Examining the importance of folate biosynthetic enzymes in infectious fungi

检查叶酸生物合成酶在传染性真菌中的重要性

• 批准号: 10308098
• 负责人: Glen Palmer
• 金额: $ 19万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10308098
• 关键词: Anti-Bacterial Agents; Antifungal Agents; Antifungal Therapy; Antineoplastic Agents; Antiprotozoal Agents; Aspergillus fumigatus; Biochemical; Biological Assay; Candida; Candida albicans; Candida auris; Carbon; Cause of Death; Cells; Chemicals; Chloroguanide; Collection; Complement; Development; Dietary intake; Dihydrofolate Reductase; Dihydrofolate Reductase Inhibitor; Dihydroneopterin aldolase; Dihydropteroate Synthase; Diphosphotransferases; Disease; Doxycycline; Drug Targeting; Enzyme Inhibitor Drugs; Enzymes; Eukaryota; Folate Biosynthesis Pathway; Folic Acid; Folic Acid Antagonists; Fostering; Fungal Drug Resistance; Genes; Goals; Human; In Vitro; Incidence; Infection; Investigation; Laboratories; Lead; Life; Ligase; Mammals; Metabolic; Methionine; Methotrexate; Modification; Molds; Molecular; Mucous Membrane; Multi-Drug Resistance; Mycoses; Parasites; Pathogenicity; Pathway interactions; Patient-Focused Outcomes; Patients; Performance; Permeability; Pharmaceutical Preparations; Physiological; Predisposition; Prevalence; Prokaryotic Cells; Property; Proteins; Purine Nucleotides; Pyrimethamine; Pyrimidine Nucleotides; Reaction; Resistance; Saccharomyces cerevisiae; Series; Source; System; Testing; Toxic effect; Trimethoprim; Yeasts; anti-cancer; base; dihydrofolate; enzyme activity; enzyme pathway; enzyme structure; fungus; improved; improved outcome; in vivo; inhibitor; microbial; mortality; mouse model; novel; pathogen; pathogenic fungus; prevent; scaffold; screening; small molecule; small molecule inhibitor; success; sulfa drug

The folate biosynthetic (FOL) pathway has been targeted with enormous success in the development of anticancer, antibacterial as well as antiprotozoal drugs. Methotrexate and trimethoprim are potent inhibitors of mammalian and bacterial dihydrofolate reductase (DHFR) respectively, while a collection of ‘sulfa drugs’ perturb dihydropteroate synthase function in some bacterial as well as protozoan parasites. Additional antiprotozoal drugs that target this pathway include the DHFR inhibitors pyrimethamine, proguanil and chlorproguanil, as well as the DHPS inhibitor dapsone. However, these conventional antifolate drugs have little or no activity upon the major human fungal pathogens, either because of divergence of the fungal enzymes structure, or permeability issues that prevent them from entering fungal cells. Furthermore, efforts to adapt conventional antifolate scaffolds have failed to yield derivatives with the requisite properties of a viable antifungal drug and have focused almost exclusively upon DHFR, with the remaining enzymes almost completely uncharacterized in any pathogenic species. We propose that efforts to exploit this pathway for antifungal development should focus upon the FOL biosynthetic enzymes that have not yet been the subject of significant investigation and that are completely absent from mammals. In addition, they should seek novel antifolate scaffolds that are active upon whole fungal cells. The objective of this proposal is to substantiate the validity and feasibility of targeting fungal Fol1p and Fol3p, which together possess four FOL enzyme activities that are entirely absent from mammals. In aim 1 we will confirm the essentiality of the Fol1p and Fol3p proteins in two of the most prevalent human fungal pathogens, the yeast Candida albicans and the infectious mold Aspergillus fumigatus, and establish the potential antifungal efficacy that can be achieved in targeting these enzymes using mouse models of invasive fungal infection. In aim 2 we will establish and validate high-throughput compatible cell-based and biochemical assays that can be applied to identify small molecules inhibitors of these enzymes activity. Collectively, these studies will determine if FOL enzymes that are absent from mammals can provide chemically tractable and efficacious targets to devise new antifungal therapies and potentially yield lead compounds that can form the basis of such medications.

叶酸生物合成（FOL）途径已成为靶点，在开发 抗癌、抗菌以及抗原生动物药物。甲氨蝶呤和甲氧苄啶是有效的抑制剂， 哺乳动物和细菌的二氢叶酸还原酶（DHFR），而一系列的“磺胺药物”干扰 二氢蝶酸合酶在一些细菌以及原生动物寄生虫中起作用。其他抗原虫 针对这一途径的药物包括DHFR抑制剂乙胺嘧啶、氯胍和氯胍， 作为DHPS抑制剂氨苯砜。然而，这些常规的抗叶酸药物对肿瘤细胞几乎没有活性或没有活性。 主要的人类真菌病原体，无论是因为真菌酶结构的分歧，或渗透性 这些问题阻止它们进入真菌细胞。此外，调整传统抗叶酸剂的努力 支架未能产生具有可行的抗真菌药物的必要性质的衍生物， 几乎完全依赖于DHFR，其余的酶几乎完全没有任何特征， 致病物种我们建议，努力利用这一途径的抗真菌发展应集中在 对FOL生物合成酶，尚未成为重要研究的主题， 完全不存在于哺乳动物中此外，他们应该寻找新的抗叶酸支架， 真菌细胞本研究的目的是为了证实靶向真菌的有效性和可行性， Fol1p和Fol3p，它们共同拥有四种FOL酶活性，这些活性在哺乳动物中完全不存在。在 目的1我们将证实Fol1p和Fol3p蛋白在两种最流行的人类真菌中的重要性。 病原体，酵母菌白色念珠菌和感染性霉菌烟曲霉，并建立潜在的 使用侵袭性真菌的小鼠模型靶向这些酶可以实现的抗真菌功效 感染在目标2中，我们将建立和验证高通量相容的基于细胞和生化的检测方法 可以应用于鉴定这些酶活性的小分子抑制剂。总的来说，这些研究 将确定哺乳动物中不存在的FOL酶是否可以提供化学上易处理和有效的 目标是设计新的抗真菌疗法，并可能产生可以形成这种基础的先导化合物， 药物治疗