MECHANISMS OF PYRIDOXAL-5'-PHOSPHATE DEPENDENT ENZYMES

描述（改编自申请人摘要）：研究者正在研究 吡哆醛-5 '-磷酸依赖酶的机制， 碳碳键这些酶包括色氨酸吲哚裂解酶、酪氨酸 酚裂合酶、色氨酸合酶、细菌和人犬尿氨酸酶，以及 天冬氨酸脱羧酶。他们正在评估 酪氨酸酚裂解酶和色氨酸吲哚裂解酶。调查人员正在 确定特定氨基酸在催化和反应中的作用 通过定点诱变和通过合成C-末端 含有非天然氨基酸的肽。调查人员正在调查 通过各种动力学技术研究这些酶的反应机理， 包括快速扫描停流分光光度法和快速化学 淬火。他们将设计，合成和评估新的抑制剂， 色氨酸吲哚裂解酶，可用于治疗嗜血杆菌 流感性脑膜炎犬尿氨酸酶的有效竞争性抑制剂， 他们正在设计和合成，基于他们对细菌的研究， 酶，已获得专利，并正在进行研究，以评估其 治疗神经系统疾病如中风的潜力。的 研究人员将确定和比较结构和反应机理， 细菌和人类犬尿氨酸酶以及天冬氨酸脱羧酶。 有关犬尿氨酸酶结构和机制的更多信息将导致 设计其他更具选择性和效力的抑制剂。的核心作用 吡哆醛-5 '磷酸盐依赖酶在氨基酸代谢和 胺和重要的生物活性代谢物的生物合成，使他们 用于设计基于机制的抑制剂的有吸引力的靶点， 对药物有用。因此，这项研究的结果可能会使一个 对改善美国人医疗保健的目标做出了重大贡献， 未来

DESCRIPTION (adapted from applicant's abstract): The investigators are studying the mechanism of pyridoxal-5'-phosphate-dependent enzymes that break or form carbon-carbon bonds. These enzymes include tryptophan indole-lyase, tyrosine phenol-lyase, tryptophan synthase, bacterial and human kynureninases, and aspartate beta-decarboxylase. They are evaluating the reaction mechanism of tyrosine phenol-lyase and tryptophan indole-lyase. The investigators are determining the roles of specific amino acids in catalysis and reaction specificity by both site-directed mutagenesis and by synthesis of a C-terminal peptide containing unnatural amino acids. The investigators are probing the mechanism of the reaction of these enzymes by various kinetic techniques, including rapid scanning stopped flow spectrophotometry and rapid chemical quench. They will design, synthesize, and evaluate novel inhibitors of tryptophan indole-lyase that may be useful in the treatment of Haemophilus influenzae meningitis. The potent competitive inhibitors of kynureninase that they are designing and synthesizing, based on their studies of the bacterial enzyme, have been patented and are undergoing studies to evaluate their potential in the treatment of neurological disorders such as stroke. The investigators will determine and compare the structure and reaction mechanism of bacterial and human kynureninases as well as aspartate beta-decarboxylase. More information on the structure and mechanism of kynureninases mat lead to the design of other more selective and potent inhibitors. The central role of pyridoxal-5'phosphate-dependent enzymes in the metabolism of amino acids and amines and in the biosynthesis of important bioactive metabolites, makes them attractive targets for the design of mechanism-based inhibitors which may be useful for drugs. Thus the results of this research are likely to make a significant contribution to the goal of improving health care for Americans in the future.