Identification of the catalytic histidine residue participating in the charge-relay system of carboxypeptidase Y

Protein Sci. 1995 Nov;4(11):2433-5. doi: 10.1002/pro.5560041123.

Abstract

The essential histidine residue of carboxypeptidase Y (CPY) was modified by a site-specific reagent, a chloromethylketone derivative of benzyloxycarbonyl-L-phenylalanine. The single modified histidine residue was converted to N tau-carboxy-methyl histidine (cmHis) upon performic acid oxidation. A peptide containing cmHis was isolated from the tryptic-thermolytic digest. Based on the amino acid composition and sequence analysis, the peptide is shown to be Val-Phe-Asp-Gly-Gly-cmHis-MetO2-Val-Pro, which was derived from CPY cleaved by trypsin at Arg 391 and thermolysin at Phe 401, and thus His 397 was modified. This histidine residue has been implicated previously by X-ray analysis to participate in the charge-relay system of CPY.

MeSH terms

  • Amino Acid Chloromethyl Ketones / chemistry
  • Amino Acid Sequence
  • Amino Acids / analysis
  • Binding Sites
  • Carboxypeptidases / chemistry*
  • Carboxypeptidases / metabolism
  • Cathepsin A
  • Chromatography, High Pressure Liquid
  • Formates
  • Histidine / chemistry*
  • Histidine / metabolism
  • Indicators and Reagents
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Peptide Fragments / analysis
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Structure-Activity Relationship
  • Thermolysin / metabolism
  • Trypsin / metabolism

Substances

  • Amino Acid Chloromethyl Ketones
  • Amino Acids
  • Formates
  • Indicators and Reagents
  • Peptide Fragments
  • peroxyformic acid
  • ZPCK
  • Histidine
  • Carboxypeptidases
  • Cathepsin A
  • Trypsin
  • Thermolysin