ISSN:
1573-4927
Keywords:
aminopeptidase
;
naphthylamidase
;
Mytilus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract A genetically variable naphthylamidase enzyme, previously described as “leucine aminopeptidase,” was purified approximately fiftyfold, and its biochemical properties were investigated. The enzyme was renamed “aminopeptidase I.” Substrate affinities demonstrate that it is an α-aminoacyl peptide hydrolase (E.C. 3.4.11.-). Aminopeptidase I had a monomer molecular weight of 65–68,000, average pI of pH 4.88, and broad pH optima between 6.5 and 8.0. The enzyme was inactivated rapidly between 40 and 50 C. Antibodies from purified enzyme did not cross-react with other naphthylamidases, but aminopeptidase I activity was inhibited by immune serum. The enzyme exhibited highest naphthylamidase activity for aromatic and hydrophobic aminoacyl naphthylamides. Aminopeptidase activity was highest for aromatic and hydrophobic N-terminal residues of tripeptides. Certain divalent metal cations, p-O H-mercuribenzoate, and N-ethylmaleimide were strongly inhibitory while chelating agents activated the enzyme.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00498971
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