde B were identified, and their IC50 values were determined as 213.03 and 96.96 μM, respectively. The ligand-enzyme interactions of magnaldehyde B were further investigated by molecular docking. Our findings proved that enzyme-adsorbed nanotube could be used as a feasible and selective affinity medium for the rapid screening of enzyme inhibitors from complex mixtures.

  15. Structure-Based Inhibitor Design for an Enzyme That Binds Different Steriods

    SciTech Connect

    Qiu,W.; Zhou, M.; Mazumdar, M.; Azzi, A.; Ghanmi, D.; Luu-The, V.; Labrie, F.; Lin, S.

    2007-01-01

    Human type 5 17{beta}-hydroxysteroid dehydrogenase plays a crucial role in local androgen formation in prostate tissue. Several chemicals were synthesized and tested for their ability to inhibit this enzyme, and a series of estradiol derivatives bearing a lactone on the D-ring were found to inhibit its activity efficiently. The crystal structure of the type 5 enzyme in complex with NADP and such a novel inhibitor, EM1404, was determined to a resolution of 1.30 {angstrom}. Significantly more hydrogen bonding and hydrophobic interactions were defined between EM1404 and the enzyme than in the substrate ternary complex. The lactone ring of EM1404 accounts for important interactions with the enzyme, whereas the amide group at the opposite end of the inhibitor contributes to the stability of three protein loops involved in the construction of the substrate binding site. EM1404 has a strong competitive inhibition, with a K{sub i} of 6.9 {+-} 1.4 nM, demonstrating 40 times higher affinity than that of the best inhibitor previously reported. This is observed despite the fact that the inhibitor occupies only part of the binding cavity. Attempts to soak the inhibitor into crystals of the binary complex with NADP were unsuccessful, yielding a structure with a polyethylene glycol fragment occupying the substrate binding site. The relative crystal packing is discussed. Combined studies of small molecule inhibitor synthesis, x-ray crystallography, enzyme inhibition, and molecular modeling make it possible to analyze the plasticity of the substrate binding site of the enzyme, which is essential for developing more potent and specific inhibitors for hormone-dependent cancer therapy.

  16. [Search for actinomycetes that produce inhibitors of proteolytic enzymes].

    PubMed

    Bezborodov, A M; Andreeva, N A; Chermenskiĭ, D N; Petrova, N T

    1977-01-01

    The inhibiting activity of filtrates of the cultural broth against trypsin and chymotrypsin was studied among 66 actinomycetes. The highest activity against trypsin was found, after selection, in the following cultures: Act. janthinus 118, Act. violatus 125, Act. violaceus confinus 2476, Act. violaceus vicinus 1074. The antitrypsin activity was detected in the cultural broth of Act. janthinus 118 during the first day of its growth, and reached maximum by the third day. The inhibiting substance in the cultural broth is thermo- and pH-stable, is not extracted with organic solvents, and remains in the bag during dialysis. Apparently, the inhibitor (s) of trypsin produced by Act. janthinus 118 differes from trypsin inhibitors of microbial origin and low molecular weight which have been described so far. PMID:882008

  17. The role of ACE2 in cardiovascular physiology.

    PubMed

    Oudit, Gavin Y; Crackower, Michael A; Backx, Peter H; Penninger, Josef M

    2003-04-01

    The renin-angiotensin system (RAS) is critically involved in cardiovascular and renal function and in disease conditions, and has been shown to be a far more complex system than initially thought. A recently discovered homologue of angiotensin-converting enzyme (ACE)--ACE2--appears to negatively regulate the RAS. ACE2 cleaves Ang I and Ang II into the inactive Ang 1-9 and Ang 1-7, respectively. ACE2 is highly expressed in kidney and heart and is especially confined to the endothelium. With quantitative trait locus (QTL) mapping, ACE2 was defined as a QTL on the X chromosome in rat models of hypertension. In these animal models, kidney ACE2 messenger RNA and protein expression were markedly reduced, making ACE2 a candidate gene for this QTL. Targeted disruption of ACE2 in mice failed to elicit hypertension, but resulted in severe impairment in myocardial contractility with increased angiotensin II levels. Genetic ablation of ACE in the ACE2 null mice rescued the cardiac phenotype. These genetic data show that ACE2 is an essential regulator of heart function in vivo. Basal renal morphology and function were not altered by the inactivation of ACE2. The novel role of ACE2 in hydrolyzing several other peptides-such as the apelin peptides, opioids, and kinin metabolites-raises the possibility that peptide systems other than angiotensin and its derivatives also may have an important role in regulating cardiovascular and renal function.

  18. Is there any difference between angiotensin converting enzyme inhibitors and angiotensin receptor blockers for heart failure?

    PubMed

    Rain, Carmen; Rada, Gabriel

    2015-07-06

    Angiotensin receptor blockers are usually considered as equivalent to angiotensin converting enzyme inhibitors for patients with heart failure and low-ejection fraction. Some guidelines even recommend the former as first line treatment given their better adverse effects profile. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified four systematic reviews including eight pertinent randomized controlled trials. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded angiotensin receptor blockers and angiotensin converting enzyme inhibitors probably have a similar effect on mortality, and they might be equivalent in reducing hospitalization risk too. Treatment withdrawal due to adverse effects is probably lower with angiotensin receptor blockers than with angiotensin converting enzyme inhibitors.

  19. Computational design of a protein-based enzyme inhibitor

    PubMed Central

    Procko, Erik; Hedman, Rickard; Hamilton, Keith; Seetharaman, Jayaraman; Fleishman, Sarel J.; Su, Min; Aramini, James; Kornhaber, Gregory; Hunt, John F.; Tong, Liang; Montelione, Gaetano T.; Baker, David

    2013-01-01

    While there has been considerable progress in designing protein-protein interactions, the design of proteins that bind polar surfaces is an unmet challenge. We describe the computational design of a protein that binds the acidic active site of hen egg lysozyme and inhibits the enzyme. The design process starts with two polar amino acids that fit deep into the enzyme active site, identifies a protein scaffold that supports these residues and is complementary in shape to the lysozyme active site region, and finally optimizes the surrounding contact surface for high affinity binding. Following affinity maturation, a protein designed using this method bound lysozyme with low nanomolar affinity, and a combination of NMR studies, crystallography and knockout mutagenesis confirmed the designed binding surface and orientation. Saturation mutagenesis with selection and deep sequencing demonstrated that specific designed interactions extending well beyond the centrally grafted polar residues are critical for high affinity binding. PMID:23827138

  20. Identification of quinazolinyloxy biaryl urea as a new class of SUMO activating enzyme 1 inhibitors.

    PubMed

    Kumar, Ashutosh; Ito, Akihiro; Hirohama, Mikako; Yoshida, Minoru; Zhang, Kam Y J

    2013-09-15

    SUMO activating enzyme 1 (SUMO E1) is the first enzyme in sumoylation pathway and an important cancer drug target. However, only a few inhibitors were reported up to now that includes three natural products, semi-synthetic protein inhibitors and one AMP mimic. Here, we report the identification of quinazolinyloxy biaryl urea as a new class of SUMO E1 inhibitors. The most active compound of this class inhibited the in vitro sumoylation with an IC50 of 13.4 μM. This compound inhibits sumoylation by blocking the formation of SUMOE1-SUMO thioester intermediate. The biological activity of the most active compound is comparable to previously reported inhibitors with properties suitable for medicinal chemistry optimization for potency and druggability.

  1. Selective inhibitors of digestive enzymes from Aedes aegypti larvae identified by phage display.

    PubMed

    Soares, Tatiane Sanches; Soares Torquato, Ricardo Jose; Alves Lemos, Francisco Jose; Tanaka, Aparecida Sadae

    2013-01-01

    Dengue is a serious disease transmitted by the mosquito Aedes aegypti during blood meal feeding. It is estimated that the dengue virus is transmitted to millions of individuals each year in tropical and subtropical areas. Dengue control strategies have been based on controlling the vector, Ae. aegypti, using insecticide, but the emergence of resistance poses new challenges. The aim of this study was the identification of specific protease inhibitors of the digestive enzymes from Ae. aegypti larvae, which may serve as a prospective alternative biocontrol method. High affinity protein inhibitors were selected by all of the digestive serine proteases of the 4th instar larval midgut, and the specificity of these inhibitors was characterized. These inhibitors were obtained from a phage library displaying variants of HiTI, a trypsin inhibitor from Haematobia irritans, that are mutated in the reactive loop (P1-P4'). Based on the selected amino acid sequence pattern, seven HiTI inhibitor variants were cloned, expressed and purified. The results indicate that the HiTI variants named T6 (RGGAV) and T128 (WNEGL) were selected by larval trypsin-like (IC(50) of 1.1 nM) and chymotrypsin-like enzymes (IC(50) of 11.6 nM), respectively. The variants T23 (LLGGL) and T149 (GGVWR) inhibited both larval chymotrypsin-like (IC(50) of 4.2 nM and 29.0 nM, respectively) and elastase-like enzymes (IC(50) of 1.2 nM for both). Specific inhibitors were successfully obtained for the digestive enzymes of Ae. aegypti larvae by phage display. Our data also strongly suggest the presence of elastase-like enzymes in Ae. aegypti larvae. The HiTI variants T6 and T23 are good candidates for the development as a larvicide to control the vector.

  2. Structure-based repurposing of FDA-approved drugs as inhibitors of NEDD8-activating enzyme.

    PubMed

    Zhong, Hai-Jing; Liu, Li-Juan; Chan, Daniel Shiu-Hin; Wang, Hui-Min; Chan, Philip Wai Hong; Ma, Dik-Lung; Leung, Chung-Hang

    2014-07-01

    We report the discovery of an inhibitor of NEDD8-activating enzyme (NAE) by an integrated virtual screening approach. Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity. Furthermore, piperacillin 1 was able to inhibit the degradation of the NAE downstream protein substrate p27(kip1). Our molecular modeling and kinetic studies suggested that this compound may act as a non-covalent ATP-competitive inhibitor of NAE.

  3. 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

  4. Selective Targeting of Extracellular Insulin-Degrading Enzyme by Quasi-Irreversible Thiol-Modifying Inhibitors.

    PubMed

    Abdul-Hay, Samer O; Bannister, Thomas D; Wang, Hui; Cameron, Michael D; Caulfield, Thomas R; Masson, Amandine; Bertrand, Juliette; Howard, Erin A; McGuire, Michael P; Crisafulli, Umberto; Rosenberry, Terrone R; Topper, Caitlyn L; Thompson, Caroline R; Schürer, Stephan C; Madoux, Franck; Hodder, Peter; Leissring, Malcolm A

    2015-12-18

    Many therapeutically important enzymes are present in multiple cellular compartments, where they can carry out markedly different functions; thus, there is a need for pharmacological strategies to selectively manipulate distinct pools of target enzymes. Insulin-degrading enzyme (IDE) is a thiol-sensitive zinc-metallopeptidase that hydrolyzes diverse peptide substrates in both the cytosol and the extracellular space, but current genetic and pharmacological approaches are incapable of selectively inhibiting the protease in specific subcellular compartments. Here, we describe the discovery, characterization, and kinetics-based optimization of potent benzoisothiazolone-based inhibitors that, by virtue of a unique quasi-irreversible mode of inhibition, exclusively inhibit extracellular IDE. The mechanism of inhibition involves nucleophilic attack by a specific active-site thiol of the enzyme on the inhibitors, which bear an isothiazolone ring that undergoes irreversible ring opening with the formation of a disulfide bond. Notably, binding of the inhibitors is reversible under reducing conditions, thus restricting inhibition to IDE present in the extracellular space. The identified inhibitors are highly potent (IC50(app) = 63 nM), nontoxic at concentrations up to 100 μM, and appear to preferentially target a specific cysteine residue within IDE. These novel inhibitors represent powerful new tools for clarifying the physiological and pathophysiological roles of this poorly understood protease, and their unusual mechanism of action should be applicable to other therapeutic targets.

  5. Discovery of novel bacterial elongation condensing enzyme inhibitors by virtual screening.

    PubMed

    Zheng, Zhong; Parsons, Joshua B; Tangallapally, Rajendra; Zhang, Weixing; Rock, Charles O; Lee, Richard E

    2014-06-01

    The elongation condensing enzymes in the bacterial fatty acid biosynthesis pathway represent desirable targets for the design of novel, broad-spectrum antimicrobial agents. A series of substituted benzoxazolinones was identified in this study as a novel class of elongation condensing enzyme (FabB and FabF) inhibitors using a two-step virtual screening approach. Structure activity relationships were developed around the benzoxazolinone scaffold showing that N-substituted benzoxazolinones were most active. The benzoxazolinone scaffold has high chemical tractability making this chemotype suitable for further development of bacterial fatty acid synthesis inhibitors.

  6. 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.

  7. Discovery of Potent Inhibitors of Schistosoma mansoni NAD⁺ Catabolizing Enzyme.

    PubMed

    Jacques, Sylvain A; Kuhn, Isabelle; Koniev, Oleksandr; Schuber, Francis; Lund, Frances E; Wagner, Alain; Muller-Steffner, Hélène; Kellenberger, Esther

    2015-04-23

    The blood fluke Schistosoma mansoni is the causative agent of the intestinal form of schistosomiasis (or bilharzia). Emergence of Schistosoma mansoni with reduced sensitivity to praziquantel, the drug currently used to treat this neglected disease, has underlined the need for development of new strategies to control schistosomiasis. Our ability to screen drug libraries for antischistosomal compounds has been hampered by the lack of validated S. mansoni targets. In the present work, we describe a virtual screening approach to identify inhibitors of S. mansoni NAD(+) catabolizing enzyme (SmNACE), a receptor enzyme suspected to be involved in immune evasion by the parasite at the adult stage. Docking of commercial libraries into a homology model of the enzyme has led to the discovery of two in vitro micromolar inhibitors. Further structure-activity relationship studies have allowed a 3-log gain in potency, accompanied by a largely enhanced selectivity for the parasitic enzyme over the human homologue CD38.

  8. 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

  9. 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

  10. Multivalent inhibitors for carbohydrate-processing enzymes: beyond the "lock-and-key" concept.

    PubMed

    Gouin, Sébastien G

    2014-09-01

    During the last decades, tremendous chemical efforts have been dedicated to design monovalent inhibitors of carbohydrate-processing enzymes, with comparatively few rewards in terms of marketed drugs. Recently, an alternative to the traditional "lock and key" approach has emerged. Multivalency, a widely used strategy for lectin inhibition, has been successfully applied to specific glycosidases and glycosyltransferases.

  11. 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.

  12. 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.

  13. Angiotensin-converting enzyme overexpression in myelomonocytes prevents Alzheimer’s-like cognitive decline

    PubMed Central

    Bernstein, Kenneth E.; Koronyo, Yosef; Salumbides, Brenda C.; Sheyn, Julia; Pelissier, Lindsey; Lopes, Dahabada H.J.; Shah, Kandarp H.; Bernstein, Ellen A.; Fuchs, Dieu-Trang; Yu, Jeff J.-Y.; Pham, Michael; Black, Keith L.; Shen, Xiao Z.; Fuchs, Sebastien; Koronyo-Hamaoui, Maya

    2014-01-01

    Cognitive decline in patients with Alzheimer’s disease (AD) is associated with elevated brain levels of amyloid β protein (Aβ), particularly neurotoxic Aβ1–42. Angiotensin-converting enzyme (ACE) can degrade Aβ1–42, and ACE overexpression in myelomonocytic cells enhances their immune function. To examine the effect of targeted ACE overexpression on AD, we crossed ACE10/10 mice, which overexpress ACE in myelomonocytes using the c-fms promoter, with the transgenic APPSWE/PS1ΔE9 mouse model of AD (AD+). Evaluation of brain tissue from these AD+ACE10/10 mice at 7 and 13 months revealed that levels of both soluble and insoluble brain Aβ1–42 were reduced compared with those in AD+ mice. Furthermore, both plaque burden and astrogliosis were drastically reduced. Administration of the ACE inhibitor ramipril increased Aβ levels in AD+ACE10/10 mice compared with the levels induced by the ACE-independent vasodilator hydralazine. Overall, AD+ACE10/10 mice had less brain-infiltrating cells, consistent with reduced AD-associated pathology, though ACE-overexpressing macrophages were abundant around and engulfing Aβ plaques. At 11 and 12 months of age, the AD+ACE10/WT and AD+ACE10/10 mice were virtually equivalent to non-AD mice in cognitive ability, as assessed by maze-based behavioral tests. Our data demonstrate that an enhanced immune response, coupled with increased myelomonocytic expression of catalytically active ACE, prevents cognitive decline in a murine model of AD. PMID:24487585

  14. Antioxidative galloyl esters as enzyme inhibitors of p-hydroxybenzoate hydroxylase.

    PubMed

    Abe, I; Kashiwagi, K; Noguchi, H

    2000-10-20

    Gallic acid and its esters were evaluated as enzyme inhibitors of recombinant p-hydroxybenzoate hydroxylase (PHBH), a NADPH-dependent flavin monooxygenase from Pseudomonas aeruginosa. n-Dodecyl gallate (DG) (IC(50)=16 microM) and (-)-epigallocatechin-3-O-gallate (EGCG) (IC(50)=16 microM), a major component of green tea polyphenols, showed the most potent inhibition, while product-like gallic acid did not inhibit the enzyme significantly (IC(50)>250 microM). Inhibition kinetics revealed that both DG and EGCG inhibited PHBH in a non-competitive manner (K(I)=18.1 and 14.0 microM, respectively). The enzyme inhibition was caused by specific binding of the antioxidative gallate to the enzyme, and by scavenging reactive oxygen species required for the monooxygenase reaction. Molecular modeling predicted that EGCG binds to the enzyme in the proximity of the FAD binding site via formation of three hydrogen bonds.

  15. 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

  16. 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.

  17. Angiotensin-converting enzyme inhibitors modulate kynurenic acid production in rat brain cortex in vitro.

    PubMed

    Zakrocka, Izabela; Turski, Waldemar A; Kocki, Tomasz

    2016-10-15

    It is well established that the renin-angiotensin system (RAS) is present in the brain and that glutamate activates the brain centers responsible for blood pressure control. An antagonist of glutamate, kynurenic acid (KYNA) was shown to decrease blood pressure after intracerebral administration. KYNA is an endogenous metabolite of tryptophan produced from the breakdown of kynurenine by kynurenine aminotransferases (KAT), mainly within astrocytes. The purpose of this study was to evaluate the influence of three angiotensin-converting enzyme inhibitors (lisinopril, perindopril and ramipril) on KYNA production and KAT activity in the rat brain cortex in vitro. The effect of the angiotensin-converting enzyme inhibitors on KYNA production was examined on rat brain cortical slices incubated for 2h in the presence of l-kynurenine and the angiotensin-converting enzyme inhibitors. To analyze KAT I and KAT II activity, brain cortical homogenates were incubated for 2h with L-kynurenine and the tested drugs. KYNA was separated by HPLC and quantified fluorometrically. Among the examined angiotensin-converting enzyme inhibitors, lisinopril increased KYNA production, perindopril was ineffective, and ramipril decreased KYNA synthesis in rat brain cortical slices. Lisinopril increased KAT I activity and perindopril did not affect it. However, ramipril lowered KAT I activity in rat brain cortex in vitro. Neither lisinopril nor perindopril affected KAT II activity, but ramipril decreased KAT II activity in the rat brain cortex in vitro. Our study reveals that angiotensin-converting enzyme inhibitors show various influences on KYNA production in rat brain cortical slices and activity of KATs.

  18. 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

  19. Structural insights into chitinolytic enzymes and inhibition mechanisms of selective inhibitors.

    PubMed

    Liu, Tian; Chen, Lei; Ma, Qiang; Shen, Xu; Yang, Qing

    2014-01-01

    Chitin biodegradation is linked to fungi cell differentiation, nematode egg hatching, arthropods morphogenesis and human defense against malaria and other pathogens infection as well. Two classes of enzymes for chitin degradation include glycosyl hydrolase (GH) family 18 chitinases and family 20 β-N-acetyl-D-hexosaminidases. However, more and more research papers have revealed that either GH 18 family chitinases or GH 20 family β-N-acetyl-D-hexosaminidases are a family composed of a number of isoforms, each of which plays an exclusive role in different life processes. The development of novel and specific inhibitors towards chitinolytic enzymes is of great importance in the investigation of or interference with chitin biodegradation. This review focuses on identified enzymes that are specifically involved in chitin degradation. And the latest progresses on crystal structures and specific inhibitors are summarized within the realm of this field.

