A novel peptidyl‐prolyl cisltrans isomerase from Escherichia coli

Authors:
Publisher website
Google Scholar
Abstract
A novel peptidyl‐prolyl cis/trans isomerase was isolated from Escherichia coli cell extract and characterized partially. Determination of the molecular mass by electrospray mass spectrometry indicated a protein of 10102 ± 2 Da, smaller than cyclophilins or FK506 binding proteins currently known. The specificity constant k cat/K m determined with Succinyl‐Ala‐Xaa‐Pro‐Phe‐4‐nitroanilide (Xaa = Leu) had a value comparable to those from cyclophilins from the same organism. However, the pattern of subsite specificity (Xaa = Gly, Ala, Val, Ile, Leu, Phe, Trp, His, Lys and Glu) was reminiscent of FK506 binding peptidyl‐prolyl cis/trans isomerases. The enzyme activity was not inhibited by cyclosporin A or FK506 at inhibitor concentrations of < 5 μM, concentrations that affect most bacterial peptidyl‐prolyl cis/trans isomerases. Computer‐assisted analysis of 21 amino acid residues of the N‐terminus determined by Edman degradation revealed no homology to known peptidyl‐prolyl cis/trans isomerases.

This publication has 27 references indexed in Scilit: