고구마 중 Polyphenol Oxidase의 분리 및 특성에 관한 연구 = Isolation and Characterization of the Polyphenol Oxidase from Sweet Potato

다국어 초록 (Multilingual Abstract)

Polyphenoloxidase(E.C. 1.10.3.1) was isolated and purified through ammonium sulfate fraction, dialysis and chromatography on Sephadex G-100-120 from Sweet Potato (Ipomoea Batatas). The temperature and pH optima for the enzyme were 30℃ and 6.0, respectively. For thermal inactivation, half activity of the enzyme were lost after 25 and 20 minute at 65℃ and 75℃, respectively. Michaelis constant, KM, was 2.78×10￣³M with (-) epicatechin as a substrate. For inhibitor studies, the L-ascorbic acid and L-cysteine were most potent. The purified enzyme exibited one migrating band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of approximately 28.0 KDa.