To discern the differences in the protein profiles of these two strains, a comparative analysis of proteins expressed in vitro was conducted by a two-dimensional protein gel electrophoresis and is shown in Figures 4A and 4B. Intensity of individual polypeptide spots was measured after gel electrophoresis. For each polypeptide, the relative abundance was calculated from individual spot intensity against that of all measured polypeptide spots. The learn more polypeptides that were expressed at significantly differential

levels in the two strains are summarized in Table 1. Out of 591 polypeptide spots selleck products analyzed, 26 were found to have at least a 10-fold increase in relative abundance in B31 than in N40D10/E9. On the other hand, 22 polypeptide spots had at least a 10-fold increase in relative abundance in N40D10/E9 than in B31. The increase in relative abundance indicated that the polypeptides could be uniquely expressed in a particular selleck kinase inhibitor strain, or they could be severely repressed in the other strain. One or more of the proteins

expressed uniquely in N40D10/E9 or at higher levels in this strain during infection could contribute to the higher level of infectivity and disease severity relative to dose of infection of the N40D10/E9 strain. Figure 4 Two-dimensional gel electrophoresis of B31 and N40D10/E9 strains total proteins. Polypeptide spots with increased relative abundance (more than 1.7 fold increase) in B31 versus N40D10/E9 are outlined in blue while spots with decreased relative abundance (more than 1.7 fold decrease) in B31 versus N40 are outlined in red. Several of these spots were sent for MALDI-MS analysis.

Table 1 Polypeptide spots that showed at least a 10-fold increase in relative abundance in B31 or N40D10/E9 on 2D protein gel Spot # pI MW (kDa) Relative abundance in B31, and N40 (%) Fold change B31 vs N40 Identification MALDI-MS analyses (SwissProt or NCBI accession #) Spot # pI MW (kDa) Relative abundance in B31, and N40 (%) Fold change N40 vs B31 Identification MALDI-MS analyses (SwissProt or NCBI accession #) 33 6.2 88.96 0.036, 0.003 11.2   136 5.6 64.58 0.002, 0.029 14.7   110 5.1 63.92 Tau-protein kinase 0.050, 0.003 15.1   208 5.8 53.07 0.015, 0.340 22.7   127 5.3 65.24 0.037, 0.003 11.5   231 6.9 52.81 0.019, 0.226 11.8   211 6.1 55,65 0.875, 0.048 18.0   272 6.2 46.29 0.000, 0.054 685.4 *Flagellin (GI:120230), Basic membrane protein A (GI:3913169) 225 6.1 57.07 0.193, 0.005 35.3   293 6.0 43.53 0.000, 0.170 698.2 *Flagellin (GI:120230) 325 5.6 38.32 0.114, 0.010 11.3   311 6.0 39.99 0.005, 0.165 30.6   403 5.4 31.03 0.071, 0.002 29.1   347 6.0 35.06 0.003, 0.185 59.8   404 5.4 31.00 0.404, 0.003 124.1 OspD (GI:495462) 348 5.6 34.95 0.007, 0.258 36.3   405 5.5 28.78 1.006, 0.031 32.7   349 6.0 34.36 0.003, 0.095 32.4   458 5.7 26.07 0.051, 0.003 15.2   352 6.5 34.25 0.