  20. 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.

  1. Synthesis and evaluation of 2,5-dihydrochorismate analogues as inhibitors of the chorismate-utilising enzymes.

    PubMed

    Payne, Richard J; Bulloch, Esther M M; Toscano, Miguel M; Jones, Michelle A; Kerbarh, Olivier; Abell, Chris

    2009-06-01

    A library of 2,5-dihydrochorismate analogues were designed as inhibitors of the chorismate-utilising enzymes including anthranilate synthase, isochorismate synthase, salicylate synthase and 4-amino-4-deoxychorismate synthase. The inhibitors were synthesised in seven or eight steps from shikimic acid, sourced from star anise. The compounds exhibited moderate but differential inhibition against the four chorismate-utilising enzymes.

  2. Discovery of the first inhibitors of bacterial enzyme D-aspartate ligase from Enterococcus faecium (Aslfm).

    PubMed

    Škedelj, Veronika; Perdih, Andrej; Brvar, Matjaž; Kroflič, Ana; Dubbée, Vincent; Savage, Victoria; O'Neill, Alex J; Solmajer, Tom; Bešter-Rogač, Marija; Blanot, Didier; Hugonnet, Jean-Emmanuel; Magnet, Sophie; Arthur, Michel; Mainardi, Jean-Luc; Stojan, Jure; Zega, Anamarija

    2013-09-01

    The D-aspartate ligase of Enterococcus faecium (Aslfm) is an attractive target for the development of narrow-spectrum antibacterial agents that are active against multidrug-resistant E. faecium. Although there is currently little available information regarding the structural characteristics of Aslfm, we exploited the knowledge that this enzyme belongs to the ATP-grasp superfamily to target its ATP binding site. In the first design stage, we synthesized and screened a small library of known ATP-competitive inhibitors of ATP-grasp enzymes. A series of amino-oxazoles derived from bacterial biotin carboxylase inhibitors showed low micromolar activity. The most potent inhibitor compound 12, inhibits Aslfm with a Ki value of 2.9 μM. In the second design stage, a validated ligand-based pharmacophore modeling approach was used, taking the newly available inhibition data of an initial series of compounds into account. Experimental evaluation of the virtual screening hits identified two novel structural types of Aslfm inhibitors with 7-amino-9H-purine (18) and 7-amino-1H-pyrazolo[3,4-d]pyrimidine (30 and 34) scaffolds, and also with Ki values in the low micromolar range. Investigation the inhibitors modes of action confirmed that these compounds are competitive with respect to the ATP molecule. The binding of inhibitors to the target enzyme was also studied using isothermal titration calorimetry (ITC). Compounds 6, 12, 18, 30 and 34 represent the first inhibitors of Aslfm reported to date, and are an important step forward in combating infections due to E. faecium.

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

    PubMed

    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

  4. 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

  5. Rapid screening of enzyme inhibitors using profiling of enzyme-metabolite assay by HPLC (PREMA-HPLC).

    PubMed

    Vasantha, K Y; Murugesh, C S; Sattur, A P

    2012-02-01

    A number of isolates from different ecosystems were screened for their ability to inhibit tyrosinase resulting in the selection of isolate CFR 101, which showed an inhibition of 72%. The metabolites present in the crude extract of the selected isolate was profiled through high-performance liquid chromatography (HPLC) before the enzyme inhibition assay to reveal a 66% decrease in area of the peak at room temperature for 13.9 min, after the assay. Upon purification, this peak was identified as kojic acid, a known inhibitor of tyrosinase. This unique technique of combining a reaction assay mixture with HPLC profile wherein inhibitors can be rapidly pinpointed in crude extracts addresses the drawback of rapid chemical high-throughput screening (HTS) systems, which is limited to the chemical nature of metabolites without any evidence of their biological activities.

  6. 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

  7. Immobilization of angiotensin-converting enzyme on glyoxyl-agarose.

    PubMed

    Megías, Cristina; Pedroche, Justo; del Mar Yust, María; Alaiz, Manuel; Girón-Calle, Julio; Millán, Francisco; Vioque, Javier

    2006-06-28

    The assay of angiotensin-converting enzyme (ACE) inhibition by food-derived peptides is usually carried out by using soluble ACE in a batch process. The purification of this enzyme from tissues is not an easy task, and the resulting preparation loses activity very fast. In addition, ACE commercial preparations are very expensive. In this work the immobilization of ACE, through lysine amino groups, to 4% beads cross-linked (4 BCL) glyoxyl-agarose is described. The amount of immobilized enzyme increased with increasing concentrations of enzyme and with incubation time until a saturation point was reached at 50 mg protein/mL gel and 3.5 hours, respectively. The IC50 values for a noncompetitive sunflower peptide inhibitor were similar for the soluble (30.56 microM) and immobilized (32.7 microM) enzymes. An immobilized derivative was obtained that was 60 times more stable than the soluble enzyme at 60 degrees C. This procedure yields a derivative that can be reused and has increased thermal stability compared to that of the soluble enzyme. Thus, ACE immobilization is a good alternative to using soluble freshly prepared or commercial preparations because of economical and practical reasons.

  8. 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

  9. 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

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

    PubMed

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

    2015-11-20

    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-active pharmacological tools for inhibiting AGPS, which may provide chemical scaffolds for future AGPS inhibitor development for cancer therapy.

  11. 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

  12. 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

  13. A prospective, double-blind, randomized controlled trial of the angiotensin-converting enzyme inhibitor Ramipril In Aortic Stenosis (RIAS trial)

    PubMed Central

    Bull, Sacha; Loudon, Margaret; Francis, Jane M.; Joseph, Jubin; Gerry, Stephen; Karamitsos, Theodoros D.; Prendergast, Bernard D.; Banning, Adrian P.; Neubauer, Stefan; Myerson, Saul G.

    2015-01-01

    Aims Angiotensin-converting enzyme (ACE) inhibitors improve left ventricular (LV) remodelling and outcome in heart failure and hypertensive heart disease. They may be similarly beneficial in patients with aortic stenosis (AS), but historical safety concerns have limited their use, and no prospective clinical trials exist. Methods and results We conducted a prospective, randomized, double-blind, placebo-controlled trial in 100 patients with moderate or severe asymptomatic AS to examine the physiological effects of ramipril, particularly LV mass (LVM) regression. Subjects were randomized to ramipril 10 mg daily (n = 50) or placebo (n = 50) for 1 year, and underwent cardiac magnetic resonance, echocardiography, and exercise testing at 0, 6, and 12 months, with follow-up data available in 77 patients. There was a modest but progressive reduction in LVM (the primary end point) in the ramipril group vs. the placebo group (mean change −3.9 vs. +4.5 g, respectively, P = 0.0057). There were also trends towards improvements in myocardial physiology: the ramipril group showed preserved tissue Doppler systolic velocity compared with placebo (+0.0 vs. −0.5 cm/s, P = 0.04), and a slower rate of progression of the AS (valve area 0.0 cm2 in the ramipril group vs. −0.2 cm2 in the placebo arm, P = 0.067). There were no significant differences in major adverse cardiac events. Conclusion ACE inhibition leads to a modest, but progressive reduction in LVM in asymptomatic patients with moderate–severe AS compared with placebo, with trends towards improvements in myocardial physiology and slower progression of valvular stenosis. A larger clinical outcome trial to confirm these findings and explore their clinical relevance is required. PMID:25796267

  14. 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

  15. 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.

  16. Angiotensin converting enzyme gene polymorphism in familial hypertrophic cardiomyopathy patients

    SciTech Connect

    Yu, B; Peric, S.; Ross, D.

    1994-09-01

    An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene is a useful predictor of human plasma ACE levels. ACE levels tend to be lowest in subjects with ACE genotype DD and intermediate in subjects with ACE genotype ID. Angiotensin II (Ang II) as a product of ACE is a cardiac growth factor and produces a marked hypertrophy of the chick myocyte in cell culture. Rat experiments also suggest that a small dose of ACE inhibitor that does not affect the afterload results in prevention or regression of cardiac hypertrophy. In order to study the relationship of ACE and the severity of hypertrophy, the ACE genotype has been determined in 28 patients with a clinical diagnosis of familial hypertrophic cardiomyopathy (FHC) and 51 normal subjects. The respective frequencies of I and D alleles were: 0.52 and 0.48 (in FHC patients) and 0.44 and 0.56 (in the normal controls). There was no significant difference in the allele frequencies between FHC and normal subjects ({chi}{sup 2}=0.023, p>0.05). The II, ID, and DD genotypes were present in 7, 15, and 6 FHC patients, respectively. The averages of maximal thickness of the interventricular septum measured by echocardiography or at autopsy were 18 {plus_minus}3, 19{plus_minus}4, and 19{plus_minus}3 mm in II, ID and DD genotypes, respectively. The ACE gene polymorphism did not correlate with the severity of left ventricular hypertrophy in FHC patients (r{sub s}=0.231, p>0.05). These results do not necessarily exclude the possible effect of Ang II on the hypertrophy since the latter may be produced through the action of chymase in the human ventricles. However, ACE gene polymorphism is not a useful predictor of the severity of myocardial hypertrophy in FHC patients.

  17. Investigating the selectivity of metalloenzyme inhibitors.

    PubMed

    Day, Joshua A; Cohen, Seth M

    2013-10-24

    The inhibitory activity of a broad group of known metalloenzyme inhibitors against a panel of metalloenzymes was evaluated. Clinically approved inhibitors were selected as well as several other reported metalloprotein inhibitors in order to represent a broad range of metal binding groups (MBGs), including hydroxamic acid, carboxylate, hydroxypyridinonate, thiol, and N-hydroxyurea functional groups. A panel of metalloenzymes, including carbonic anhydrase (hCAII), several matrix metalloproteinases (MMPs), angiotensin converting enzyme (ACE), histone deacetylase (HDAC-2), and tyrosinase (TY), was selected based on their clinical importance for a range of pathologies. In addition, each inhibitor was evaluated for its ability to remove Fe(3+) from holo-transferrin to gauge the ability of the inhibitors to access Fe(3+) from a primary transport protein. The results show that the metalloenzyme inhibitors are quite selective for their intended targets, suggesting that despite their ability to bind metal ions, metalloprotein inhibitors are not prone to widespread off-target enzyme inhibition activity.

  18. Investigating the Selectivity of Metalloenzyme Inhibitors

    PubMed Central

    Day, Joshua A.; Cohen, Seth M.

    2013-01-01

    The inhibitory activity of a broad group of known metalloenzyme inhibitors against a panel of metalloenzymes was evaluated. Clinically approved inhibitors were selected as well as several other reported metalloprotein inhibitors, in order to represent a broad range of metal binding groups (MBGs), including hydroxamic acid, carboxylate, hydroxypyridinonate, thiol, and N-hydroxyurea functional groups. A panel of metalloenzymes, including carbonic anhydrase (hCAII), several matrix metalloproteinases (MMPs), angiotensin converting enzyme (ACE), histone deacetylase (HDAC-2), and tyrosinase (TY) was selected based on their clinical importance for a range of pathologies. In addition, each inhibitor was evaluated for its ability to remove Fe3+ from holo-transferrin to gauge the ability of the inhibitors to access Fe3+ from a primary transport protein. The results show that the metalloenzyme inhibitors are quite selective for their intended targets, suggesting that despite their ability to bind metal ions, metalloprotein inhibitors are not prone to widespread off-target enzyme inhibition activity. PMID:24074025

  19. Enzyme- and transporter-mediated drug interactions with small molecule tyrosine kinase inhibitors.

    PubMed

    Shao, Jie; Markowitz, John S; Bei, Di; An, Guohua

    2014-12-01

    Among the novel and target-specific classes of anticancer drugs, small molecule tyrosine kinase inhibitors (TKIs) represent an extremely promising and rapidly expanding group. TKIs attack cancer-specific targets and therefore have a favorable safety profile. However, as TKIs are taken orally along with other medications on a daily basis, there is an elevated risk of potentially significant drug-drug interactions. Most TKIs are metabolized primarily through CYP3A4. In addition, many TKIs are also CYP3A4 inhibitors at the same time. In addition to drug metabolizing enzymes (DMEs), another determinant of TKI disposition are drug transporters. There is accumulating evidence showing that the majority of currently marketed TKIs interact with ATP-binding cassette transporters, particularly P-glycoprotein as well as Breast Cancer Resistance Protein and serve as both substrates and inhibitors. Considering the dual roles of TKIs on both DMEs and drug transporters, and the importance of these enzyme and transporters in drug disposition, the potential for enzyme- and transporter-mediated TKI-drug interactions in patients with cancer is an important consideration. This review provides a comprehensive overview of drug interactions with small molecule TKIs mediated by DMEs and drug transporters. The TKI-drug interactions with TKIs being victims and/or perpetrators are summarized.

  20. 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.

  1. 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

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

    PubMed Central

    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.

    2010-01-01

    Background 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. Methodology/Principal Findings 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 ∼106 times more potent than existing inhibitors, non-toxic, and surprisingly selective for IDE vis-à-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. PMID:20498699

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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…

  9. 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).

  10. 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.

  11. 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

  12. Cardiac and renal distribution of ACE and ACE-2 in rats with heart failure.

    PubMed

    Cohen-Segev, Ravit; Francis, Bahaa; Abu-Saleh, Niroz; Awad, Hoda; Lazarovich, Aviva; Kabala, Aviva; Aronson, Doron; Abassi, Zaid

    2014-10-01

    Congestive heart failure is often associated with impaired kidney function. Over-activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid salt and water retention in heart failure. While the expression of angiotensin converting enzyme (ACE), a key enzyme in the synthesis of angiotensin II (Ang II), is well established, the expression of angiotensin converting enzyme-2 (ACE-2), an enzyme responsible for angiotensin 1-7 generation, is largely unknown. This issue is of a special interest since angiotensin 1-7 counteracts many of the proliferative and hypertensive effects of angiotensin II. Therefore, the present study was designed to investigate the expression of both enzymes in the kidney and heart of rats with heart failure. Heart failure (CHF) was induced in male Sprague Dawley rats (n=9) by the creation of a surgical aorto-caval fistula. Sham-operated rats served as controls (n=8). Two weeks after surgery, the animals were sacrificed and their hearts and kidneys were harvested for assessment of cardiac remodeling and ACE and ACE-2 immunoreactivity by immunohistochemical staining. ACE immunostaining was significantly increased in the kidneys (4.34 ± 0.39% vs. 2.96 ± 0.40%, P<0.05) and hearts (4.57 ± 0.54% vs. 2.19 ± 0.37%, P<0.01) of CHF rats as compared with their sham controls. In a similar manner, ACE-2 immunoreactivity was also elevated in the kidneys (4.65 ± 1.17% vs. 1.75 ± 0.29%, P<0.05) and hearts (5.48 ± 1.11% vs. 1.13 ± 0.26%, P<0.01) of CHF rats as compared with their healthy controls. This study showed that both ACE and ACE-2 are overexpressed in the cardiac and renal tissues of animals with heart failure as compared with their sham controls. The increased expression of the beneficial ACE-2 in heart failure may serve as a compensatory response to the over-activity of the deleterious isoform, namely, angiotensin converting enzyme 1(ACE-1).

  13. 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

  14. 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.

  15. 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

  16. 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

  17. A kinetic study of irreversible enzyme inhibition by an inhibitor that is rendered unstable by enzymic catalysis. The inhibition of polyphenol oxidase by L-cysteine.

    PubMed Central

    Valero, E; Varón, R; García-Carmona, F

    1991-01-01

    A kinetic study of the irreversible inhibition of an enzyme by an inhibitor that is depleted in the medium by its reaction with the product of enzymic analysis was made. The model is illustrated by the study of the inhibition of catecholase activity of polyphenol oxidase by L-cysteine. The inhibition is characterized by an initial lag period followed by a concomitant decrease in enzymic activity expressed when the steady state is reached, both kinetic parameters being modulated by enzyme, substrate and inhibitor concentrations. There is no analytical solution to the non-linear differential-equation system that describes the kinetics of the reaction, and so computer simulations of this dynamic behaviour are presented. The results obtained show that the system here studied presents kinetic co-operativity for a target enzyme that follows the simple Michaelis-Menten mechanism in its action on the substrate. PMID:1908225

  18. 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

  19. ACES: Final performance report

    NASA Astrophysics Data System (ADS)

    Baxter, V. D.

    1981-04-01

    The performance of the ACES in a single family residence near Knoxville, Tennessee was compared with that of two different air to air heat pumps in an identical house. Results show that energy was saved for the testing years. In addition to reducing consumption, the ACES significantly reduced integrated peak utility demands. Reinsulation of the ice storage bin reduced heat leakage rates by about 40 percent and resulted in increasing ground temperatures by an average of 5.60 C over first year levels. The demonstration project and the ACES concept are described. Data acquisition procedures, system modifications, steady state performance, annual cycle performance, and effects of modifications are discussed.

  20. 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.

  1. 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

  2. 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

  3. Sex Hormones Promote Opposite Effects on ACE and ACE2 Activity, Hypertrophy and Cardiac Contractility in Spontaneously Hypertensive Rats

    PubMed Central

    Dalpiaz, P. L. M.; Lamas, A. Z.; Caliman, I. F.; Ribeiro, R. F.; Abreu, G. R.; Moyses, M. R.; Andrade, T. U.; Gouvea, S. A.; Alves, M. F.; Carmona, A. K.; Bissoli, N. S.

    2015-01-01

    Background There is growing interest in sex differences and RAS components. However, whether gender influences cardiac angiotensin I-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity is still unknown. In the present work, we determined the relationship between ACE and ACE2 activity, left ventricular function and gender in spontaneously hypertensive rats (SHRs). Methodology / Principal Findings Twelve-week-old female (F) and male (M) SHRs were divided into 2 experimental groups (n = 7 in each group): sham (S) and gonadectomized (G). Fifty days after gonadectomy, we measured positive and negative first derivatives (dP/dt maximum left ventricle (LV) and dP/dt minimum LV, respectively), hypertrophy (morphometric analysis) and ACE and ACE2 catalytic activity (fluorimetrically). Expression of calcium handling proteins was measured by western blot. Male rats exhibited higher cardiac ACE and ACE2 activity as well as hypertrophy compared to female rats. Orchiectomy decreased the activity of these enzymes and hypertrophy, while ovariectomy increased hypertrophy and ACE2, but did not change ACE activity. For cardiac function, the male sham group had a lower +dP/dt than the female sham group. After gonadectomy, the +dP/dt increased in males and reduced in females. The male sham group had a lower -dP/dt than the female group. After gonadectomy, the -dP/dt increased in the male and decreased in the female groups when compared to the sham group. No difference was observed among the groups in SERCA2a protein expression. Gonadectomy increased protein expression of PLB (phospholamban) and the PLB to SERCA2a ratio in female rats, but did not change in male rats. Conclusion Ovariectomy leads to increased cardiac hypertrophy, ACE2 activity, PLB expression and PLB to SERCA2a ratio, and worsening of hemodynamic variables, whereas in males the removal of testosterone has the opposite effects on RAS components. PMID:26010093

  4. Effective virtual screening strategy toward covalent ligands: identification of novel NEDD8-activating enzyme inhibitors.

