Soluble fibrin species in arterial thrombi.

The aim of this study was to characterize soluble fibrin(ogen) species in human, arterial, in-vivo-formed thrombi, using the immunoblotting technique. Specimens were collected via intra-arterial catheters in six patients scheduled for catheter-directed thrombolysis. Unreduced and reduced samples of the supernatants from the arterial thrombi-derived specimens were electrophoresed on polyacrylamide gels and immunoblotted, using specific mono- and polyclonal anti-fibrin(ogen) antibodies.

The AGDV residues on the gamma chain carboxyl terminus of platelet-bound fibrinogen are needed for platelet aggregation.

It has been clear that only the carboxyl terminus of fibrinogen (Fg) gamma chain is required for the initial binding of Fg from solution to its GPIIbIIIa (glycoprotein IIb and IIIa) receptor on activated platelets, whereas the two RGD sites on the A alpha chain do not play any role. In this study, we examined the role of these three putative adhesive domains on Fg already bound to its receptors in mediating platelet aggregation. Activated platelets were first incubated with Fg to let the Fg bind, then with monoclonal antibodies (mAb) to block the putative adhesive domains, and the platelet suspension was then sheared or stirred to induce aggregation.

A chimeric streptokinase with unexpected fibrinolytic selectivity.

Chimeric 59D8-SK was designed to confer fibrin-selectivity to streptokinase by fusion of the Fab fragment of anti-fibrin antibody 59D8 to the N-terminus of streptokinase (SK: Ile1-Lys414). It was expressed in a mouse hybridoma cell line and purified by affinity chromatography on a 59D8-antigen column. Chimeric 59D8-SK is a disulfide-linked heterodimer composed of an antibody light chain (Mr 27,000) and a N-glycosylated chimeric heavy chain (M(r) 90,000).

Design of heterotetrameric coiled coils: evidence for increased stabilization by Glu(-)-Lys(+) ion pair interactions.

Electrostatic interactions between charged amino acids often affect heterospecificity in coiled coils as evidenced by the interaction between the oncoproteins, fos and jun. Such interactions have been successfully exploited in the design of heteromeric coiled coils in a number of laboratories. It has been suggested that heterospecificity in these dimeric coiled-coil systems is driven not by specific electrostatic interactions in the heterodimers but rather by electrostatic repulsion acting to destabilize the homodimer state relative to the heterodimer state.