Acetylation of erythrocytic membrane peptides by aspirin.

Acetylation of erythrocytic membranes by aspirin has not been reported. When erythrocytes or erythrocytic membranes are incubated with [acetyl-14C]aspirin, there is good evidence of very tight binding to membrane peptides in concentrations known to occur in vivo, 20 to 200 microM. No such evidence is observed with [carboxy-14C] aspirin. This indicates acetylation of membrane peptides. Although pronounced selectivity is not observed among the different peptides by gel filtration on Bio-Gel A-5M and sodium dodecyl sulfate polyacrylamide gel electrophoresis, there is overall saturation with a half-maximum at about 10 mM. The clinical significance of acetylation of membrane peptides of erythrocytes is unclear.