Mitsuru Monma

Purification of the glucoamylase components of Chalara paradoxa by affinity chromatography and chromatofusing

Abstract The six major glucoamylase components (A1–A6) in the culture filtrate of Chalara paradoxa , which had different isoelectric points, were isolated electrophoretically pure by affinity chromatography on α-CD(cyclomaltohexaose)-Sepharose 6B and positive pH-gradient chromatofocusing using CM-Sepharose CL-6B and Polybuffer 74. The isoelectric points were: A1, 3.80; A2, 3.75; A3, 3.70; A4, 3.65; A5, 3.60; and A6, 3.55, A1–A3 had molecular weights of 76,000, 77,000, 78,000, respectively, were most active at pH 5.0–6.0 and 50°, and were stable in the pH range 4.5–8.0 and up to 45°. Each of the purified glucoamylases A1–A3 attacked soluble starch to give β- d -glucose.