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Purification and characterization of the Manduca sexta neuropeptide processing enzyme carboxypeptidase E
Author(s) -
Stone Tracey E.,
Li Jorge P.,
Bernasconi Paul
Publication year - 1994
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940270305
Subject(s) - manduca sexta , carboxypeptidase , biology , biochemistry , enzyme , neuropeptide , carboxypeptidase a , peptide , insect , botany , receptor
The neuropeptide processing enzyme carboxypeptidase E (CPE) (E.C.3.4.17.10) has been well studied in vertebrates but its presence in invertebrates has not yet been reported. CPE activity in insects is present in membrane‐bound and soluble forms. The soluble CPE has been purified to homogeneity from the brain of the tobacco hornworm Manduca sexta. It is a 57 kDa glycoprotein containing 9% sugars. It is activated 9.2 ± 1.8 fold by CoCl 2 and inhibited by chelating agents. Its sensitivity to guanidinoethyl‐mercaptosuccinic acid, and its molecular mass, make this enzyme a good candidate to be the insect equivalent of the mammalian CPE. Furthermore, its lack of sensitivity towards p ‐(chloromercuri)benzenesulfonate puts it closer to the vertebrate carboxypeptidase M (CPM). We postulate that insects may possess a single protein fulfilling both CPE and CPM functions. © 1994 Wiley‐Liss, Inc.