Plasminogen activation by tissue activator is accelerated in the presence of fibrin(ogen) cyanogen bromide fragment FCB-2.

Fibrin, in contrast to fibrinogen, strongly accelerates the plasminogen activation by extrinsic activator (tissue-type plasminogen activator, t-PA). However, when fibrin and fibrinogen are digested with cyanogen bromide, both digests potentiate the t-PA-mediated plasminogen activation equally well. In this report, evidence is presented that this potentiating activity resides in CNBr fragment FCB-2 (= Ho1-DSK) and that a polymeric structure such as fibrin is not a prerequisite for the potentiation.