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Characterization and expression of a novel Porphyromonas gingivalis outer membrane protein, Omp28

N Slakeski1, M Margetts, C Moore

  • 1School of Dental Science, The University of Melbourne, 711 Elizabeth Street, Victoria 3000, Australia.

Oral Microbiology and Immunology
|May 29, 2002
PubMed

Insights

We characterized the Porphyromonas gingivalis Omp28 protein, a potential adhesin. Recombinant Omp28 was recognized by various antisera, suggesting it is widely expressed across P. gingivalis strains.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Immunology

Background:

  • Porphyromonas gingivalis is a key pathogen in chronic periodontitis.
  • Outer membrane proteins of P. gingivalis are potential virulence factors and diagnostic targets.

Purpose of the Study:

  • To characterize the Porphyromonas gingivalis omp28 gene and its encoded protein.
  • To investigate the potential role of Omp28 as a surface adhesin/receptor.
  • To determine the expression and distribution of Omp28 in P. gingivalis strains.

Main Methods:

  • Gene cloning and expression of recombinant Omp28 (rOmp28) in Escherichia coli.
  • Western blot analysis using antisera against P. gingivalis and rOmp28.
  • Sequence analysis of the omp28 gene.

Main Results:

  • The omp28 gene encodes a 28-kDa outer membrane protein with a leader sequence and lipoprotein attachment site.
  • Omp28 shares limited sequence identity with other proteins but has a segment similar to a Dichelobacter nodosus fimbrial protein, suggesting adhesive properties.
  • Recombinant Omp28 was recognized by antisera from P. gingivalis-infected animals and humans, as well as by sera from periodontitis patients.
  • Anti-rOmp28 antisera reacted strongly with diverse laboratory strains and clinical isolates of P. gingivalis from multiple geographic locations.

Conclusions:

  • Omp28 is a surface-exposed protein of P. gingivalis with potential adhesin/receptor functions.
  • Omp28 is conserved and widely expressed among different P. gingivalis strains, making it a potential diagnostic marker or vaccine candidate.

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