    PubMed

    Zhang, Shengping; Tan, Jiani; Lai, Zhonghui; Li, Ying; Pang, Junxia; Xiao, Jianhu; Huang, Zhangjian; Zhang, Yihua; Ji, Hui; Lai, Yisheng

    2014-06-23

    The NEDD8-activating enzyme (NAE) is an emerging target for cancer therapy, which regulates the degradation and turnover of a variety of cancer-related proteins by activating the cullin-RING E3 ubiquitin ligases. Among a limited number of known NAE inhibitors, the covalent inhibitors have demonstrated the most potent efficacy through their covalently linked adducts with NEDD8. Inspired by this unique mechanism, in this study, a novel combined strategy of virtual screening (VS) was adopted with the aim to identify diverse covalent inhibitors of NAE. To be specific, a docking-enabled pharmacophore model was first built from the possible active conformations of chosen covalent inhibitors. Meanwhile, a dynamic structure-based phamacophore was also established based on the snapshots derived from molecular dynamic simulation. Subsequent screening of a focused ZINC database using these pharmacophore models combined with covalent docking discovered three novel active compounds. Among them, compound LZ3 exhibited the most potent NAE inhibitory activity with an IC50 value of 1.06 ± 0.18 μM. Furthermore, a cell-based washout experiment proved the proposed covalent binding mechanism for compound LZ3, which confirmed the successful application of our combined VS strategy, indicating it may provide a viable solution to systematically discover novel covalent ligands.

  5. 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

  6. 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.

  7. Enzyme inhibition by hydroamination: design and mechanism of a hybrid carmaphycin-syringolin enone proteasome inhibitor.

    PubMed

    Trivella, Daniela B B; Pereira, Alban R; Stein, Martin L; Kasai, Yusuke; Byrum, Tara; Valeriote, Frederick A; Tantillo, Dean J; Groll, Michael; Gerwick, William H; Moore, Bradley S

    2014-06-19

    Hydroamination reactions involving the addition of an amine to an inactivated alkene are entropically prohibited and require strong chemical catalysts. While this synthetic process is efficient at generating substituted amines, there is no equivalent in small molecule-mediated enzyme inhibition. We report an unusual mechanism of proteasome inhibition that involves a hydroamination reaction of alkene derivatives of the epoxyketone natural product carmaphycin. We show that the carmaphycin enone first forms a hemiketal intermediate with the catalytic Thr1 residue of the proteasome before cyclization by an unanticipated intramolecular alkene hydroamination reaction, resulting in a stable six-membered morpholine ring. The carmaphycin enone electrophile, which does not undergo a 1,4-Michael addition as previously observed with vinyl sulfone and α,β-unsaturated amide-based inhibitors, is partially reversible and gives insight into the design of proteasome inhibitors for cancer chemotherapy.

  8. Chick-Erythrocyte Nucleus Reactivation in Heterokaryons: Suppression by Inhibitors of Proteolytic Enzymes

    PubMed Central

    Darzynkiewicz, Zbigniew; Chelmicka-Szorc, Ewa; Arnason, Barry G. W.

    1974-01-01

    Reactivation of chick-erythrocyte nuclei in heterokaryons (obtained by Sendai virus-induced fusion of chick erythrocytes with HeLa cells) is suppressed by specific inhibitors of trypsin and trypsin-like enzymes. N-α-tosyl-L-lysyl-chloromethane and N-α-tosyl-L-arginine methylester inhibit erythrocyte nuclear enlargement and suppress RNA and DNA synthesis in nuclei of erythrocytes and HeLa cells in heterokaryons at concentrations that only minimally influence individual HeLa cells or HeLa homokaryons. Although other unknown mechanisms of action cannot be formally excluded, the data are interpreted as fitting best with an intracellular site of action of the protease inhibitors studied, and as suggesting a role for cellular proteases in reactivation of chick-erythrocyte nuclei in heterokaryons. PMID:4522779

  9. Enzyme inhibition by hydroamination: Design and mechanism of a hybrid carmaphycin-syringolin enone proteasome inhibitor

    PubMed Central

    Trivella, Daniela B. B.; Pereira, Alban R.; Stein, Martin L.; Kasai, Yusuke; Byrum, Tara; Valeriote, Frederick A.; Tantillo, Dean J.; Groll, Michael; Gerwick, William H.; Moore, Bradley S.

    2014-01-01

    Summary Hydroamination reactions involving the addition of an amine to an inactivated alkene are entropically prohibited and require strong chemical catalysts. While this synthetic process is efficient at generating substituted amines, there is no equivalent in small molecule-mediated enzyme inhibition. Here we report a new mechanism of proteasome inhibition by hydroamination involving alkene derivatives of the epoxyketone natural product carmaphycin. We show that the carmaphycin enone first forms a hemiketal intermediate with the catalytic Thr1 residue of the proteasome before cyclization by an unanticipated intramolecular alkene hydroamination reaction resulting in a stable 6-membered morpholine ring. The carmaphycin enone electrophile, which does not undergo a 1,4-Michael addition as previously observed with vinyl sulfone and α,β-unsaturated amide-based inhibitors, is partially reversible and gives insight to the design of proteasome inhibitors for cancer chemotherapy. PMID:24930969

  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. 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

  12. 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

  13. 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

  14. Natural and synthetic iminosugars as carbohydrate processing enzyme inhibitors for cancer therapy.

    PubMed

    Wrodnigg, Tanja M; Steiner, Andreas J; Ueberbacher, Bernhard J

    2008-01-01

    Iminosugars, featuring a basic nitrogen at the hetero atom position in carbohydrate rings, gain increasing interest in the search for novel approaches towards cancer drug development. This compound class is known as competitive inhibitors of carbohydrate manipulation enzymes, such as glycosidases, which are involved in tumor cell invasion and migration. Such enzymes are also responsible for the attachment of oligosaccharides to the cell surface of tumor cells, displayed as glycoproteins, glycolipids, and proteoglycans, which play an important role in malignant phenotype and tumor growth. Furthermore, cancer cells show an extremely active lysosomal system which is reflected by enhancement of glycoprotein turnover. Iminosugars were found to interact with glycosyl hydrolases responsible for this kind of action in cancer cells and thus open a new compound class in the research field of finding new anti-cancer activities. This review will focus on the role of iminosugars in cancer therapy and will give an overview of their properties.

  15. 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

  16. 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.

  17. The response to the first dose of an angiotensin converting enzyme inhibitor in uncomplicated hypertension--a placebo controlled study utilising ambulatory blood pressure recording.

    PubMed Central

    MacFadyen, R J; Bainbridge, A D; Lees, K R; Reid, J L

    1991-01-01

    1. The importance of total dose to the initial hypotensive response with an angiotensin converting enzyme inhibitor (quinapril) was assessed using a suggested 'maintenance' dose (20 mg) or matched placebo in a randomised double-blind study in patients with uncomplicated hypertension. 2. Thirty-two patients were recruited who were not on therapy or had not received diuretic therapy in their existing drug treatment in the preceding 4 weeks. Secondary causes of hypertension had previously been excluded and sustained clinic blood pressures of SBP greater than 160 mmHg and/or DBP greater than 90 mmHg were taken as indications for a trial of adjuvant or monotherapy with an ACE inhibitor. 3. After uneventful supervised therapy with quinapril in an open pilot study (n = 5) 27 patients entered a double-blind, randomised, crossover study of quinapril or placebo using ambulatory monitoring to assess BP response. 4. All patients remained asymptomatic and both therapy and monitoring were well tolerated. A smooth onset of antihypertensive effect was noted with an overall 24 h placebo corrected fall in systolic BP of 9.9 mmHg (7.2-12.6 95% CI) and diastolic BP of 6.4 mmHg (4.2-8.8) with no significant effect on heart rate. Individual placebo corrected maximal responses during the first 8 h following quinapril showed a wide range for both systolic (+1.56 to 44.0 mmHg) and diastolic (+2.3 to -35.6 mmHg) pressure. Larger falls tended to be associated with higher baseline pretreatment pressures but in no case did absolute systolic pressure fall below 100 mmHg during the first 8 h following administration of placebo or quinapril.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1777377

  18. 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

  19. 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.

  20. Preparation of a dual-enzyme co-immobilized capillary microreactor and simultaneous screening of multiple enzyme inhibitors by capillary electrophoresis.

    PubMed

    Lin, Pingtan; Zhao, Shulin; Lu, Xin; Ye, Fanggui; Wang, Hengshan

    2013-08-01

    A CE method based on a dual-enzyme co-immobilized capillary microreactor was developed for the simultaneous screening of multiple enzyme inhibitors. The capillary microreactor was prepared by co-immobilizing adenosine deaminase and xanthine oxidase on the inner wall at the inlet end of the separation capillary. The enzymes were first immobilized on gold nanoparticles, and the functionalized gold nanoparticles were then assembled on the inner wall at the inlet end of the separation capillary treated with polyethyleneimine. With the developed CE method, the substrates and products were baseline separated within 3 min. The activity of the immobilized enzyme can be directly detected by measuring the peak height of the products. A statistical parameter Z' factor was recommended for evaluation of the accuracy of a drug screening system. In the present study, it was calculated to be larger than 0.5, implying a good accuracy. Finally, screening a small compound library containing two known enzyme inhibitors and 20 natural extracts by the proposed method was demonstrated. The known inhibitors were identified, and some natural extracts were found to be positive for two-enzyme inhibition by the present method.

  1. 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.

  2. Folding in solution of the C-catalytic protein fragment of angiotensin-converting enzyme.

    PubMed

    Vamvakas, Sotirios-Spyridon M; Leondiadis, Leondios; Pairas, George; Manessi-Zoupa, Evy; Spyroulias, Georgios A; Cordopatis, Paul

    2009-08-01

    Angiotensin-converting enzyme (ACE) is a key molecule of the renin-angiotensin-aldosterone system which is responsible for the control of blood pressure. For over 30 years it has become the target for fighting off hypertension. Many inhibitors of the enzyme have been synthesized and used widely in medicine despite the lack of ACE structure. The last 5 years the crystal structure of ACE separate domains has been revealed, but in order to understand how the enzyme works it is necessary to study its structure in solution. We present here the cloning, overexpression in Escherichia coli, purification and structural study of the Ala(959) to Ser(1066) region (ACE_C) that corresponds to the C-catalytic domain of human somatic angiotensin-I-converting enzyme. ACE_C was purified under denatured conditions and the yield was 6 mg/l of culture. Circular dichroism (CD) spectroscopy indicated that 1,1,1-trifluoroethanol (TFE) is necessary for the correct folding of the protein fragment. The described procedure can be used for the production of an isotopically labelled ACE(959-1066) protein fragment in order to study its structure in solution by NMR spectroscopy.

  3. Novel inhibitors of Rad6 ubiquitin conjugating enzyme: design, synthesis, identification, and functional characterization.

    PubMed

    Sanders, Matthew A; Brahemi, Ghali; Nangia-Makker, Pratima; Balan, Vitaly; Morelli, Matteo; Kothayer, Hend; Westwell, Andrew D; Shekhar, Malathy P V

    2013-04-01

    Protein ubiquitination is important for cell signaling, DNA repair, and proteasomal degradation, and it is not surprising that alterations in ubiquitination occur frequently in cancer. Ubiquitin-conjugating enzymes (E2) mediate ubiquitination by selective interactions with ubiquitin-activating (E1) and ubiquitin ligase (E3) enzymes, and thus selective E2 small molecule inhibitor (SMI) will provide specificity unattainable with proteasome inhibitors. Here we describe synthesis and functional characterization of the first SMIs of human E2 Rad6B, a fundamental component of translesion synthesis DNA repair. A pharmacophore model for consensus E2 ubiquitin-binding sites was generated for virtual screening to identify E2 inhibitor candidates. Twelve triazine (TZ) analogs screened in silico by molecular docking to the Rad6B X-ray structure were verified by their effect on Rad6B ubiquitination of histone H2A. TZs #8 and 9 docked to the Rad6B catalytic site with highest complementarity. TZs #1, 2, 8, and 9 inhibited Rad6B-ubiquitin thioester formation and subsequent ubiquitin transfer to histone H2A. SMI #9 inhibition of Rad6 was selective as BCA2 ubiquitination by E2 UbcH5 was unaffected by SMI #9. SMI #9 more potently inhibited proliferation, colony formation, and migration than SMI #8, and induced MDA-MB-231 breast cancer cell G2-M arrest and apoptosis. Ubiquitination assays using Rad6 immunoprecipitated from SMI #8- or 9-treated cells confirmed inhibition of endogenous Rad6 activity. Consistent with our previous data showing Rad6B-mediated polyubiquitination stabilizes β-catenin, MDA-MB-231 treatment with SMIs #8 or 9 decreased β-catenin protein levels. Together these results describe identification of the first Rad6 SMIs.

  4. 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

  5. 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

  6. 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

  7. Enzyme-coupled nanoparticles-assisted laser desorption ionization mass spectrometry for searching for low-mass inhibitors of enzymes in complex mixtures.

    PubMed

    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.

  8. 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.

  9. 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.

  10. 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

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

    PubMed Central

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

    2011-01-01

    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

  12. Genetic and biochemical evidence that recombinant Enterococcus spp. strains expressing gelatinase (GelE) produce bovine milk-derived hydrolysates with high angiotensin converting enzyme-inhibitory activity (ACE-IA).

    PubMed

    Gútiez, Loreto; Borrero, Juan; Jiménez, Juan J; Gómez-Sala, Beatriz; Recio, Isidra; Cintas, Luis M; Herranz, Carmen; Hernández, Pablo E

    2014-06-18

    In this work, genes encoding gelatinase (gelE) and serine proteinase (sprE), two extracellular proteases produced by Enterococcus faecalis DBH18, were cloned in the protein expression vector pMG36c, containing the constitutive P32 promoter, generating the recombinant plasmids pCG, pCSP, and pCGSP encoding gelE, sprE, and gelE-sprE, respectively. Transformation of noncaseinolytic E. faecalis P36, E. faecalis JH2-2, E. faecium AR24, and E. hirae AR14 strains with these plasmids permitted detection of caseinolytic activity only in the strains transformed with pCG or pCGSP. Complementation of a deletion (knockout) mutant of E. faecalis V583 for production of gelatinase (GelE) with pCG unequivocally supported that gelE is responsible for the caseinolytic activity of the transformed strain grown in bovine skim milk (BSM). RP-HPLC-MS/MS analysis of hydrolysates of transformed Enterococcus spp. strains grown in BSM permitted the identification of 38 major peptide fragments including peptides with previously reported angiotensin converting enzyme-inhibitory activity (ACE-IA), antihypertensive activity, and antioxidant activity.

  13. Angiotensin-converting enzyme inhibitors reduce oxidative stress intensity in hyperglicemic conditions in rats independently from bradykinin receptor inhibitors

    PubMed Central

    Mikrut, Kinga; Kupsz, Justyna; Koźlik, Jacek; Krauss, Hanna; Pruszyńska-Oszmałek, Ewa; Gibas-Dorna, Magdalena

    2016-01-01

    Aim To investigate whether bradykinin-independent antioxidative effects of angiotensin-converting enzyme inhibitors (ACEIs) exist in acute hyperglycemia. Methods Male Wistar rats were divided into the normoglycemic group (n = 40) and the hyperglycemic group (n = 40). Hyperglycemia was induced by a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) dissolved in 0.1 mol/L citrate buffer (pH 4.5) 72 hours before sacrifice. The normoglycemic group received the same volume of citrate buffer. Each group was divided into five subgroups (n = 8): control group, captopril group, captopril + bradykinin B1 and B2 receptor antagonists group, enalapril group, and enalapril + bradykinin B1 and B2 receptor antagonists group. Captopril, enalapril, B1 and B2 receptor antagonists, or 0.15 mol/L NaCl were given at 2 and 1 hour before sacrifice. Oxidative status was determined by measuring the concentration of malondialdehyde and H2O2, and the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Results In STZ-induced hyperglycemic rats ACEIs significantly reduced H2O2 and MDA concentration, while they significantly enhanced SOD and GPx activity. The hyperglycemic group treated simultaneously with ACEIs and bradykinin B1 and B2 receptor antagonists showed a significant decrease in H2O2 concentration compared to the control hyperglycemic group. Conclusion These results suggest the existence of additional antioxidative effect of ACEIs in hyperglycemic conditions, which is not related to the bradykinin mediation and the structure of the drug molecule. PMID:27586552

  14. 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

  15. 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

  16. New immunocapture enzyme (ICE) assay for quantification of cancer procoagulant activity: studies of inhibitors.

    PubMed

    Mielicki, W P; Tagawa, M; Gordon, S G

    1994-04-01

    A new, sensitive and specific immunocapture enzyme (ICE) assay for quantitation of the enzymatic activity of cancer procoagulant (CP) has been developed. The assay had good reproducibility (inter- and intra-assay CV were 6.4% and 5.7% respectively) and was linear for concentrations of CP from 0.5 microgram/ml to 10 micrograms/ml (r2 = 0.995). Using this assay the inhibition of CP by iodoacetamide, mercuric chloride, E-64, leupeptin and antipain was demonstrated. There was no significant effect of cystatin and natural plasma proteinase inhibitors alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-macroglobulin and antithrombin-III/heparin, on the activity of the CP.

  17. Screening, identification, and characterization of mechanistically diverse inhibitors of the Mycobacterium tuberculosis enzyme, pantothenate kinase (CoaA).

    PubMed

    Venkatraman, Janani; Bhat, Jyothi; Solapure, Suresh M; Sandesh, Jatheendranath; Sarkar, Debasmita; Aishwarya, Sundaram; Mukherjee, Kakoli; Datta, Santanu; Malolanarasimhan, Krishnan; Bandodkar, Balachandra; Das, Kaveri S

    2012-03-01

    The authors describe the discovery of anti-mycobacterial compounds through identifying mechanistically diverse inhibitors of the essential Mycobacterium tuberculosis (Mtb) enzyme, pantothenate kinase (CoaA). Target-driven drug discovery technologies often work with purified enzymes, and inhibitors thus discovered may not optimally inhibit the form of the target enzyme predominant in the bacterial cell or may not be available at the desired concentration. Therefore, in addition to addressing entry or efflux issues, inhibitors with diverse mechanisms of inhibition (MoI) could be prioritized before hit-to-lead optimization. The authors describe a high-throughput assay based on protein thermal melting to screen large numbers of compounds for hits with diverse MoI. Following high-throughput screening for Mtb CoaA enzyme inhibitors, a concentration-dependent increase in protein thermal stability was used to identify true binders, and the degree of enhancement or reduction in thermal stability in the presence of substrate was used to classify inhibitors as competitive or non/uncompetitive. The thermal shift-based MoI assay could be adapted to screen hundreds of compounds in a single experiment as compared to traditional biochemical approaches for MoI determination. This MoI was confirmed through mechanistic studies that estimated K(ie) and K(ies) for representative compounds and through nuclear magnetic resonance-based ligand displacement assays.

  18. 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

  19. Screening-based discovery of the first novel ATP competitive inhibitors of the Staphylococcus aureus essential enzyme UMP kinase.

    PubMed

    Doig, Peter; Gorseth, Elise; Nash, Tory; Patten, Arthur; Gao, Ning; Blackett, Carolyn

    2013-07-19

    UMP kinase (PyrH) is an essential enzyme found only in bacteria, making it ideal as a target for the discovery of antibacterials. To identify inhibitors of PyrH, an assay employing Staphylococcus aureus PyrH coupled to pyruvate kinase/lactate dehydrogenase was developed and was used to perform a high throughput screen. A validated aminopyrimidine series was identified from screening. Kinetic characterization of this aminopyrimidine indicated it was a competitive inhibitor of ATP. We have shown that HTS can be used to identify potential leads for this novel target, the first ATP competitive inhibitor of PyrH reported.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review.

