T.gondii pyrimidine synthesis as a chemotherapy target

弓形虫嘧啶合成作为化疗靶点

• 批准号: 6706203
• 负责人: DAVID J BZIK
• 金额: $ 35.55万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6706203
• 关键词: Toxoplasma gondii; aminohydrolases; carbamoylphosphate synthase; chemical synthesis; drug design /synthesis /production; drug screening /evaluation; enzyme activity; enzyme inhibitors; gene complementation; gene deletion mutation; gene expression; gene induction /repression; intracellular transport; laboratory mouse; parasite infection mechanism; parasitic disease chemotherapy; parasitism; polymerase chain reaction; pyrimidines; southern blotting; thymidine kinase; thymidylate synthase; uracil

DESCRIPTION (provided by applicant): Toxoplasma gondii chronically infects approximately 30% of the United States population. Chemotherapy, largely based on anti-folates, is available for acute infection with tachzyzoites, but life-long treatment is required to protect against infections in AIDS. Unfortunately, a high frequency of adverse reactions are associated with chronic treatment, frequently complicating clinical treatment of T. gondii. Thus it is a high priority to develop new and improved treatment strategies for T. gondii infection in AIDS. This grant focuses on new approaches to develop improved treatments for T. gondii infection based on targeting the parasite carbamoyl phosphate synthetase II (CPSII) activity required for de novo pyrimidine biosynthesis. Preliminary biochemical and genetic studies indicate that T. gondii expresses a novel CPSII that can be disrupted to induce starvation for uridine monophosphate (UMP), and other pyrimidine nucleotides required for parasite RNA and DNA synthesis. Disruption of CPSII activity in T. gondii blocks parasite replication in vitro, rapidly resulting in loss of parasite viability. Disruption of CPSII abolished parasite growth and virulence in mice that lack interferon-y. The present proposal will expand our studies of CPSII to focus on the development of specific inhibitors of this essential parasite enzyme. We will characterize the essential activities and regulation to gain information on CPSII functions that can be effectively targeted for chemotherapy. We will determine the crystal structure of active T. gondii CPSII enzyme(s) to establish a structural basis for drug development. We will evaluate lead inhibitor compounds of T. gondii CPSII, and will identify or synthesize new inhibitors. It is our hypothesis that targeting CPSII and de novo pyrimidine biosynthesis can lead to improved treatments. The proposed research formally brings together expertise from three research groups at Dartmouth. Dr. David Bzik is a molecular parasitologist with training in genetics and biochemistry. Dr. Amy Anderson is a structural biochemist with training in biochemistry and crystallography. Dr. Gordon Gribble is a medicinal/synthetic chemist with training in chemical synthesis of compounds for the treatment of disease. Together, the expertise of these three research groups will provide a unique opportunity to develop and evaluate new drugs for treatment of T. gondii infection based on inhibition of parasite CPSII.

描述（由申请人提供）： 弓形虫慢性感染约30%的美国人口。主要以抗叶酸剂为基础的化疗可用于速殖子急性感染，但需要终身治疗以防止艾滋病感染。不幸的是，高频率的不良反应与长期治疗有关，经常使T的临床治疗复杂化。刚地。因此，开发新的和改进的T.艾滋病的弓形虫感染该基金主要用于开发T.弓形虫感染的基础上，针对寄生虫氨甲酰磷酸合成酶II（CPSII）的活性所需的从头嘧啶生物合成。初步的生化和遗传研究表明，T。弓形虫表达一种新的CPSII，其可以被破坏以诱导对尿苷一磷酸（UMP）和寄生虫RNA和DNA合成所需的其他嘧啶核苷酸的饥饿。在T.弓形虫在体外阻断寄生虫复制，迅速导致寄生虫生存能力丧失。CPSII的破坏消除了缺乏干扰素-y的小鼠中寄生虫的生长和毒力。目前的建议将扩大我们的研究CPSII专注于开发这种重要的寄生虫酶的特异性抑制剂。我们将描述的基本活动和调节，以获得信息的CPSII功能，可以有效地针对化疗。我们将测定活性T的晶体结构。弓形虫CPSII酶（s），以建立药物开发的结构基础。我们将评估T.弓形虫CPSII，并将确定或合成新的抑制剂。我们的假设是，靶向CPSII和从头嘧啶生物合成可以导致改善的治疗。这项拟议中的研究正式汇集了达特茅斯三个研究小组的专业知识。大卫·布兹克博士是一位分子寄生虫学家，接受过遗传学和生物化学方面的培训。Amy安德森博士是一位结构生物化学家，接受过生物化学和晶体学方面的培训。Gordon Gribble博士是一名药物/合成化学家，接受过用于治疗疾病的化合物的化学合成培训。这三个研究小组的专业知识将为开发和评估治疗T的新药提供独特的机会。弓形虫感染的基础上抑制寄生虫CPSII。