Purification and Some Properties of Acid Phosphatase from Shii-take

Abstract

Three kinds of phosphatases, one main component (phosphatase A) and two secondary components (phosphatase B₁ and B₂), were separated and partially purified from Shii-take, fruit body of Lentinus edodes, by ammonium sulfate fractionation, two steps of ion-exchange chromatography and gel filtration. Phosphatase A was homogeneous on disc polyacrylamide gel electrophoresis. The appearent molecular weight was estimated to be 21×10⁴ by gel filtration and 7×10⁴ by SDS-polyacrylamide gel electrophoresis. Phosphatase A was identified as an acid phosphatase (EC 3. 1. 3. 2), since it effectively hydrolyzed various phosphomonoesters but not phosphodiesters, and the optimum pH for some phosphomonoesters was 4.0. It was markedly inhibited by NaF, K₂Cr₂O₇, Na₂MoO₄, Na₂WO₄. It was stable at pH 4.0 below 60°C, but relatively unstable at pH range above 7.0 on heating. Phosphatase B₁ and B₂ resembled to phosphatase A in substrate specificity, pH-activity curve, thermostability, but were distinguishable by elution pattern on ion-exchange chromatography and molecular weight.