Studies of the Structure and Synthesis of Immunoglobulins by Isoelectric Focusing

Abstract

The technique of isoelectric focusing was first applied to immunoglobulins by Awdeh et al., in 1968. In this paper the technique of isoelectric focusing (IF) in polyacrylamide gel was used, and photographs were presented showing the IF patterns of a mouse IgG myeloma protein (5563), of several homogeneous proteins, of the total IgG fraction from a nonimmunized rabbit, and of specifically purified antibodies from rabbits and mice immunized with hemocyanin, ribonuclease, and 2,4-dinitrophenyl (DNP) protein. The 5563 myeloma protein gave a pattern consisting of four closely spaced lines, decreasing in intensity toward the anode. The total IgG fraction and the specifically purified antibodies all gave complex patterns consisting of many lines of variable spacing and intensity. Further studies by Awdeh et al. (1970) on the IF pattern of myeloma 5563 showed that when the myeloma protein was freshly isolated from cells grown in vitro, the IF pattern consisted of only two bands. The other two bands seen in myeloma isolated from serum or ascites appeared later upon standing. The focusing patterns of heavy and light chains prepared by reduction and alkvlation were first shown in 1969 by Awdeh et al.