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 C₆₀, such as C₆₀-Pro, C₆₀-ɛ aminocapronic acid, and C₆₀-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 Mg²⁺ ions. In contrast to the first two derivatives, C₆₀-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 C₆₀ are transported across biological membranes as lipophil ions, thus causing depolarization of the membranes.