USE OF CARBOXYPEPTIDASE-A FOR SIMULTANEOUS ASSESSMENT OF PURITY AND ASSIGNMENT OF HUMAN BENCE JONES PROTEINS AND LIGHT CHAINS TO K AND L CLASSES

A simple and rapid method involving the use of carboxypeptidase A was developed to assess the purity of human Bence Jones proteins and light chains and simultaneously to assign them to their principal antigenic class (K- or L-type). Only serine was released from purified L-type proteins by the action of the enzyme, while no amino acids were liberated from K-type proteins. The heavy chain of a human myeloma IgG protein was also not susceptible to hydrolysis, but serine was released from the L-type light chain of the intact myeloma protein. © 1969.