Purification and Properties of α- <scp>d</Scp> -Galactosidase Produced by Corticium Rolfsii

Abstract

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-galactopyrano-side 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 0.26 × 10−3m for o-nitrophenyl α-d-galactopyranoside. The values of Vmax were also determined to be 26.6 μmoles and 28.6 μmoles per min per mg for p- and o-nitrophenyl α-d-galactopyranoside, respectively.