Enzymic and chemical properties of an endopeptidase from the larva of the hornet Vespa crabro

Abstract

An endopeptidase from the larvae of the hornet Vespa crabro has been purified to homogeneity. The enzyme has been characterized with respect to molecular weight, amino acid compositon, and amino- and carboxyl-terminal sequences. The catalytic properties of the hornet protease are similar to those of bovine chymotrypsin with respect to inactivation by phenylmethanesulfonyl fluoride and carbobenzoxyphenylalanine chloro ketone and preferential peptide bond cleavage at aromatic amino acid residues. In contrast to bovine chymotrypsin, the hornet protease is not inhibited by the basic pancreatic Kunitz inhibitor, soybean inhibitor, or chicken ovomucoid. The molecular weight, as determined by several independent methods, was found to be 14 500. The protease is a single-chain protein containing two disulfide bonds. The terminal sequences are: NH2-Ile-Val-Gly-Gly-Ile-Asp.....Gly-Lys-Tyr-Pro-Tyr-Gln-Val-Ser-Leu-Arg-COOH.

Properties of two chymotrypsins from the digestive gland of prawn Penaeus monodon

“…Calculation based on the specific activities of purified Pl and P2 and that of the crude extract indicated that PI and P2 together represent about 6-8070 of the proteins in the hepatopancreas extract. The cleavage sites of the shrimp chymotrypsins on oxidized bovine insulin chain B ( fig.2) suggest that their peptide-bond specificities are similar to that of chymotrypsins from crab [2], hornet and Streptomyces griseus [16]. They prefer bonds at the carboxyl side of tyrosyl, phenylalanyl and leucyl residues, and to a lesser extent, those of lysyl, arginyl and glutaminyl residues.…”

A gene family inDrosophila melanogastercoding for trypsin-like enzymes

“…8). However, the three sequenced invertebrate enzymes (12,13,14) including hornet chymotrypsin, and now this sequenced Drosophila trypsin-like enzyme, all lack the 136-201 bridge. The possibility that either the vertebrate enzymes all picked up the fourth bridge independently or that the invertebrate enzymes all lost the bridge after a single trypsinchymotrypsin divergence is unlikely.…”

Studies on the Degradation of Fibrinogen by Proteolytic Enzymes from the Larvae of Lanomia achelous (Cramer)

“…iany et al (31) described an endopeptidase belonging to the chymotrypsin family in the larvae of the hornet Vespa crabro, and Yates (32) described trypsin-like enzymes in the female of Aedes aegypty; Garda et al (33) purified a sulphydryl-dependent proteare from Rhodnius prolixus midgut (prolixasa) similar to o, .t yrrotrypsin and not inhibited by TLCK. An alkaline protease of molecular weight 14,000 associated with a granulosis virus of Plodia interpunctella which is inhibited by PMSF has also been described (35) but the action of those enzymes upon fibrinogen has not been studied.…”