BIOCHEMISTRY AND GENETICS OF LIPOAMIDE DEHYDROGENASE

脂酰胺脱氢酶的生物化学和遗传学

• 批准号: 3278191
• 负责人: JOHN R SOKATCH
• 金额: $ 10.47万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-07-01 至 1989-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3278191
• 关键词: Pseudomonas; bacterial genetics; branched chain aminoacid; dihydrolipoamide dehydrogenase; enzyme complex; enzyme structure; microorganism metabolism; mutant; oxoglutarate dehydrogenase; pyruvate dehydrogenase; structural genes; valine

The long term objective of this research is to study the biochemistry and genetics of lipoamide dehydrogenases in pseudomonads which are unique in that they produce two structurally and functionally distinct lipoamide dehydrogenases. Mammals produce a single lipoamide dehydrogenase which serves pyruvate, 2-ketoglutarate and branched chain keto acid dehydrogenase. In man, genetic deficiency of lipoamide dehydrogenase results in lactic acidosis in newborns which is manifested by rapid neurological deterioration and an early death. Escherichia coli produces a single lipoamide dehydrogenase which is the E3 subunit of pyruvate and 2-ketoglutarate dehydrogenases. In contrast, both P. putida and P. aeruginosa produce two lipoamide dehydrogenases, LPD-glc and LPD-val. LPD-glc is the only lipoamide dehydrogenase produce during growth on glucose synthetic medium and is the E3 subunit of 2-ketoglutarate dehydrogenase and the L-factor in glycine oxidation. LPD-val is produced during growth in valine synthetic medium and is the specific E3 subunit of branched chain keto acid dehydrogenase. Recent data raised the possibility that there is also a separate lipoamide dehydrogenase for pyruvate dehydrogenase in P. putida. E. coli and pig heart lipoamide dehydrogenases, human glutathione reductase and mercuric reductase are all redox-active disulfide flavoproteins and share significant regions of homology suggesting a common evolutionary pathway for these apparently disparate enzymes. Studies based on amino acid compositions suggest the LPD-glc is related to E. coli and pig heart lipoamide dehydrogenases, but not to LPD-val. LPD-val appears to be unrelated to any of the other redox-active disulfide flavoproteins, except possibly mercuric reductase. The Specific Aims of this study are to 1: Determine the primary structure of LPD-val and LPD-glc. The objective of this research will be to determine the evolutionary relationships between these two proteins and other redox-active disulfide flavoproteins. 2. Purify pyruvate dehydrogenase from P. putida to determine if there is a separate structural gene for this complex.

这项研究的长期目标是研究生物化学和 假单胞菌中lipoamide脱氢酶的遗传学，在 它们在结构和功能上不同的脂酰胺上产生两个 脱氢酶。 哺乳动物产生单脂酰胺脱氢酶，该脱氢酶 供应丙酮酸，2-酮戊二酸酯和分支链酮酸酸 脱氢酶。 在人类中，脂酰胺脱氢酶的遗传缺乏症 结果导致新生儿中的乳酸性酸中毒，这表现为快速 神经系统恶化和提前死亡。 大肠杆菌产生 单脂酰胺脱氢酶，是丙酮酸的E3亚基和 2-酮戊二酸脱氢酶。 相比之下，P。putida和P.均为P. 铜绿可产生两个lpd-GLC和LPD-VAL的lipoamide脱氢酶。 LPD-GLC是生长过程中唯一的脂酰胺脱氢酶产生的 葡萄糖合成培养基，是2-酮戊二酸的E3亚基 甘氨酸氧化中的脱氢酶和L因子。 生产LPD-VAL 在Valine合成介质的生长过程中，是特定的E3亚基 分支链酮酸脱氢酶。 最近的数据增加了可能性 丙酮酸也有一个单独的lipoamide脱氢酶 P. p. putida中的脱氢酶。 大肠杆菌和猪心lipoamide 脱氢酶，人谷胱甘肽还原酶和汞还原酶都是 氧化还原活性二硫键蛋白，并具有重要区域 同源性暗示了这些显然是一种共同的进化途径 不同的酶。 基于氨基酸组成的研究表明 LPD-GLC与大肠杆菌和猪心脂酰胺脱氢酶有关，但 不适合lpd-val。 LPD-VAL似乎与其他任何一个无关 除氧化还原活性二硫化物黄蛋蛋白外，除了可能的汞还原酶。 这项研究的具体目的是1：确定主要结构 LPD-VAL和LPD-GLC的。 这项研究的目的是 确定这两种蛋白质和 其他氧化还原活性二硫化物黄蛋蛋白。 2。纯化丙酮酸 来自P. p. putida的脱氢酶，以确定是否存在单独的结构 该复合物的基因。