茶树鲜叶中维生素B_6代谢酶PNPO的活性分析  

Analysis on the Activity of PNPO of VB_6-metabolizing Enzymes from Tea Leaf

作　　者：李艳霞[1] 张剑韵[2] 黄龙全[1] 

机构地区：[1]安徽农业大学茶与食品科技学院,安徽合肥230036 [2]安徽农业大学生命科学学院,安徽合肥230036

出　　处：《茶叶科学》2010年第4期273-276,共4页Journal of Tea Science

基　　金：安徽省教育厅自然科学重点科研项目(KJ2010A116)

摘　　要：采用液氮研磨、Tris-HCl+KPO4缓冲液(pH8.5)浸提法和硫酸铵沉淀法从茶树鲜叶中提取磷酸吡哆醇氧化酶(PNPO)粗酶液,并通过苯肼法研究其酶学性质。结果表明,以磷酸吡哆胺(PMP)为底物,PNPO催化反应的最佳时间为30min,最适温度为50℃,最适pH6.5。在pH6.0~9.0,温度10~40℃的条件下,此酶稳定。在最适条件下测得反应底物PMP的Km值为2.34mmol/L。The crude extract of Pyridoxamine(Pyridoxine)-5 -phosphate Oxidase(PNPO) extracted from fresh tea leaves which were grinded by liquid nitrogen with Tris-HCL+ KPO buffer(pH8.5) and fractionated with solid ammonium sulfate,the enzymatic properties were investigated with phenyl hydrazine method.Results showed that when Pyridoxamine phosphate(PMP) as the substrate,the best time for the PNPO oxidation was 30 min,and the optimum pH was 6.5,and the optimum temperature was 50℃.When the value of pH was from 6.0 to 9...

关 键 词：茶树 磷酸吡哆醇氧化酶 维生素B6 

分 类 号：S571.1[农业科学—茶叶生产加工]