Cell adhesion and spreading factor: Similarity to cold insoluble globulin in human serum

Data are presented which indicate that the serum factor required for cell adhesion and spreading is very similar to cold insoluble globulin. Clotting of plasma under conditions that remove cold insoluble globulin also remove the adhesion and spreading factor. The activity of the adhesion and spreading factor co-chromatographs with cold insoluble globulin antigenicity on DEAE-cellulose and the mobilities of adhesion and spreading factor and cold insoluble globulin are the same in disc gel electrophoresis. Finally, antibody which is directed against cold insoluble globulin cross-reacts with a single component in the adhesion and spreading factor and inhibits its activity. The close similarity of the cell adhesion and spreading factor with cold insoluble globulin suggests that, in vivo, cold insoluble globulin which is adsorbed to collagen or part of a fibrin clot may constitute the normal substratum for fibroblast adhesion and migration.