Amino-acid derivatives of fullerene C60 behave as lipophilic ions penetrating through biomembranes

Abstract

It was found using potential-sensitive probes that the water-soluble amino-acid derivatives of fullerene C 60 , such as C 60 -Pro, C 60 -ɛ aminocapronic acid, and C 60 -Arg, possess a pronounced membranotropic activity. The first two cause concentration-dependent dissipation of the membrane potential (Δψ) of the symbiosomes of the nodules of the yellow lupine generated in the presence of ATP and Mg 2+ ions. In contrast to the first two derivatives, C 60 -Arg, which carries a strong positive charge at the physiological pH, has no effect on the dissipation of Δψ in this model. On the contrary, this derivative caused a noticeable dissipation of the K + diffusion potential (“minus” inside) generated on the membrane of human erythrocytes with the help of the K + ionophore of valinomycin. The regularities obtained indicate that the derivatives of C 60 are transported across biological membranes as lipophil ions, thus causing depolarization of the membranes.