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Structure-function analysis of a lupus anti-DNA autoantibody: central role of the heavy chain complementarity-determining region 3 Arg in binding of double- and single-stranded DNA.
- Source :
-
European journal of immunology [Eur J Immunol] 2000 Jul; Vol. 30 (7), pp. 2015-26. - Publication Year :
- 2000
-
Abstract
- To determine the contribution of the somatic point mutations and that of the complementarity-determining region (CDR)3 Arg to DNA binding, we engineered the germline V(H) and V(kappa) gene revertant and site-mutagenized the CDR3 Arg residues of the mutated and "antigen-selected" mAb 412.67. This anti-DNA autoantibody was derived from B-1 cells of a lupus patient and bore two H-CDR3 Arg, Arg105 and Arg107, encoded by N segment additions, and one kappa-CDR3 Arg, Arg97, resulting from a point mutation (Kasaian et al. 1994. J. Immunol. 152: 3137-3151; Kasaian et al. 1995. Ann. N.Y Acad. Sci. 764: 410-423). The germ-line revertant bound double-stranded (ds) DNA and single-stranded (ss) DNA as effectively as its wild-type counterpart (relative avidity: 6.4x10(-7) and 9.9x10(-9) vs. 6.7x10(-7) and 9.1 x10(-9) g/microl), raising the possibility that an antigen other than DNA was responsible for the selection of the mAb 412.67 V(H) and V(kappa) point mutations. H-CDR3 Arg105 and Arg107 were both required for dsDNA binding, but either Arg105 or Arg107 was sufficient for ssDNA binding. The central role of Arg105 and Arg107 in DNA binding reflected their solvent-exposed orientation at the apex of the H-CDR3 main loop. Consistent with its inward orientation afar from the antigen-binding surface, the kappa-CDR3 Arg97 played no role in either dsDNA or ssDNA binding.
- Subjects :
- Amino Acid Sequence
Animals
Antibodies, Antinuclear chemistry
Antibodies, Antinuclear genetics
Antibodies, Monoclonal chemistry
Antibodies, Monoclonal genetics
Arginine chemistry
Arginine genetics
Arginine immunology
Base Sequence
Cell Line
Humans
Immunoglobulin Fragments chemistry
Immunoglobulin Fragments immunology
Immunoglobulin Heavy Chains chemistry
Immunoglobulin Heavy Chains genetics
Immunoglobulin Joining Region genetics
Immunoglobulin Joining Region immunology
Immunoglobulin Variable Region chemistry
Immunoglobulin Variable Region genetics
Immunoglobulin Variable Region immunology
Immunoglobulin kappa-Chains chemistry
Immunoglobulin kappa-Chains genetics
Immunoglobulin kappa-Chains immunology
Mice
Models, Molecular
Molecular Sequence Data
Point Mutation
Sequence Homology, Amino Acid
Structure-Activity Relationship
Antibodies, Antinuclear immunology
Antibodies, Monoclonal immunology
Complementarity Determining Regions
DNA, Single-Stranded immunology
Immunoglobulin Heavy Chains immunology
Lupus Vulgaris immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0014-2980
- Volume :
- 30
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- European journal of immunology
- Publication Type :
- Academic Journal
- Accession number :
- 10940891
- Full Text :
- https://doi.org/10.1002/1521-4141(200007)30:7<2015::AID-IMMU2015>3.0.CO;2-5