[Soluble complexes of the NH2-terminal disulfide knot of fibrin with molecules containing D domains].

Soluble complexes of an NH2-terminal disulphide knot of fibrin (N-DSK alpha) with fragment D, its dimer (DD) and fibrinogen were detected by sepharose gel filtration. The main component of fragment D and N-DSK alpha mixture is represented by a specific complex eluted as a separate peak. Inactive fibrinogen N-DSK produce no complexes with fragment D. The DD-N-DSK complex is eluted together with free DD. Soluble oligomers which are partially eluted in the free column volume as well as insoluble aggregates of N-DSK alpha and fibrinogen are formed in mixture of these components. The molar D/N-DSK alpha ratio was determined in complexes isolated from mixtures with different D/N-DSK alpha ratio. A conclusion is drawn that a N-DSK alpha molecule may bind at most two fragment D molecules.