1
|
Khatun M, Haque N, Siddique AE, Wahed AS, Islam MS, Khan S, Jubayar AM, Sadi J, Kabir E, Shila TT, Islam Z, Sarker MK, Banna HU, Hossain S, Sumi D, Saud ZA, Barchowsky A, Himeno S, Hossain K. Arsenic Exposure-Related Hypertension in Bangladesh and Reduced Circulating Nitric Oxide Bioavailability. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:47003. [PMID: 38573329 PMCID: PMC10993991 DOI: 10.1289/ehp13018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 04/05/2024]
Abstract
BACKGROUND Hypertension is a major cause of death worldwide. Although arsenic exposure has been associated with the risk of hypertension, this association appears nonuniform due to inconsistent results from studies conducted in different populations. Moreover, hypertension is a complex condition with multiple underlying mechanisms and factors. One factor is impaired production and bioavailability of vascular nitric oxide (NO). However, the implications of the effects of arsenic exposure on circulating NO and its association with hypertension in humans are largely unknown. OBJECTIVE We investigated the dose-response relationship between arsenic exposure and hypertension with vascular NO levels as a potential mediator of arsenic-related hypertension in individuals exposed to a broad range of arsenic. METHODS A total of 828 participants were recruited from low- and high-arsenic exposure areas in Bangladesh. Participants' drinking water, hair, and nail arsenic concentrations were measured by inductively coupled plasma mass spectroscopy. Hypertension was defined as a systolic blood pressure (SBP) value of ≥ 140 and a diastolic (DBP) value of ≥ 90 mmHg . Serum NO levels reflected by total serum nitrite concentrations were measured by immunoassay. A formal causal mediation analysis was used to assess NO as a mediator of the association between arsenic level and hypertension. RESULTS Increasing concentrations of arsenic measured in drinking water, hair, and nails were associated with the increasing levels of SBP and DBP. The odds of hypertension were dose-dependently increased by arsenic even in participants exposed to relatively low to moderate levels (10 - 50 μ g / L ) of water arsenic [odds ratios (ORs) and 95% confidence intervals (CIs): 2.87 (95% CI: 1.28, 6.44), 2.67 (95% CI: 1.27, 5.60), and 5.04 (95% CI: 2.71, 9.35) for the 10 - 50 μ g / L , 50.01 - 150 μ g / L , and > 150 μ g / L groups, respectively]. Causal mediation analysis showed a significant mediating effect of NO on arsenic-related SBP, DBP, and hypertension. CONCLUSION Increasing exposure to arsenic was associated with increasing odds of hypertension. The association was mediated through the reduction of vascular NO bioavailability, suggesting that impaired NO bioavailability was a plausible underlying mechanism of arsenic-induced hypertension in this Bangladeshi population. https://doi.org/10.1289/EHP13018.
Collapse
Affiliation(s)
- Moriom Khatun
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Nazmul Haque
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Abu Eabrahim Siddique
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa, USA
| | - Abdus S. Wahed
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, New York, USA
| | - Md. Shofikul Islam
- Department of Applied Nutrition and Food Technology, Islamic University, Kushtia, Bangladesh
| | - Shuchismita Khan
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Ahsanul Mahbub Jubayar
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Junayed Sadi
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Ehsanul Kabir
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Tasnim Tabassum Shila
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Zohurul Islam
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | | | - Hasan Ul Banna
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Shakhawoat Hossain
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Daigo Sumi
- Laboratory of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Zahangir Alam Saud
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| | - Aaron Barchowsky
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Seiichiro Himeno
- Laboratory of Molecular Toxicology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
- Division of Health Chemistry, School of Pharmacy, Showa University, Tokyo, Japan
| | - Khaled Hossain
- Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi, Bangladesh
| |
Collapse
|
2
|
Buhr A, Schiemann R, Meyer H. Neprilysin 4: an essential peptidase with multifaceted physiological relevance. Biol Chem 2023; 404:513-520. [PMID: 36653344 DOI: 10.1515/hsz-2022-0286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023]
Abstract
Neprilysins are highly conserved ectoenzymes that hydrolyze and thus inactivate signaling peptides in the extracellular space. Herein, we focus on Neprilysin 4 from Drosophila melanogaster and evaluate the existing knowledge on the physiological relevance of the peptidase. Particular attention is paid to the role of the neprilysin in regulating feeding behavior and the expression of insulin-like peptides in the central nervous system. In addition, we assess the function of the peptidase in controlling the activity of the sarcoplasmic and endoplasmic reticulum Ca2+ ATPase in myocytes, as well as the underlying molecular mechanism in detail.
