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Role of conformational dynamics in sequence‐specific autoantibody•ssDNA recognition
Author(s) -
Bobeck Melissa J.,
Glick Gary D.
Publication year - 2007
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20692
Subject(s) - chemistry , complementarity determining region , serine , förster resonance energy transfer , arginine , conformational change , salt bridge , mutation , circular dichroism , mutagenesis , stereochemistry , biophysics , biochemistry , peptide sequence , amino acid , enzyme , fluorescence , gene , biology , mutant , physics , quantum mechanics
11F8 is a sequence‐specific monoclonal anti‐ssDNA autoantibody isolated from a lupus prone mouse that forms pathogenic complexes with ssDNA, resulting in kidney damage. Prior studies show that specificity is mediated by a somatic mutation from serine at 31 V H to arginine. Reversion back to serine in 11F8 resulted in >30‐fold decrease in affinity and altered thermodynamic and kinetic parameters for sequence‐specific recognition of its cognate ssDNA ligand. Mutagenesis and structural studies suggest that R31 V H contacts ssDNA via a salt bridge and a bidentate hydrogen bond and may further contribute to specificity by altering binding‐site conformation. Fluorescence resonance energy transfer experiments were conducted to assess the kinetics of conformational change during 11F8•ssDNA association. The extent of rearrangement between the six complementary determining regions in the 11F8•ssDNA complex with germline serine or somatically mutated arginine at residue 31 of the heavy chain was examined. Our studies show that greater conformational change occurs in five of six complementarity determining regions after the heavy chain germline J558 sequence undergoes mutation to arginine at 31 V H . © 2007 Wiley Periodicals, Inc. Biopolymers 85: 481–489, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com