    PubMed

    Stout, Stephen M; Cimino, Nina M

    2014-02-01

    Exogenous cannabinoids are structurally and pharmacologically diverse compounds that are widely used. The purpose of this systematic review is to summarize the data characterizing the potential for these compounds to act as substrates, inhibitors, or inducers of human drug metabolizing enzymes, with the aim of clarifying the significance of these properties in clinical care and drug interactions. In vitro data were identified that characterize cytochrome P-450 (CYP-450) enzymes as potential significant contributors to the primary metabolism of several exogenous cannabinoids: tetrahydrocannabinol (THC; CYPs 2C9, 3A4); cannabidiol (CBD; CYPs 2C19, 3A4); cannabinol (CBN; CYPs 2C9, 3A4); JWH-018 (CYPs 1A2, 2C9); and AM2201 (CYPs 1A2, 2C9). CYP-450 enzymes may also contribute to the secondary metabolism of THC, and UDP-glucuronosyltransferases have been identified as capable of catalyzing both primary (CBD, CBN) and secondary (THC, JWH-018, JWH-073) cannabinoid metabolism. Clinical pharmacogenetic data further support CYP2C9 as a significant contributor to THC metabolism, and a pharmacokinetic interaction study using ketoconazole with oromucosal cannabis extract further supports CYP3A4 as a significant metabolic pathway for THC and CBD. However, the absence of interaction between CBD from oromucosal cannabis extract with omeprazole suggests a less significant role of CYP2C19 in CBD metabolism. Studies of THC, CBD, and CBN inhibition and induction of major human CYP-450 isoforms generally reflect a low risk of clinically significant drug interactions with most use, but specific human data are lacking. Smoked cannabis herb (marijuana) likely induces CYP1A2 mediated theophylline metabolism, although the role of cannabinoids specifically in eliciting this effect is questionable.

  6. 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.

  7. 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

  8. The acute renal actions of angiotensin converting enzyme inhibitors in the sodium-depleted conscious primate are mediated by inhibition of the renin-angiotensin system.

    PubMed

    Humke, U; Levens, N; Wood, J; Hofbauer, K

    1992-01-01

    The purpose of this study was to determine if the changes in renal function acutely produced by an inhibitor of angiotensin converting enzyme (ACE) in the sodium-depleted conscious marmoset can be explained primarily by blockade of the renin-angiotensin system. Intravenous injection of a dose of the ACEI, enalaprilate (2 mg/kg), that produced a maximal lowering of blood pressure (BP), also decreased renal vascular resistance and increased renal blood flow. Glomerular filtration rate was unchanged by enalaprilat, leading to a fall in the filtration fraction. In comparison, a dose of the renin inhibitory monoclonal antibody, R-3-36-16 (0.1 mg/kg), that also produced a maximal fall in BP, produced similar changes in renal hemodynamics to those observed after administration of the ACEI. Combined administration of 2 mg/kg enalaprilat and 0.1 mg/kg R-3-36-16 produced changes in BP and renal hemodynamics similar to those produced by the same doses of either agent administered alone. Enalaprilat (2 mg/kg) significantly increased urine volume (UV) and urinary sodium excretion (UNaV). In contrast, these parameters were not significantly altered by 0.1 mg/kg R-3-36-16. However, when given at a 10-fold higher dose, the monoclonal antibody produced an increase in UNaV and UV identical to that produced by the ACEI alone. Enalaprilat did not increase UV and UNaV excretion to a greater extent than the high dose of the renin inhibitory antibody. These results demonstrate that acute administration of an ACEI affects BP and renal function in the sodium-depleted conscious primate primarily by inhibition of the renin-angiotensin system.

  9. 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

  10. 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.

  11. Medroxyprogesterone acetate and dexamethasone are competitive inhibitors of different human steroidogenic enzymes.

    PubMed

    Lee, T C; Miller, W L; Auchus, R J

    1999-06-01

    Medroxyprogesterone acetate (MPA), a widely used progestin, can suppress the hypothalamic-pituitary-gonadal axis but can also directly inhibit gonadal steroidogenesis; the success of MPA as a treatment for gonadotropin-independent sexual precocity derives from its direct action on steroidogenic tissues. Dexamethasone, a widely used glucocorticoid, can suppress the hypothalamic-pituitary-adrenal axis, but its potential effect directly on the adrenal is unclear. Previous reports suggested that these two drugs may act on the initial steps in the rodent steroidogenic pathway; therefore, we investigated their abilities to inhibit the first three human enzymes in steroidogenesis: the cholesterol side-chain cleavage enzyme (P450scc), the 17alpha-hydroxylase/17,20-lyase (P450c17), and type II 3beta-hydroxysteroid dehydrogenase/isomerase (3betaHSDII). We found no effect of either drug on P450scc in intact human choriocarcinoma JEG-3 cells. Using microsomes from yeast expressing human P450c17 or microsomes from human adrenals, we found that dexamethasone inhibited P450c17 with a Ki of 87 micromol/L, which is about 1000 times higher than typical therapeutic concentrations, but that MPA has no detectable action on P450c17. Using microsomes from yeast expressing human 3betaHSDII, we found that this enzyme has indistinguishable apparent Km values of 5.2-5.5 micromol/L and similar maximum velocities of 0.34-0.56 pmol steroid/min x microg microsomal protein for the three principal endogenous substrates, pregnenolone, 17-hydroxypregnenolone, and dehydroepiandrosterone. In this system, MPA inhibited 3betaHSDII with a Ki of 3.0 micromol/L, which is near concentrations achieved by high therapeutic doses of 5-20 mg MPA/kg x day. These data establish the mechanism of action of MPA as an inhibitor of human steroidogenesis, and are in contrast with the results of earlier studies indicating that MPA inhibited both P450c17 and 3betaHSD in rat Leydig cells. These studies establish the

  12. 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.

  13. Natural plant enzyme inhibitors. Characterization of an unusual alpha-amylase/trypsin inhibitor from ragi (Eleusine coracana Geartn.).

    PubMed Central

    Shivaraj, B; Pattabiraman, T N

    1981-01-01

    An inhibitor I-1, capable of acting on both alpha-amylase and trypsin, was purified to homogeneity from ragi (finger-millet) grains. The factor was found to be stable to heat treatment at 100 degrees C for 1 h in the presence of NaCl and also was stable over the wide pH range 1-10. Pepsin and Pronase treatment of inhibitor I-1 resulted in gradual loss of both the inhibitory activities. Formation of trypsin-inhibitor I-1 complex, amylase-inhibitor I-1 complex and trypsin-inhibitor I-1-amylase trimer complex was demonstrated by chromatography on a Bio-Gel P-200 column. This indicated that the inhibitor is 'double-headed' in nature. The inhibitor was retained on a trypsin-Sepharose 4B column at pH 7.0. Elution at acidic pH resulted in almost complete recovery of amylase-inhibitory and trypsin-inhibitory activities. alpha-Amylase was retained on a trypsin-Sepharose column to which inhibitor I-1 was bound, but not on trypsin-Sepharose alone. Modification of amino groups of the inhibitor with 2,4,6-trinitrobenzenesulphonic acid resulted in complete loss of amylase-inhibitory activity but only 40% loss in antitryptic activity. Modification of arginine residues by cyclohexane-1,2-dione led to 85% loss of antitryptic activity after 5 h, but no effect on amylase-inhibitory activity. The results show that a single bifunctional protein factor is responsible for both amylase-inhibitory and trypsin-inhibitory activities with two different reactive sites. Images Fig. 1. Fig. 2. Fig. 3. PMID:6796040

  14. 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.

  15. 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 ...

  16. Autodisplay of catalytically active human hyaluronidase hPH-20 and testing of enzyme inhibitors.

    PubMed

    Kaessler, Andre; Olgen, Sureyya; Jose, Joachim

    2011-01-18

    Hyaluronic acid (HA) is the major biopolymer of the extracellular matrix and contributes significantly to cell proliferation and migration. Human hyaluronidase hPH-20 has been identified as a tumor marker for breast and laryngeal cancer. A hPH-20-autotransporter fusion protein for cell surface display was transformed into Escherichia coli BL21 (DE3) and hPH-20 was displayed on the surface of E. coli. Enzymatic activity, however, was not detectable due to competitive inhibition by lipopolysaccharide (LPS). Finally, expression in E. coli F470, a strain missing the O-polysaccharide of LPS, yielded cells with sufficient hyaluronidase activity. 6-Palmitoyl-l-ascorbic acid (Vcpal) and two indole-carboxamides, N-(4-fluorobenzyl)-1-benzyl-1H-indole-2-carboxamide (1) and N-(4-chlorobenzyl)-1-(4-fluorobenzyl)-1H-indole-3-carboxamide (2), were tested on inhibition of hPH-20. Vcpal with a concentration of 5 μM inhibited hPH-20 to 93% at pH 7, compounds 1 and 2 showed 61% and 21% inhibition at a concentration of 50 μM. At the same inhibitor concentrations the most frequently used bovine testes hyaluronidase (BTH) was inhibited by Vcpal to a similar extent (95%), whereas compound 1 (80%) and compound 2 (66%) showed much differing inhibition. Thus it can be assumed that BTH is not applicable as an alternative to human PH-20. These results indicate that Autodisplay enables the expression of human target enzymes normally forming inclusion bodies in E. coli and accelerates inhibitor testing as shown by the example of human hyaluronidase PH-20.

  17. [Angiotensin converting enzyme and Alzheimer's disease].

    PubMed

    Kugaevskaia, E V

    2013-01-01

    Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system, leading to dementia. The basis of AD is neurodegenerative process that leads to death of neurons in the cerebral cortex. This neurodegenerative process is associated with the formation of neurofibrillary tangles in the brain and the deposition of senile plaques, the main component of which is a beta-amyloid peptide (Abeta). Risk factors for AD are age, as well as hypertension, atherosclerosis, diabetes and hypercholesterolemia in the pathogenesis of which involved angiotensin converting enzyme (ACE)--key enzyme of the renin-angiotensin (RAS) and kallikrein-kinin (KKS) systems. Recently it was discovered that ACE, along with other metallopeptidases, participates in the metabolism of Abeta, cleaving the bonds at the N-terminal and C-terminal region of the molecule Abeta. The role of the ACE in the degradation processes of Abeta takes an interest. It is associated with the fact that the using of ACE inhibitors is the main therapeutic approach used in the treatment of various forms of hypertension and other cardiovascular diseases. However, until now not been resolved, can be used antihypertensive drugs that inhibit RAS for the treatment or prevention of AD. Currently, there are numerous studies on finding the relationship between RAS and AD. PMID:23650720

  18. 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

  19. 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

  20. Effects of flavocoxid, a dual inhibitor of COX and 5-lipoxygenase enzymes, on benign prostatic hyperplasia

    PubMed Central

    Altavilla, D; Minutoli, L; Polito, F; Irrera, N; Arena, S; Magno, C; Rinaldi, M; Burnett, BP; Squadrito, F; Bitto, A

    2012-01-01

    BACKGROUND AND PURPOSE Inflammation plays a key role in the development of benign prostatic hyperplasia (BPH). Eicosanoids derived from the COX and 5-lipoxygenase (5-LOX) pathways are elevated in the enlarging prostate. Flavocoxid is a novel flavonoid–based ‘dual inhibitor’ of the COX and 5-LOX enzymes. This study evaluated the effects of flavocoxid in experimental BPH. EXPERIMENTAL APPROACH Rats were treated daily with testosterone propionate (3 mg·kg−1 s.c.) or its vehicle for 14 days to induce BPH. Animals receiving testosterone were randomized to receive vehicle (1 mL·kg−1, i.p.) or flavocoxid (20 mg·kg−1, i.p.) for 14 days. Histological changes, eicosanoid content and mRNA and protein levels for apoptosis-related proteins and growth factors were assayed in prostate tissue. The effects of flavocoxid were also tested on human prostate carcinoma PC3 cells. KEY RESULTS Flavocoxid reduced prostate weight and hyperplasia, blunted inducible expression of COX-2 and 5-LOX as well as the increased production of PGE2 and leukotriene B4 (LTB4), enhanced pro-apoptotic Bax and caspase-9 and decreased the anti-apoptotic Bcl-2 mRNA. Flavocoxid also reduced EGF and VEGF expression. In PC3 cells, flavocoxid stimulated apoptosis and inhibited growth factor expression. Flavocoxid-mediated induction of apoptosis was inhibited by the pan-caspase inhibitor, Z-VAD-FMK, in PC3 cells, suggesting an essential role of caspases in flavocoxid-mediated apoptosis during prostatic growth. CONCLUSION AND IMPLICATIONS Our results show that a ‘dual inhibitor’ of the COX and 5-LOX enzymes, such as flavocoxid, might represent a rational approach to reduce BPH through modulation of eicosanoid production and a caspase-induced apoptotic mechanism. PMID:22471974

  1. Recent advances in inhibitors of bacterial fatty acid synthesis type II (FASII) system enzymes as potential antibacterial agents.

    PubMed

    Wang, Yi; Ma, Shutao

    2013-10-01

    Bacterial infections are a constant and serious threat to human health. With the increase of multidrug resistance of clinically pathogenic bacteria, common antibiotic therapies have been less effective. Fatty acid synthesis type II (FASII) system enzymes are essential for bacterial membrane lipid biosynthesis and represent increasingly promising targets for the discovery of antibacterial agents with new mechanisms of action. This review highlights recent advances in inhibitors of bacterial FASII as potential antibacterial agents, paying special attention to the activities, mechanisms, and structure-activity relationships of those inhibitors that mainly target β-ketoacyl-ACP synthase, β-ketoacyl-ACP reductase, β-hydroxyacyl-ACP dehydratase, and enoyl-ACP reductase. Although inhibitors with low nanomolar and selective activity against various bacterial FASII have entered clinical trials, further research is needed to expand upon both available and yet unknown scaffolds to identify new FASII inhibitors that may have antibacterial potential, particularly against resistant bacterial strains.

  2. 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

  3. [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.

  4. [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

  5. 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

  6. Design, synthesis, and enzyme kinetics of novel benzimidazole and quinoxaline derivatives as methionine synthase inhibitors.

    PubMed

    Elshihawy, Hosam; Helal, Mohamed A; Said, Mohamed; Hammad, Mohamed A

    2014-01-01

    Methionine synthase catalyzes the transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine, producing methionine and tetrahydrofolate. Benzimidazole and deazatetrahydrofolates derivatives have been shown to inhibit methionine synthase by competing with the substrate 5-methyltetrahydrofolate. In this study, a novel series of substituted benzimidazoles and quinoxalines were designed and assessed for inhibitory activity against purified rat liver methionine synthase using a radiometric enzyme assay. Compounds 3g, 3j, and 5c showed the highest activity against methionine synthase (IC₅₀: 20 μM, 18 μM, 9 μM, respectively). Kinetic analysis of these compounds using Lineweaver-Burk plots revealed characteristics of mixed inhibition for 3g and 5c; and uncompetitive inhibition for 3j. Docking study into a homology model of the rat methionine synthase gave insights into the molecular determinants of the activity of this class of compounds. The identification of these drug-like inhibitors could lead the design of the next generation modulators of methionine synthase.

  7. 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

  8. In vitro studies of eggplant (Solanum melongena) phenolics as inhibitors of key enzymes relevant for type 2 diabetes and hypertension.

    PubMed

    Kwon, Y-I; Apostolidis, E; Shetty, K

    2008-05-01

    National Diabetes Education Program of NIH, Mayo Clinic and American Diabetes Association recommend eggplant-based diet as a choice for management of type 2 diabetes. The rationale for this suggestion is the high fiber and low soluble carbohydrate content of eggplant. We propose that a more physiologically relevant explanation lies in the phenolic-linked antioxidant activity and alpha-glucosidase inhibitory potential of eggplant which could reduce hyperglycemia-induced pathogenesis. Results from this study indicate that phenolic-enriched extracts of eggplant with moderate free radical scavenging-linked antioxidant activity had high alpha-glucosidase inhibitory activity and in specific cases moderate to high angiotensin I-converting enzyme (ACE) inhibitory activity. Inhibition of these enzymes provide a strong biochemical basis for management of type 2 diabetes by controlling glucose absorption and reducing associated hypertension, respectively. This phenolic antioxidant-enriched dietary strategy also has the potential to reduce hyperglycemia-induced pathogenesis linked to cellular oxidation stress. These results provide strong rationale for further animal and clinical studies.

  9. The probability that complex enzyme kinetic curves can be caused by activators of inhibitors.

    PubMed

    Solano-Muñoz, F; Bardsley, W G; Indge, K J

    1981-06-01

    Numerous chemical compounds are known that alter the rate of conversion of substrates into products in enzyme-catalysed reactions by interacting with the enzyme rather than substrates. Where this takes place in such a way that the effect is reversible on removing the compound, say by dialysis, and where the compound is unchanged chemically by the enzyme system, we refer to such a compound as a modifier. So protons, inorganic salts, activators, inhibitors or even specific allosteric effectors would all be modifiers, and any chemically reasonable kinetic scheme that is proposed to account for such effects is referred to as modifier mechanism. Three versions of a modifier mechanism of enzyme action are studied. The implicit representation is 2:2 in [S] (with alpha(0)=0) and 2:2 in [M] (with alpha(0) not equal0), and this is a short-hand scheme for the minimum chemical formulation, the explicit one, involving discrete ES and EP species, which is 2:2 in [S] (with alpha(0)=0) and 3:3 in [M] (with alpha(0) not equal0). If m extra steps are allowed between interconversion of ES and EP species, the degree of the rate equation remains 2:2 in [S] (with alpha(0)=0), but increases to degree (m+3):(m+3) in modifier (with alpha(0) not equal0). It is proved that this increase in degree is genuine and that highly complex v([M]) (i.e. v-versus-[M]) curves can occur. Computation of the probabilities of the five possible double-reciprocal plots in 1/v versus 1/[S] show that all of these formulations of the modifier mechanism give similar probabilities, and these are characteristic for the mechanism and quite distinct from the intrinsic curve-shape probabilities. It is also established that the probabilities of alternative complex v([M]) plots are similar for the various formulations, and again the probabilities of the allowed complex curves for the mechanism are quite distinct from the instrinsic probabilities of the ten possible v([M]) curves for a 2:2 function (with alpha(0) not

  10. 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.

  11. 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

  12. 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.

  13. Chronic monoamine oxidase-B inhibitor treatment blocks monoamine oxidase-A enzyme activity.

    PubMed

    Bartl, Jasmin; Müller, Thomas; Grünblatt, Edna; Gerlach, Manfred; Riederer, Peter

    2014-04-01

    Patients with Parkinson's disease receive selective irreversible monoamine oxidase (MAO)-B inhibitors, but their effects on MAO-A activity are not known during long-term application. We determined MAO-A inhibition in plasma samples from patients with MAO-B inhibitor intake or without MAO-B inhibitor treatment and from healthy controls. We detected a 70 % reduction of MAO-A activity in patients with MAO-B inhibitor therapy in comparison to the other groups. Our results suggest that treatment with MAO-B inhibitor may also influence MAO-A activity in vivo, when administered daily.

  14. γ-Aminobutyric Acid (GABA) Production and Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Fermented Soybean Containing Sea Tangle by the Co-Culture of Lactobacillus brevis with Aspergillus oryzae.

    PubMed

    Jang, Eun Kyeong; Kim, Nam Yeun; Ahn, Hyung Jin; Ji, Geun Eog

    2015-08-01

    To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30°C and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

  15. 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

  16. Paracrine systems in the cardioprotective effect of angiotensin-converting enzyme inhibitors on myocardial ischemia/reperfusion injury in rats.

