School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, India.
J Appl Microbiol. 2019 Jul;127(1):121-133. doi: 10.1111/jam.14293. Epub 2019 May 21.
The aim of the study was to investigate the proteomic changes and antioxidant enzyme activity in chromium-resistant Bacillus cereus VITSH1 in response to heavy metal toxicity.
The variation in protein expression and antioxidant enzyme activity in the presence and absence of metal was studied in B. cereus VITSH1. The differentially expressed proteins in chromium-treated conditions were determined by SDS PAGE. The proteins involved in metal binding, protein biosynthesis, protein folding, energy metabolism and motility were identified by mass spectrometry coupled with bioinformatics search tools. The in gel assays for antioxidant enzymes indicated a change in their activity under metal stress conditions.
The findings of this study suggest that the organism combats metal stress probably by restricting the entry of metal inside the cell. The role of the differentially expressed proteins clearly indicates that the first line of defence is to avoid the entry of metal into the cell either by possessing a modified outer membrane or by moving away from the toxicant. Further work on the identification of other proteins playing a role in resistance would help in integrating the available knowledge on the resistance mechanisms the organisms employ to combat toxicity.
The proteomic changes in the metal-exposed bacteria would give an insight into the proteins involved in metal resistance mechanisms and thereby aid in the development of biosensor-based technology for heavy metal detection.
本研究旨在探讨抗铬芽孢杆菌 VITSH1 应对重金属毒性时的蛋白质组变化和抗氧化酶活性。
研究了芽孢杆菌 VITSH1 在存在和不存在金属的情况下蛋白质表达和抗氧化酶活性的变化。通过 SDS PAGE 确定了铬处理条件下差异表达的蛋白质。通过质谱联用生物信息学搜索工具鉴定了参与金属结合、蛋白质生物合成、蛋白质折叠、能量代谢和运动的蛋白质。凝胶内酶活性测定表明，在金属胁迫条件下，抗氧化酶的活性发生了变化。
本研究结果表明，该生物体可能通过限制金属进入细胞内部来应对金属应激。差异表达蛋白的作用清楚地表明，第一道防线是通过拥有修饰的外膜或远离毒物来阻止金属进入细胞。进一步研究其他在抵抗中起作用的蛋白质将有助于整合生物体用于抵抗毒性的现有抗性机制的知识。
暴露于金属的细菌的蛋白质组变化将深入了解参与金属抗性机制的蛋白质，从而有助于开发基于生物传感器的重金属检测技术。
