Effect of the β-amyloid peptide Aβ25–35 and fullerene C60 on the activity of enzymes in erythrocytes

Abstract

The effect of the beta-amyloid peptide Abeta25-35 and fullerene C60 on the activity of the cytoplasmic enzymes lactate dehydrogenase (LDH) and glutathione peroxidase (GLP), and membrane-bound phosphofructokinase (PFK) and Na+,K(+)-ATPase in human erythrocytes has been studied. When used in combination, the cytotoxins decrease the activity of LDH and PFK in a nonadditive manner; in this case, Abeta25-35 protects PFK against the inhibitory effect of C60. The activity of LDH, GLP, and PFK decreases within the first 2-20 min of incubation of erythrocytes with Abeta25-35 in the absence of glucose. The addition of glucose sharply decreases the inhibitory action of Abeta25-35 on LDH and GLP but does not affect the fourfold decrease in activity of PFK; the activity of membrane-bound Na+,K(+)-ATPase does not depend on the presence of glucose. Possible mechanisms of interaction of Abeta25-35 and fullerene C60 with the erythrocyte membrane and enzymes are discussed.