Department of Biochemistry, Microbiology and Biotechnology, Far Eastern Federal University, Sukhanov St., 8, Vladivostok 690600, Russia.
FEBS Lett. 2013 Jul 11;587(14):2260-5. doi: 10.1016/j.febslet.2013.05.056. Epub 2013 Jun 4.
The present work aimed to compare the effects of different lysophosphatidylethanolamine (LPE) content in lipids derived from Yersinia pseudotuberculosis cells exposed and not exposed to phenol on the conformation of OmpF-like porin of these bacteria. Differential scanning calorimetry and intrinsic protein fluorescence showed that the 2.5-fold increase of LPE content and the corresponding increase in the phase transition temperature of bacterial lipids were accompanied by enhanced protein thermostability. Integral conformational rearrangement of protein was supported by drastic changes in the microenvironment of the tryptophan residues, likely resulting in a convergence of monomers in trimeric porin and exposure of outer tryptophan residues to the water environment. These conformational changes may impede the porin channel permeability under stress conditions in bacteria.
本工作旨在比较在不同条件下,脂双层中溶血磷脂酰乙醇胺(LPE)含量的变化对耶尔森氏菌 OmpF 样孔蛋白构象的影响。差示扫描量热法和内源蛋白荧光实验表明,当 LPE 含量增加到 2.5 倍时,相应的细菌脂相变温度也升高,蛋白热稳定性增强。蛋白整体构象发生变化,其色氨酸残基微环境发生剧烈变化,可能导致三聚体孔蛋白单体聚合,暴露出外源性色氨酸残基,与水环境相互作用。这些构象变化可能会阻碍细菌在应激条件下孔道的通透性。