Proteolytic cleavage of synthetic fragments of vesicle-associated membrane protein, isoform-2 by botulinum type B neurotoxin

摘要: Recent data suggest that botulinum type-B neurotoxin is a protease which acts on vesicle-associated membrane protein, isoform 2 (VAMP-2). In this report, shown to cleave synthetic fragment (HV62) of VAMP-2, corresponding the bulk hydrophillic domain (amino acids 33–94). The at single site between Gln76 and Phe77. Little or no proteolytic activity by was observed with peptides containing 7, 10 20 amino spanning cleavage. action strongly inhibited EDTA o-phenanthroline whereas captopril phosphoramidon were ineffective. A series model peptide substrates synthesised in order define smallest VAMP-2 be cleaved neurotoxin. Data obtained from these belongs novel class zinc-endoprotease; more than 12 acid residues are required both NH2-and COOH-terminal side cleavage for optimal activity. results demonstrate other components cellular vesicles specific VAMP-2. further show highly not dictated solely properties but also dependent sequences distal its action.