Spin label studies of human erythrocyte membranes in aging.

Spin-labeling studies of erythrocyte membranes from people more than 65 years of age and those less than 25 years of age have been performed. No statistically significant alteration in lipid fluidity in ghost membranes from older persons could be demonstrated. However, use of a protein-specific, covalently bound spin label demonstrated a highly significant alteration in electron spin resonance spectra of the probe in erythrocyte ghost membranes in aging, suggesting that the physical state of membrane proteins is altered in senescence. These results suggest a possible role of membrane proteins in the molecular biology of aging.