Comparative anlysis of the differential expressed proteins in serum between healthy and Brucellaovis infected sheep

Disease-related serum proteins in sheep infected with Brucellaovis were assessed by conventional two-dimensional gel electrophoresis (2-DE). High-abundance proteins in serum were depleted by Albumin & IgG Depletion Spintrap^TM, with the remaining proteins retrieved using the 2-D clean-up kit. Differentially expressed proteins were detected with the PDQUest8.0 software and identified by a high performance liquid chromatography system equipped with an ion trap mass spectrometer. Both SDS-PAGE and 2-DE gel electrophoresis confirmed that high-abundance protein components were removed thoroughly by the 2-D clean-up kit and Albumin & IgG Depletion Spintrap^TM. A total of 9 differentially expressed protein spots were successfully identified as haptoglobin, serum amyloid A, Ig heavy chain, IgX-1 chain, and apolipoprotein C-III, known to be involved in stress response, energy metabolism, and material transport. These findings provide a valuable clue for investigating host immune response to pathogens at the protein level; further understanding of these novel proteins identified would be helpful for finding out potential candidate targets for diagnosis and developing new vaccines for brucellosis.