Differences in the carbohydrate moieties of plasma and amniotic fluid fibronectins as revealed by crossed immunoaffinity electrophoresis with concanavalin A.

Human fibronectins isolated from pooled human plasma and amniotic fluid were studied as to differences in their carbohydrate moieties. The chemical analyses showed that amniotic fluid fibronectin is different from adult plasma fibronectin in carbohydrate content and composition while there seems to be no significant differences in amino acid composition. Crossed immunoaffinity electrophoresis with free concanavalin A, as well as rocket immunoelectrophoresis with immobilized concanavalin A intermediate gel, indicated that amniotic fluid fibronectin has little or no reactivity with this lectin while adult plasma fibronectin is strongly reactive. Fetal cord plasma fibronectin apparently interacted with concanavalin A, but its reactivity was weaker than that of adult plasma fibronectin. Fibronectin isolated from ascitic fluid of an ovarian cancer patient which was examined in additional experiments showed much weaker Con A-reactivity than fetal cord plasma fibronectin. These results suggest that fibronectins from various body fluids differ in their carbohydrate structures.