Pham Trong Khoa, Chong Poh Kuan, Gan Chee Sian, Wright Phillip C
Biological and Environmental Systems Group, Department of Chemical and Process Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
J Proteome Res. 2006 Dec;5(12):3411-9. doi: 10.1021/pr060377p.
Saccharomyces cerevisiae KAY446 was utilized for ethanol production, with glucose concentrations ranging from 120 g/L (normal) to 300 g/L (high). Although grown in a high glucose environment, S. cerevisiae still retained the ability to produce ethanol with a high degree of glucose utilization. iTRAQ-mediated shotgun proteomics was applied to identify relative expression change of proteins under the different glucose conditions. A total of 413 proteins were identified from three replicate, independent LC-MS/MS runs. Unsurprisingly, many proteins in the glycolysis/gluconeogenesis pathway showed significant changes in expression level. Twenty five proteins involved in amino acid metabolism decreased their expression, while the expressions of 12 heat-shock related proteins were also identified. Under high glucose conditions, ethanol was produced as a major product. However, the assimilation of glucose as well as a number of byproducts was also enhanced. Therefore, to optimize the ethanol production under very high gravity conditions, a number of pathways will need to be deactivated, while still maintaining the correct cellular redox or osmotic state. Proteomics is demonstrated here as a tool to aid in this forward metabolic engineering.
酿酒酵母KAY446用于乙醇生产，葡萄糖浓度范围为120 g/L（正常）至300 g/L（高）。尽管在高葡萄糖环境中生长，但酿酒酵母仍保留了以高度葡萄糖利用率生产乙醇的能力。应用iTRAQ介导的鸟枪法蛋白质组学来鉴定不同葡萄糖条件下蛋白质的相对表达变化。从三次独立的液相色谱-串联质谱（LC-MS/MS）运行中总共鉴定出413种蛋白质。不出所料，糖酵解/糖异生途径中的许多蛋白质表达水平出现了显著变化。25种参与氨基酸代谢的蛋白质表达下降，同时还鉴定出12种与热休克相关的蛋白质的表达。在高葡萄糖条件下，乙醇作为主要产物产生。然而，葡萄糖的同化以及一些副产物也增加了。因此，为了在超高浓度条件下优化乙醇生产，需要停用一些途径，同时仍维持正确的细胞氧化还原或渗透状态。本文证明蛋白质组学是有助于这种正向代谢工程的一种工具。
