Bence Jones KWR protein structures determined by X-ray crystallography

Bence Jones KWR protein, an immunoglobulin light-chain dimer, was crystallized under a variety of conditions after 40 y storage. Structures were obtained with packing arrangements consistent with biochemical and biophysical observations suggestive of an AL-type amyloid-fibril structure. Obtaining molecular-replacement solutions for these crystals proved to be a crystallographic challenge, probably owing to intradomain flexibility and the presence of disordered and proteolytically modified regions.