[Analysis and research of the proteins for the wild type and the rough type of Salmonella typhi by 2D-PAGE].

To find out the protein properties of the wild type and the rough type of Salmonella typhi (S. typhi); to probe the genetic mechanism of the rough variation of S. typhi. The proteins were separated from the wild type and the rough type of S. typhi, and then the samples were processed by 2D-PAGE and stained by Coomassie Brilliant R-250. The properties and relationship of the protein patterns were analyzed by the software Imagemaster 6.0. By the 2D-PAGE, the similar protein patterns with 78% Sd (similar data) would be found between the wild type and the rough type of S. typhi. The distribution of most protein spots was in the range of pH 3.0 - 6.4 where the molecular weight of protein was smaller than 30kDa. According to the characters of differential proteins, there is not only the polysaccharide side chain of the O antigen but also some proteins that could be lost or changed in the rough strain of S. typhi. Most proteins in it would be the same as those in the parental bacteria so that the characteristic protein pattern of Salmonella can be found by 2D-PAGE. This property is useful for analysis and identification of the homologue between variations and their parental bacteria.