Collapse
Affiliation(s)
- Annika Buhr
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Ronja Schiemann
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Heiko Meyer
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany.,Center for Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
| |
Collapse
|
3
|
Meyer H, Buhr A, Callaerts P, Schiemann R, Wolfner MF, Marygold SJ. Identification and bioinformatic analysis of neprilysin and neprilysin-like metalloendopeptidases in Drosophila melanogaster. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000410. [PMID: 34189422 PMCID: PMC8223033 DOI: 10.17912/micropub.biology.000410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The neprilysin (M13) family of metalloendopeptidases comprises highly conserved ectoenzymes that cleave and thereby inactivate many physiologically relevant peptides in the extracellular space. Impaired neprilysin activity is associated with numerous human diseases. Here, we present a comprehensive list and classification of M13 family members in Drosophila melanogaster. Seven Neprilysin (Nep) genes encode active peptidases, while 21 Neprilysin-like (Nepl) genes encode proteins predicted to be catalytically inactive. RNAseq data demonstrate that all 28 genes are expressed during development, often in a tissue-specific pattern. Most Nep proteins possess a transmembrane domain, whereas almost all Nepl proteins are predicted to be secreted.
Collapse
Affiliation(s)
- Heiko Meyer
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany,
Correspondence to: Heiko Meyer (); Steven J. Marygold ()
| | - Annika Buhr
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KULeuven, University of Leuven, B-3000 Leuven, Belgium
| | - Ronja Schiemann
- Department of Zoology & Developmental Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Mariana F. Wolfner
- Department of Molecular Biology & Genetics, Cornell University, Ithaca NY 14853 USA
| | - Steven J. Marygold
- FlyBase, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, U.K.,
Correspondence to: Heiko Meyer (); Steven J. Marygold ()
| |
Collapse
|
4
|
Hallier B, Schiemann R, Cordes E, Vitos-Faleato J, Walter S, Heinisch JJ, Malmendal A, Paululat A, Meyer H. Drosophila neprilysins control insulin signaling and food intake via cleavage of regulatory peptides. eLife 2016; 5. [PMID: 27919317 PMCID: PMC5140268 DOI: 10.7554/elife.19430] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/14/2016] [Indexed: 12/11/2022] Open
Abstract
Insulin and IGF signaling are critical to numerous developmental and physiological processes, with perturbations being pathognomonic of various diseases, including diabetes. Although the functional roles of the respective signaling pathways have been extensively studied, the control of insulin production and release is only partially understood. Herein, we show that in Drosophila expression of insulin-like peptides is regulated by neprilysin activity. Concomitant phenotypes of altered neprilysin expression included impaired food intake, reduced body size, and characteristic changes in the metabolite composition. Ectopic expression of a catalytically inactive mutant did not elicit any of the phenotypes, which confirms abnormal peptide hydrolysis as a causative factor. A screen for corresponding substrates of the neprilysin identified distinct peptides that regulate insulin-like peptide expression, feeding behavior, or both. The high functional conservation of neprilysins and their substrates renders the characterized principles applicable to numerous species, including higher eukaryotes and humans. DOI:http://dx.doi.org/10.7554/eLife.19430.001 The hormone insulin and similar molecules called insulin-like peptides act as signals to control many processes in the body, including growth, stress responses and aging. Disrupting these signaling pathways can cause many diseases, with diabetes being the most common of these. Although the roles of the signaling pathways have been well studied, it is less clear how the body controls the production of insulin and insulin-like peptides. Neprilysins are enzymes that can cut other proteins and peptides by a process known as hydrolysis. Their targets (known as “substrates”) include peptides that regulate a range of cell processes, and neprilysins have therefore been linked with many diseases. Fruit flies have at least five different neprilysin enzymes, but their substrates have not yet been identified. One of these, known as Nep4A, is produced in muscle tissue and appears to be important for muscles to work properly. Hallier, Schiemann et al. reveal that Nep4A regulates the production of insulin-like peptides. The experiments used fruit fly larvae that had been genetically engineered so that the level of Nep4A could be altered in muscle tissue. Larvae with very high or very low levels of Nep4A eat less food, have smaller bodies and produce different amounts of insulin-like peptides compared to normal larvae. Further experiments show that Nep4A can hydrolyze a number of peptides that regulate the production and the release of insulin-like peptides. This suggests that the enzymatic activity of neprilysins plays a direct role in controlling the production of insulin. The next challenge is to find out whether these findings apply to humans and other animals that also have neprilysins. DOI:http://dx.doi.org/10.7554/eLife.19430.002
Collapse
Affiliation(s)
- Benjamin Hallier
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Ronja Schiemann
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Eva Cordes
