Purification and Properties of Glucoamylase form Yeast Candida tsukuaensis

The glucoamylase of Candida tsuubaensis was purified to homogeneity form culture filtrate by means of ultrafiltration, Sephacryl S-200 gel filtration and Sp-Sephadex C-50 chromatography. The purified enzyme was a glycoprotein with a molecular mass of approximately 50 kDa, which was a monomeric protein. Km values were 5.8 mg/ml for soluble starch and 0.04 mM for maltose. Glucoamylase also released only glucose from both pullulan and isomaltose. The analysis of amino acid composition revealed that the enzyme contained a high content of acidic and polar amino acids. In addition, Western blotting analysis indicates that C. tsukubaensis glucoamylase is resistant to glucose repression.