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

基本信息

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
项目类别：
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

项目摘要

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）途径已在开发中取得了巨大成功抗癌、抗菌以及抗原虫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“磺胺药物”则扰乱二氢蝶酸合酶在一些细菌和原生动物寄生虫中发挥作用。靶向该途径的药物包括 DHFR 抑制剂乙胺嘧啶、氯胍和氯丙胍，以及然而，这些传统的抗叶酸药物对 DHPS 抑制剂氨苯砜几乎没有活性。主要的人类真菌病原体，要么是因为真菌酶结构的差异，要么是渗透性此外，还需要努力适应传统的抗叶酸剂。支架未能产生具有可行抗真菌药物所需特性的衍生物，并且已将重点放在几乎完全依赖于 DHFR，其余酶几乎完全没有在任何我们建议应重点关注利用这一途径进行抗真菌开发。尚未成为重要研究对象的 FOL 生物合成酶此外，他们应该寻找具有活性的新型抗叶酸支架。该提案的目的是证实靶向真菌的有效性和可行性。 Fol1p 和 Fol3p 共同具有哺乳动物中完全不存在的四种 FOL 酶活性。目标 1 我们将确认 Fol1p 和 Fol3p 蛋白在两种最常见的人类真菌中的重要性病原体、白色念珠菌和传染性霉菌烟曲霉，并建立潜在的使用侵袭性真菌小鼠模型靶向这些酶可以实现抗真菌功效在目标 2 中，我们将建立并验证高通量兼容的基于细胞和生化检测。总的来说，这些研究可用于鉴定这些酶活性的小分子抑制剂。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且有效的酶目标是设计新的抗真菌疗法并可能产生可构成此类基础的先导化合物药物。