Chain Variable Region Determinants

Light-chain variable region determinants for immunoglobulin k chains are among the most precisely localized antigenic determinants, in large measure because of the work of Solomon and his associates. 

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Antigenic Features of Immunoglobulins B. Heavy-Chain Variable Region Determinants... 

Feizi et al. (1977) have described a heavy-chain variable region marker (VnMar) that was detected using an antiserum raised against human IgM cold agglutinins. Evidence was presented that the relevant determinant was associable with cross-reactive idiotypes characteristic of the cold agglutinins. It was of particular interest that this antigen is found in both normal pooled IgG and some unselected myeloma paraproteins. 

The differences in sequence within the variable region produce a practically unlimited number of possible three-dimensional arrangements for the amino acid side chains to form the complementarity-determining region (CDR), which actually binds to the antigen. 

Sequence determinations showed that in some regions of immunoglobulin molecules there is extreme variation in the amino acid sequence between one homogeneous antibody and the next other regions have a constant sequence. The molecule can also be divided into domains. The variable regions, which occupy the N-terminal ends of the chains, are designated... 

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