镉胁迫下嗜温鞘氨醇杆菌降解丁草胺的蛋白质组学研究

Proteomics of butachlor-degrading bacterium Sphingobacterium thalpophilum under cadmium stress

为了从蛋白表达水平阐释丁草胺降解菌应答镉胁迫及胁迫情况下降解丁草胺的分子机制,对丁草胺高效降解菌嗜温鞘氨醇杆菌(Sphingobacterium thalpophilum)在重金属镉胁迫下蛋白质组变化进行研究,设置10 mg·L-1镉胁迫处理和不加镉的对照,7 d后分别取样提取菌株总蛋白,利用双向(2-D)电泳和质谱鉴定技术分析两者之间的差异表达蛋白,并进行差异蛋白功能分析。2-D电泳结果分析共获得93个差异蛋白点,其中上调蛋白49个,下调蛋白44个。选取重复性好且差异最为明显的23个蛋白质点酶解脱盐后进行MALDI-TOF-MS分析,成功鉴定出15个差异蛋白,其中8个为上调蛋白,7个为下调蛋白;差异蛋白分别按GO和COG进行了蛋白功能的生物信息学分类。研究表明:差异显著蛋白主要为参与丁草胺代谢的蛋白、响应镉胁迫敏感蛋白及在镉胁迫下参与丁草胺代谢的蛋白;获得2个镉高度敏感蛋白(蛋白编号分别为A0A0M7HIV1和A0A0D6IIE6)以及1个抗镉胁迫同时参与丁草胺代谢的蛋白(蛋白编号为D4FMF4),推测它们在镉胁迫下丁草胺的降解中起重要作用。

In order to determine the molecular mechanism of a highly efficient butachlor-degradation bacterium under cadmium stress at the protein expression level,the proteome change of Sphingobacterium thalpophilum sp.15#was studied under cadmium stress.A10mg·L^-1cadmium stress treatment and a control without cadmium were employed.After seven days,the total protein of the strain from both the stress treatment and the control was sampled and extracted.Then,the differentially expressed proteins between the two treatments were analyzed by2-D electrophoresis and mass spectrometry.A total of93differential protein spots were obtained,including49up-regulated protein spots and44down-regulated protein spots.23protein spots with good reproducibility and exhibiting the most obvious differences were further analyzed by MALDI-TOF-MS.15differential proteins were successfully identified,eight of which were up-regulated and seven of which were down-regulated.The identified proteins were annotated by bioinformatics of protein functions according to GO and COG.The proteins exhibiting significant differences were mainly those involved in the metabolism of butachlor,proteins that respond to cadmium stress,and proteins involved in the metabolism of butachlor under cadmium stress.Two cadmium-sensitive proteins(protein No.A0A0M7HIV1and A0A0D6IIE6,respectively)and one protein that was resistant to cadmium stress and involved in butachlor metabolism(protein No.D4FMF4)were obtained.The obtained proteins are thought to play an important role in the degradation of butachlor under cadmium stress.