菠萝蜜多酚氧化酶必需基团的研究  

Essential groups of polyphenol oxidase from jackfruit

作　　者：马义丽[1] 陶毅明[1] 

机构地区：[1]桂林医学院生物技术学院,桂林541004

出　　处：《食品科技》2014年第4期26-29,共4页Food Science and Technology

基　　金：国家自然科学基金项目(31260214)

摘　　要：以菠萝蜜果肉多酚氧化酶(Polyphenol oxidase,PPO)为研究对象,选用对氯汞苯甲酸、溴乙酸、β-巯基乙醇、PMSF、乙酰丙酮等8种化学修饰剂,研究PPO酶活的必需基团。并观察苹果酸、柠檬酸、β-环糊精、山梨醇、抗坏血酸、半胱氨酸、谷胱甘肽等9种食品添加剂对PPO活性的影响。结果表明,组氨酸是酶活的必需基团,可能位于酶活中心;丝氨酸和赖氨酸对酶活有一定贡献;二硫键对酶活有重要贡献。1 mmol/L EDTA·Na抑制15%酶活,抗坏血酸、半胱氨酸和谷胱甘肽可显著抑制酶活,IC50依次为0.3、0.2、0.56 mmol/L。In order to study the essential groups of polyphenol oxidase （PPO） from jackfruit, 8 chemicals including pCMB, β-mercaptoethanol, PMSF and acetyl acetone were chosen to modify the PPO enzyme. Effects of 9 food additives on PPO activity were also studied. The results showed that His was the essential group of PPO and might be located at the activity site. Ser and Lys made certain contributions to the enzyme activity. Disulfide bond plays a very important role in enzyme activity. 1 mmol/L EDTA.Na inhibited 15% of the enzyme activity, while ascorbic acid, Cys and GSH could significantly inhibit the activity, with the IC50 values of 0.3 mmol/L, 0.2 mmol/L and 0.56 mmol/L, respectively.

关 键 词：多酚氧化酶 菠萝蜜 酶活中心 必需基团 食品添加剂 

分 类 号：TS201.25[轻工技术与工程—食品科学]