Purification and Properties of α-D-Galactosidase Produced by Corticium rolfsii

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An α-D-galactosidase was purified from the culture filtrate of Corticium rolfsii IFO 6146 by a combination of QAE-Sephadex A-50 and SE-Sephadex C-50 chromatography. The purified enzyme was demonstrated to be free of other possibly interfering glycosidases and glycanases. The maximum activity of the enzyme towards p-nitrophenyl α-D-galactopyranoside was found to be at pH 2.5 to 4.5, and the enzyme was fairly active at pH 1.1 to 2.0. The enzyme was stable over a pH range 4.0 to 7.0 at 5°C for 72 hr and relatively unstable at pH 1.1 to 2.0 as compared with endo-polygalacturonase, α-L-arabinofuranosidase and β-D-galactosidase produced by C. rolfsii. The enzymic activity was completely inhibited by Hg²⁺and Ag⁺ ions, respectively. Km values were determined to be 0.16×10^-3_M for p-nitrophenyl α-D-galactopyranoside and 026×10^-3_M for o-nitrophenyl α-D-galactopyranoside. The values of V_mas were also determined to be 26.6μmoles and 28.6μmoles per min per mg for p- and o-nitrophenyl α-D-galactopyranoside, respectively.