高效毛细管电泳法测定吲哚乙酸氧化酶的活力

目的]为霍山石斛的进一步研究和开发提供依据。方法]采用高效毛细管电泳技术,以pH值为9.0的80mmol/L硼砂缓冲溶液和15mmol/L葡萄糖溶液所组成的缓冲体系为流动相,研究吲哚乙酸氧化酶活性的最佳测定条件。结果]当反应80min后,酶活力下降。当底物浓度较低时,酶活力随底物浓度的增加而增加,当底物浓度大于20mg/L时,酶活力不再增加,保持在5.7g(/mg·h)左右。当pH值在6.0左右时,酶活性最高。温度对酶活性有很大的影响。当反应温度为5℃时,酶活力较低,然后酶活力随温度的升高而逐渐升高,30℃后明显下降。当温度为20～30℃时,吲哚乙酸氧化酶活力最高。结论]当温度为25℃、pH值为6.0、底物浓度为20mg/L时,吲哚乙酸氧化酶的活力最高。

Study on the Determination of IAA Oxidase Activity by High Performance Capillary Electrophoresis

Objective] The aim of the research was to provide basis for further research and development of Dendrobium huoshanense. Method] Taking the buffer system consisted of 80 mmol/L borax buffer and 15 mmol/L glucose solutions with pH value of 9.0 as the background electrolyte, the optimum conditions for determining the activity of indoleacetic acid (IAA) oxidase were studied by high performance capillary electrophoresis technique. Result] When the reaction was made for 80 min, the enzyme activity was reduced. When the substrate concentration was lower, the enzyme was increased with the increasing of the substrate concn. When the substrate concn. was more than 20 mg/L, the enzyme activity was not increased but maintained at the level of about 5.7 g/(mg·h). When pH value was about 6.0, the enzyme activity was highest. Temperature had greater effects on the enzyme activity. When the reaction temperature was 5 ℃, the enzyme activity was lower, then the enzyme activity was gradually increased with the increasing of temperature and it was obviously decreased after 30 ℃. When the temperature was 20-30 ℃, the activity of IAA oxidase was highest. Conclusion] When the temperature was 25 ℃, pH value was 6.0 and the substrate concn. was 20 mg/L, the activity of IAA oxidase was the highest.