Characterization of trypsin-modified bovine lens acylpeptide hydrolase

Biochem Biophys Res Commun. 1998 Jun 9;247(1):136-41. doi: 10.1006/bbrc.1998.8747.

Abstract

Acylpeptide hydrolase, which removes the N-acetylated amino acids from peptide substrates was purified from bovine lens, truncated in vitro to a 55 kDa enzyme by trypsin digestion and characterized. The activity of the trypsin-modified enzyme was investigated using alpha A-crystallin and oxidized insulin A chain. The trypsin-modified enzyme was able to unblock alpha A-crystallin and displayed endoprotease activity unlike the native enzyme. SDS-PAGE analysis and amino acid sequencing of (3H)iPr2P-F labeled bovine lens acylpeptide hydrolase showed that the lens has a 55 kDa truncated form of the enzyme. The in vivo truncated form of the enzyme was generated by the cleavage of the Gly203-Asp204 peptide bond in the native enzyme.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cattle
  • Enzyme Activation
  • Hydrolysis
  • Insulin / metabolism
  • Lens, Crystalline / enzymology*
  • Molecular Sequence Data
  • Molecular Weight
  • Peptide Hydrolases / chemistry*
  • Peptide Hydrolases / isolation & purification
  • Peptide Hydrolases / metabolism
  • Substrate Specificity
  • Trypsin*

Substances

  • Insulin
  • Peptide Hydrolases
  • acylaminoacyl-peptidase
  • Trypsin