Properties of Polyphenol Oxidase from Prunus salicina (Red)

재래종(在來種) 적색(赤色)자두(Prunus salicina) Polyphenol oxidase의 일반적(一般的) 성질(性質)

  • Ham, Seung-Shi (Department of Food Science and Technology, Kangweon National University) ;
  • Hong, Eun-Hee (Department of Food Science and Technology, Kangweon National University) ;
  • Omura, Hirohisa (Food Science and Technology Institute, Kyushu Univ.)
  • Published : 1987.05.30

Abstract

Polyphenol oxidase in Prunus salicina(Red) was extracted, some properties and its partially purification were investigated as follows; Polyphenol oxidase was purified about 15 folds after ammonium sulfate saturation and about 64 folds after Sephadex G-100 column chromatography. Polyphenol oxidase showed optimum pH for activity at 6.5 and optimum temperature at at $35^{\circ}C$ and high affinity to catechol in o-diphenol compounds. Thermal stability were about 85% and 75% of initial polyphenol oxidase activity remained after heating at $50^{\circ}C$ for 5 minutes and 30 minutes respectively. The Michaelis constant of the enzyme was 2.58mM. L-cysteine, glutathione, ascorbic acid and potassium cyanide appeared to be most effective inhibitors. EDTA showed a slight inhibition.

재래식(在來式) 적색(赤色)자두(Prunus salicina)로부터 효소(酵素)를 추출(抽出) 정제(精製)하여 그 성질(性質)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 적색(赤色)자두의 PPO는 crude extract보다 $(NH_4)_2SO_4$로 포화(飽和)했을 예 15배(倍), 그리고 Sephadex G-100 column chromatograph를 행하였을 애 64배(倍)로 정제(精製)되었다. 2. 효소반응(酵素反應)의 최적조건(最適條件)은 최적온도(最適溫度) 및 pH가 $35^{\circ}C$ 6.5였으며 주요기질(主要基質) 은 o-diphenol인 catechol로 나타났다. 3. 적색(赤色)자두 PPO의 열안정성(熱安定性)은 $50^{\circ}C$에서 5분간(分間) 처리(處理)하였을 매 초기(初期) PPO의 활성중(活性中) 85%, 30분간(分間) 처리시(處理時)에는 75%의 잔존활성(殘存活性)을 나타내었다. 4. 본(本) 효소(酵素)의 K값은 2.58mM이었다. 5. 저해제(沮害劑)의 효과(效果) 중 L-cysteine, glutathione, ascorbic acid와 potassium cyanide는 1mM 농도(濃度)에서 완전히 효소활성(酵素活性)을 저해(沮害)하였으나 EDTA는 저해효과(沮害效果)가 대단히 약하게 나타났다.

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