Heat stabilities of acid phosphatases from pinto bean leaves.

Two acid phosphatases were demonstrable by polyacrylamide gel electrophoresis. They had different mobilities and different heat stabilities in 1.0M acetate buffer, pH 5.2. Both phosphatases had the same electro-phoretic mobility in tris buffer at pH 7.5, gave one boundary in the analytical ultracentrifuge in tris or acetate buffer, and had the same sedimentation coefficient. The difference in these properties suggests an alteration in conformation of the proteins by the buffer systems.