The isolation and properties of a peptide ionophore from beef heart mitochondria

Abstract

Summary An ionophoretic peptide has been obtained from beef heart mitochondria by extraction with organic solvents. The purified peptide interacts with both sodium and potassium ions and facilitates the transport of these ions across the mitochondrial inner membrane. The similarity in behavior between this endogenous ion carrier and certain depsipeptide antibiotics (e.g., gramicidin-D and valinomycin) suggests that the mechanism of monovalent cation permeation in mitochondrial membrane systems is accountable in terms of endogenous ion carriers analogous to known, microbiologically derived ionophores.