    PubMed

    Liu, Y H; Yang, X P; Sharov, V G; Sigmon, D H; Sabbath, H N; Carretero, O A

    1996-01-01

    After transient episodes of ischemia, benefits of thrombolytic or angioplastic therapy may be limited by reperfusion injury. Angiotensin-converting enzyme inhibitors protect the heart against ischemia/reperfusion injury, an effect mediated by kinins. We examined whether the protective effect of the angiotensin-converting enzyme inhibitor ramiprilat on myocardial ischemia/reperfusion is due to kinin stimulation of prostaglandin and/or nitric oxide release. The left anterior descending coronary artery of Lewis inbred rats was occluded for 30 minutes, followed by 120 minutes of reperfusion. Immediately before reperfusion rats were treated with vehicle, ramiprilat, or the angiotensin II type 1 receptor antagonist losartan. We tested whether pretreatment with the kinin receptor antagonist Hoe 140, the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester, or the cyclooxygenase inhibitor indomethacin blocked the effect of ramiprilat on infarct size and reperfusion arrhythmias. In controls, infarct size as a percentage of the area at risk was 79 +/- 3%; ramiprilat reduced this to 49 +/- 4% (P < .001), but losartan had little effect (74 +/- 6%, P = NS). Pretreatment with Hoe 140, NG-nitro-L-arginine methyl ester, or indomethacin abolished the beneficial effect of ramiprilat. Compared with the 30-minute ischemia/120-minute reperfusion group, nonreperfused hearts with 30 minutes of ischemia had significantly smaller infarct size as a percentage of the area at risk, whereas in the 150-minute ischemia group it was significantly larger. This suggests that reperfusion caused a significant part of the myocardial injury, but it also suggests that compared with prolonged ischemia, reperfusion salvaged some of the myocardium. Ventricular arrhythmias mirrored the changes in infarct size. Thus, angiotensin-converting enzyme inhibitors protect the myocardium against ischemia/reperfusion injury and arrhythmias; these beneficial effects are mediated primarily by a kinin

  17. Hyperkalemia associated with use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers.

    PubMed

    Raebel, Marsha A

    2012-06-01

    The aims of this article are to review the current understanding of hyperkalemia associated with angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) therapy. This includes reviewing the pathophysiology of how these agents affect potassium handling within the kidney, risk factors for developing hyperkalemia, incidence, clinical signs and symptoms, and providing a practical approach to treatment of the patient who is either at risk of, or experiencing, hyperkalemia. ACEi and ARB are effective therapeutic agents used in a variety of clinical scenarios. However, related to their effects on the renin-angiotensin-aldosterone system, their use can be associated with hyperkalemia, particularly in patients who have chronic renal insufficiency. Published incidence estimates of hyperkalemia associated with ACEi or ARB vary, but up to 10% of patients may experience at least mild hyperkalemia. Important considerations when initiating ACEi or ARB therapy include obtaining an estimate of glomerular filtration rate and a baseline serum potassium concentration, as well as assessing whether the patient has excessive potassium intake from diet, supplements, or drugs that can also increase serum potassium. Serum potassium monitoring shortly after initiation of therapy can assist in preventing hyperkalemia. If hyperkalemia does develop, prompt recognition of cardiac dysrhythmias and effective treatment to antagonize the cardiac effects of potassium, redistribute potassium into cells, and remove excess potassium from the body is important.Understanding the mechanism of action of ACEi and ARB coupled with judicious drug use and clinical vigilance can minimize the risk to the patient of developing hyperkalemia. Should hyperkalemia occur, prompt recognition and management can optimize clinical outcome.

  18. 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.

  19. SLCO1B1 Variants and Angiotensin Converting Enzyme Inhibitor (Enalapril) -Induced Cough: a Pharmacogenetic Study

    PubMed Central

    Luo, Jian-Quan; He, Fa-Zhong; Wang, Zhen-Min; Sun, Ning-Ling; Wang, Lu-Yan; Tang, Gen-Fu; Liu, Mou-Ze; Li, Qing; Chen, Xiao-Ping; Liu, Zhao-Qian; Zhou, Hong-Hao; Zhang, Wei

    2015-01-01

    Clinical observations suggest that incidence of cough in Chinese taking angiotensin converting enzyme inhibitors is much higher than other racial groups. Cough is the most common adverse reaction of enalapril. We investigate whether SLCO1B1 genetic polymorphisms, previously reported to be important determinants of inter-individual variability in enalapril pharmacokinetics, are associated with the enalapril-induced cough. A cohort of 450 patients with essential hypertension taking 10 mg enalapril maleate were genotyped for the functional SLCO1B1 variants, 388A > G (Asn130Asp, rs2306283) and 521T > C (Val174Ala, rs4149056). The primary endpoint was cough, which was recorded when participants were bothered by cough and respiratory symptoms during enalapril treatment without an identifiable cause. SLCO1B1 521C allele conferred a 2-fold relative risk of enalapril-induced cough (95% confidence interval [CI] = 1.34–3.04, P = 6.2 × 10−4), and haplotype analysis suggested the relative risk of cough was 6.94-fold (95% CI = 1.30–37.07, P = 0.020) in SLCO1B1*15/*15 carriers. Furthermore, there was strong evidence for a gene-dose effect (percent with cough in those with 0, 1, or 2 copy of the 521C allele: 28.2%, 42.5%, and 71.4%, trend P = 6.6 × 10−4). Our study highlights, for the first time, SLCO1B1 variants are strongly associated with an increased risk of enalapril-induced cough. The findings will be useful to provide pharmacogenetic markers for enalapril treatment. PMID:26607661

  20. Risk of suicide in users of β-adrenoceptor blockers, calcium channel blockers and angiotensin converting enzyme inhibitors

    PubMed Central

    Sørensen, Henrik Toft; Mellemkjær, Lene; Olsen, Jørgen H

    2001-01-01

    Aims To examine the risk of suicide in users of β-adrenoceptor blockers, calcium channel blockers, and angiotensin converting enzyme inhibitors. Methods We conducted a cohort study based on linkage of a population-based prescription registry in North Jutland County, Denmark, and the nationwide Death Registry. From 1989 to 1995 there were 58 529 users of β-adrenoceptor blockers, calcium channel blockers, and angiotensin converting enzyme inhibitors. The mortality rates from suicides in the cohort members were compared with the rates in the general population. Results One hundred and four suicides occurred in the cohorts. The standardized mortality ratio for suicide in users of β-adrenoceptor blockers was 1.6 (95% confidence interval: 1.2–2.1), in users of calcium channel blockers 1.2 (95% confidence interval: 0.8–1.7), and in users of angiotensin converting enzyme inhibitors 1.2 (95% confidence interval: 0.7–1.8). In users of β-adrenoceptor blockers, the risk of suicide was increased during the first 12 months after the start of therapy, standardized mortality ratio 2.1 (95% confidence interval: 1.2–3.5). There was a trend in the standardized mortality ratio of suicide from 0.9 (95% confidence interval: 0.4–1.9) in users of β-adrenoceptor blockers with low lipid solubility, to 1.6 (0.8–2.8) and 2.7 (1.7–4.1) in users of β-adrenoceptor blockers with medium and high lipid solubility, respectively. Conclusions Users of medium and high lipid soluble β-adrenoceptor blockers may have an increased risk of suicide. Users of calcium channel blockers and angiotensin converting enzyme inhibitors do not seem to have a significantly increased risk of suicide. PMID:11560564

  1. Static and dynamic interactions between GALK enzyme and known inhibitors: guidelines to design new drugs for galactosemic patients.

    PubMed

    Chiappori, Federica; Merelli, Ivan; Milanesi, Luciano; Marabotti, Anna

    2013-05-01

    The search for inhibitors of galactokinase (GALK) enzyme is interesting for their possible therapeutic application capable to alleviate symptoms in people with classic galactosemia. Several high-throughput screenings in the past have found candidate ligands showing a moderate affinity for GALK. Computational analysis of the binding mode of these compounds in comparison to their target protein has been performed only on crystallographic static structures, therefore missing the evolution of the complex during time. In this work, we applied static and dynamics simulations to analyze the interactions between GALK and its potential inhibitors, while taking into account the temporal evolution of the complexes. The collected data allowed us to identify the most important and persistent anchoring points of the known active site and of the newly identified secondary cavity. These data will be of use to increase the specificity and the affinity of a new generation of GALK inhibitors.

  2. 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

  3. 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

  4. Small-molecule inhibitors of bacterial AddAB and RecBCD helicase-nuclease DNA repair enzymes.

    PubMed

    Amundsen, Susan K; Spicer, Timothy; Karabulut, Ahmet C; Londoño, Luz Marina; Eberhart, Christina; Fernandez Vega, Virneliz; Bannister, Thomas D; Hodder, Peter; Smith, Gerald R

    2012-05-18

    The AddAB and RecBCD helicase-nucleases are related enzymes prevalent among bacteria but not eukaryotes and are instrumental in the repair of DNA double-strand breaks and in genetic recombination. Although these enzymes have been extensively studied both genetically and biochemically, inhibitors specific for this class of enzymes have not been reported. We developed a high-throughput screen based on the ability of phage T4 gene 2 mutants to grow in Escherichia coli only if the host RecBCD enzyme, or a related helicase-nuclease, is inhibited or genetically inactivated. We optimized this screen for use in 1536-well plates and screened 326,100 small molecules in the NIH molecular libraries sample collection for inhibitors of the Helicobacter pylori AddAB enzyme expressed in an E. coli recBCD deletion strain. Secondary screening used assays with cells expressing AddAB or RecBCD and a viability assay that measured the effect of compounds on cell growth without phage infection. From this screening campaign, 12 compounds exhibiting efficacy and selectivity were tested for inhibition of purified AddAB and RecBCD helicase and nuclease activities and in cell-based assays for recombination; seven were active in the 0.1-50 μM range in one or another assay. Compounds structurally related to two of these were similarly tested, and three were active in the 0.1-50 μM range. These compounds should be useful in further enzymatic, genetic, and physiological studies of these enzymes, both purified and in cells. They may also lead to useful antibacterial agents, since this class of enzymes is needed for successful bacterial infection of mammals.

  5. Combined rational design and a high throughput screening platform for identifying chemical inhibitors of a Ras-activating enzyme.

    PubMed

    Evelyn, Chris R; Biesiada, Jacek; Duan, Xin; Tang, Hong; Shang, Xun; Papoian, Ruben; Seibel, William L; Nelson, Sandra; Meller, Jaroslaw; Zheng, Yi

    2015-05-15

    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.

  6. 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

  7. Structure-activity relationships of new cyanothiophene inhibitors of the essential peptidoglycan biosynthesis enzyme MurF.

    PubMed

    Hrast, Martina; Turk, Samo; Sosič, Izidor; Knez, Damijan; Randall, Christopher P; Barreteau, Hélène; Contreras-Martel, Carlos; Dessen, Andréa; O'Neill, Alex J; Mengin-Lecreulx, Dominique; Blanot, Didier; Gobec, Stanislav

    2013-08-01

    Peptidoglycan is an essential component of the bacterial cell wall, and enzymes involved in its biosynthesis represent validated targets for antibacterial drug discovery. MurF catalyzes the final intracellular peptidoglycan biosynthesis step: the addition of D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc-L-Ala-γ-D-Glu-meso-DAP (or L-Lys). As MurF has no human counterpart, it represents an attractive target for the development of new antibacterial drugs. Using recently published cyanothiophene inhibitors of MurF from Streptococcus pneumoniae as a starting point, we designed and synthesized a series of structurally related derivatives and investigated their inhibition of MurF enzymes from different bacterial species. Systematic structural modifications of the parent compounds resulted in a series of nanomolar inhibitors of MurF from S. pneumoniae and micromolar inhibitors of MurF from Escherichia coli and Staphylococcus aureus. Some of the inhibitors also show antibacterial activity against S. pneumoniae R6. These findings, together with two new co-crystal structures, represent an excellent starting point for further optimization toward effective novel antibacterials.

  8. Altered cardiac bradykinin metabolism in experimental diabetes caused by the variations of angiotensin-converting enzyme and other peptidases.

    PubMed

    Adam, Albert; Leclair, Patrick; Montpas, Nicolas; Koumbadinga, Gérémy Abdull; Bachelard, Hélène; Marceau, François

    2010-04-01

    The peptidases angiotensin-converting enzyme (ACE) and neutral endopeptidase 24.11 (NEP) mediate most of the kinin catabolism in normal cardiac tissue and are the molecular targets of inhibitory drugs that favorably influence diabetic complications. We studied the variations of those kininases in the myocardium of rats in experimental diabetes. ACE and NEP activities were significantly decreased in heart membranes 4-8weeks post-streptozotocin (STZ) injection. However, insulin-dependent diabetes did not modify significantly bradykinin (BK) half-life (t(1/2)) while the effect of both ACE (enalaprilat) and ACE and NEP (omapatrilat) inhibitors on BK degradation progressively decreased, which may be explained by the upregulation of other unidentified metallopeptidase(s). In vivo insulin treatment restored the activities of both ACE and NEP. ACE and NEP activities were significantly higher in hearts of young Zucker rats than in those of Sprague-Dawley rats. BK t(1/2) and the effects of peptidase inhibitors on t(1/2) varied accordingly. It is concluded that kininase activities are subjected to large and opposite variations in rat cardiac tissue in type I and II diabetes models. A number of tissue or molecular factors may determine these variations, such as remodeling of cardiac tissue, ectoenzyme shedding to the extracellular fluid and the pathologic regulation of peptidase gene expression.

  9. Antihypertensive Effects of Artemisia scoparia Waldst in Spontaneously Hypertensive Rats and Identification of Angiotensin I Converting Enzyme Inhibitors.

    PubMed

    Cho, Jeong-Yong; Park, Kyung-Hee; Hwang, Do Young; Chanmuang, Saoraya; Jaiswal, Lily; Park, Yang-Kyun; Park, Sun-Young; Kim, So-Young; Kim, Haeng-Ran; Moon, Jae-Hak; Ham, Kyung-Sik

    2015-11-03

    We investigated the antihypertensive effects of Artemisia scoparia (AS) in spontaneously hypertensive rats (SHR). The rats were fed diets containing 2% (w/w) hot water extracts of AS aerial parts for 6 weeks. The AS group had significantly lower systolic and diastolic blood pressure levels than the control group. The AS group also had lower angiotensin I converting enzyme (ACE) activity and angiotensin II content in serum compared to the control group. The AS group showed higher vascular endothelial growth factor and lower ras homolog gene family member A expression levels in kidney compared to the control group. The AS group had significantly lower levels of plasma lipid oxidation and protein carbonyls than the control group. One new and six known compounds were isolated from AS by guided purification. The new compound was determined to be 4'-O-β-D-glucopyranoyl (E)-4-hydroxy-3-methylbut-2-enyl benzoate, based on its nuclear magnetic resonance and electrospray ionization-mass spectroscopy data.

  10. Antihypertensive Effects of Artemisia scoparia Waldst in Spontaneously Hypertensive Rats and Identification of Angiotensin I Converting Enzyme Inhibitors.

    PubMed

    Cho, Jeong-Yong; Park, Kyung-Hee; Hwang, Do Young; Chanmuang, Saoraya; Jaiswal, Lily; Park, Yang-Kyun; Park, Sun-Young; Kim, So-Young; Kim, Haeng-Ran; Moon, Jae-Hak; Ham, Kyung-Sik

    2015-01-01

    We investigated the antihypertensive effects of Artemisia scoparia (AS) in spontaneously hypertensive rats (SHR). The rats were fed diets containing 2% (w/w) hot water extracts of AS aerial parts for 6 weeks. The AS group had significantly lower systolic and diastolic blood pressure levels than the control group. The AS group also had lower angiotensin I converting enzyme (ACE) activity and angiotensin II content in serum compared to the control group. The AS group showed higher vascular endothelial growth factor and lower ras homolog gene family member A expression levels in kidney compared to the control group. The AS group had significantly lower levels of plasma lipid oxidation and protein carbonyls than the control group. One new and six known compounds were isolated from AS by guided purification. The new compound was determined to be 4'-O-β-D-glucopyranoyl (E)-4-hydroxy-3-methylbut-2-enyl benzoate, based on its nuclear magnetic resonance and electrospray ionization-mass spectroscopy data. PMID:26540035

  11. Antihypertensive Effects of Artemisia scoparia Waldst in Spontaneously Hypertensive Rats and Identification of Angiotensin I Converting Enzyme Inhibitors.

    PubMed

    Cho, Jeong-Yong; Park, Kyung-Hee; Hwang, Do Young; Chanmuang, Saoraya; Jaiswal, Lily; Park, Yang-Kyun; Park, Sun-Young; Kim, So-Young; Kim, Haeng-Ran; Moon, Jae-Hak; Ham, Kyung-Sik

    2015-01-01

    We investigated the antihypertensive effects of Artemisia scoparia (AS) in spontaneously hypertensive rats (SHR). The rats were fed diets containing 2% (w/w) hot water extracts of AS aerial parts for 6 weeks. The AS group had significantly lower systolic and diastolic blood pressure levels than the control group. The AS group also had lower angiotensin I converting enzyme (ACE) activity and angiotensin II content in serum compared to the control group. The AS group showed higher vascular endothelial growth factor and lower ras homolog gene family member A expression levels in kidney compared to the control group. The AS group had significantly lower levels of plasma lipid oxidation and protein carbonyls than the control group. One new and six known compounds were isolated from AS by guided purification. The new compound was determined to be 4'-O-β-D-glucopyranoyl (E)-4-hydroxy-3-methylbut-2-enyl benzoate, based on its nuclear magnetic resonance and electrospray ionization-mass spectroscopy data. PMID:26561794

  12. Divergent actions by inhibitors of DP IV and APN family enzymes on CD4+ Teff cell motility and functions.

    PubMed

    Biton, Aliza; Ansorge, Siegfried; Bank, Ute; Täger, Michael; Reinhold, Dirk; Brocke, Stefan

    2011-12-01

    Dipeptidyl peptidase IV (DP IV)/CD26 and aminopeptidase N (APN)/CD13 family enzymes control T cell functions. We have previously defined these peptidases as targets to treat autoimmune disease, but the underlying mechanism is unclear. Here, we determined the effect of enzymatic inhibitors on chemotaxis by CD4+ effector T (Teff) cells. Exposure of Teff cells to the inhibitor of DP IV activity, Lys[Z(NO2)]-pyrrolidide (LZNP) and the inhibitor of APN activity, actinonin has no effect on chemotaxis or unstimulated cell migration, even at high inhibitor concentrations. LZNP and actinonin also fail to suppress migration of unfractionated lymph node cells, excluding paracrine action through other leukocyte subsets. In contrast, inhibition of DP IV and APN activities selectively suppresses lymphocyte functions including proliferation and production of the T helper type (Th)1 cytokine IFN-γ, the Th17 cytokine IL-17, as well as TNF-α, and ameliorates autoimmunity in vivo. The present results combined with previous studies suggest that LZNP and actinonin do not prevent migration of pathogenic Teff cells into target tissues, but rather suppress disease through inhibitor induced release of TGF-β by T cells at the site of inflammation.

  13. Functional comparison of homologous members of three groups of Kunitz-type enzyme inhibitors from potato tubers (Solanum tuberosum L.).

    PubMed

    Heibges, A; Salamini, F; Gebhardt, C

    2003-07-01

    For functional studies, nine cDNAs encoding Kunitz-type enzyme inhibitors from potato tubers were expressed as GST (glutathione S transferase)-tagged fusion proteins in the fission yeast Schizosaccharomyces pombe. The inhibitors represented the three major homology groups A, B and C found in tubers. Members of the same homology group were at least 90% identical in sequence. The purified GST fusion proteins were tested for their ability to inhibit the proteases trypsin, alpha-chymotrypsin, subtilisin, papain and aspergillopepsin I, and for inhibition of the growth of fungi. Fusion proteins belonging to the same and different homology groups were found to exhibit distinct protease inhibition profiles. Removal of the GST tag by cleavage with enterokinase did not change the inhibition profile but increased the inhibitory activity. Group A and B inhibitors affected the proteases to different extents, whereas group C inhibitors showed only weak or no protease inhibition. One fusion protein completely inhibited aspergillopepsin I. One fusion protein each of groups A and B strongly inhibited mycelial growth of the fungus Fusarium moniliforme. The results suggest functional polymorphism among closely related members of the Kunitz-type inhibitor family.

  14. 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

  15. Correlation between ultra-high performance liquid chromatography-tandem mass spectrometry and reversed-phase thin-layer chromatography hydrophobicity data for evaluation of angiotensin-converting enzyme inhibitors absorption.

    PubMed

    Odovic, Jadranka V; Markovic, Bojan D; Injac, Rade D; Vladimirov, Sote M; Karljikovic-Rajic, Katarina D

    2012-10-01

    In this research seven ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril) were studied to evaluate the correlation between their absorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS) and reversed-phase thin-layer chromatography (RP-TLC) hydrophobicity data (φ(0) or C(0) parameters, respectively). Their absorption values were in the range of 25-60%, while calculated KOWWIN logP values were from -0.94 to 6.61. Additionally, perindopril (absorption 70%, KOWWIN logP 2.59) and moexipril (absorption 22%, KOWWIN logP 3.36) were introduced for the theoretical considerations due to their high/low absorption values which were on the opposite sites in comparison with the majority of ACE inhibitors (25-60%). In the theoretical considerations it was shown that the solubility data (logS) must be considered, as independent variable, simultaneously with KOWWIN logP to obtain reliable correlation (r(2)=0.7208) between absorption and ACE inhibitors lipophilicity. As the main topic of this study, the relationships between literature available and absorption data predicted by multiple linear regression (MLR) using logS values besides chromatographically obtained hydrophobicity parameters C(0) (r(2)=0.6424) or φ(0) (r(2)=0.6762) were studied proving that these parameters could be used in ACE inhibitors absorption evaluation. The UHPLC-MS method provides the direct application of experimentally obtained φ(0) values that is the advantage of this method. For better MLR correlation of ACE inhibitors absorption with C(0) parameters (RP-TLC) and logS, mathematical conversion of C(0) parameters to logC(0) values was necessary based on requisite for probability value of regression analysis (P<0.05). The accordance and differences between hydrophobicity parameters obtained by UHPLC-MS and RP-TLC were defined.

