摘要
采用硫酸铵沉淀．SephadexG-100层析DEAE-Sepharose纯化烟草中的谷草转氨酶（GOT）．并对酶的最适温度、最适pH值和金属离子对酶活力的影响等进行了研究。结果表明，该酶最适反应温度为37℃，最适pH范围为8．5～9．0，nn2＋Zn^2＋，Fe^2＋对GOT起激活作用，最佳氨基供体为L-天冬氨酸，酶促反应的Vmax为0．575μmol／L·min，L-天冬氨酸和a-酮戊二酸的米氏常数分别为0．929μmol／L和0．105μmol／L；研究还表明，GOT不能催化吡哆胺转变为吡哆醛，证明在植物体内有另外一种转氨酶催化该反应，为植物体内VB。代谢途径的进～步研究提供了依据。
Glutamic-oxaloacetie transaminase was purified from tobacco by ammonium sulfate, DEAE-Sepharose Fast Flow ion exchange chromatography, Sephadex G-100 gel filtration. And the characteristics were intensively studied. The optimum reaction conditions of GOT were gained： temperature 37℃, pH 8.5-9.0. Mnz＋, Zn2＋, Fe2＋ could activate the activity of GOT, the best amino donor was L-Aspartate. The maximum reaction rate of the enzymatic reactions was 0.575 μmol/L .min, and the Michaelis constant of L- Aspartate and a-ketoglatarate were 0.929 μmol/L and 0.105 μmol/L. The study also showed that GOT couldn＇t catalyze the reaction between pyridoxine and pyridoxal, which could prove that there was another transaminase to catalyze the reaction in higher plants.
出处
《广东农业科学》
CAS
CSCD
北大核心
2013年第10期146-148,175,共4页
Guangdong Agricultural Sciences
关键词
烟草
谷草转氨酶
纯化
酶学性质
tobacco
glutamic-oxaloacetic transaminase
purification
enzymatic characteristics
