Chongcharoen K, Sharma K K
Mason Eye Institute, Department of Ophthalmology, University of Missouri, Columbia 65212, USA.
Biochem Biophys Res Commun. 1998 Jun 9;247(1):136-41. doi: 10.1006/bbrc.1998.8747.
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.
