Variable region framework differences result in decreased or increased affinity of variant anti-digoxin antibodies.
- 1 May 1988
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 85 (9), 3080-3084
- https://doi.org/10.1073/pnas.85.9.3080
Abstract
Rare spontaneous variants of the antidigoxin antibody-producing hybridoma 40-150 (Ko = 5.4 .times. 109 M-1) were selected for altered antigen binding by two-color fluorescence-activated cell sorting. The parent antibody binds digoxin 890-fold greater than digitoxin. The variant 40-150 A2.4 has reduced affinity for digoxin (Ko = 9.2 .times. 106 M-1) and binds digoxin 33-fold greater than digitoxin. A second-order variant, derived from 40-150 A2.4 (designated 40-150 A2.4 P.10), demonstrated partial regain of digoxin binding (Ko = 4.4 .times. 108 M-1). The altered binding of the variant 40-150 A2.4 was accounted for by a point mutation resulting in substitution of arginine for serine at position 94 in the heavy chain variable region. Antibody 40-150 A2.4 P.10 also contains this arginine but owes its enhanced antigen binding to deletion of two amino acids from the heavy chain amino terminus. This unusual sequence alteration in an immunoglobulin framework region confers increased affinity for antigen.This publication has 32 references indexed in Scilit:
- Complete amino acid sequences of the heavy and light chain variable regions from two A/J mouse antigen nonbinding monoclonal antibodies bearing the predominant (p-azophenyl)arsonate idiotypeBiochemistry, 1987
- Phosphocholine binding immunoglobulin Fab McPC603Journal of Molecular Biology, 1986
- Drastic change in idiotypic but not antigen-binding specificity of an antibody by a single amino-acid substitutionNature, 1985
- Complete amino acid sequence of the heavy-chain variable region from an A/J mouse antigen-nonbinding monoclonal antibody bearing the predominant arsonate idiotypeBiochemistry, 1984
- How signal sequences maintain cleavage specificityJournal of Molecular Biology, 1984
- Patterns of Amino Acids near Signal‐Sequence Cleavage SitesEuropean Journal of Biochemistry, 1983
- Somatic generation of antibody diversityNature, 1983
- Crystallographic refinement and atomic models of the intact immunoglobulin molecule Kol and its antigen-binding fragment at 3.0 Å and 1.9 Å resolutionJournal of Molecular Biology, 1980
- Continuous cultures of fused cells secreting antibody of predefined specificityNature, 1975
- Structural Studies of ImmunoglobulinsScience, 1973