Expanded flux variability analysis on metabolic network of Escherichia coli

• Published in: Chinese science bulletin Vol. 54; no. 15; pp. 2610 - 2619
• Main Authors: Chen, Tong, Xie, ZhengWei, Ouyang, Qi
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science in China Press 01.08.2009
• Subjects: Biophysics; Chemistry/Food Science; Earth Sciences; Engineering; Escherichia coli; Humanities and Social Sciences; Life Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); 代谢反应; 代谢网络; 变异性分析; 增长速度; 大肠杆菌; 细胞代谢; 质量守恒定律; essentiality; modularity; flux balance analysis; metabolic network
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1007/s11434-009-0341-x

Flux balance analysis, based on the mass conservation law in a cellular organism, has been extensively employed to study the interplay between structures and functions of cellular metabolic networks. Consequently, the phenotypes of the metabolism can be well elucidated. In this paper, we introduce the Expanded Flux Variability Analysis （EFVA） to characterize the intrinsic nature of metabolic reactions, such as flexibility, modularity and essentiality, by exploring the trend of the range, the maximum and the minimum flux of reactions. We took the metabolic network of Escherichia coli as an example and analyzed the variability of reaction fluxes under different growth rate constraints. The average variability of all reactions decreases dramatically when the growth rate increases. Consider the noise effect on the metabolic system, we thus argue that the microorganism may practically grow under a suboptimal state. Besides, under the EFVA framework, the reactions are easily to be grouped into catabolic and anabolic groups. And the anabolic groups can be further assigned to specific biomass constitute. We also discovered the growth rate dependent essentiality of reactions.