Fanous Ali, Weiss Walter, Görg Angelika, Jacob Fritz, Parlar Harun
Department of Chemical-Technical Analysis, Research Center Weihenstephan for Brewing and Food Quality, Technical University of Munich, Freising-Weihenstephan, Germany.
Proteomics. 2008 Dec;8(23-24):4976-86. doi: 10.1002/pmic.200800165.
Cadmium and mercury are well-known toxic heavy metals, but the basis of their toxicity is not well understood. In this study, we analyzed the cellular response of Corynebacterium glutamicum to sublethal concentrations of cadmium and mercury ions using 2-DE and MS. Mercury induced the over-expression of 13 C. glutamicum proteins, whereas 35 proteins were induced, and 8 proteins were repressed, respectively, under cadmium stress. The principal response to these metals was protection against oxidative stress, as demonstrated by upregulation of, e.g., Mn/Zn superoxide dismutase. Thioredoxin and oxidoreductase responded most strongly to cadmium and mercury. The increased level of heat-shock proteins, enzymes involved in energy metabolism, as well as in lipoic acid and terpenoid biosynthesis after the treatment of cells with cadmium was also registered. Identification of these proteins and their mapping into specific cellular processes enable a global understanding of the way in which C. glutamicum adapts to heavy-metal stress and may help to gain deeper insight into the toxic mechanism of these metals.
镉和汞是众所周知的有毒重金属，但它们毒性的基础尚未得到很好的理解。在本研究中，我们使用二维电泳（2-DE）和质谱（MS）分析了谷氨酸棒杆菌对亚致死浓度镉离子和汞离子的细胞反应。汞诱导了13种谷氨酸棒杆菌蛋白质的过表达，而在镉胁迫下，分别有35种蛋白质被诱导，8种蛋白质被抑制。对这些金属的主要反应是抵御氧化应激，例如锰/锌超氧化物歧化酶的上调就证明了这一点。硫氧还蛋白和氧化还原酶对镉和汞的反应最为强烈。在用镉处理细胞后，热休克蛋白、参与能量代谢以及硫辛酸和萜类生物合成的酶的水平也有所增加。对这些蛋白质的鉴定及其在特定细胞过程中的定位，有助于全面了解谷氨酸棒杆菌适应重金属胁迫的方式，并可能有助于更深入地了解这些金属的毒性机制。
