Amino acid sequence studies with Bence-Jones proteins.

Precise structural studies with Bence-Jones proteins have assumed much greater significance following the suggestion by Edelman and Poulik' that they are poly- peptide chains associated with the ey-globulins of patients with multiple myeloma and the confirmation of this suggestion by the findings2 that these myeloma globu- lins after reduction and alkylation give bands in starch gel electrophoresis which are at the same position as those given by the Bence-Jones protein (which has been similarly reduced and alkylated) from the same patient.This concept has been further strengthened by the findings of Edelman and Gally,3 Putnam,4 Schwartz and Edelman,5 and Mannik and Kunkel.6It is now accepted that the Bence-Jones proteins correspond in most instances to the light chains of the myelorna protein from the same patient.The light chains are known7 to be im- portant in antibody structure.Structural differences between different Bence- Jones proteins might not only reveal certain features responsible for antibody speci- ficity but might also yield more detailed information concerning the genetic mech- anism which determines the synthesis of light chains of antibodies.A study of the amino acid sequence of the Bence-Jones proteins from certain se- lected patients was therefore undertaken.The patients were selected on the basis of minimal heterogeneity with respect to preliminary chemical studies8 and the physical and immunological studies carried out in the laboratories of Dr. H.