The release of Bβ 1-42 from fibrinogen and fibrin by plasmin

Anne Hurlet-Jensen, James A. Koehn, Hymie L. Nossel

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

The balance between thrombin and plasmin action has been postulated to be an important determinant of thrombosis. Measurement of plasma concentrations of fibrinopeptide A (FPA), which reflect thrombin action on the NH2-terminal end of the Aα chain, and of Bβ 1-42 (thrombin-increasable fibrinopeptide B immunoreactivity - TIFPB) which reflect plasmin action on the NH2-terminal end of the Bβ chain have shown systematic changes in the relative concentrations of the two peptides in thrombotic states. This paper reports kinetic data for TIFPB release by plasmin using fibrinogen, fibrin I monomer, and fibrin I polymer as substrates. For fibrinogen and fibrin I monomer the data fit the Michaelis-Menten equation. Experiments were performed with human proteins in 0.15M Trisbuffered saline at pH 7.4 and at 37°C. With fibrinogen as substrate the Km was calculated to be 0.87 μM and the Vmax 3.75 × 10-5 M/min/unit of plasmin. With fibrin I monomer as the substrate the Km was calculated to be 1.25 μM and the Vmax 5.5 × 10-5 M/min/unit of plasmin. With fibrin I polymer as substrate the data did not fit the Michaelis-Menten equation but there appeared to be no dramatic differences in rates from those obtained with the other two substrates. The influence of factor XIIIa-induced cross-linking of fibrin was not examined. It is concluded from these findings that fibrinogen and non-cross-linked fibrin I are equally good substrates for plasmin cleavage of the NH2-terminal end of the Bβ chain.

Original languageEnglish
Pages (from-to)609-617
Number of pages9
JournalThrombosis Research
Volume29
Issue number6
DOIs
StatePublished - 15 Mar 1983
Externally publishedYes

Keywords

  • Bβ 1-42
  • Fibrin(ogen) and Fibrinopeptide A
  • Plasmin
  • Thrombin

Fingerprint

Dive into the research topics of 'The release of Bβ 1-42 from fibrinogen and fibrin by plasmin'. Together they form a unique fingerprint.

Cite this