A Bence Jones cryoglobulin: chemical, physical and immunological properties.

Abstract

A Bence Jones protein with cryoglobulin properties has been isolated from the urine of a myeloma patient. The Bence Jones cryoglobulin was of type K and had a sedimentation coefficient of 3·5S at a concentration of 5 mg/ml. The concentration dependence of cryoglobulin formation suggested that it was due to reversible association. This was confirmed by ultracentrifugal analyses which demonstrated the formation of aggregates with a sedimentation coefficient of approximately 50–100S and higher. Quantitative amino acid analyses revealed that the Bence Jones cryoglobulin was completely devoid of methionine. On starch gel electrophoresis, three to four protein bands could be detected. They were all devoid of methionine and there was no significant difference in their content of other amino acids. On the basis of amino acid and ultracentrifugal analyses the presence of several components on starch gel electrophoresis is consistent with the formation of aggregates by a single molecular species.