Premium
His507 of acylaminoacyl peptidase stabilizes the active site conformation, not the catalytic intermediate
Author(s) -
Kiss András L,
Szeltner Zoltán,
Fülöp Vilmos,
Polgár László
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.06.054
Subject(s) - oligopeptidase , residue (chemistry) , tyrosine , chemistry , alanine , serine , stereochemistry , enzyme , active site , amino acid residue , biochemistry , amino acid , peptide sequence , gene
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 p K 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.