Reconstitution of proton pumping activity of a plasma membrane ATPase purified from radish

Abstract

Plasma membrane ATPase partially purified from radish seedlings (Raphanus sativum L.) (2.4–3.5 μmol P_i min⁻¹ mg⁻¹ protein) has been reconstituted in proteoliposomes by the cholate-dialysis technique. Proteoliposomes are able to acidify their internal volume in the presence of Mg:ATP. Mg:ATP-dependent proton pumping is prevented by N,N′-dicyclohexylcarbodiimide (DCCD) and by vanadate at the same concentrations which are effective on the phosphohydrolyzing activity of the plasma membrane ATPase.