Purine Metabolism in Trichomonas vaginalis

阴道毛滴虫的嘌呤代谢

基本信息

批准号：
7420991
负责人：
Ching Chung WANG
金额：
$ 28.18万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-06-01 至 2010-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7420991
关键词：
2&apos -deoxyadenosine 2-Fluoroadenine 6-methylpurine Adenine Adenosine Adenosine Kinase Alcohols Bacterial Typing Binding Biological Assay Biological Availability Catalysis Cells Chemicals Cloning Computer Graphics Crystallography Data Depth Disease Disulfiram Enzyme Inhibitor Drugs Enzyme Inhibitors Enzyme Kinetics Enzymes Escherichia coli Future Growth Guanosine HIV Infections Human Infection Kinetics Lead Libraries Medical Metronidazole Metronidazole resistance Modeling Modification Monitor Mutagenesis Nucleosides Nucleotides Organism Outcomes Research Parasites Pathway interactions Pharmaceutical Preparations Phosphorylase a Play Predisposition Protein Sequence Analysis Proteins Purine Nucleoside Phosphorylase Inhibitor Purine Nucleosides Purine Nucleotides Purine-Nucleoside Phosphorylase Purines Purpose Pyrimidine Nucleotides Reaction Recombinant Proteins Recombinants Reporting Research Rodent Role Sexually Transmitted Diseases Site-Directed Mutagenesis Specificity Structure Structure-Activity Relationship Substrate Specificity Testing Therapeutic Toxic effect Trichomonas Infections Trichomonas vaginalis United States Urethritis Vaginitis Woman X ray diffraction analysis X-Ray Crystallography X-Ray Diffraction analog base chemical synthesis chemotherapy combinatorial design enzyme structure enzyme substrate formycin guanosine kinase improved inhibitor/antagonist kinase inhibitor men novel strategies nucleoside kinase pathogen prototype purine purine metabolism small molecule libraries social

项目摘要

DESCRIPTION (provided by applicant): Trichomonas vaginalis is one of the most prevalent infectious pathogens with a worldwide distribution and about 5 million new cases occurring every year. It has vulnerability in lacking de novo synthesis of purine nucleotides and relying on the sequential actions of a purine nucleoside phosphorylase (PNP) and a purine nucleoside kinase (PNK) for salvaging the external purine bases. Inhibition of either enzyme can result in cessation of T. vaginalis growth and could thus lead to a therapeutic gain. T. vaginalis PNP is a bacterial type hexameric protein with an overwhelming catalytic efficiency in converting adenine to adenosine, whereas human PNP is a trimeric protein not even recognizing adenine as a substrate. T. vaginalis PNK is primarily a bacterial type guanosine kinase, whereas human PNK uses only adenosine as substrate. There are thus many opportunities for designing selective inhibitors against the two parasite enzymes. The parasite PNP was cloned, expressed and had its kinetic mechanism of catalysis well analyzed by us. In the future plan, its structure will be studied by crystallography and its structure-function relationship will be dissected by site-directed mutagenesis. Computer graphic modeling will be used for selecting specific enzyme inhibitors and combinatorial library synthesis will be involved in improving the lead compounds. Well known bacterial PNP inhibitors, such as formycin A, and the subversive substrates of Escherichia coli PNP will be tested and structurally modified for improved potency against the parasite enzyme. T. vaginalis PNK will be cloned sequenced and expressed. The kinetic mechanism of its catalytic function will be examined and compared with that of human adenosine kinase (AK). Following crystallographic structural analysis and site-directed mutagenesis to verify the mechanisms of substrate binding, product release, etc., computer graphic modeling and combinatorial library synthesis will be applied for selection of potent and specific enzyme inhibitors. Many well-known inhibitors of human AK with demonstrated bioavailability will be structurally modified to convert them from human AK inhibitors into potentially selective T. vaginalis PNK inhibitors for anti-Trichomoniasis chemotherapy. The prospect in a successful outcome from this research plan appears good.

描述（由申请人提供）：阴道Trichomonas是最普遍的感染性病原体之一，每年发生大约500万例新病例。它在缺乏嘌呤核苷酸的从头合成和依赖嘌呤核苷磷酸化酶（PNP）和嘌呤核苷激酶（PNK）的顺序作用方面具有脆弱性。两种酶的抑制作用可能导致阴道念珠菌的生长停止，从而导致治疗性增长。阴道链球菌PNP是一种细菌型六聚体蛋白，在将腺嘌呤转化为腺苷方面具有压倒性的催化效率，而人PNP是一种三聚体蛋白，甚至不识别腺嘌呤为底物。阴道链球菌PNK主要是一种细菌型鸟苷激酶，而人PNK仅使用腺苷作为底物。因此，有很多机会可以针对两种寄生虫酶设计选择性抑制剂。寄生虫PNP被克隆，表达并具有我们的动力学机制，由我们很好地分析。在未来的计划中，它的结构将通过晶体学研究，其结构 - 功能关系将通过定位的诱变进行解剖。计算机图形建模将用于选择特定的酶抑制剂，组合库合成将参与改善铅化合物。众所周知的细菌PNP抑制剂（例如甲霉素A）和大肠杆菌PNP的颠覆性底物将进行测试并在结构上修饰，以提高针对寄生虫酶的效力。 T.阴道PNK将被克隆测序并表达。将检查其催化功能的动力学机制，并将其与人类腺苷激酶（AK）进行比较。鉴于晶体结构分析和定位诱变，以验证底物结合，产品释放等的机制，将应用计算机图形建模和组合库合成，以选择有效和特定的酶抑制剂。许多具有生物利用度的人AK的众所周知的抑制剂将在结构上进行修饰，以将其从人AK抑制剂转化为潜在选择性的阴道链球菌PNK PNK抑制剂进行抗三分法化学疗法。该研究计划成功结果的前景似乎很好。