Preparation and immunological characterization of surface proteins of Porphyromonas gingivalis
Bunjerd Yapong, D. of Oral Biology and Occlusion, F. of Dentistry, PSU.
Sittichai Koontongkaew, Assoc. Prof., D. of Oral Biology and Occlusion, F. of Dentistry, PSU.
Metta Ongsakul, D. of Microbiology, F. of Sci., PSU.
Corresponding e-mail : ksittich@ratree.psu.ac.th
Grant : Prince of Songkla University
Published : J Dent Assoc Thai 1999, 49(2) : 97-103
Key words : immune, surface proteins, Porphyromonas gingivalis
The preparation of major surface proteins of P. gingivalis was carried out in this study. A soni-cate extract of P. gingivalis ATCC 33277 was obtained following selective solubilization membranes with N-laurylsarcosinate (SLS). Protein profiles of the SLS sonicate were exmained by sodium dode-cyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Four major proteins of 78, 61, 55 and 44 kDa were identified in the SLS sonicate. In order to identify potential antigens of this periodontopathic organism, rabbit antisera to the SLS sonicate were generated. Outer membrane proteins of this orga-nism were prepared. The SDS-PAGE analysis of the outer membrane demonstrated ten major proteins with molecular weights ranging 98-20 kDa. Western blot analysis indicated that 6 major proteins of
98, 78, 61, 57, 55 and 44 kDa could strongly react with the rabbit antisera against SLS sonicates. In-direct immunofluorescence confirmed that our prepared antibodies were specific to P. gingivalis.
The antibodies did not exhibit immunological cross reactivity with other oral bacteria. This finding suggests that the 78, 61, 55 and 44 kDa proteins are the important surface antigens of P. gingivalis.
The role of these antigens in the pathogenesis of periodontal diseases remains to be investigated.
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