Pyrophosphate as a central energy carrier in the hydrogen-producing extremely thermophilic Caldicellulosiruptor saccharolyticus
Pyrophosphate as a central energy carrier in the hydrogen-producing extremely thermophilic Caldicellulosiruptor saccharolyticus
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DOI：
10.1111/j.1574-6968.2010.01957.x
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发表时间：
2010-06-01
影响因子：
2.1
通讯作者：
Kengen, Serve W. M.
中科院分区：
文献类型：
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作者：
Bielen, Abraham A. M.;Willquist, Karin;Kengen, Serve W. M.
研究了无机焦磷酸盐（PPi）作为能量载体在极端嗜热菌Caldicellulosiruptorsaccharolyticus代谢中心的作用。与其注释的基因组序列一致，细胞提取物显示出PPi依赖性磷酸果糖激酶和丙酮酸磷酸二激酶活性。此外，膜结合的焦磷酸酶活性被证明，而没有显着的胞质焦磷酸酶活性被检测到。在指数生长期，发现高PPi水平（约4 +/- 2 mM）和相对低的ATP水平（0.43 +/- 0.07 mM），当细胞进入稳定期时，PPi/ATP比降低13倍。丙酮酸激酶活性似乎是变构的影响PPi。总之，这些发现表明PPi在C.解糖菌
The role of inorganic pyrophosphate (PPi) as an energy carrier in the central metabolism of the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was investigated. In agreement with its annotated genome sequence, cell extracts were shown to exhibit PPi-dependent phosphofructokinase and pyruvate phosphate dikinase activity. In addition, membrane-bound pyrophosphatase activity was demonstrated, while no significant cytosolic pyrophosphatase activity was detected. During the exponential growth phase, high PPi levels (approximately 4 +/- 2 mM) and relatively low ATP levels (0.43 +/- 0.07 mM) were found, and the PPi/ATP ratio decreased 13-fold when the cells entered the stationary phase. Pyruvate kinase activity appeared to be allosterically affected by PPi. Altogether, these findings suggest an important role for PPi in the central energy metabolism of C. saccharolyticus.