论文部分内容阅读
目的验证血红素加氧酶－１（ＨＯ－１）中的第３９位赖氨酸（Ｋ３９）对电子传递的影响。方法通过定点诱变将Ｋ３９置换为酸性氨基酸谷氨酸（Ｅ），并将得到的变异型酶基因克隆到高度表达的载体上表达，提纯变异型ＨＯ，测定其活性，比较变异型酶与野生型酶的活性区别，以了解高保守的碱性氨基酸Ｋ３９对电子传递的影响。结果 ＨＯ催化血红素的体外反应，由抗坏血酸提供电子时，变异型酶Ｋ３９Ｅ与野生型酶比较活性没有显著性差异；而ＨＯ催化血红素的模拟体内反应，由ＮＡＤＰＨ－细胞色素Ｐ４５０还原酶提供电子时，变异型酶Ｋ３９Ｅ与野生型酶相比活性有显著性差异。结论 ＨＯ的碱性氨基酸Ｋ３９在接受并传递ＮＡＤＰＨ－细胞色素Ｐ４５０所提供的电子时具有重要作用。
Objective To verify the effect of lysine 39 (39) on the electron transport in heme oxygenase-1 (HO-1). Methods K39 was replaced by acidic amino acid glutamic acid (E) by site-directed mutagenesis. The mutant gene was cloned into a highly expressed vector and expressed. The mutant HO was purified and its activity was compared. Type enzyme activity to understand the impact of the highly conserved basic amino acid K39 on electron transfer. Results When HO catalyzed the reaction of heme in vitro and the ascorbic acid supplied electrons, the activity of mutant K39E was not significantly different from that of wild-type enzyme. The HO-catalyzed heme simulates the in vivo reaction and is supplied by NADPH-cytochrome P450 reductase , The activity of mutant K39E was significantly different from that of wild-type enzyme. Conclusion The basic amino acid K39 of HO plays an important role in accepting and transmitting the electrons provided by NADPH-cytochrome P450.