Identification of the Proteolytic Thrombin Fragments Formed after Cleavage with Rat Mast Cell Protease 1

Abstract

We have previously identified rat mast cell protease 1 (RMCP-1), a chymotrypsin-like secretory granule serine protease, as a potent inactivator of thrombin. The present study outlines the cleavage pattern obtained after degradation of thrombin by RMCP-1. The cleavage sites in thrombin were identified by N-terminal amino acid sequence analysis of recovered thrombin fragments. Incubation of thrombin with RMCP-1 resulted in the rapid formation of a 37-kDa fragment, due to cleavage of the Phe1G-Gly1F bond in the thrombin A chain (numbering of amino acid residues according to topological equivalencies with chymotrypsinogen). Further incubation resulted in cleavage of the Trp148-Thr149 bond in the B chain, along with the formation of fragments of 27 kDa and 15 kDa. When the RMCP-1/thrombin mixtures were incubated further, successive degradation of the 37-kDa, 27-kDa and 15-kDa fragments was observed, along with cleavage of the Tyr117-Ile118 bond in the B chain and the formation of fragments of 12, 9 and 6 kDa. No residual thrombin activity was detected after the degradation process had proceeded to this stage. Heparin was shown to markedly enhance the rate of thrombin degradation by RMCP-1.

Keywords

THROMBIN; RAT MAST CELL PROTEASE 1; CHYMASE; MAST CELL; HEPARIN

Published in

European Journal of Biochemistry
1995, Volume: 227, number: 1-2, pages: 102-107
Publisher: SPRINGER VERLAG

SLU Authors

• Pejler, Gunnar

  • Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences
    

• Berg, Lotta

  • Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Immunology in the medical area
Cell and Molecular Biology


Publication identifier

DOI: https://doi.org/10.1111/j.1432-1033.1995.tb20364.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/52784