STRESS-70 PROTEINS IN PLASMA FROM STRESSED AND UNSTRESSED PIGS

Abstract

Blood protein patterns from stressed and unstressed pigs were compared by denaturing and reducing gel electrophoresis and immunological detection by Western blotting and ELISA. No substantial differences in protein patterns or immunodetection with commercial anti-pig antibody were seen. However, in both stressed and unstressed pigs, the presence of a 70 kDa stress protein was found utilizing two anti-heat shock protein (HSP) antisera : an anti- 70 kDa E. coli and an anti-recombinant pea HSP 70. Analysis of denatured and reduced proteins from the cellular fraction by Western blot using the anti-HSP antibody did not detect cross-reacting material from either, stressed or unstressed animals. In contrast, in plasma, both antibodies recognized 2 polypeptides of approximately 70 kDa. Analysis of the native plasma proteins by ELISA detected cross-reactivity only with the anti-E. coli HSP antiserum. These results indicate that stress-70 proteins are present in pig plasma and contain epitopes common to bacteria and plant stress- 70 proteins.