Modification of membrane protein organization during in vitro aging of human erythrocytes

In in vitro aged human erythrocytes, the presence of protein clusters can be found on the membrane; these clusters are made up of peptides held together by disulfide bridges, since they can be nearly completely dissociated by dithiothreitol treatment. SDS-polyacrylamide gel electrophoresis after dithiothreitol dissociation indicates that the aggregates are made of peptide fragments with a molecular weight ranging from 20 to approximately 110 kdalton; none of these fragments correspond to an intact protein component of the membrane. Their formation results from oxidation and proteolysis of membrane, and perhaps cytoplasmic proteins.