Increased band 3 protein aggregation and anti-band 3 binding of erythrocyte membranes on treatment with sesamol

The influence of sesamol, an antioxidant in processed sesame oil, on oxidat ive modification of human erythrocyte membrane proteins was investigated. H uman erythrocytes were incubated with sesamol at various concentrations up to 10 mM at 37 degrees C for 1 h. The amounts of hemoglobin bound to the me mbranes and detergent C12E8-insoluble membrane protein aggregates were incr eased as the concentration of sesamol increased. Western blot analysis indi cated that aggregates of band 3 protein were increased by the treatment. Bi nding of anti-band 3 antibody to the erythrocytes was increased by the trea tment. Isolated cell membranes were incubated with sesamol similarly. Aggre gates of band 3 protein were also increased, indicating that the band 3 pro tein aggregation was little affected by hemoglobin bound to the membranes. Aggregation of band 3 protein in the treatment of isolated cell membranes w as partially prevented when the treatment was conducted under anaerobic con ditions, suggesting that augmentation of the protein aggregation by sesamol involved both oxygen-dependent and oxygen-independent pathways. Among phen olics, sesamol showed a distinctive feature to increase band 3 protein aggr egation in erythrocyte membranes and to enhance anti-band 3 binding to eryt hrocytes.