Cross-reactivity of specific antibodies directed to heat shock proteins from periodontopathogenic bacteria and of human origin [corrected].

This study describes the immunological characterization of two different classes of heat shock proteins isolated from periodontopathogenic bacteria. Analysis of the N-terminal amino acid sequence of a 74-kDa protein from Bacteroides forsythus showed a high degree of homology with the DnaK protein from Escherichia coli. However, this heat shock protein from B. forsythus reacted very weakly with a commercial anti-DnaK polyclonal antibody by dot-blotting. GroEL-like proteins isolated from Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and B. forsythus showed a high degree of homology of their N-terminal amino acid sequences. In general, polyclonal antibodies raised against each GroEL-like protein showed a high level of cross-reactivity. The cross-reactivity of antibodies to bacterial DnaK-like proteins was much more limited. Our findings suggest that DnaK- and GroEL-like proteins from periodontal pathogens are well conserved and that the GroEL-like proteins resemble each other more closely.