Structural features of fibrinogen associated with binding to chelated zinc.

Fibrinogen absorbed to zinc chelate columns at pH 7.8 and was eluted sharply with a pK of 5.8 indicative of the involvement of a histidine residue. The binding was unaffected by high concentrations of calcium or zinc. Fibrinogen degradation products X and Y also bound to zinc chelate columns. On passage of fibrinogen fragments D and E through these columns fragment E was not bound and fragment D was eluted subsequently in a pure form with a pK of 6.1.