Some characteristics of Ligularia fischeri polyphenol oxidase

곰취 Polyphenol oxidase의 효소화학적 성질

Four types of polyphenol oxidase were isolated from the crude extract of a Ligularia fischeri by gel filtration on Sephadex G-150. Optimum pH and temperature for the activity of partially purified enzyme were 7.5 and $25^{\circ}C$, respectively. It was stable at temperature $40^{\circ}C$ when examined at pH 7.5 for 5 min, and lost 90% of its activity at $70^{\circ}C$ in 30 min at pH 7.5. The enzyme has good activity on catechol and chlorogenic acid but was inactive on dopamine.

Sephadex G-150 column chromatography에 의해 부분 정제된 곰취 polyphenol oxidase의 최적 pH와 최적온도는 7.5와 $25^{\circ}C$였으며, pH 7.5에서 5분간 처리시에는 $40^{\circ}C$에서 안정하였으나, 30분간 처리시에는 $70^{\circ}C$에서 약 90% 실활하였다. polyphenol oxidase는 ascorbic acid와 potassium cyanide(0.5mM)에 의해 불활성화 덕었으며, L-Lysine, glutathione (0.5 and 1mM), ascorbic acid와 potassium cyanide(1mM)에서는 완전 실활하였다. catechol과 chlorogenic acid의 기질은 높은 특이성을 나타낸 반면 dopamine은 7.4%로서 가장 낮았다.