Purification and partial characterization of an acid phosphatase (EC 3.1.3.2) produced by Propionibacterium acnes

A strain of Propionibacterium acnes (type I; Marples & McGinley, 1974), isolated from a blackhead acne lesion, produced an acid phosphatase which was present in the culture supernatant in the late-exponential and early-stationary phases of growth. This acid phosphatase was purified more than 45 000-fold (4.5% yeild). The purified enzyme gave two protein bands on sodium dodecyl sulphate-polyacrylamide gel electrophoresis corresponding to molecular weights of 155 000 and 87 100. The enzyme had a single peak of activity on Sephadex G-100, with a molecular weight corresponding to 93 000. The highly purified acid phosphatase had an optimum activity at pH 5.8, was stable from pH 4.0 to 5.5 and was totally inactivated after 30 min at 55 degrees C. The enzyme did not show an absolute requirement for metal ions, but was stimulated by Mg2+, Ca2+, Zn2+ and K+ at concentrations between 0.1 and 1 mM. The acid phosphatase was active against a number of monophosphate esters.