Sub-department of Veterinary Preventive, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland.
J Med Microbiol. 2013 Dec;62(Pt 12):1897-1901. doi: 10.1099/jmm.0.064857-0. Epub 2013 Sep 11.
The aim of this study was to evaluate the effect of heat stress in in vitro conditions on the induction of heat-shock protein (Hsp)70 by Escherichia coli cells, and to determine the localization of Hsps in cell fractions. The material consisted of wild strains of E. coli isolated from the digestive tract of calves, suspended in an exponential-phase culture and subjected to 41.5 °C for 2 h. Individual fractions were analysed by SDS-PAGE and two-dimensional electrophoresis. Western blotting with mouse anti-Hsp70 and anti-Hsp60 mAbs was used to identify the proteins. Electrophoretic analysis of the heat-treated cells detected Hsp70 in all three fractions, cytoplasmic, periplasmic and membrane, which was confirmed by Western blotting. The proteins obtained had diverse localizations in the pH gradient in two-dimensional electrophoresis, which may indicate changes in their conformation and physical properties leading to stabilization and protection of intracellular structures in stress conditions. The presence of these Hsps in different cell fractions indicates a very strong protective adaptation in the bacteria in unfavourable conditions, which is critical for the organism infected by them.
本研究旨在评估体外热应激对大肠杆菌细胞热休克蛋白（Hsp）70 诱导的影响，并确定 Hsp 在细胞成分中的定位。材料由从犊牛消化道分离的大肠杆菌野生株组成，悬浮于指数生长期培养物中，在 41.5°C 下孵育 2 小时。通过 SDS-PAGE 和二维电泳分析各个成分。使用小鼠抗 Hsp70 和抗 Hsp60 mAb 进行 Western blot 以鉴定蛋白质。对热处理细胞的电泳分析在细胞质、周质和膜这三个成分中均检测到 Hsp70，Western blot 进一步证实了这一点。在二维电泳的 pH 梯度中获得的蛋白质具有不同的定位，这可能表明其构象和物理性质发生变化，从而在应激条件下稳定和保护细胞内结构。这些 Hsp 在不同细胞成分中的存在表明细菌在不利条件下具有非常强的保护适应性，这对于受其感染的生物体至关重要。