  16. 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

  17. Large negatively charged organic host molecules as inhibitors of endonuclease enzymes.

    PubMed

    Tauran, Yannick; Anjard, Christophe; Kim, Beomjoon; Rhimi, Moez; Coleman, Anthony W

    2014-10-01

    Three large negatively charged organic host molecules; β-cyclodextrin sulphate, para-sulphonato-calix[6]arene and para-sulphonato-calix[8]arene have been shown to be effective inhibitors of endonuclease in the low micromolar range, additionally para-sulphonato-calix[8]arene is a partial inhibitor of rhDNase I.

  18. Two sites of action for PLD2 inhibitors: The enzyme catalytic center and an allosteric, phosphoinositide biding pocket.

    PubMed

    Ganesan, Ramya; Mahankali, Madhu; Alter, Gerald; Gomez-Cambronero, Julian

    2015-03-01

    Phospholipase D (PLD) has been implicated in many physiological functions, such as chemotaxis and phagocytosis, as well as pathological functions, such as cancer cell invasion and metastasis. New inhibitors have been described that hamper the role of PLD in those pathologies but their site of action is not known. We have characterized the biochemical and biological behavior of the PLD1/2 dual inhibitor 5-Fluoro-2-indolyl des-chlorohalopemide (FIPI), and the specific PLD2 inhibitor, N-[2-[1-(3-Fluorophenyl)-4-oxo-1,3,-8-triazaspiro[4.5]dec-8-yl]ethyl]-2-naphthalenecarboxamide (NFOT), and found that both FIPI and NFOT are mixed-kinetics inhibitors. Mutagenesis studies indicate that FIPI binds at S757 of PLD2, which is within the HKD2 catalytic site of the enzyme, whereas NFOT binds to PLD2 at two different sites, one being at S757/S648 and another to an allosteric site that is a natural site occupied by PIP2 (R210/R212). This latter site, along with F244/L245/L246, forms a hydrophobic pocket in the PH domain. The mechanism of action of FIPI is a direct effect on the catalytic site (and as such inhibits both PLD1 and PLD2 isoforms), whereas PLD2 affects both the catalytic site (orthosteric) and blocks PIP2 binding to PLD2 (allosteric), which negates the natural enhancing role of PIP2. Moreover, NFOT prevents cell invasion of cancer cells, which does not occur in cells overexpressing PLD2-F244A/L245A/L246A, or PLD2-R210A/R212A, or PLD2-S757/S648 mutants. This study provides new specific knowledge of enzyme regulation and mechanisms of activation and inhibition of PLD2 that are necessary to understand its role in cell signaling and to develop new inhibitors for cancer cell invasion and metastasis.

  19. 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

  20. Structure-based Design of Potent HIV-1 Protease Inhibitors with Modified P1 - Biphenyl Ligands: Synthesis, Biological Evaluation, and Enzyme-inhibitor X-ray Structural studies

    PubMed Central

    Ghosh, Arun K.; Yu, Xufen; Osswald, Heather L.; Agniswamy, Johnson; Wang, Yuan-Fang; Amano, Masayuki; Weber, Irene T.; Mitsuya, Hiroaki

    2016-01-01

    We report the design, synthesis, X-ray structural studies, and biological evaluation of a novel series of HIV-1 protease inhibitors. We designed a variety of functionalized biphenyl derivatives to make enhanced van der Waals interactions in the S1 subsite of HIV-1 protease. These biphenyl derivatives were conveniently synthesized using a Suzuki-Miyaura cross-coupling reaction as the key step. We examined the potential of these functionalized biphenyl-derived P1 ligands in combination with 3-(S)-tetrahydrofuranyl urethane and bis-tetrahydrofuranyl urethane as the P2 ligands. Inhibitor 21e, with a 2-methoxy-1, 1’-biphenyl derivative as P1 ligand and bis-THF as the P2 ligand, displayed the most potent enzyme inhibitory and antiviral activity. This inhibitor also exhibited potent activity against a panel of multidrug-resistant HIV-1 variants. A high resolution X-ray crystal structure of related Boc-derivative 17a-bound HIV-1 protease provided important molecular insight into the ligand-binding site interactions of the biphenyl core in the S1 subsite of HIV-1 protease. PMID:26107245

  1. Delayed toxicity of two chitinolytic enzyme inhibitors (psammaplin a and pentoxifylline) against eastern subterranean termites (Isoptera: Rhinotermitidae).

    PubMed

    Hiusen, Timothy J; Kamble-Shripat, T

    2013-08-01

    By using a no-choice feeding bioassay, delayed toxicity and concentration-dependent mortality of two chitinolytic enzyme inhibitors, pentoxifylline and psammaplin A, were evaluated by determining LT50, LT90, and LT99 (lethal time) against the economically important eastern subterranean termite, Reticulitermes flavipes (Kollar). Pentoxifylline- and psammaplin A-incorporated diets (filter paper) were assayed at 0.01, 0.02, 0.04, 0.08, and 0.21% and 0.0375, 0.075, 0.15, and 0.3% active ingredient (wt:wt), respectively. Acetone-only treated filter paper served as diet for the control treatments. Termite workers were allowed to feed on diet until 100% test population mortality occurred (80-95 d). Both chitinase inhibitors were shown to be toxic to R. flavipes. Concentration-dependent toxicity occurred within the pentoxifylline treatments over the range of 0.01-0.08%, with 0.08% treatments producing an LT50 of 32.2 d. However, mortality in response to psammaplin A treatments lacked concentration-dependent toxicity. Treatment with 0.3% psammaplin A produced an LT50 of 21.3 d. Mortality in response to lower psammaplin A treatments displayed no concentration-dependent trends. This study provides the first report on delayed toxicity of chitinolytic enzyme inhibitors against eastern subterranean termites (order Isoptera) and toxicological data on pentoxifylline and psammaplin A over a range of concentrations.

  2. 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

  3. 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.

  4. Outside or inside: role of the subcellular localization of DP4-like enzymes for substrate conversion and inhibitor effects.

    PubMed

    Bank, Ute; Heimburg, Anke; Wohlfarth, Astrid; Koch, Gudrun; Nordhoff, Karsten; Julius, Heiko; Helmuth, Martin; Breyer, Doreen; Reinhold, Dirk; Täger, Michael; Ansorge, Siegfried

    2011-03-01

    The discovery of the DP4-related enzymes DP8 and DP9 raised controversial discussion regarding the physiological and pathophysiological function of distinct members of the DP4 family. Particularly with regard to their potential relevance in regulating immune functions, it is of interest to know which role the subcellular distribution of the enzymes play. Synthetic substrates as well as low molecular weight inhibitors are widely used as tools, but little is yet known regarding their features in cell experiments, such as their plasma membrane penetration capacity. The fluorogenic substrates Gly-Pro-AMC or (Ala-Pro)₂-R110 predominantly detect plasma membrane-bound activities of viable cells (less than 0.1% of fluorochromes R110 or AMC inside viable cells after 1 h incubation). Additionally, the selective and non-selective DP8/9 inhibitors allo-Ile-isoindoline and Lys[Z(NO₂)]-pyrrolidide were found to be incapable of passing the plasma membrane easily. This suggests that previously reported cellular effects are not due to inhibition of the cytosolic enzymes DP8 or DP9. Moreover, our enzymatic studies with viable cells provided evidence that DP8 and/or DP9 are also present on the surface of immune cells under certain circumstances and could gain relevance particularly in the absence of DP4 expression. In summary, in cells which do express DP4 on the surface, this archetypical member of the DP4 family is the most relevant peptidase in the regulation of cellular functions.

  5. 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.

  6. Recent Update on Human Lactate Dehydrogenase Enzyme 5 (hLDH5) Inhibitors: A Promising Approach for Cancer Chemotherapy.

    PubMed

    Rani, Reshma; Kumar, Vinit

    2016-01-28

    Human lactate dehydrogenase (hLDH5), a glycolytic enzyme responsible for the conversion of pyruvate to lactate coupled with oxidation of NADH to NAD(+), plays a crucial role in the promotion of glycolysis in invasive tumor cells. Recently, hLDH5 has been considered a vital therapeutic target for invasive cancers. Selective inhibition of hLDH5 using small molecules holds potential prospects for the treatment of cancer and associated diseases. Consequently, significant progress has been made in the discovery of selective small-molecule hLDH5 inhibitors displaying remarkable inhibitory potencies. The purpose of this review is to discuss briefly the roles of hLDH isoforms and to compile small hLDH5 inhibitors into groups based on their chemical classes and pharmacological applications.

  7. In vitro modeling of angiotensin-converting enzyme inhibitor's absorption with chromatographic retention data and selected molecular descriptors.

    PubMed

    Odović, Jadranka; Marković, Bojan; Vladimirov, Sote; Karljiković-Rajić, Katarina

    2014-03-15

    Set of nine angiotensin-converting enzyme inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril, perindopril and moexipril) were studied to evaluate the correlation between their intestinal absorption and salting-out thin-layer chromatography hydrophobicity parameters (RM(0) or C0) obtained by ascending technique applying four different salts, (NH4)2SO4, NH4NO3, NH4Cl and NaCl as mobile phases. The best correlations between KOWWIN logP and both hydrophobicity parameters, RM(0) and C0, (R(2)>0.850) were observed for NaCl (1.0-3.0M) while the lowest R(2) was obtained for (NH4)2SO4 (0.649 and 0.427, respectively) due to highest salting-out effect of (NH4)2SO4. The effect of selected inorganic salts in the salting-out mobile phases, on the solutes solubility and retention was evaluated. The topological polar surface area should be selected as independent variable (only this molecular descriptor showed low correlation with chromatographic hydrophobicity parameters) for multiple linear regression analysis, to obtain reliable correlation between angiotensin-converting enzyme inhibitor's intestinal absorption data and salting-out thin-layer chromatograpic hydrophobicity parameters. These correlations provide R(2)=0.823 for RM(0) or R(2)=0.799 for C0 indicating good relationship between predicted and literature available intestinal absorption (ranged from 22% to 70%) of investigated angiotensin-converting enzyme inhibitors. The proposed in vitro model was checked with three in addition experimentally analyzed drugs, zofenopril, trandolapril and captoril. The satisfactory absorption prediction was obtained for zofenopril and trandolapril, while divergence established for captopril resulted from considerably different structure.

  8. In silico screening of mutational effects on enzyme-proteic inhibitor affinity: a docking-based approach

    PubMed Central

    Dell'Orco, Daniele; De Benedetti, Pier Giuseppe; Fanelli, Francesca

    2007-01-01

    Background Molecular recognition between enzymes and proteic inhibitors is crucial for normal functioning of many biological pathways. Mutations in either the enzyme or the inhibitor protein often lead to a modulation of the binding affinity with no major alterations in the 3D structure of the complex. Results In this study, a rigid body docking-based approach has been successfully probed in its ability to predict the effects of single and multiple point mutations on the binding energetics in three enzyme-proteic inhibitor systems. The only requirement of the approach is an accurate structural model of the complex between the wild type forms of the interacting proteins, with the assumption that the architecture of the mutated complexes is almost the same as that of the wild type and no major conformational changes occur upon binding. The method was applied to 23 variants of the ribonuclease inhibitor-angiogenin complex, to 15 variants of the barnase-barstar complex, and to 8 variants of the bovine pancreatic trypsin inhibitor-β Trypsin system, leading to thermodynamic and kinetic estimates consistent with in vitro data. Furthermore, simulations with and without explicit water molecules at the protein-protein interface suggested that they should be included in the simulations only when their positions are well defined both in the wild type and in the mutants and they result to be relevant for the modulation of mutational effects on the association process. Conclusion The correlative models built in this study allow for predictions of mutational effects on the thermodynamics and kinetics of association of three substantially different systems, and represent important extensions of our computational approach to cases in which it is not possible to estimate the absolute free energies. Moreover, this study is the first example in the literature of an extensive evaluation of the correlative weights of the single components of the ZDOCK score on the thermodynamics and

  9. 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

  10. 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.

  11. Are angiotensin-converting enzyme inhibitors or angiotensin 2 receptor antagonists effective in heart failure with preserved ejection fraction?

    PubMed

    Rain, Carmen; Rada, Gabriel

    2015-03-19

    Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) constitute first line treatment for patients with heart failure with reduced ejection fraction. However, their role in patients with preserved ejection fraction remains controversial. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified five systematic reviews including five randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded ACEI and ARB do not decrease mortality or hospitalization risk in this group of patients.

  12. Inhibitors of the Glyoxylate Cycle Enzyme ICL1 in Candida albicans for Potential Use as Antifungal Agents

    PubMed Central

    Cheah, Hong-Leong; Lim, Vuanghao; Sandai, Doblin

    2014-01-01

    Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1), are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF), rosmarinic acid (ROS), and apigenin (API)) were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis. PMID:24781056

  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. UDP-galactose 4'-epimerase from the liver fluke, Fasciola hepatica: biochemical characterization of the enzyme and identification of inhibitors.

    PubMed

    Zinsser, Veronika L; Lindert, Steffen; Banford, Samantha; Hoey, Elizabeth M; Trudgett, Alan; Timson, David J

    2015-03-01

    Leloir pathway enzyme uridine diphosphate (UDP)-galactose 4'-epimerase from the common liver fluke Fasciola hepatica (FhGALE) was identified and characterized. The enzyme can be expressed in, and purified from, Escherichia coli. The recombinant enzyme is active: the K(m) (470 μM) is higher than the corresponding human enzyme (HsGALE), whereas the k(cat) (2.3 s(-1)) is substantially lower. FhGALE binds NAD(+) and has shown to be dimeric by analytical gel filtration. Like the human and yeast GALEs, FhGALE is stabilized by the substrate UDP-galactose. Molecular modelling predicted that FhGALE adopts a similar overall fold to HsGALE and that tyrosine 155 is likely to be the catalytically critical residue in the active site. In silico screening of the National Cancer Institute Developmental Therapeutics Program library identified 40 potential inhibitors of FhGALE which were tested in vitro. Of these, 6 showed concentration-dependent inhibition of FhGALE, some with nanomolar IC50 values. Two inhibitors (5-fluoroorotate and N-[(benzyloxy)carbonyl]leucyltryptophan) demonstrated selectivity for FhGALE over HsGALE. These compounds also thermally destabilized FhGALE in a concentration-dependent manner. Interestingly, the selectivity of 5-fluoroorotate was not shown by orotic acid, which differs in structure by 1 fluorine atom. These results demonstrate that, despite the structural and biochemical similarities of FhGALE and HsGALE, it is possible to discover compounds which preferentially inhibit FhGALE.

  15. Binding to large enzyme pockets: small-molecule inhibitors of trypanothione reductase.

    PubMed

    Persch, Elke; Bryson, Steve; Todoroff, Nickolay K; Eberle, Christian; Thelemann, Jonas; Dirdjaja, Natalie; Kaiser, Marcel; Weber, Maria; Derbani, Hassan; Brun, Reto; Schneider, Gisbert; Pai, Emil F; Krauth-Siegel, R Luise; Diederich, François

    2014-08-01

    The causative agents of the parasitic disease human African trypanosomiasis belong to the family of trypanosomatids. These parasitic protozoa exhibit a unique thiol redox metabolism that is based on the flavoenzyme trypanothione reductase (TR). TR was identified as a potential drug target and features a large active site that allows a multitude of possible ligand orientations, which renders rational structure-based inhibitor design highly challenging. Herein we describe the synthesis, binding properties, and kinetic analysis of a new series of small-molecule inhibitors of TR. The conjunction of biological activities, mutation studies, and virtual ligand docking simulations led to the prediction of a binding mode that was confirmed by crystal structure analysis. The crystal structures revealed that the ligands bind to the hydrophobic wall of the so-called "mepacrine binding site". The binding conformation and potency of the inhibitors varied for TR from Trypanosoma brucei and T. cruzi.

  16. Absence of cell surface expression of human ACE leads to perinatal death.

    PubMed

    Michaud, Annie; Acharya, K Ravi; Masuyer, Geoffrey; Quenech'du, Nicole; Gribouval, Olivier; Morinière, Vincent; Gubler, Marie-Claire; Corvol, Pierre

    2014-03-15

    Renal tubular dysgenesis (RTD) is a recessive autosomal disease characterized most often by perinatal death. It is due to the inactivation of any of the major genes of the renin-angiotensin system (RAS), one of which is the angiotensin I-converting enzyme (ACE). ACE is present as a tissue-bound enzyme and circulates in plasma after its solubilization. In this report, we present the effect of different ACE mutations associated with RTD on ACE intracellular trafficking, secretion and enzymatic activity. One truncated mutant, R762X, responsible for neonatal death was found to be an enzymatically active, secreted form, not inserted in the plasma membrane. In contrast, another mutant, R1180P, was compatible with life after transient neonatal renal insufficiency. This mutant was located at the plasma membrane and rapidly secreted. These results highlight the importance of tissue-bound ACE versus circulating ACE and show that the total absence of cell surface expression of ACE is incompatible with life. In addition, two missense mutants (W594R and R828H) and two truncated mutants (Q1136X and G1145AX) were also studied. These mutants were neither inserted in the plasma membrane nor secreted. Finally, the structural implications of these ACE mutations were examined by molecular modelling, which suggested some important structural alterations such as disruption of intra-molecular non-covalent interactions (e.g. salt bridges).

  17. Toward very potent, non-covalent organophosphonate inhibitors of cathepsin C and related enzymes by 2-amino-1-hydroxy-alkanephosphonates dipeptides.

    PubMed

    Drąg, Marcin; Wieczerzak, Ewa; Pawełczak, Małgorzata; Berlicki, Łukasz; Grzonka, Zbigniew; Kafarski, Paweł

    2013-08-01

    Cathepsins play an important role in several human disorders and therefore the design and synthesis of their inhibitors attracts considerable interest in current medicinal chemistry approaches. Due to the presence of a strong sulphydryl nucleophile in the active center of the cysteine type cathepsins, most strategies to date have yielded covalent inhibitors. Here we present a series of non-covalent β-amino-α-hydroxyalkanephosphonate dipeptidic inhibitors of cathepsin C, ranking amongst the best low-molecular weight inhibitors of this enzyme. Their binding modes determined by molecular modelling indicate that the hydroxymethyl fragment of the molecule, not the phosphonate moiety, acts as a transition state analogue of peptide bond hydrolysis. These dipeptide mimetics appear also to be potent inhibitors of other cysteine proteases such as papain, cathepsin B and cathepsin K, thus providing new leading structures for these medicinally important enzymes.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Discovery of desketoraloxifene analogues as inhibitors of mammalian, Pseudomonas aeruginosa, and NAPE phospholipase D enzymes.

    PubMed

    Scott, Sarah A; Spencer, Cierra T; O'Reilly, Matthew C; Brown, Kyle A; Lavieri, Robert R; Cho, Chul-Hee; Jung, Dai-Il; Larock, Richard C; Brown, H Alex; Lindsley, Craig W

    2015-02-20

    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.

  4. 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

  5. Chemical inhibitors of CYP450 enzymes in liver microsomes: combining selectivity and unbound fractions to guide selection of appropriate concentration in phenotyping assays.

