Neprilysin (NEP), a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe 563 and Ser 546. Among the mutants studied in detail we observed changes in their activity towards leucine 5-enkephalin, insulin B chain, and amyloid β 1-40. For example, NEP F563I displayed an increase in preference towards cleaving leucine 5-enkephalin relative to insulin B chain, while mutant NEP S546E was less discriminating than neprilysin. Mutants NEP F563L and NEP S546E exhibit different cleavage site preferences than neprilysin with insulin B chain and amyloid ß 1-40 as substrates. These data indicate that it is possible to alter the cleavage site specificity of neprilysin opening the way for the development of substrate specific or substrate exclusive forms of the enzyme with enhanced therapeutic potential.
|State||Published - Feb 23 2012|
Bibliographical noteFunding Information:
Cleavage of physiological peptides was measured via reverse phase high performance liquid chromatography (HPLC) following incubation of the purified NEP or its mutants with 15 µM insulin B chain (Sigma Aldrich), 24 µM Aß (Anaspec), or 64 µM leu-ENK (Sigma) in 100 µL of 20 mM MES, pH 6.5, at 37°C. Reactions were run in triplicate. HPLC was carried out in a Vydac C4 column using a linear gradient from 0.1% trifluoroacetic acid (TFA) in 95% water, 5% acetonitrile to 0.1% TFA in 50% acetonitrile/water at a flow rate of 1 mL/min. Peptides and hydrolysis products were detected at 214 nm and quantified by measuring peak areas. Peptides obtained from HPLC were analyzed on an Applied Biosystems 4800 MALDI TOF/TOF Proteomics Analyzer at the University of Kentucky Proteomics core. This facility is supported in part by grant P20RR020171 from the NIH/NCRR. 1–40
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology (all)
- Agricultural and Biological Sciences (all)