| 摘要 |
PURPOSE:To obtain a new polyphenol oxidase having such stability as to be applicable to areas like food processing and clinical analysis in terms of pH stability and optimal temperature etc., and capable of mass production in high purity as an enzyme. CONSTITUTION:This enzyme, polyphenol oxidase, is obtained by culturing e.g. Trametes gibbosa MS3940l (FERM P-14063) and has the following physicochemical characteristics: (1) oxidative to various phenolic compounds, esp. high oxidative activity on (+)-catechin, catechol, 2,3-dihydroxybenzoic acid, caffeic acid, protocatechuic acid, weak in oxidative activity on phenol, cresols, etc., and nonoxidative to L-tyrosine; (2) optimal pH: 4.5-5.0, and stable at pH5.0-7.5 for treatment at 35 deg.C for 30min; (3) optimal temperature for its activity is 55 deg.C, being stable up to 60 deg.C for treatment at pH6.0 for 30min; (4) molecular weight determined by SDS electrophoresis: 70000; and (5) isoelectric point determined by Ampholine focus electrophoresis: 3.40. |
