A novel metallocarboxypeptidase-like enzyme from the marine annelid Sabellastarte magnifica--a step into the invertebrate world of proteases.

摘要: After screening 25 marine invertebrates, a novel metallocarboxypeptidase (SmCP) has been identified by activity and MS analytical approaches, isolated from the annelid Sabellastarte magnifica. The enzyme, which is minor component of molecularly complex animal body, as shown 2D gel electrophoresis, purified crude extracts to homogeneity affinity chromatography on potato carboxypeptidase inhibitor ion exchange chromatography. SmCP protease 33792 Da, displaying N-terminal internal sequence homologies with M14 metallocarboxypeptidase-like enzymes, determined automated Edman degradation. enzyme contains one atom Zn per molecule, activated Ca2+ drastically inhibited metal chelator 1,10-phenanthroline, well excess Zn2+ or Cu2+, but moderately so EDTA. also strongly specific inhibitors metallocarboxypeptidases, such benzylsuccinic acid protein found in leech (i.e. recombinant forms, both at nanomolar levels). displays high peptidase efficiency towards pancreatic carboxypeptidase-A synthetic substrates, those hydrophobic residues C-terminus but, remarkably, acidic ones. This property, previously described for carboxypeptidase O-like activity, long peptide substrates MS. results obtained present study indicate that member metallocarboxypeptidases family (assignable M14A pancreatic-like subfamily) wider specificity not previously.