Neutralizing monoclonal antibodies to an extracellular Pseudomonas cepacia protease.
Pseudomonas cepacia produces at least two extracellular proteases with apparent molecular masses of 36,000 and 40,000 Da. The 36-kDa protease has high proteolytic activity and the 40-kDa protease has low proteolytic activity with hide powder azure as a substrate. Monoclonal antibodies (MAbs) were raised against the purified 36- and 40-kDa proteases. Several MAbs directed against the 36-kDa protease were found to recognize the 40-kDa protease by Western immunoblot analysis. Similarly, a MAb directed against the 40-kDa protease recognized the 36-kDa protease, suggesting that these two proteases may be immunologically related. A MAb directed against the 36-kDa protease, designated 36-6-8, and a MAb directed against the 40-kDa protease (MAb G-11) cross-reacted with other extracellular proteases, such as Pseudomonas aeruginosa elastase and alkaline protease, Pseudomonas pseudomallei protease, and the Vibrio cholerae hemagglutinin/protease. MAb 36-6-8 neutralized the P. cepacia 36-kDa protease, P. aeruginosa elastase, P. pseudomallei protease, and V. cholerae hemagglutinin/protease but did not affect P. aeruginosa alkaline protease activity. In contrast, MAb G-11 to the 40-kDa protease neutralized only the P. cepacia 36-kDa protease. This evidence suggests that the neutralizing MAb, 36-6-8, recognizes an epitope conserved among some metalloproteases. This epitope may lie at or near the active site of the P. cepacia 36-kDa protease and P. aeruginosa elastase.
Kooi
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C
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Centre, Alberta, Canada.
Cox
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A
Darling
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Sokol
P A
PA
D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D016956:Burkholderia cepacia / Q000201:enzymology* / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D008666:Metalloendopeptidases / Q000276:immunology* / Q000302:isolation & purification; D008970:Molecular Weight; D009500:Neutralization Tests; D013045:Species Specificity
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000939:Epitopes; D008666:Metalloendopeptidases