Proton gradient-coupled uphill transport of glycylsarcosine in rabbit renal brush-border membrane vesicles.

An inward-directed proton gradient energizes the transport of intact glycylsarcosine against a concentration gradient in rabbit renal brush-border membrane vesicles. Dissipation of the proton gradient abolishes the uphill transport. Generation of an inside-negative membrane potential nearly doubles the intravesicular concentration of the dipeptide at the peak of the overshoot without altering the equilibrium value. These data provide direct evidence for peptide-proton cotransport in the renal brush-border membrane.