REGULATION OF FOLYLPOLYGLUTAMATE SYNTHESIS

叶酰聚谷氨酸合成的调控

基本信息

批准号：
3182650
负责人：
BARRY SHANE
金额：
$ 9.99万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-07-01 至 1989-01-31
项目状态：
已结题

项目摘要

We propose to continue our investigations on the mechanism by which conversion of folate compounds to polyglutamate forms regulates one-carbon metabolism. Our investigations will proceed along several fronts: 1. Folylpolyglutamate synthetase will be purified from bacterial and mammalian sources and its substrate specificity and kinetic properties examined to determine whether they are responsible for the different types of pteroylpolyglutamates found in different cell lines. Pteroylpolyglutamate substrates and potential analog inhibitors of the synthetase will be synthesized. 2. Studies will be carried out with the Corynebacterium or E. coli folylpolyglutamate synthetase-dihydrofolate synthetase to map the folate binding site(s) of this protein and to determine whether the protein is bifunctional or whether both activities are catalyzed by a single catalytic site. 3. The metabolism of folate antagonists to polyglutamate forms will be studied in vitro using purified folypolyglutamate synthetases and in vivo using cultured mammalian cells. The ability of polyglutamate forms of these analogs to inhibit individual folate-dependent enzymes will be assessed. 4. Inhibitors of folylpolyglutamate synthetase will be tested for their ability to cause cellular folate depletion by preventing the formation of pteroylpolyglutamates, the forms of the vitamin that are retained by tissues. As pteroylmonoglutamates are poorer substrates than pteroylpolyglutamates for folate-dependent reactions, the ability of folylpolyglutamate synthetase inhibitors to increase the exogenous requirements for products of one-carbon metabolism, and to potentiate any differences in nutritional requirements between tumorigenic and nontumorigenic cells, will be studied. (B)

我们建议继续研究机制叶酸化合物向聚谷氨酸形式的转化调节一碳代谢。我们的调查将沿着几个方面进行： 1.从细菌和细菌中纯化叶酰聚谷氨酸合成酶哺乳动物来源及其底物特异性和动力学特性检查以确定他们是否对不同类型负责在不同细胞系中发现的蝶酰聚谷氨酸。蝶酰聚谷氨酸底物和潜在的类似物抑制剂将合成合成酶。 2. 将用棒状杆菌或大肠杆菌进行研究叶酰聚谷氨酸合成酶-二氢叶酸合成酶绘制叶酸图谱该蛋白质的结合位点并确定该蛋白质是否是双功能或两种活性是否由单一催化剂催化地点。 3. 叶酸拮抗剂代谢为聚谷氨酸形式使用纯化的叶聚谷氨酸合成酶进行体外研究，并进行体内研究使用培养的哺乳动物细胞。聚谷氨酸形式的能力这些抑制个体叶酸依赖性酶的类似物将评估。 4. 叶酰聚谷氨酸合成酶抑制剂的检测通过阻止叶酸形成而导致细胞叶酸消耗的能力蝶酰聚谷氨酸盐，保留的维生素形式组织。由于蝶酰单谷氨酸是比蝶酰聚谷氨酸盐用于叶酸依赖性反应，叶酰聚谷氨酸合成酶抑制剂可增加外源性对一碳代谢产物的要求，并增强任何致瘤性和致瘤性营养需求差异将研究非致瘤细胞。 (二)