FLAVIN-PROTEIN INTERACTIONS IN FLAVOENZYME CATALYSIS

我们将研究控制电子的基本参数。 转移反应氧化还原酶。动力学激光光解耦合 定点突变将阐明氨基酸侧的作用 链条等结构特征在生产中的生成 蛋白质-蛋白质或结构域-结构域相互作用以及电子转移 在假肢组之间。蛋白质间和蛋白质内的反应 将在以下具体系统中进行研究。 铁氧还蛋白/铁氧还蛋白：NADP+还原酶：我们将调查 位点特异性还原酶突变体与野生型和 突变的铁氧还蛋白，以提供对 期间发生的关联/识别和电子转移事件 生产遇到黄色素b2(乳酸脱氢酶)： 将在血红素-黄素结构域进行保守突变 界面，以及这些变化对分子内电子的影响 假体组之间的转移将被确定。再加上 突变蛋白的X射线结构，这些研究应该提供 距离和方位对氧化还原作用的重要见解 美分通信。细胞色素P4SOBM-3(脂肪酸单加氧酶)： 比较了全酶的电子转移性能。 与蛋白质的可表达亚域(血红素，Fad-FMN， FAD、FMN和FMN-HEME)。这将提供有关效果的信息 这些区域之间在中心间电子转移上的相互作用。 我们还将研究多肽连接物突变的影响。 区域的域间电子转移。对甲酚甲基羟基酶 (黄色素c)：我们将研究亚基间的电子转移 黄素酶切位点或黄素酶切位点改变的突变体的动力学 亚基接口区。这些研究，以及x射线结构 突变蛋白的测定应提供有关ET的信息 黄素-血红素电子的路径、距离和取向效应 调职。

We will investigate the fundamental parameters which control electron transfer reactions redox enzymes. Kinetic laser photolysis coupled with site-specific mutagenesis will elucidate the roles of amino acid side chains and other structural features in the generation of productive protein-protein or domain-domain interactions, and in electron transfer between prosthetic groups. Both interprotein and intraprotein reactions will be studied in the following specific systems. Ferredoxin/ferredoxin : NADP+ reductase: We will investigate the interactions of site-specific reductase mutants with both wild-type and mutant ferredoxins in order to provide new insights int the association/recognition and electron transfer events which occur during productive encounter Flavocytochrome b2 (lactate dehydrogenase): Conservative mutations will be made at the heme-flavin domain interface, and the effects of such changes on intramolecular electron transfer between the prosthetic groups will be determined. Coupled with x-ray structures of the mutant proteins, these studies should provide important insights into the role of distance and orientation on redox cents communication. Cytochrome P4SOBM-3 (fatty acid monooxygenase): The electron transfer properties of the holoenzyme will be compared with those of expressible subdomains of the protein (heme, FAD-FMN, FAD, FMN, and FMN-heme). This will provide information on the effects of interactions between these domains on intercenter electron transfer. We will also study the effect of mutations in the polypeptide linker region on interdomain electron transfer. p-Cresol methylhydroxylase ( flavocytochrome c): We will study intersubunit electron transfer kinetics in mutants which are alterated at the flavin site or in the subunit interface region. These studies, along with x-ray structure determinations of mutant proteins, should provide information on et pathways and distance and orientation effects on flavin-heme electron transfer.