13C-NMR study of acetate assimilation in Thermoproteus neutrophilus.
13C-NMR study of acetate assimilation in Thermoproteus neutrophilus.
复制标题
嗜中性嗜热变形杆菌中乙酸同化的 13C-NMR 研究。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
G. Fuchs
中科院分区：
文献类型：
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作者：
S. Schäfer;T. Paalme;R. Vilu;G. Fuchs
以~(13)C核磁共振为标记物，研究了极端嗜热厌氧古细菌嗜中性热蛋白杆菌的醋酸盐同化为氨基酸和中枢生物合成途径的功能。乙酸乙酯通过乙酰辅酶A还原羧化生成丙酮酸，丙酮酸转化为磷酸烯醇式丙酮酸，再经羧化生成草酰乙酸酯。2-羟基戊二酸主要通过柠檬酸生成。然而，谷氨酸和丙氨酸的标记模式与通过还原柠檬酸循环同时合成约15%的2-羟基戊二酸和5%的丙酮酸是一致的。在天冬氨酸和所有通过草酰乙酸酯衍生的氨基酸中都观察到了扰乱现象。氨基酸的标记模式与它们的标准生物合成途径一致，但有两个显著的例外：异亮氨酸通过柠檬酸途径合成，赖氨酸通过2-氨基己二酸酯途径合成，这是以前只在真核微生物中报道的。
Acetate assimilation into amino acids and the functioning of central biosynthetic pathways in the extremely thermophilic anaerobic archaebacterium Thermoproteus neutrophilus was investigated using 13C NMR as the method for determination of the labelling patterns. Acetate was assimilated via reductive carboxylation of acetyl-CoA to pyruvate and pyruvate conversion to phosphoenolpyruvate which was further carboxylated to oxaloacetate. 2-Oxoglutarate was mainly formed via citrate. However, the labelling patterns of glutamic acid and alanine were in agreement with the concurrent synthesis of about 15% 2-oxoglutarate and 5% pyruvate through the reductive citric acid cycle. A scrambling phenomenon occurring in aspartate and all amino acids derived through oxaloacetate was observed. The labelling patterns of amino acids were in agreement with their standard biosynthetic pathways, with two remarkable exceptions: isoleucine was synthesized via the citramalate pathway and lysine was synthesized via the 2-aminoadipate pathway which has previously been reported only in eukaryotic microorganisms.