Amino acid sequence of the variable regions of light chains from two idiotypically cross-reactive human IgM anti-gamma-globulins of the Wa group.

The amino acids sequences of the variable regions of the light chains derived from two idiotypically related human monoclonal rheumatoid factors are reported. The sequences were obtained through automated Edman degradations of the intact light chains, peptides generated from tryptic digests of citraconylated light chains, and peptides obtained from chymotryptic digestions of light chains. Comparison of the sequences suggests that the idiotypic determinant(s) many reside in the framework portions of the two chains or their J segments.