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Jessica Vitos-Faleato
- Department of Biomedical Research, Institute for Research in Biomedicine, Barcelona, Spain
| | - Stefan Walter
- Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | | | - Anders Malmendal
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Achim Paululat
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Heiko Meyer
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| |
Collapse
|
5
|
Lu X, Li X, Zhao Y, Zheng Z, Guan S, Chan P. Contemporary epidemiology of gout and hyperuricemia in community elderly in Beijing. Int J Rheum Dis 2013; 17:400-7. [PMID: 24118986 DOI: 10.1111/1756-185x.12156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiaolan Lu
- Department of Rheumatology; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
- Department of Geriatrics; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| | - Xiaoxia Li
- Department of Rheumatology; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| | - Yi Zhao
- Department of Rheumatology; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| | - Zheng Zheng
- Department of Geriatrics; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| | - Shaochen Guan
- Department of Geriatrics; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| | - Piu Chan
- Department of Geriatrics; Beijing Institute of Geriatrics; Xuanwu Hospital of Capital Medical University; Beijing China
| |
Collapse
|
6
|
Ul-Haq Z, Iqbal S, Moin ST. Dynamic changes in the secondary structure of ECE-1 and XCE account for their different substrate specificities. BMC Bioinformatics 2012; 13:285. [PMID: 23113990 PMCID: PMC3558449 DOI: 10.1186/1471-2105-13-285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 10/27/2012] [Indexed: 11/16/2022] Open
Abstract
Background X-converting enzyme (XCE) involved in nervous control of respiration, is a member of the M13 family of zinc peptidases, for which no natural substrate has been identified yet. In contrast, it’s well characterized homologue endothelin-converting enzyme-1 (ECE-1) showed broad substrate specificity and acts as endopeptidase as well as dipeptidase. To explore the structural differences between XCE and ECE-1, homology model of XCE was built using the complex structure of ECE-1 with phosphoramidon (pdb-id: 3DWB) as template. Phosphoramidon was docked into the binding site of XCE whereas phosphate oxygen of the inhibitor was used as water molecule to design the apo forms of both enzymes. Molecular dynamics simulation of both enzymes was performed to analyze the dynamic nature of their active site residues in the absence and presence of the inhibitor. Results Homology model of XCE explained the role of non-conserved residues of its S2’ subsite. Molecular dynamics (MD) simulations identified the flexible transitions of F149/I150, N566/N571, W714/W719, and R145/R723 residues of ECE-1/XCE for the strong binding of the inhibitor. Secondary structure calculations using DSSP method reveals the folding of R145/R723 residue of ECE-1/XCE into β-sheet structure while unfolding of the S2’ subsite residues in aECE-1 and sustained compact folding of that of aXCE. The results evaluated are in good agreement with available experimental data, thus providing detailed molecular models which can explain the structural and specificities differences between both zinc peptidases. Conclusions Secondary structure changes of both enzymes during the simulation time revealed the importance of β-sheet structure of R145/R723 for its binding with the terminal carboxylate group of the inhibitor. Unfolding of the α-helix comprising the S2’ subsite residues in aECE-1 correlate well with its endopeptidase activity while their compact folding in aXCE may account for the inactivity of the enzyme towards large C-terminal containing substrates.
Collapse
Affiliation(s)
- Zaheer Ul-Haq
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
| | | | | |
Collapse
|
7
|
Panz M, Vitos-Faleato J, Jendretzki A, Heinisch JJ, Paululat A, Meyer H. A novel role for the non-catalytic intracellular domain of Neprilysins in muscle physiology. Biol Cell 2012; 104:553-68. [DOI: 10.1111/boc.201100069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 05/10/2012] [Indexed: 11/28/2022]
|
8
|
Abstract
Cardiovascular diseases are the leading cause of death worldwide. Essential hypertension is a major risk factor for the development of other cardiovascular diseases and is caused by a combination of environmental and genetic factors, with up to 50% of blood pressure variance currently attributed to an individual's genetic makeup. By studying genes that cause monogenic forms of hypertension and pathways relevant to blood pressure control, a number of polymorphisms have been identified that increase an individual's risk of developing high blood pressure. We report on candidate gene association studies and genome-wide association studies that have been performed to date in the field of hypertension research. It is becoming clear that for the majority of people there is no single gene polymorphism that causes hypertension, but rather a number of common genetic variants, each having a small effect. Using pharmacogenomics to personalize the treatment of hypertension holds promise for achieving and sustaining normotensive pressures quickly, while minimizing the risk of adverse reactions and unwanted side-effects. This will decrease the risk of stroke and myocardial infarction in individuals and lead to a reduced burden of disease upon society as a whole.
