Summary
In the presence of activated factor XIII, 2-diethylbenzyl-aminoethylthiol-14C-transcinnamate bromide completely inhibited the crosslinking of fibrin. However,
all three fibrin chains bound the cinnamic acid, and, in the α- and γ-chains, the
binding of label was not restricted to the crosslinking donor sites as might be expected.
Furthermore, even in the absence of activated factor XIII, fibrinogen and fibrin incorporated
cinnamic acid. Thus, as well as reacting with the functional thiol group of factor
XIII, the thiocholine ester of cinnamic acid is incorporated non-specifically throughout
the fibrinogen and fibrin subunit chains. The thiocholine ester used differs in this
respect from dansyl cadaverine which is incorporated enzymatically and exclusively
to the (acceptor) sites involved in crosslinking. Thiocholine ester of cinnamic acid
cannot be used as a label for localization of specific crosslinking donor sites.