Membrane proteins isolated from the coleoptile and mesocotyl tissues of corn seedlings were solubilized with Triton X100 and reconstituted with phosphatidylcholine at 2$0^{circ}C$. The proteoliposomes were incubated and proton uptake into the vesicles was measured with a spectrophotometer. Addition of ATP to the reaction mixture was found to result in an active accumulation of proton into the vesicles. These results indicate that the preparation contains tightly bound phosphatidylcholine vesicles with reconstituted H+ -ATPase from the plant cell membranes.