STRUCTURAL STUDIES OF HUMAN γG-MYELOMA PROTEINS OF DIFFERENT ANTIGENIC SUBGROUPS AND GENETIC SPECIFICITIES

Abstract

1. Peptide maps of Fc fragments or heavy chains of 36 G myeloma proteins and two "heavy chain disease" proteins belonging to the four γ-chain subgroups revealed very striking similarities between them. However differences in a few peptides were noted. This was most pronounced for the Ge(γ₂d) subgroup which lacked three peptides characteristic of the other three subgroups. While Fc fragments from different proteins belonging to the same subgroup appeared very similar, minor differences in addition to those based on currently recognized Gm factors were occasionally noted.