HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 278, Issue 17, 14704-14711, April 25, 2003

This Article Full Text Full Text (PDF) All Versions of this Article: 278/17/14704    most recent M211242200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mzhavia, N. Articles by Devi, L. A. Search for Related Content PubMed PubMed Citation Articles by Mzhavia, N. Articles by Devi, L. A. Social Bookmarking                      What's this?

Characterization of Endothelin-converting Enzyme-2
IMPLICATION FOR A ROLE IN THE NONCLASSICAL PROCESSING OF REGULATORY PEPTIDES^*

Nino Mzhavia, Hui Pan, Fa-Yun Che^§, Lloyd D. Fricker^§, and Lakshmi A. Devi^¶

From the  Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, New York, New York 10029 and the ^§ Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461

Most neuroendocrine peptides are generated by proteolysis of the precursors at basic residue cleavage sites. Prohormone convertases belonging to the subtilisin family of serine proteases are primarily responsible for processing at these "classical sites." In addition to the classical cleavages, a subset of bioactive peptides is generated by processing at "nonclassical" sites. The proteases responsible for these cleavages have not been well explored. Members of several metalloprotease families have been proposed to be involved in nonclassical processing. Among them, endothelin-converting enzyme-2 (ECE-2) is a good candidate because it exhibits a neuroendocrine distribution and an acidic pH optimum. To examine the involvement of this protease in neuropeptide processing, we purified the recombinant enzyme and characterized its catalytic activity. Purified ECE-2 efficiently processes big endothelin-1 to endothelin-1 by cleavage between Trp²¹ and Val²² at acidic pH. To characterize the substrate specificity of ECE-2, we used mass spectrometry with a panel of 42 peptides as substrates to identify the products. Only 10 of these 42 peptides were processed by ECE-2. A comparison of residues around the cleavage site revealed that ECE-2 exhibits a unique cleavage site selectivity that is related to but distinct from that of ECE-1. ECE-2 tolerates a wide range of amino acids in the P1-position and prefers aliphatic/aromatic residues in the P1'-position. However, only a small fraction of the aliphatic/aromatic amino acid-containing sites were cleaved, indicating that there are additional constraints beyond the P1- and P1'-positions. The enzyme is able to generate a number of biologically active peptides from peptide intermediates, suggesting an important role for this enzyme in the biosynthesis of regulatory peptides. Also, ECE-2 processes proenkephalin-derived bovine adrenal medulla peptides, and this processing leads to peptide products known to have differential receptor selectivity. Finally, ECE-2 processes PEN-LEN, an endogenous inhibitor of prohormone convertase 1, into products that do not inhibit the enzyme. Taken together, these results are consistent with an important role for ECE-2 in the processing of regulatory peptides at nonclassical sites.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. C. Palmer, S. Baig, P. G. Kehoe, and S. Love Endothelin-Converting Enzyme-2 Is Increased in Alzheimer's Disease and Up-Regulated by A{beta} Am. J. Pathol., July 1, 2009; 175(1): 262 - 270. [Abstract] [Full Text] [PDF]