Specific Inhibitors of Aminopeptidase P
Aminopeptidase P (APP, EC 18.104.22.168) is a metal-dependent proline-specific peptidase. The enzyme splits N-terminal Xaa-Pro peptide bonds and plays an important role in the regulation of the physiological activity of peptides, e. g. bradykinin.1, 2 Only recently, the first specific inhibitor of APP, apstatin, was discovered.’ It is known, however, that peptides containing N-terminal 2-hydroxy-3-amino acids like bestatin and amastatin are inhibitors of the metal-dependent peptidases leucine aminopeptidase (LAP), aminopeptidase B and aminopeptidase M.4 X-ray crystallografic results demonstrated the bestatin chelation of one of the active Zinc ions of bovine lens LAP.’ Bestatin seems to be a natural mimetic of the tetrahedral intermediat of LAP-catalyzed substrate hydrolysis.
KeywordsDouble Reciprocal Plot Tetrahedral Intermediat Peptide Hydrolysis Cellular Peptidase Continuous Assay
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