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Specific degradation of H. pylori urease by a catalytic antibody light chain.
- Source :
-
The FEBS journal [FEBS J] 2005 Sep; Vol. 272 (17), pp. 4497-505. - Publication Year :
- 2005
-
Abstract
- Catalytic antibodies capable of digesting crucial proteins of pathogenic bacteria have long been sought for potential therapeutic use. Helicobacter pylori urease plays a crucial role for the survival of this bacterium in the highly acidic conditions of human stomach. The HpU-9 monoclonal antibody (mAb) raised against H. pylori urease recognized the alpha-subunit of the urease, but only slightly recognized the beta-subunit. However, when isolated both the light and the heavy chains of this antibody were mostly bound to the beta-subunit. The cleavage reaction catalyzed by HpU-9 light chain (HpU-9-L) followed the Michaelis-Menten equation with a K(m) of 1.6 x 10(-5) m and a k(cat) of 0.11 min(-1), suggesting that the cleavage reaction was enzymatic. In a cleavage test using H. pylori urease, HpU-9-L efficiently cleaved the beta-subunit but not the alpha-subunit, indicating that the degradation by HpU-9-L had a specificity. The cleaved peptide bonds in the beta-subunit were L121-A122, E124-G125, S229-A230, Y241-D242, and M262-A263. BSA was hardly cleaved by HpU-9-L, again indicating the digestion by HpU-9-L was specific. In summary, we succeeded in the preparation of a catalytic antibody light chain capable of specifically digesting the beta-subunit of H. pylori urease.
- Subjects :
- Amino Acid Sequence
Animals
Antibodies, Monoclonal metabolism
Binding Sites
Helicobacter pylori genetics
Humans
In Vitro Techniques
Kinetics
Mice
Models, Molecular
Molecular Sequence Data
Peptide Fragments chemistry
Peptide Fragments immunology
Peptide Fragments metabolism
Protein Subunits
Urease chemistry
Urease genetics
Antibodies, Catalytic metabolism
Helicobacter pylori enzymology
Helicobacter pylori immunology
Urease immunology
Urease metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1742-464X
- Volume :
- 272
- Issue :
- 17
- Database :
- MEDLINE
- Journal :
- The FEBS journal
- Publication Type :
- Academic Journal
- Accession number :
- 16128818
- Full Text :
- https://doi.org/10.1111/j.1742-4658.2005.04869.x