ANTIGENIC ANALYSIS OF PSEUDOMONAS-AERUGINOSA AND PSEUDOMONAS-CEPACIA GROEL PROTEINS AND DEMONSTRATION OF A LIPOPOLYSACCHARIDE-ASSOCIATED GROEL FRACTION IN PSEUDOMONAS-AERUGINOSA

Quantitative crossed immunoelectrophoresis was used to evaluate the an tigenic similarity of Pseudomonas aeruginosa and Pseudomonas cepacia G roEL proteins. We found that the two proteins showed 75% identity. By using a panel of monoclonal antibodies against the P. aeruginosa GroEL protein, we identified 10 monoclonal antibodies which cross-reacted w ith the P. cepacia GroEL protein and 21 monoclonal antibodies which re cognized type-specific epitopes on the P. aeruginosa GroEL protein. In crossed immunoelectrophoresis two different fractions of GroEL reacti ve material could be resolved. These fractions showed a reaction of pa rtial identity. Examination of the two immunoprecipitates by Western b lotting, showed that both fractions consisted of anti-60 kDa GroEL rea ctive protein. One fraction, in addition, contained LPS with a charact eristic 'ladder' reaction in modified Western blotting. We therefore c onclude that this fraction represents a complex between LPS and GroEL.