Proteolytic susceptibility of membrane proteins during erythrocyte aging.

Susceptibility of membrane proteins to digestion with chymotrypsin was compared in various age fractions of bovine erythrocytes by SDS-polyacrylamide gel electrophoresis. The extent of protein digestion was found to be higher in membranes of older erythrocytes, as judged from the disappearance of original protein bands and accumulation of digestion products. These results are consistent with the hypothesis of a proteolytic generation of a "senescent cell antigen" in red blood cells.