His507 of acylaminoacyl peptidase stabilizes the active site conformation, not the catalytic intermediate

被引：11

作者：

Kiss, AL

Szeltner, Z

Fülöp, V

Polgár, L

机构：

[1] Hungarian Acad Sci, Biol Res Ctr, Inst Enzymol, H-1518 Budapest 112, Hungary

[2] Univ Warwick, Dept Sci Biol, Coventry CV4 7AL, W Midlands, England

来源：

FEBS LETTERS | 2004年 / 571卷 / 1-3期

基金：

匈牙利科学研究基金会; 英国惠康基金;

关键词：

oligopeptidase; acylaminoacyl peptidase; oxyanion binding site; catalytic mechanism;

D O I：

10.1016/j.febslet.2004.06.054

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Acylaminoacyl peptidase is a member of the prolyl oligopeptidase family. amino acid sequence alignment suggests that the stabilization of the tetrahedral intermediate should be mediated by His507 rather than by a tyrosine residue found in the other family members of this serine peptidase group. The pH dependence of k(cat)/K-m did not reveal any effect of His507. Substitution of an alanine for His507 gave the same bell-shaped pH rate profile with the same pK(a) values (7.0 and 8.7). However, the value of the rate constant was 85 times lower with the modified enzyme, which indicated that His507 is an important residue that is probably involved in the formation of the 3-dimensional structure. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

引用

页码：17 / 20

页数：4

共 19 条

[1] Binding to human dipeptidyl peptidase IV by adenosine deaminase and antibodies that inhibit ligand binding involves overlapping, discontinuous sites on a predicted β propeller domain [J].