Characterization and Localization of Purine Synthesis Enzymes from Soybean Nodules

大豆根瘤嘌呤合成酶的表征和定位

• 批准号: 8904549
• 负责人: Eric Triplett
• 金额: $ 19.37万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-15 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904549&HistoricalAwards=false
• 关键词: Characterization; Localization; Purine; Synthesis; Enzymes

The pathway for purine biosynthesis has been detected in plastids which suggests that the genes for purine synthesis may be of prokaryotic or eukaryotic origin. Also, preliminary evidence suggests that there may be isozymes of the purine synthesis reactions. None of the enzymes of purine synthesis have been purified to homogeneity from a plant source. Soybean root nodules are an excellent model system for the study of purine synthesis in plants because these organs assimilate fixed nitrogen into the ureides, allantoin and allantoic acid, via purine synthesis. As a result, the purine synthesis pathway is highly expressed in nodules compared to other plant organs. These experiments address several important problems of purine synthesis in plants. Two enzymes of purine synthesis from nodules, glycinamide ribonucleotide transformylase and aminoimidazole ribonucleotide synthetase, will be purified and characterized. These enzymes catalyze the third and fifth committed steps, respectively, of purine synthesis. Using immunochemical and enzymatic assays, the distribution of these enzymes will be determined at the subcellular, cellular, and whole plant levels.%%% Little is known about purine synthesis in plants despite its importance in nitrogen metabolism. The production of ureides which are derived from purine synthesis is part of the process of supplying leaves and stems with nitrogen source they require. These studies will characterize two of the enzymes of the purine biosynthesis pathway as well as examine the expression and location of the genes responsible for purine synthesis. This research will provide a better understanding of nitrogen nutrition in plants.***//

嘌呤生物合成的途径已经在 这表明嘌呤合成的基因 可以是原核或真核来源的。 还有， 初步证据表明，可能存在 嘌呤合成反应。 没有一种酶 嘌呤合成已经从一种 植物源。 大豆根瘤是一个极好的模型 系统的研究嘌呤合成的植物，因为 这些器官将固定的氮同化到酰亚胺中， 尿囊素和尿囊酸，通过嘌呤合成。 作为 结果，嘌呤合成途径在 与其他植物器官相比。 这些实验 解决嘌呤合成中的几个重要问题， 植物 两种由根瘤合成嘌呤的酶， 甘氨酰胺核糖核苷酸转化酶和氨基咪唑 核糖核苷酸合成酶，将被纯化， 表征了 这些酶催化第三和第五种 嘌呤合成的关键步骤。 使用 免疫化学和酶测定，分布 这些酶将在亚细胞， 细胞和整个植物水平。% 关于植物中嘌呤的合成知之甚少， 氮代谢的重要性。 酰脲的生产 嘌呤合成的一部分， 为茎叶提供氮源的方法 他们要求。 这些研究将描述其中两个 嘌呤生物合成途径的酶以及检查 基因的表达和定位 嘌呤合成 这项研究将提供更好的 了解植物的氮素营养。*//