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30 min,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2.34 mmol/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 9.0 and temperature was from 10℃ to 40℃, the enzyme was stable. The Kmpmp of the reactive substrate PMP was 2.34 mmol/L under the optimum measure condition.
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