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Monoclonal antibodies against Pseudomonas aeruginosa elastase: A neutralizing antibody which recognizes a conformational epitope related to an active site of elastase
- YOKOTA, Shinâichi, OHTSUKA, Hiroshi, NOGUCHI, Hiroshi
- European journal of biochemistry 1992 v.206 no.2 pp. 587-593
- EDTA (chelating agent), Pseudomonas aeruginosa, Western blotting, active sites, chelating agents, elastase, elastin, enzyme activity, enzyme-linked immunosorbent assay, epitopes, fluorescein, hybridomas, metalloproteinases, mice, monoclonal antibodies, neutralization, neutralizing antibodies
- We have established seven murine hybridoma cell lines which produce monoclonal antibodies (mAbs) against Pseudomonas aeruginosa elastase. The seven mAbs recognized at least six different epitopes on the elastase molecule. All mAbs inhibited both enzymatic activities of elastase and protease, in which elastin fluorescein and hide powder azure were used as substrates, respectively. One of them, mAb Eâ4D3, strongly neutralized enzymatic activities of peptidase in which furylacryloylâglycylâleucinamide was used as a substrate, as well as of elastase and protease. In contrast, the other six mAbs did not neutralize peptidase activity at all. The Ki value for furylacryloylglycylâleucinamide of Eâ4D3, as well as its Fab fragment, was comparable to those for metalloprotease inhibitors such as phosphoramidon and Zincov inhibitor. The binding of mAb Eâ4D3 was inhibited by phosphoramidon and Zincov inhibitor, but not by metal chelators such as EDTA and oâphenanthroline. A line of evidence suggests that mAb Eâ4D3 directly interacts with active site and highly neutralizes enzymatic activity of P. aeruginosa elastase. Data of Western blotting and ELISA suggest that mAb Eâ4D3 is likely to recognize an elastase molecule in a conformationâdependent manner as an epitope. In contrast, the neutralizing activity of the other mAbs against elastase and protease seems to be caused by a low acessibility of an enzyme to insoluble and highâmolecularâmass substrates through the binding and steric hindrance of the mAbs to an enzyme.