Abstract
Platelet thrombospondin interacts with fibrinogen in a specific and saturable manner. Thrombospondin was found to specifically bind to the A alpha- and B beta-chains of fibrinogen; binding was independent of divalent ions. Binding could be blocked either by preincubation of thrombospondin with 9.4 microM fibrinogen or by preincubation of fibrinogen with 1.1 nM thrombospondin. Thrombospondin bound only to the beta-chain component of the D and DD plasmin fragment of fibrinogen. Thrombospondin interaction with fibrinogen was not blocked by preincubation with synthetic peptides which have previously been identified as either the fibrinogen receptor (alpha 572-575, the synthetic tetrapeptide arginyl-glycyl-aspartyl-serine) or cell attachment (gamma 400-411) domains. Fibrinogen, therefore, possesses at least two unique and distinct sites, within the A alpha- and B beta-chains, for its interaction with thrombospondin.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have