SDS-PAGE ANALYSIS OF MYCOBACTERIUM-LEPRAE PROTEIN ANTIGENS REACTING WITH ANTIBODIES FROM SERA FROM LEPROMATOUS PATIENTS AND INFECTED ARMADILLOS

Google Scholar
  • 1 January 1982
    • journal article
    • research article
    • Vol. 49  (3) , 523-531
Abstract
Studies were conducted to characterize M. leprae antigens from purified leprae bacilli derived from infected armadillos. The proteins of the mycobacterial extracts were fractionated by sodium dodecul sulfate-polyacrylamide gel electrophoresis. The proteins in the gel were then electrophoretically transferred on a strip of nitrocellulose paper by the technique of electrophoretic blotting. The separated bacterial protein bands thus immobilized on the nitrocellulose paper were made to react immunologically with sera from the lepromatous patients, infected armadillo sera and other experimental mycobacterial antisera. Most M. leprae proteins contained antigenic determinants also present on proteins of BCG. Only 2 specific antigen bands of 33,000 kilodaltons (33KD) and 12KD were conspicuously detected by the patients'' sera and the infected armadillo sera. These substances were further identified as polysaccharide or glycoproteins since they could only be stained by Schiff''s reagent or alcian blue. Only 12KD glycoprotein band reacted with concanavalin A; wheat germ agglutinin did not react with them. These 33KD and 12KD glycoprotein antigens lost their antigenicity after pepsin treatment and can thus be considered glycoproteins. Radiolabeling experiments showed that 12KD antigen underwent radioiodination under usual conditions, but 33KD glycoprotein failed to be similarly radiolabeled. Evidently, these protein antigens have M. leprae-specific determinants on a cross-reacting component.