Unknown

Dataset Information

0

Sheep mast cell proteinase-1: characterization as a member of a new class of dual-specific ruminant chymases.


ABSTRACT: Sheep mast cell proteinase 1 (SMCP-1), which is abundantly expressed in gastrointestinal but not skin mast cells, was isolated and its substrate specificity was investigated. Peptide substrates, including angiotensin I, substance P, bradykinin and oxidized insulin B chain were hydrolysed at P1 Phe, Leu or Tyr residues, conforming to the known chymotrypsin-like properties of the enzyme. However, SMCP-1 was found to hydrolyse some chromogenic substrates with P1 Lys and Arg residues. The enzyme also demonstrated trypsin-like activity against protein substrates, cleaving BSA at Lys114-Leu115, Lys238-Val239, Lys260-Tyr261 and Lys376-His377. Bovine fibrinogen beta-chain was cleaved at Lys28-Lys29. To ensure homogeneity of the enzyme, the ratio of chymotrypsin-like to trypsin-like activity was observed; it was found to be constant during purification and between different preparations of SMCP-1. Treatment of SMCP-1 with a range of inhibitors decreased chymotrypsin-like and trypsin-like activities by similar extents, supporting the assertion that both activities are the property of a single enzyme. In terms of activity, and by N-terminal amino acid sequencing, SMCP-1 strongly resembles the similarly dual-specific bovine duodenal proteinase, duodenase. It is proposed that SMCP-1 and duodenase represent a new class of ruminant chymases with unusual dual specificities.

SUBMITTER: Pemberton AD 

PROVIDER: S-EPMC1218120 | BioStudies | 1997-01-01

SECONDARY ACCESSION(S): 10.1042/bj3210665

REPOSITORIES: biostudies

Similar Datasets

1997-01-01 | S-EPMC1218375 | BioStudies
1998-01-01 | S-EPMC1219647 | BioStudies
1995-01-01 | S-EPMC1136500 | BioStudies
2020-01-01 | S-EPMC7377536 | BioStudies
1984-01-01 | S-EPMC1153428 | BioStudies
2008-01-01 | S-EPMC2271166 | BioStudies
1988-01-01 | S-EPMC1149203 | BioStudies
1976-01-01 | S-EPMC1172832 | BioStudies
1994-01-01 | S-EPMC1137985 | BioStudies
1000-01-01 | S-EPMC2143802 | BioStudies