Regulation of plasminogen activation by components of the extracellular matrix.

Published

Journal Article

The kinetics of activation of Glu-plasminogen (Glu-Pg) and Lys77-Pg by two-chain recombinant tissue plasminogen activator (t-PA) were determined in the presence of isolated protein components of the extracellular matrix (ECM) and compared to activation in the presence of fibrinogen and fibrinogen fragments and in the absence of added protein. Several ECM protein components were as effective as fibrinogen fragments at stimulating Pg activation. Stimulation of Glu-Pg activation resulted from both a decrease in Km and an increase in Vmax, whereas stimulation of Lys77-Pg was due primarily to increases in Vmax. The most effective stimulators of activation were basement membrane type IV collagen and gelatin which resulted in a 21- and 55-fold increase, respectively, in the kcat/Km of Glu-Pg (relative to a 10-fold increase observed with fibrinogen fragments). Amidolytic activity of t-PA was also enhanced up to 12-fold by ECM proteins. However, plasmin amidolytic activity was unaffected by the presence of added proteins. These data suggest that several ECM-associated proteins can enhanced the activation of Pg in the absence of fibrin.

Full Text

Duke Authors

Cited Authors

  • Stack, S; Gonzalez-Gronow, M; Pizzo, SV

Published Date

  • May 22, 1990

Published In

Volume / Issue

  • 29 / 20

Start / End Page

  • 4966 - 4970

PubMed ID

  • 2114170

Pubmed Central ID

  • 2114170

International Standard Serial Number (ISSN)

  • 0006-2960

Language

  • eng

Conference Location

  • United States