    PubMed

    Nirogi, Ramakrishna; Palacharla, Raghava Choudary; Uthukam, Venkatesham; Manoharan, Arunkumar; Srikakolapu, Surya Rao; Kalaikadhiban, Ilayaraja; Boggavarapu, Rajesh Kumar; Ponnamaneni, Ranjith Kumar; Ajjala, Devender Reddy; Bhyrapuneni, Gopinadh

    2015-02-01

    1. Chemical inhibition is the widely used method in reaction phenotyping assays for estimation of specific enzyme contribution to a given metabolic pathway. The results from phenotyping assays depend on the selectivity of chemical inhibitor and the concentration of inhibitor used in the incubation. 2. The higher protein concentrations used in the in vitro phenotyping assays will impact the inhibitory potency of chemical inhibitors. The objective of the study is to evaluate comprehensively the selectivity of chemical inhibitors and to guide in selecting appropriate concentration of the chemical inhibitors to be used in the phenotyping assays based on unbound fractions. 3. Selectivity of chemical inhibitors against nine major CYP450 isoforms was determined in liver microsomes using standard probe substrates. The unbound fractions of the selective inhibitors were determined in human liver microsomes using high-throughput equilibrium dialysis. Combining unbound inhibitor concentrations that are required to inhibit the CYP450 activities by 90% and unbound fractions of the chemical inhibitors in liver microsomes appropriate total concentrations of the inhibitors to be used in the phenotyping assays were reported. 4. The findings suggest that non-specific binding of the chemical inhibitors need to be taken into account while selecting concentrations for phenotyping assays.

  6. [Response of N transformation related soil enzyme activities to inhibitor applications].

    PubMed

    Chen, Lijun; Wu, Zhijie; Jiang, Yong; Zhou, Likai

    2002-09-01

    With an aerobic incubation test, this paper studied the response of soil urease, nitrate reductase, nitrite reductase, and hydroxylamine reductase to urease inhibitor hydroquinone (HQ) applied in combination with nitrification inhibitor encapsulated calcium carbide (HQ + ECC) or dicyandiamide (HQ + DCD). The results showed that HQ + DCD could inhibit urease activity and increase activities of nitrate reductase, nitrite reductase, and hydroxylamine reductase significantly in comparison with CK, HQ and HQ + ECC. Under the condition of our test, there existed a significant relationship between soil urease, nitrate reductase, nitrite reductase, and hydroxylamine reductase activities and soil NH4+ and NO3- contents, NH3 volatilization and N2O emission rate, and regression analysis indicated that there were significantly positive relationships between soil urease, nitrite reductase and hydroxylamine reductase activities.

  7. 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

  8. 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

  9. An enzyme-linked immunosorbent assay to screen for inhibitors of the oncogenic anaplastic lymphoma kinase.

    PubMed

    Gunby, Rosalind Helen; Tartari, Carmen Julia; Porchia, Francesca; Donella-Deana, Arianna; Scapozza, Leonardo; Gambacorti-Passerini, Carlo

    2005-07-01

    The discovery of novel anti-cancer drugs targeting anaplastic lymphoma kinase (ALK), an oncogenic tyrosine kinase, raises the need for in vitro assays suitable for screening compounds for ALK inhibition. To this aim we have developed and optimized an ALK-specific enzyme-linked immunosorbent assay that employs a novel ALK peptide substrate and purified ALK kinase domain. PMID:15996942

  10. Screening of neuraminidase inhibitors from traditional Chinese medicines by integrating capillary electrophoresis with immobilized enzyme microreactor.

    PubMed

    Zhao, Haiyan; Chen, Zilin

    2014-05-01

    A simple and effective neuraminidase-immobilized capillary microreactor was fabricated by glutaraldehyde cross-linking technology for screening the neuraminidase inhibitors from traditional Chinese medicines. The substrate and product were separated by CE in short-end injection mode within 2 min. Dual-wavelength ultraviolet detection was employed to eliminate the interference from the screened compounds. The parameters relating to the separation efficiency and the activity of immobilized neuraminidase were systematically evaluated. The activity of the immobilized neuraminidase remained 90% after 30 days storage at 4°C. The immobilized NA microreactor could be continuously used for more than 200 runs. The Michaelis-Menten constant of neuraminidase was determined by the microreactor as 136.6 ± 10.8 μM. In addition, six in eighteen natural products were found as potent inhibitors and the inhibition potentials were ranked in the following order: bavachinin>bavachin>baicalein>baicalin>chrysin and vitexin. The half-maximal inhibitory concentrations were 59.52 ± 4.12, 65.28 ± 1.07, 44.79 ± 1.21 and 31.62 ± 2.04 for baicalein, baicalin, bavachin and bavachinin, respectively. The results demonstrated that the neuraminidase-immobilized capillary microreactor was a very effective tool for screening neuraminidase inhibitors from traditional Chinese medicines.

  11. 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

  12. 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

  13. ALTUS Cumulus Electrification Study (ACES)

    NASA Technical Reports Server (NTRS)

    Kim, Tony; Blakeslee, Richard; Russell, Larry W. (Technical Monitor)

    2002-01-01

    The ALTUS Cumulus Electrification Study (ACES) is an uninhabited aerial vehicle (UAV)-based project that will investigate thunderstorms in the vicinity of the Florida Everglades in August 2002. ACES is being conducted to both investigate storm electrical activity and its relationship to storm morphology, and validate Tropical Rainfall Measurement Mission (TRMM) satellite measurements. In addition, as part of NASA's UAV-based science demonstration program, this project will provide a scientifically useful demonstration of the utility and promise of UAV platforms for Earth science and applications observations. Part of the demonstration involves getting approvals from the Federal Aviation Administration and the NASA airworthiness flight safety review board. ACES will employ the ALTUS II aircraft, built by General Atomics - Aeronautical Systems, Inc. Key science objectives simultaneously addressed by ACES are to: (1) investigate lightning-storm relationships, (2) study storm electrical budgets, and (3) provide Lightning Imaging Sensor validation. The ACES payload, already developed and flown on ALTUS, includes electrical, magnetic, and optical sensors to remotely characterize the lightning activity and the electrical environment within and around thunderstorms. ACES will contribute important electrical and optical measurements not available from other sources. Also, the high altitude vantage point of the UAV observing platform (up to 55,000 feet) offers a useful 'cloud-top' perspective. By taking advantage of its slow flight speed (70 to 100 knots), long endurance, and high altitude flight, the ALTUS will be flown near, and when possible, above (but never into) thunderstorms for long periods of time, allowing investigations to be conducted over entire storm life cycles. In addition, concurrent ground-based observations will enable the UAV measurements to be more completely interpreted and evaluated in the context of the thunderstorm structure, evolution, and

  14. 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

  15. 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.

  16. Transition-state inhibitors of purine salvage and other prospective enzyme targets in malaria.

    PubMed

    Ducati, Rodrigo G; Namanja-Magliano, Hilda A; Schramm, Vern L

    2013-07-01

    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.

  17. 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

  18. 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

  19. 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

  20. The Hepatitis B Virus Ribonuclease H Is Sensitive to Inhibitors of the Human Immunodeficiency Virus Ribonuclease H and Integrase Enzymes

    PubMed Central

    Tavis, John E.; Totten, Michael; Cao, Feng; Michailidis, Eleftherios; Aurora, Rajeev; Meyers, Marvin J.; Jacobsen, E. Jon; Parniak, Michael A.; Sarafianos, Stefan G.

    2013-01-01

    Nucleos(t)ide analog therapy blocks DNA synthesis by the hepatitis B virus (HBV) reverse transcriptase and can control the infection, but treatment is life-long and has high costs and unpredictable long-term side effects. The profound suppression of HBV by the nucleos(t)ide analogs and their ability to cure some patients indicates that they can push HBV to the brink of extinction. Consequently, more patients could be cured by suppressing HBV replication further using a new drug in combination with the nucleos(t)ide analogs. The HBV ribonuclease H (RNAseH) is a logical drug target because it is the second of only two viral enzymes that are essential for viral replication, but it has not been exploited, primarily because it is very difficult to produce active enzyme. To address this difficulty, we expressed HBV genotype D and H RNAseHs in E. coli and enriched the enzymes by nickel-affinity chromatography. HBV RNAseH activity in the enriched lysates was characterized in preparation for drug screening. Twenty-one candidate HBV RNAseH inhibitors were identified using chemical structure-activity analyses based on inhibitors of the HIV RNAseH and integrase. Twelve anti-RNAseH and anti-integrase compounds inhibited the HBV RNAseH at 10 µM, the best compounds had low micromolar IC50 values against the RNAseH, and one compound inhibited HBV replication in tissue culture at 10 µM. Recombinant HBV genotype D RNAseH was more sensitive to inhibition than genotype H. This study demonstrates that recombinant HBV RNAseH suitable for low-throughput antiviral drug screening has been produced. The high percentage of compounds developed against the HIV RNAseH and integrase that were active against the HBV RNAseH indicates that the extensive drug design efforts against these HIV enzymes can guide anti-HBV RNAseH drug discovery. Finally, differential inhibition of HBV genotype D and H RNAseHs indicates that viral genetic variability will be a factor during drug development. PMID

  1. The hepatitis B virus ribonuclease H is sensitive to inhibitors of the human immunodeficiency virus ribonuclease H and integrase enzymes.

    PubMed

    Tavis, John E; Cheng, Xiaohong; Hu, Yuan; Totten, Michael; Cao, Feng; Michailidis, Eleftherios; Aurora, Rajeev; Meyers, Marvin J; Jacobsen, E Jon; Parniak, Michael A; Sarafianos, Stefan G

    2013-01-01

    Nucleos(t)ide analog therapy blocks DNA synthesis by the hepatitis B virus (HBV) reverse transcriptase and can control the infection, but treatment is life-long and has high costs and unpredictable long-term side effects. The profound suppression of HBV by the nucleos(t)ide analogs and their ability to cure some patients indicates that they can push HBV to the brink of extinction. Consequently, more patients could be cured by suppressing HBV replication further using a new drug in combination with the nucleos(t)ide analogs. The HBV ribonuclease H (RNAseH) is a logical drug target because it is the second of only two viral enzymes that are essential for viral replication, but it has not been exploited, primarily because it is very difficult to produce active enzyme. To address this difficulty, we expressed HBV genotype D and H RNAseHs in E. coli and enriched the enzymes by nickel-affinity chromatography. HBV RNAseH activity in the enriched lysates was characterized in preparation for drug screening. Twenty-one candidate HBV RNAseH inhibitors were identified using chemical structure-activity analyses based on inhibitors of the HIV RNAseH and integrase. Twelve anti-RNAseH and anti-integrase compounds inhibited the HBV RNAseH at 10 µM, the best compounds had low micromolar IC(50) values against the RNAseH, and one compound inhibited HBV replication in tissue culture at 10 µM. Recombinant HBV genotype D RNAseH was more sensitive to inhibition than genotype H. This study demonstrates that recombinant HBV RNAseH suitable for low-throughput antiviral drug screening has been produced. The high percentage of compounds developed against the HIV RNAseH and integrase that were active against the HBV RNAseH indicates that the extensive drug design efforts against these HIV enzymes can guide anti-HBV RNAseH drug discovery. Finally, differential inhibition of HBV genotype D and H RNAseHs indicates that viral genetic variability will be a factor during drug development. PMID

  2. 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

  3. Angiotensin converting enzyme inhibitors and angiotensin II receptor antagonist attenuate tumor growth via polarization of neutrophils toward an antitumor phenotype

    PubMed Central

    Shrestha, Sanjeeb; Noh, Jae Myoung; Kim, Shin-Yeong; Ham, Hwa-Yong; Kim, Yeon-Ja; Yun, Young-Jin; Kim, Min-Ju; Kwon, Min-Soo; Song, Dong-Keun; Hong, Chang-Won

    2016-01-01

    ABSTRACT Tumor microenvironments polarize neutrophils to protumoral phenotypes. Here, we demonstrate that the angiotensin converting enzyme inhibitors (ACEis) and angiotensin II type 1 receptor (AGTR1) antagonist attenuate tumor growth via polarization of neutrophils toward an antitumoral phenotype. The ACEis or AGTR1 antagonist enhanced hypersegmentation of human neutrophils and increased neutrophil cytotoxicity against tumor cells. This neutrophil hypersegmentation was dependent on the mTOR pathway. In a murine tumor model, ACEis and AGTR1 antagonist attenuated tumor growth and enhanced neutrophil hypersegmentation. ACEis inhibited tumor-induced polarization of neutrophils to a protumoral phenotype. Neutrophil depletion reduced the antitumor effect of ACEi. Together, these data suggest that the modulation of Ang II pathway attenuates tumor growth via polarization of neutrophils to an antitumoral phenotype. PMID:26942086

  4. 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.

  5. 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

  6. Targeting protein neddylation with an NEDD8-activating enzyme inhibitor MLN4924 induced apoptosis or senescence in human lymphoma cells

    PubMed Central

    Wang, Yanchun; Luo, Zhongguang; Pan, Yongfu; Wang, Weige; Zhou, Xiaoyan; Jeong, Lak Shin; Chu, Yiwei; Liu, Jie; Jia, Lijun

    2015-01-01

    Recent studies indicate that post-translational protein neddylation is required for the maintenance of cell viability in several lymphoma cell lines, while inhibition of the neddylation pathway with an NEDD8-activating enzyme (NAE) inhibitor MLN4924 induces apoptosis in lymphoma cells. However, the mechanism by which neddylation inhibition induces apoptosis in lymphoma cells has not been fully elucidated. Moreover, it is unknown whether neddylation inhibition triggers non-apoptotic cell-killing responses, such as cell senescence, in lymphoma cells. Here, we report that MLN4924 specifically inhibited protein neddylation, inactivated cullin-RING E3 ligase (CRL), the best-known neddylation substrate, and induced the accumulation of tumor-suppressive CRL substrates in lymphoma cells. Moreover, MLN4924 potently suppressed the growth of lymphoma cells by inducing G2 cell-cycle arrest, followed by apoptosis or senescence in a cell line-dependent manner. MLN4924-induced apoptosis was mediated by intrinsic apoptotic signaling with substantial up-regulation of pro-apoptotic Bik and Noxa as well as down-regulation of anti-apoptotic XIAP, c-IAP1 and c-IAP2, while senescence induction upon neddylation inhibition seemed dependent on the expression of tumor suppressor p21/p27. Together, these findings expand our understanding on how lymphoma cells respond to neddylation inhibition and support the development of neddylation inhibitors (e.g. MLN4924) for the treatment of lymphoma. PMID:25782162

  7. ACEE program rationale and implementation

    SciTech Connect

    Aiken, W.S. Jr.; Petersen, R.H.

    1982-08-01

    The impact of the Aircraft Energy Efficiency program (ACEE) on commercial aviation is examined. In addition to the emphasis on air transport fuel efficiency, topics such as airline operating costs, air transport effects on U.S. trade, and fuel price forecasts are addressed. An overview of the program and its contribution to aviation technology is included.

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

    SciTech Connect

    Mazzola Jr., Robert D.; Zhu, Zhaoning; Sinning, Lisa; McKittrick, Brian; Lavey, Brian; Spitler, James; Kozlowski, Joseph; Neng-Yang, Shih; Zhou, Guowei; Guo, Zhuyan; Orth, Peter; Madison, Vincent; Sun, Jing; Lundell, Daniel; Niu, Xiaoda

    2010-10-01

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

  9. The Ace locus of Drosophila melanogaster: structural gene for acetylcholinesterase with an unusual 5' leader.

    PubMed Central

    Hall, L M; Spierer, P

    1986-01-01

    The Ace locus of Drosophila melanogaster has been mapped at the molecular level. cDNA clones from the locus have been isolated and their sequence determined, confirming that Ace forms the structural gene for acetylcholinesterase (AChE). The cDNAs have a 1950 nucleotide open reading frame from which the complete amino acid sequence of AChE has been deduced. The Drosophila enzyme is found to have extensive homology to the known sequence of Torpedo AChE. Ace cDNAs have an unusual structure with a long 5' leader and several short upstream open reading frames. Images Fig. 2. PMID:3024971

  10. 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

  11. Interaction between angiotensin-converting enzyme gene insertion/deletion polymorphism and angiotensin-converting enzyme inhibition on survival in hemodialyzed patients.

    PubMed

    Kiss, István; Ambrus, Csaba; Kulcsár, Imre; Szegedi, János; Kerkovits, Lóránt; Tislér, András; Kiss, Zoltán

    2014-12-01

    The association between ACE (angiotensin-converting enzyme) gene insertion/deletion (I/D) polymorphism and mortality has been inconsistently observed in earlier studies in patients on maintenance hemodialysis. We hypothesized that the effect of ACE gene I/D polymorphism on mortality may be influenced by concurrent ACE inhibitor therapy in this population. In this prospective, multicenter cohort, observational study, data was collected from 716 prevalent chronic hemodialysis patients, blood samples were genotyped for I/D single nucleotide polymorphism. Patient mortality was assessed in tree genotype groups insertion/insertion, insertion/deletion and deletion/deletion (I/I, I/D, and D/D) using multivariate Cox proportional hazard models. The most frequent genotype was I/D (42.6%), followed by D/D (37.7%) and I/I (19.7%) genotypes. The mean age was 54.9±15.5 years, 53.2% of all patients were male and in the total group the prevalence of diabetes was 19.3%. ACE inhibitor therapy was prescribed for 47.9% of all patients. The median duration of dialysis before blood sampling was 23.8 months (IQR 11.2-47.1). Patients were followed for 10 years, the median follow-up time was 29.8 months (IQR 12.6-63.4). Patient characteristics were well balanced among the genotype groups. D/D genotype, was associated with inferior survival (I/I vs D/D: log-rank test: P=0.04) in patients not receiving ACE inhibitor therapy, and the presence of this therapy diminished this difference. There was no difference in survival among unselected patients with different genotypes. In multivariate Cox regression models, D/D genotype (compared to I/I) was a significant predictor of mortality only in patients without ACE inhibitor therapy (HR 0.67, 95% CI 0.46-0.97, P=0.03). Our data suggests that hemodialyzed patients with the deletion/deletion (D/D) genotype might have inferior outcome, and ACE inhibitor therapy may be associated with improved survival in this subgroup. PMID:25526485

  12. 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

  13. Two Kunitz-type inhibitors with activity against trypsin and papain from Pithecellobium dumosum seeds: purification, characterization, and activity towards pest insect digestive enzyme.

    PubMed

    Oliveira, A S; Migliolo, L; Aquino, R O; Ribeiro, J K C; Macedo, L L P; Bemquerer, M P; Santos, E A; Kiyota, S; de Sales, M P

    2009-01-01

    Two trypsin inhibitors (called PdKI-3.1 and PdKI-3.2) were purified from the seeds of the Pithecellobium dumosum tree. Inhibitors were obtained by TCA precipitation, affinity chromatography on Trypsin-Sepharose and reversed-phase-HPLC. SDS-PAGE analysis with or without reducing agent showed that they are a single polypeptide chain, and MALDI-TOF analysis determined molecular masses of 19696.96 and 19696.36 Da, respectively. The N-terminal sequence of both inhibitors showed strong identity to the Kunitz family trypsin inhibitors. They were stable over a wide pH (2-9) and temperature (37 to 100 degrees C) range. These inhibitors reduced over 84% of trypsin activity with inhibition constant (Ki) of 4.20 x 10(-8) and 2.88 x 10(-8) M, and also moderately inhibited papain activity, a cysteine proteinase. PdKI-3.1 and PdKI-3.2 mainly inhibited digestive enzymes from Plodia interpunctella, Zabrotes subfasciatus and Ceratitis capitata guts. Results show that both inhibitors are members of the Kunitz-inhibitor family and that they affect the digestive enzyme larvae of diverse orders, indicating a potential insect antifeedant.

  14. Pharmacological characterization of a novel sulfonylureid-pyrazole derivative, SM-19712, a potent nonpeptidic inhibitor of endothelin converting enzyme.

