Demonstration and characterization of CD 46, membrane cofactor protein, in stomach

Abstract

CD 46, membrane cofactor protein, is a glycoprotein widely present on the cell membranes and is different in molecular weight among organs or cells in the same individual. It acts as a cofactor of I of the complement system, which inactivates C 3 b bound to the autologous cells, and protects them from the attack of the complement. In this study CD 46 was demonstrated in the stomach immunochemically. Gastric CD 46 was expressed strongly in the mucosal epithelium, mucosa and endothelial cells of the vessels in the submucosal layer, whereas expressed weakly in the submucosa and muscle. Western blot analyses revealed that gastric CD 46 was expressed as one broad band with molecular weight ranging from 60 kDa to 69 kDa, which was distinct from that of lymphocytes in the peripheral blood.