Analysis of differential protein expression during growth states of Ferroplasma strains and insights into electron transport for iron oxidation
Analysis of differential protein expression during growth states of Ferroplasma strains and insights into electron transport for iron oxidation
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DOI：
10.1099/mic.0.28362-0
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发表时间：
2005-12-01
期刊：
影响因子：
2.8
通讯作者：
Bond, PL
中科院分区：
文献类型：
--
作者：
Dopson, M;Baker-Austin, C;Bond, PL
为了研究铁氧化极端嗜酸菌的代谢生物化学，对铁原体物种进行了化学混合营养和化学有机营养生长以及在没有有机碳的情况下蛋白质表达的蛋白质组学分析。电子传递链抑制剂研究、分光光度分析和蛋白质组学结果表明，二价铁的氧化可能是由蓝色铜血红素蛋白硫蓝蛋白介导的，并且衍生的电子传递至 cbb(3) 末端电子受体。尽管之前提出了假定的二氧化碳固定途径，但在没有有机碳的培养过程中，通常与二氧化碳固定相关的蛋白质没有明显的上调。尽管缺乏已知的二氧化碳固定蛋白并不能构成证据，但结果表明这些菌株不是自养的。与化学混合营养生长期间的蛋白质补充相比，推测参与中央代谢途径的蛋白质、可能的糖渗透酶和黄素蛋白在化学有机营养生长期间上调。这些结果反映了化学有机营养生长过程中对有机碳的更高能量需求。与“Ferroplasma Acidarmanus”Fer1 相比，Ferroplasmaacidiphilum Y-T 在化学混合营养生长过程中具有较高水平的中央代谢酶功能的蛋白质表达。这项研究解决了这些生物体在极端酸浸环境中生存的一些基本生化和生物能问题。
To investigate the metabolic biochemistry of iron-oxidizing extreme acidophiles, a proteomic analysis of chemomixotrophic and chemo-organotrophic growth, as well as protein expression in the absence of organic carbon, was carried out in Ferroplasma species. Electron transport chain inhibitor studies, spectrophotometric analysis and proteomic results suggest that oxidation of ferrous iron may be mediated by the blue copper-haem protein sulfocyanin and the derived electron passes to a cbb(3) terminal electron acceptor. Despite previous suggestions of a putative carbon dioxide fixation pathway, no up-regulation of proteins typically associated with carbon dioxide fixation was evident during incubation in the absence of organic carbon. Although a lack of known carbon dioxide fixation proteins does not constitute proof, the results suggest that these strains are not autotrophic. Proteins putatively involved in central metabolic pathways, a probable sugar permease and flavoproteins were up-regulated during chemo-organotrophic growth in comparison to the protein complement during chemomixotrophic growth. These results reflect a higher energy demand to be derived from the organic carbon during chemo-organotrophic growth. Proteins with suggested function as central metabolic enzymes were expressed at higher levels during chemomixotrophic growth by Ferroplasma acidiphilum Y-T compared to 'Ferroplasma acidarmanus' Fer1. This study addresses some of the biochemical and bioenergetic questions fundamental for survival of these organisms in extreme acid-leaching environments.