MECHANISMS OF PYRIDOXAL-5'-PHOSPHATE DEPENDENT ENZYMES

描述(改编自申请者摘要)：调查人员正在研究 依赖吡哆醛-5‘-磷酸的酶断裂或形成的机制 碳-碳键。这些酶包括色氨酸吲哚裂解酶、酪氨酸 苯酚裂解酶、色氨酸合成酶、细菌和人犬尿苷酸酶，以及 天冬氨酸β-脱羧酶。他们正在评估反应机理。 酪氨酸苯酚裂解酶和色氨酸吲哚裂解酶。调查人员是 特定氨基酸在催化和反应中的作用 定点突变和C-末端合成的特异性 含有非天然氨基酸的多肽。调查人员正在调查 用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法 熄灭。他们将设计、合成和评估新型的抑制剂 色氨酸吲哚裂解酶在嗜血杆菌治疗中的应用 流行性感冒脑膜炎。犬尿氨酸酶的强有力的竞争性抑制剂 他们正在设计和合成，基于他们对细菌的研究 酶，已经申请了专利，正在进行研究，以评估他们的 在治疗中风等神经疾病方面具有潜力。这个 研究人员将确定和比较结构和反应机理 细菌和人犬尿苷酸酶以及天冬氨酸β-脱羧酶。 更多关于犬尿苷酸酶的结构和机制的信息将导致 其他更有选择性和更有效的抑制剂的设计。的核心作用 氨基酸代谢中的吡哆醛-5‘-磷酸依赖酶 胺和重要生物活性代谢物的生物合成中，使它们 设计基于机理的抑制剂的有吸引力的目标，可能是 对毒品很有用。因此，这项研究的结果可能会使 对改善#年美国人医疗保健的目标作出重大贡献 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.