STRUCTURAL STUDIES OF REDOX ENZYMES AND MEDICALLY IMPORTANT SERINE PROTEASES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 这是一个为期2年的生物大分子结构研究APS束时间的建议。它侧重于四个氧化还原蛋白和几个哺乳动物蛋白酶突变体和天然或合成抑制剂的复合物。 四聚体肌氨酸氧化酶（TSOX）中的一种氧化还原蛋白质，TSOX是一种从嗜麦芽假单胞菌中分离出来的细菌黄素酶。它含有三种辅酶（FAD，FMN和NAD+），并包含4种不同的亚基。TSOX催化肌氨酸氧化生成甲醛和过氧化物。当存在四氢叶酸时，肌氨酸氧化与5，10-亚甲基四氢叶酸的形成偶联。 另一种氧化还原酶是nikD，其催化Streptomyces tendae中尼可霉素抗生素生物合成途径的早期步骤。它是一种45 kDa的单体，含有与半胱氨酸共价结合的FAD。已在不同pH下以封闭和开放形式测定NikD。 PCMH是从恶臭假单胞菌中分离的异四聚体黄素细胞色素c，其含有2x 59-kDa黄素酶二聚体（FPSU），该黄素酶二聚体含有共价结合的FAD和两个9 kDa细胞色素亚基。催化对甲酚氧化为对羟基苯甲醇并将电子转移至细胞色素。已知PCMH的1.85结构和FPSU的1.3结构。 Amicyanin是一种9 kDa的蓝色铜蛋白，可接受来自副球菌中甲胺脱氢酶的电子。的氧化还原电位，电子耦合和重组能的几个突变体的amicyanin显示显着的差异，从野生型蛋白质。 正在研究的哺乳动物丝氨酸蛋白酶约为30 kDa，参与血栓形成和病理性炎症反应等过程。对这些酶的研究是实验室的一个主要重点。 这些蛋白质的几种突变形式以及各种酶抑制剂复合物的结构将被确定，以阐明它们的催化机制和模式。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a 2-year proposal for APS beam time for structural studies of biological macromolecules. It focuses on four redox proteins and on several mammalian protease mutants and complexes with natural or synthetic inhibitors. One of the redox proteins in tetrameric sarcosine oxidase (TSOX), a bacterial flavoenzyme isolated from Pseudomonas maltophilia. It contains three coenzymes (FAD, FMN and NAD+) and comprises 4 different subunits. TSOX catalyzes the oxidation of sarcosine to yield formaldehyde and peroxide. When tetrahydrofolate is present, sarcosine oxidation is coupled to the formation of 5,10-methylenetetrahydrofolate. Another redox enzyme is nikD, which catalyzes an early step in the biosynthetic pathway for nikkomycin antibiotics in Streptomyces tendae. It is a monomer of 45 kDa containing FAD bound covalently to cysteine. NikD has been determined in closed and open forms at different pH. PCMH is a heterotetrameric flavocytochrome c isolated from Pseudomonas putida that contains a 2x59-kDa flavoenzyme dimer (FPSU) containing covalently bound FAD and two 9 kDa cytochrome subunits. It catalyzes the oxidation of p-cresol to p-hydroxybenzyl alcohol and electron transfer to the cytochrome. The 1.85 ¿ structure of PCMH and the 1.3 ¿ structure of FPSU are known. Amicyanin is a blue copper protein of 9 kDa that accepts electrons from methylamine dehydrogenase in Paracoccus denitrificans. The redox potentials, electronic coupling and reorganization energies of several mutants of amicyanin show significant differences from the wild type protein. The mammalian serine proteases being studied are approximately 30 kDa and are involved in processes such as thrombosis and pathological inflammatory response. Research on these enzymes represents a major focus of the laboratory. The structures of several mutant forms of these proteins, as well as of various enzyme-inhibitor complexes will be determined in order to elucidate their catalytic mechanisms and modes of