PMID: 17292396
James LC, Jones PC, McCoy A, Tennent GA, Pepys MB, Famm K, Winter G
Beta-edge interactions in a pentadecameric human antibody V kappa domain.
J Mol Biol. 2007 Mar 30;367(3):603-8. Epub 2006 Nov 3.
Antibodies are the archetypal molecules of the Ig-fold superfamily. Their highly conserved beta-sheet architecture has evolved to avoid aggregation by protecting edge strands. However, the crystal structure of a human V kappa domain described here, reveals an exposed beta-edge strand which mediates assembly of a helical pentadecameric oligomer. This edge strand is highly conserved in V kappa domains but is both shortened and capped by the use of two sequential trans-proline residues in V lambda domains. We suggest that the exposure of this beta-edge in V kappa domains may explain why light-chain deposition disease is mediated predominantly by kappa antibodies.