Collapse
|
9
|
Meyer H, Panz M, Zmojdzian M, Jagla K, Paululat A. Neprilysin 4, a novel endopeptidase from Drosophila melanogaster, displays distinct substrate specificities and exceptional solubility states. ACTA ACUST UNITED AC 2010; 212:3673-83. [PMID: 19880729 DOI: 10.1242/jeb.034272] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Proteins belonging to the family of neprilysins are typically membrane bound M13 endopeptidases responsible for the inactivation and/or activation of peptide signaling events on cell surfaces. Mammalian neprilysins are known to be involved in the metabolism of various regulatory peptides especially in the nervous, immune, cardiovascular and inflammatory systems. Although there is still much to learn about their participation in various diseases, they are potential therapeutic targets. Here we report on the identification and first characterization of neprilysin 4 (NEP4) from Drosophila melanogaster. Reporter lines as well as in situ hybridization combined with immunolocalization demonstrated NEP4 expression during embryogenesis in pericardial cells, muscle founder cells, glia cells and male gonads. Western blot analysis confirmed the prediction of one membrane bound and one soluble isoform, a finding quite unusual among neprilysins with presumably strong physiological relevance. At least one NEP4 isoform was found in every developmental stage indicating protein activities required throughout the whole life cycle of Drosophila. Heterologously expressed NEP4 exhibited substrate preferences comparable to human neprilysin 2 with distinct cleavage of substance P and angiotensin I.
Collapse
Affiliation(s)
- Heiko Meyer
- Department of Zoology/Developmental Biology, University of Osnabrück, Germany
| | | | | | | | | |
Collapse
|
10
|
Carmona AK, Juliano MA, Juliano L. The use of Fluorescence Resonance Energy Transfer (FRET) peptidesfor measurement of clinically important proteolytic enzymes. AN ACAD BRAS CIENC 2009; 81:381-92. [DOI: 10.1590/s0001-37652009000300005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 09/09/2008] [Indexed: 11/21/2022] Open
Abstract
Proteolytic enzymes have a fundamental role in many biological processes and are associated with multiple pathological conditions. Therefore, targeting these enzymes may be important for a better understanding of their function and development of therapeutic inhibitors. Fluorescence Resonance Energy Transfer (FRET) peptides are convenient tools for the study of peptidases specificity as they allow monitoring of the reaction on a continuous basis, providing a rapid method for the determination of enzymatic activity. Hydrolysis of a peptide bond between the donor/acceptor pair generates fluorescence that permits the measurement of the activity of nanomolar concentrations of the enzyme. The assays can be performed directly in a cuvette of the fluorimeter or adapted for determinations in a 96-well fluorescence plate reader. The synthesis of FRET peptides containing ortho-aminobenzoic acid (Abz) as fluorescent group and 2, 4-dinitrophenyl (Dnp) or N-(2, 4-dinitrophenyl)ethylenediamine (EDDnp) as quencher was optimized by our group and became an important line of research at the Department of Biophysics of the Federal University of São Paulo. Recently, Abz/Dnp FRET peptide libraries were developed allowing high-throughput screening of peptidases substrate specificity. This review presents the consolidation of our research activities undertaken between 1993 and 2008 on the synthesis of peptides and study of peptidases specificities.
Collapse
|
11
|
Barros NMT, Campos M, Bersanetti PA, Oliveira V, Juliano MA, Boileau G, Juliano L, Carmona AK. Neprilysin carboxydipeptidase specificity studies and improvement in its detection with fluorescence energy transfer peptides. Biol Chem 2007; 388:447-55. [PMID: 17391066 DOI: 10.1515/bc.2007.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We examined the substrate specificity of the carboxydipeptidase activity of neprilysin (NEP) using fluorescence resonance energy transfer (FRET) peptides containing ortho-aminobenzoyl (Abz) and 2,4-dinitrophenyl (Dnp) as a donor/acceptor pair. Two peptide series with general sequences Abz-RXFK(Dnp)-OH and Abz-XRFK(Dnp)-OH (X denotes the position of the altered amino acid) were synthesized to study P1 (cleavage at the X-F bond) and P2 (cleavage at R-F bond) specificity, respectively. In these peptides a Phe residue was fixed in P1' to fulfill the well-known NEP S1' site requirement for a hydrophobic amino acid. In addition, we explored NEP capability to hydrolyze bradykinin (RPPGFSPFR) and its fluorescent derivative Abz-RPPGFSPFRQ-EDDnp (EDDnp=2,4-dinitrophenyl ethylenediamine). The enzyme acts upon bradykinin mainly as a carboxydipeptidase, preferentially cleaving Pro-Phe over the Gly-Phe bond in a 9:1 ratio, whereas Abz-RPPGFSPFRQ-EDDnp was hydrolyzed at the same bonds but at an inverted proportion of 1:9. The results show very efficient interaction of the substrates' C-terminal free carboxyl group with site S2' of NEP, confirming the enzyme's preference to act as carboxydipeptidase at substrates with a free carboxyl-terminus. Using data gathered from our study, we developed sensitive and selective NEP substrates that permit continuous measurement of the enzyme activity, even in crude tissue extracts.
Collapse
Affiliation(s)
- Nilana M T Barros
- Department of Biophysics, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Três de Maio 100, 04044-020 São Paulo, Brazil
| | | | | | | | | | | | | | | |
Collapse
|