Sucralfate, a basic aluminum salt of sucrose sulfate. III. Inhibition of peptic hydrolysis of fibrinogen by sucrose sulfate.

As an extension from a previous study with serum albumins, the interaction of sucrose sulfate with bovine plasma fibrinogen was studied with respect to peptic inhibition, complexation and pH-dependence. While such features unique to this protein were found as a small degree of dependences on substrate concentration in peptic inhibition and in compositional ratios of insoluble complexes, the interaction of sucrose sulfate with fibrinogen at acid pH proved essentially similar to that with serum albumin. Both interactions are electrostatic in nature and show extensive binding that results in the formation of soluble as well as insoluble complexes resistant to peptic hydrolysis. The concentration ratio is more important than the absolute concentrations of the substrate and the inhibitor determining the degree of peptic inhibition. A sucrose sulfate to fibrinogen molar ratio of 50 represented the saturation point and was almost identical to the ratio found in the interaction with serum albumin expressed in mol of sucrose sulfate bound by a unit weight of protein. The principles found with serum albumin and fibrinogen will also apply in the interaction with other proteins at acid pH.