Evaluating 13C enrichment data of free amino acids for precise metabolic flux analysis
Evaluating 13C enrichment data of free amino acids for precise metabolic flux analysis
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DOI：
10.1002/biot.201000446
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发表时间：
2011-11-01
影响因子：
4.7
通讯作者：
Shimizu, Hiroshi
中科院分区：
文献类型：
--
作者：
Mori, Eiji;Furusawa, Chikara;Shimizu, Hiroshi
与蛋白质来源的氨基酸数据相比，利用细胞内游离氨基酸(FAAS)的C-13浓缩数据进行代谢通量分析可以提高通量估计的时间分辨率，这是因为FAAS的周转时间更快。然而，FAAS的C-13浓缩动力学的性质仍然不清楚，特别是关于它对培养条件的依赖，尽管对动态行为的了解对于精确的代谢通量估计是重要的。在本研究中，我们在一系列的大肠杆菌连续培养实验中，分析了游离氨基酸和蛋白来源氨基酸的C-13浓缩动力学。结果表明，在细胞生长条件下，蛋白质降解对Fas的C-13富集量影响不大。此外，他们还表明，FAAS的C-13浓缩动力学达到稳定状态所需的时间尺度取决于培养条件，如摄氧率，这可能是由于细胞内代谢物池的大小不同所致。结果表明，利用FAA数据分析C-13浓集动力学对于精确估计代谢通量具有重要意义。
Metabolic flux analysis using C-13 enrichment data of intracellular free amino acids (FAAs) can improve the time resolution of flux estimation compared to analysis of proteinogenic amino acid data owing to the faster turnover times of FAAs. The nature of the C-13 enrichment dynamics of FAAs remains obscure, however, especially with regard to its dependence on culture conditions, even though an understanding of dynamic behavior is important for precise metabolic flux estimation. In this study, we analyzed the C-13 enrichment dynamics of free and proteinogenic amino acids in a series of continuous culture experiments with Escherichia coli. The results indicated that the effect of protein degradation on the C-13 enrichment of FAAs was negligible under cellular growth conditions. Furthermore, they showed that the time scale necessary for C-13 enrichment dynamics of FAAs to reach a steady state depends on culture conditions such as oxygen uptake rate, which was likely due to different pool sizes of intracellular metabolites. The results demonstrate the importance of analyzing C-13 enrichment dynamics for the precise estimation of metabolic fluxes using FAA data.