Comparative Proteomics Analysis Of Shigella Flexneri 2a 2457T

Shigella flexneri is a Gram-negative facultatively intracellular pathogen responsible for bacillary dysentery in humans. That's because we know little about the nosogenesis of Shigella flexnerVs infection. Expanding the basic biology study of Shigella flexneri would provide new thought for the researching of vaccine.In this study, extracellular proteins from the culture medium and whole cell proteins in cellular extracts of S.flexneri 2a strain 2457T were examined by two-dimensional (2-D) gel electrophoresis using immobilized pH gradient (IPG) technology. Protein spots were excised from gels, in-gel digested, and then identified by using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) in combination with Mascot search program. Two-dimensional electrophoresis of 2457T proteins by using IPGstrips of variant pH gradient were run. The best proteins separation were obtained in the gels of pH4-7, in which 2265 spots were detected by the 2-D gel analysis software ImageMaster 2D Elite.This article includes two parts. In the first part, S.flexneri 2a strain 2457T and its derivative without large invasive plasmid pINV-2457T were cultured to middle logarithm phase. Whole cellular protein extracts of the two strains were examined by two dimensional(2D) electrophoresis. 17 proteins that had changed in expression were found. Almost all of the proteins except Beta-Lactamase Tem1 were concerning about the metabolizing of nucleic acid.In the second part, Reffered to the heat and cold shock disposal, S.flexneri 2a strain 2457T was cultured at 37℃ to early stationary phase and then kept on culturing at other temperature (4℃ and 42℃) for 3 hous. Whole cellular protein extracts of S.flexneri under different temperature(4 ℃, 42 ℃ and 37℃) were...