Macroglobulinemia with Bence Jones Proteinuria: Comparison of Urinary Protein and L Chain of Serum Proteins*

Abstract

A comparison was made between the serum and urine proteins isolated from a patient with Waldenstrom'' s macroglobulinemia and Bence Jones proteinuria. After reduction and alkylation in a solvent containing no denaturing agent, the macroglobulin was separated into H and L chains by gel filtration on urea-Sephadex G-100. The L chain of the macroglobulin and the Bence Jones protein had similar thermosolubility characteristics and sedimentation values. On electro-phoresis in urea-starch gel, the unmodified Bence Jones protein had the identical mobility of the L chain of the macroglobulin. L chains and Bence Jones protein prepared by reduction in urea buffers had identical but slower mobilities than the proteins reduced in buffers without urea. Peptide maps of these proteins appeared to be identical The L polypeptide chain of the serum macroglobulin and the urinary Bence Jones protein were both of Type I, whereas the L chain of the autologous serum [gamma]2-globulin manifested both Types I and II antigenic specificity. This study strongly suggests the chemical and immuno-logic identity of a Bence Jones protein and the L chain of the autologous serum macroglobulin.