Role of Structure-Based Changes due to Somatic Mutation in Highly Homologous DNA-Binding and DNA-Hydrolyzing Autoantibodies Exemplified by A23P Substitution in the VH Domain

Table 1

Affinity constants of BV04-01 and MRL-4 ScFvs and their mutants determined by SPR.

Wild type and mutant ScFv	ds DNA ELISA*	ds DNA SPR, M^1**
BV04-01	100±1.21	(1.8±0.31)×10^−9
BV04-01 A23P	1.2±0.02	(2.9±0.67)×10^−7
MRL-4	100±1.52	(1.7±0.18)×10^−8
MRL-4 P23A	4.6±0.61	(8.5±0.84)×10^−6

*Binding of wild type and mutant single chain antibodies in solid-phase ELISA with double-stranded DNA. Results for mutants are expressed in relative units by using wild types as standards, which were set to 100 relative units.
**Binding kinetics was analyzed by SPR with double-stranded DNA fragments as ligands and antibodies as analytes and calculated 𝐾_𝑑 values were presented.
¹Binding of wild type and mutant single chain antibodies to double-stranded DNA.