Lee Sung-Eun, Seo Jong-Su, Keum Young-Soo, Lee Kwang-Jun, Li Qing X
Department of Molecular Biosciences and Bioengineering, University of Hawaii, Honolulu, HI 9682, USA.
Proteomics. 2007 Jun;7(12):2059-69. doi: 10.1002/pmic.200600489.
Fluoranthene is a polycyclic aromatic hydrocarbon (PAH) commonly present in PAH-contaminated soils. We studied fluoranthene catabolism and associated proteins in Mycobacterium sp. JS14, a bacterium isolated from a PAH-contaminated soil in Hilo (HI, USA). Fluoranthene degrades in at least three separated pathways via 1-indanone, 2',3'-dihydroxybiphenyl-2,3,-dicarboxylic acid, and naphthalene-1,8-dicarboxylic acid. Part of the diverse catabolism is converged into phthalate catabolism. An increased expression of 25 proteins related to fluoranthene catabolism is found with 1-D PAGE or 2-DE and nano-LC-MS/MS. Detection of fluoranthene catabolism associated proteins coincides well with its multiple degradation pathways that are mapped via metabolites identified. Among the up-regulated proteins, PAH ring-hydroxylating dioxygenase alpha-subunit and beta-subunit and 2,3-dihydroxybiphenyl 1,2-dioxygenase are notably induced. The up-regulation of trans-2-carboxybenzalpyruvate hydratase suggests that some of fluoranthene metabolites may be further degraded through aromatic dicarboxylic acid pathways. Catalase and superoxide dismutase were up-regulated to control unexpected oxidative stress during the fluoranthene catabolism. The up-regulation of chorismate synthase and nicotine-nucleotide phosphorylase may be necessary for sustaining shikimate pathway and pyrimidine biosynthesis, respectively. A fluoranthene degradation pathway for Mycobacterium sp. JS14 was proposed and confirmed by proteomic study by identifying almost all the enzymes required during the initial steps of fluoranthene degradation.
荧蒽是一种多环芳烃（PAH），常见于受PAH污染的土壤中。我们研究了Mycobacterium sp. JS14中的荧蒽分解代谢及相关蛋白质，该菌株是从美国夏威夷希洛一处受PAH污染的土壤中分离得到的。荧蒽通过1-茚酮、2',3'-二羟基联苯-2,3-二羧酸和萘-1,8-二羧酸至少经三条不同途径降解。部分多样的分解代谢汇聚成邻苯二甲酸分解代谢。通过一维聚丙烯酰胺凝胶电泳（1-D PAGE）、二维电泳（2-DE）以及纳升液相色谱-串联质谱（nano-LC-MS/MS），发现有25种与荧蒽分解代谢相关的蛋白质表达增加。荧蒽分解代谢相关蛋白质的检测结果与其通过鉴定的代谢物所绘制的多条降解途径高度吻合。在这些上调的蛋白质中，PAH环羟基化双加氧酶的α亚基和β亚基以及2,3-二羟基联苯1,2-双加氧酶受到显著诱导。反式-2-羧基苯甲酰丙酮酸水合酶的上调表明，荧蒽的一些代谢产物可能通过芳香二羧酸途径进一步降解。过氧化氢酶和超氧化物歧化酶上调以控制荧蒽分解代谢过程中意外产生的氧化应激。分支酸合酶和烟碱核苷酸磷酸化酶的上调可能分别是维持莽草酸途径和嘧啶生物合成所必需的。通过蛋白质组学研究，鉴定出了荧蒽降解初始步骤所需的几乎所有酶，从而提出并证实了Mycobacterium sp. JS14的荧蒽降解途径。