    PubMed

    Umekawa, K; Hasegawa, H; Tsutsumi, Y; Sato, K; Matsumura, Y; Ohashi, N

    2000-09-01

    We describe the pharmacological characteristics of SM-19712 (4-chloro-N-[[(4-cyano-3-methyl-1-phenyl-1H-pyrazol-5-yl)amino]carbonyl] benzenesulfonamide, monosodium salt). SM-19712 inhibited endothelin converting enzyme (ECE) solubilized from rat lung microsomes with an IC50 value of 42 nM and, at 10 - 100 microM, had no effect on other metalloproteases such as neutral endopeptidase 24.11 and angiotensin converting enzyme, showing a high specificity for ECE. In cultured porcine aortic endothelial cells, SM-19712 at 1 - 100 microM concentration-dependently inhibited the endogenous conversion of big endothelin-1 (ET-1) to ET-1 with an IC50 value of 31 microM. In anesthetized rats, either intravenous (1-30 mg/kg) or oral (10-30 mg/kg) administration of SM-19712 dose-dependently suppressed the pressor responses induced by big ET-1. In acute myocardial infarction of rabbits subjected to coronary occlusion and reperfusion, SM-19712 reduced the infarct size, the increase in serum concentration of ET-1 and the serum activity of creatinine phosphokinase. The present study demonstrates that SM-19712 is a structurally novel, nonpeptide, potent and selective inhibitor of ECE, and SM-19712 is a valuable new tool for elucidating the pathophysiological role of ECE. PMID:11043447

  15. 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

  16. Construction of a D-amino acid oxidase reactor based on magnetic nanoparticles modified by a reactive polymer and its application in screening enzyme inhibitors.

    PubMed

    Mu, Xiaoyu; Qiao, Juan; Qi, Li; Liu, Ying; Ma, Huimin

    2014-08-13

    Developing facile and high-throughput methods for exploring pharmacological inhibitors of D-amino acid oxidase (DAAO) has triggered increasing interest. In this work, DAAO was immobilized on the magnetic nanoparticles, which were modified by a biocompatible reactive polymer, poly(glycidyl methacrylate) (PGMA) via an atom transfer radical polymerization technique. Interestingly, the enzyme immobilization process was greatly promoted with the assistance of a lithium perchlorate catalyst. Meanwhile, a new amino acid ionic liquid (AAIL) was successfully synthesized and employed as the efficient chiral ligand in a chiral ligand exchange capillary electrophoresis (CLE-CE) system for chiral separation of amino acids (AAs) and quantitation of methionine, which was selected as the substrate of DAAO. Then, the apparent Michaelis-Menten constants in the enzyme system were determined with the proposed CLE-CE method. The prepared DAAO-PGMA-Fe3O4 nanoparticles exhibited excellent reusability and good stability. Moreover, the enzyme reactor was successfully applied in screening DAAO inhibitors. These results demonstrated that the enzyme could be efficiently immobilized on the polymer-grafted magnetic nanoparticles and that the obtained enzyme reactor has great potential in screening enzyme inhibitors, further offering new insight into monitoring the relevant diseases.

  17. Angioedema Related to Angiotensin-Converting Enzyme Inhibitors: Attack Severity, Treatment, and Hospital Admission in a Prospective Multicenter Study.

    PubMed

    Javaud, Nicolas; Achamlal, Jallal; Reuter, Paul-George; Lapostolle, Frédéric; Lekouara, Akim; Youssef, Mustapha; Hamza, Lilia; Karami, Ahmed; Adnet, Frédéric; Fain, Olivier

    2015-11-01

    The number of cases of acquired angioedema related to angiotensin converting enzyme inhibitors induced (ACEI-AAE) is on the increase, with a potential concomitant increase in life-threatening attacks of laryngeal edema. Our objective was to determine the main characteristics of ACEI-AAE attacks and, in doing so, the factors associated with likelihood of hospital admission from the emergency department (ED) after a visit for an attack.A prospective, multicenter, observational study (April 2012-December 2014) was conducted in EDs of 4 French hospitals in collaboration with emergency services (SAMU 93) and a reference center for bradykinin-mediated angioedema. For each patient presenting with an attack, emergency physicians collected demographic and clinical presentation data, treatments, and clinical course. They recorded time intervals from symptom onset to ED arrival and to treatment decision, from ED arrival to specific treatment with plasma-derived C1-inhibitor (C1-INH) or icatibant, and from specific treatment to onset of symptom relief. Attacks requiring hospital admission were compared with those not requiring admission.Sixty-two eligible patients with ACEI-AAE (56% men, median age 63 years) were included. Symptom relief occurred significantly earlier in patients receiving specific treatment than in untreated patients (0.5 [0.5-1.0] versus 3.9 [2.5-7.0] hours; P < 0.0001). Even though icatibant was injected more promptly than plasma-derived C1-INH, there, however, was no significant difference in median time to onset of symptom relief between the 2 drugs (0.5 [0.5-1.3] versus 0.5 [0.4-1.0] hours for C1-INH and icatibant, respectively, P = 0.49). Of the 62 patients, 27 (44%) were admitted to hospital from the ED. In multivariate analysis, laryngeal involvement and progressive swelling at ED arrival were independently associated with admission (Odds ratio [95% confidence interval] = 6.2 [1.3-28.2] and 5.9 [1.3-26.5], respectively). A favorable course

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Targeting Fusarium graminearum control via polyamine enzyme inhibitors and polyamine analogs.

    PubMed

    Crespo-Sempere, A; Estiarte, N; Marín, S; Sanchis, V; Ramos, A J

    2015-08-01

    Fusarium graminearum not only reduces yield and seed quality but also constitutes a risk to public or animal health owing to its ability to contaminate grains with mycotoxins. Resistance problems are emerging and control strategies based on new targets are needed. Polyamines have a key role in growth, development and differentiation. In this work, the possibility of using polyamine metabolism as a target to control F. graminearum has been assessed. It was found that putrescine induces mycotoxin production, correlating with an over expression of TRI5 and TRI6 genes. In addition, a homolog of the Saccharomyces cerevisiae TPO4 involved in putrescine excretion was up-regulated as putrescine concentration increased while DUR3 and SAM3 homologues, involved in putrescine uptake, were down-regulated. When 2.5 mM D, l-α-difluoromethylornithine (DFMO) was added to the medium, DON production decreased from 3.2 to 0.06 ng/mm(2) of colony and growth was lowered by up to 70 per cent. However, exogenous putrescine could overcome DFMO effects. Five polyamine transport inhibitors were also tested against F. graminearum. AMXT-1505 was able to completely inhibit in vitro growth and DON production. Additionally, AMXT-1505 blocked F. graminearum growth in inoculated wheat spikes reducing DON mycotoxin contamination from 76.87 μg/g to 0.62 μg/g.

  3. 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

  4. Recombinant Expression and Characterization of Human and Murine ACE2: Species-Specific Activation of the Alternative Renin-Angiotensin-System

    PubMed Central

    Poglitsch, Marko; Domenig, Oliver; Schwager, Cornelia; Stranner, Stefan; Peball, Bernhard; Janzek, Evelyne; Wagner, Bettina; Jungwirth, Helmut; Loibner, Hans; Schuster, Manfred

    2012-01-01

    Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase of the renin-angiotensin-system (RAS) which is known to cleave several substrates among vasoactive peptides. Its preferred substrate is Angiotensin II, which is tightly involved in the regulation of important physiological functions including fluid homeostasis and blood pressure. Ang 1–7, the main enzymatic product of ACE2, became increasingly important in the literature in recent years, as it was reported to counteract hypertensive and fibrotic actions of Angiotensin II via the MAS receptor. The functional connection of ACE2, Ang 1–7, and the MAS receptor is also referred to as the alternative axis of the RAS. In the present paper, we describe the recombinant expression and purification of human and murine ACE2 (rhACE2 and rmACE2). Furthermore, we determined the conversion rates of rhACE2 and rmACE2 for different natural peptide substrates in plasma samples and discovered species-specific differences in substrate specificities, probably leading to functional differences in the alternative axis of the RAS. In particular, conversion rates of Ang 1–10 to Ang 1–9 were found to be substantially different when applying rhACE2 or rmACE2 in vitro. In contrast to rhACE2, rm ACE2 is substantially less potent in transformation of Ang 1–10 to Ang 1–9. PMID:22518284

  5. Molecular dynamics simulation on the low sensitivity of mutants of NEDD-8 activating enzyme for MLN4924 inhibitor as a cancer drug.

    PubMed

    Rashidieh, Behnam; Valizadeh, Mohharam; Assadollahi, Vahideh; Ranjbar, Mohammad Mehdi

    2015-01-01

    MLN4924 is an experimental cancer drug known as inhibitor of NEDD8-activating enzyme (NAE). This anti-tumor candidate is a selective small-molecule inhibitor of NAE which is conjugated to cullin protein on Cullin-RING ligases (CRLs). This covalent modification actives cullin complex to recruit an ubiquitin-charged E2 and leads to downstream target protein polyubiquitination and proteasomal degradation. MLN4924, which can form a covalent adduct with NEDD8, and block NAE at the first step in this pathway, has shown anti-tumor activity in many kinds of cancer cell lines and also xenograft models, including lung cancer, colon cancer, melanoma and lymphoma. The anti-tumor activity of MLN4924 results from inactivation of CLRs, which causes DNA re-replication and inhibition of nuclear factor (NF)-κB signaling, thus leading to cancer cell death. A mutation can reduce the enzyme's sensitivity to MLN4924. Verma et al. in 2013 studied on molecular dynamics simulation of a mutant A171T and consequently found out that this mutation reduce MLN4924 interaction with DNA Binding site of enzyme as a result of reduction of enzyme affinity to ATP. One year later, in 2014, Wei Xu et al. carried out a research on inhibitor resistant cell lines and revealed that a couple of mutations so called Y352H and I310N leads to enzyme resistance to MLN4924 inhibitor, interestingly, the cause reported was the increase of enzyme affinity to ATP. As in Wei Xu et al. experiment the molecular dynamics simulation was not considered, present study is conducted to identify enzyme mutation mechanism by molecular dynamics approach using advantages of Gromacs software version 4.5.6. PMID:26807320

  6. A low-grade increase of serum pancreatic exocrine enzyme levels by dipeptidyl peptidase-4 inhibitor in patients with type 2 diabetes.

    PubMed

    Tokuyama, Hirotake; Kawamura, Harukiyo; Fujimoto, Masaki; Kobayashi, Kazuki; Nieda, Mie; Okazawa, Tetsuya; Takemoto, Minoru; Shimada, Fumio

    2013-06-01

    A potential adverse effect of dipeptidyl peptidase-4 inhibitors (DPP-4i) on the pancreas remains controversial. We evaluated the DPP-4i effects on pancreatic amylase and lipase activity in patients with type 2 diabetes. These enzymes were slightly but significantly increased, suggesting DPP-4i cause a low-grade inflammatory change in the exocrine pancreas. PMID:23618553

  7. Human UDP-Glucuronosyltransferase (UGT) 2B10: Validation of Cotinine as a Selective Probe Substrate, Inhibition by UGT Enzyme-Selective Inhibitors and Antidepressant and Antipsychotic Drugs, and Structural Determinants of Enzyme Inhibition.

    PubMed

    Pattanawongsa, Attarat; Nair, Pramod C; Rowland, Andrew; Miners, John O

    2016-03-01

    Although there is evidence for an important role of UGT2B10 in the N-glucuronidation of drugs and other xenobiotics, the inhibitor selectivity of this enzyme is poorly understood. This study sought primarily to characterize the inhibition selectivity of UGT2B10 by UDP-glucuronosyltransferase (UGT) enzyme-selective inhibitors used for reaction phenotyping, and 34 antidepressant and antipsychotic drugs that contain an amine functional group. Initial studies demonstrated that cotinine is a highly selective substrate of human liver microsomal UGT2B10. The kinetics of cotinine N-glucuronidation by recombinant UGT and human liver microsomes (± bovine serum albumin) were consistent with the involvement of a single enzyme. Of the UGT enzyme-selective inhibitors employed for reaction phenotyping, only the UGT2B4/7 inhibitor fluconazole reduced recombinant UGT2B10 activity to an appreciable extent. The majority of antidepressant and antipsychotic drugs screened for effects on UGT2B10 inhibited enzyme activity with IC50 values <100 µM. The most potent inhibition was observed with the tricyclic antidepressants amitriptyline and doxepin and the tetracyclic antidepressant mianserin, and the structurally related compounds desloratadine and loratadine. Molecular modeling using a ligand-based approach indicated that hydrophobic and charge interactions are involved in inhibitor binding, whereas spatial features influence the potency of UGT2B10 inhibition. Respective mean Ki,u (± S.D.) values for amitriptyline, doxepin, and mianserin inhibition of human liver microsomal UGT2B10 were 0.61 ± 0.05, 0.95 ± 0.18, and 0.43 ± 0.01 µM. In vitro-in vivo extrapolation indicates that these drugs may perpetrate inhibitory drug-drug interactions when coadministered with compounds that are cleared predominantly by UGT2B10.

  8. 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

  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. Isozyme-specific enzyme inhibitors. 14. 5'(R)-C-[(L-homocystein-S-yl)methyl]adenosine 5'-(beta,gamma-imidotriphosphate), a potent inhibitor of rat methionine adenosyltransferases.

    PubMed

    Kappler, F; Vrudhula, V M; Hampton, A

    1987-09-01

    The title compound is a covalent adduct of L-methionine (Met) and beta,gamma-imido-ATP. In its synthesis the N-Boc derivative of 5'(R)-C-(aminomethyl)-N6-benzoyl-5'-O-tosyl-2',3'-O- isopropylidenadenosine was converted by the successive actions of CF3CO2H and HNO2 into the corresponding 5'(R)-C-hydroxymethyl derivative. Treatment of this with disodium L-homocysteinate led to attack of sulfur at C6', apparently via a 5',6'-epoxide, and to total stereoselective inversion at C5' to furnish, after debenzoylation, 5'(R)-C-(L-homocystein-S-ylmethyl)-2',3'-O-isopropylidene ade nosine. The 5' configuration was established by conversion of this into the known 5'(S)-C-methyl-2',3'-O-isopropylidene adenosine with Raney nickel. The alpha-amino acid residue was protected as an N-Boc methyl ester, after which the 5'-hydroxyl was phosphorylated with benzyl phosphate and dicyclohexylcarbodiimide. The phosphoanhydride bond with inorganic imidodiphosphate was then created by established methods. Finally, blocking groups were removed under conditions that gave the desired adduct with no racemization of its L-methionine residue. It was a potent inhibitor [KM(ATP)/Ki = 1080; KM(Met)/Ki = 7.7] of the M-2 (normal tissue) form of rat methionine adenosyltransferase and of the M-T (hepatoma tissue) form [KM(ATP)/Ki = 670; KM(Met)/Ki = 22]. Inhibitions were competitive with respect to ATP or to L-methionine, indicating a dual substrate site mode of binding to the enzyme forms.

  11. Selective Interaction of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Nonnucleoside Inhibitor Efavirenz and Its Thio-Substituted Analog with Different Enzyme-Substrate Complexes

    PubMed Central

    Maga, Giovanni; Ubiali, Daniela; Salvetti, Raul; Pregnolato, Massimo; Spadari, Silvio

    2000-01-01

    Accumulating data have brought the nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) into the forefront of antiretroviral therapy. Among the emerging compounds in this class, a particularly attractive one is efavirenz (Sustiva), recently approved for clinical use by the U.S. Food and Drug Administration. In the present study, the equilibrium dissociation constants for efavirenz binding to the different catalytic forms of human immunodeficiency virus type 1 RT as well as the association and dissociation rates have been determined using a steady-state kinetic approach. In addition, the same enzymological analysis has been extended to the thio-substituted analog, sefavirenz, which showed comparable activity in vitro against RT. Both compounds have been found to act as purely uncompetitive inhibitors at low drug concentrations (5 to 50 nM) and as mixed noncompetitive inhibitors at higher doses (50 to 500 nM). This behavior can be interpreted in terms of the relative affinities for the different catalytic forms of the enzyme. Both efavirenz and sefavirenz showed increasing affinities for the different forms of RT in the following order: free enzyme < (i.e., bound with lower affinity) binary RT–template-primer (TP) complex < ternary RT-TP-deoxynucleoside triphosphate (dNTP) complex. The rate of binding of the two inhibitors to the different enzyme-substrate complexes was well below the diffusion limit (on the order of 104 M−1 s−1); however, both inhibitors, when bound to the ternary RT-TP-dNTP complex, showed very low dissociation rates, on the order of 10−4 s−1 for both compounds, typical of tightly binding inhibitors. Thus, efavirenz and its thio-substituted derivative sefavirenz appear to be peculiar in their mechanism of action, being selective tightly binding inhibitors of the ternary RT-TP-dNTP complex. Efavirenz is the first clinically approved NNRTI to show this property. PMID:10770750

  12. 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

  13. 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.

  14. Structural basis of Ac-SDKP hydrolysis by Angiotensin-I converting enzyme.

    PubMed

    Masuyer, Geoffrey; Douglas, Ross G; Sturrock, Edward D; Acharya, K Ravi

    2015-09-25

    Angiotensin-I converting enzyme (ACE) is a zinc dipeptidylcarboxypeptidase with two active domains and plays a key role in the regulation of blood pressure and electrolyte homeostasis, making it the principal target in the treatment of cardiovascular disease. More recently, the tetrapetide N-acetyl-Ser-Asp-Lys-Pro (Ac-SDKP) has emerged as a potent antifibrotic agent and negative regulator of haematopoietic stem cell differentiation which is processed exclusively by ACE. Here we provide a detailed biochemical and structural basis for the domain preference of Ac-SDKP. The high resolution crystal structures of N-domain ACE in complex with the dipeptide products of Ac-SDKP cleavage were obtained and offered a template to model the mechanism of substrate recognition of the enzyme. A comprehensive kinetic study of Ac-SDKP and domain co-operation was performed and indicated domain interactions affecting processing of the tetrapeptide substrate. Our results further illustrate the molecular basis for N-domain selectivity and should help design novel ACE inhibitors and Ac-SDKP analogues that could be used in the treatment of fibrosis disorders.

  15. 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.

  16. P-glycoprotein efflux and other factors limit brain amyloid beta reduction by beta-site amyloid precursor protein-cleaving enzyme 1 inhibitors in mice.

    PubMed

    Meredith, Jere E; Thompson, Lorin A; Toyn, Jeremy H; Marcin, Lawrence; Barten, Donna M; Marcinkeviciene, Jovita; Kopcho, Lisa; Kim, Young; Lin, Alan; Guss, Valerie; Burton, Catherine; Iben, Lawrence; Polson, Craig; Cantone, Joe; Ford, Michael; Drexler, Dieter; Fiedler, Tracey; Lentz, Kimberley A; Grace, James E; Kolb, Janet; Corsa, Jason; Pierdomenico, Maria; Jones, Kelli; Olson, Richard E; Macor, John E; Albright, Charles F

    2008-08-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease. Amyloid beta (Abeta) peptides are hypothesized to cause the initiation and progression of AD based on pathologic data from AD patients, genetic analysis of mutations that cause early onset forms of AD, and preclinical studies. Based on this hypothesis, beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) inhibitors are an attractive therapeutic approach for AD because cleavage of the APP by BACE1 is required to form Abeta. In this study, three potent BACE1 inhibitors are characterized. All three inhibitors decrease Abeta formation in cultured cells with IC(50) values less than 10 nM. Analysis of APP C-terminal fragments by immunoblotting and Abeta peptides by mass spectrometry showed that these inhibitors decreased Abeta by inhibiting BACE1. An assay for Abeta1-40 in mice was developed and used to show that these BACE1 inhibitors decreased plasma Abeta1-40, but not brain Abeta1-40, in wild-type mice. Because these BACE1 inhibitors were substrates for P-glycoprotein (P-gp), a member of the ATP-binding cassette superfamily of efflux transporters, these inhibitors were administered to P-gp knockout (KO) mice. These studies showed that all three BACE1 inhibitors decreased brain Abeta1-40 in P-gp KO mice, demonstrating that P-gp is a major limitation for development of BACE1 inhibitors to test the amyloid hypothesis. A comparison of plasma Abeta1-40 and brain Abeta1-40 dose responses for these three compounds revealed differences in relative ED(50) values, indicating that factors other than P-gp can also contribute to poor brain activity by BACE1 inhibitors.

  17. 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 in