Similarities of the Light Chains and the Variable Regions of the Heavy Chains of the IgG2 λ and IgA1 λ Myeloma Proteins from a Single Patient

[摘要] High concentrations of an IgA1 and IgG2 myeloma proteins were found in the serum of a single individual. Both light chains were of λ type, had similar amino acid compositions, and could not be distinguished by peptide mapping. Their N-terminal amino acid sequences were identical for the first 30 residues and typical of the V λ III subclass. The heavy chains had the same N-terminal pentapeptide and a comparison of their peptide maps showed the existence of several peptides common to both heavy chains, suggesting similarity of their variable regions. These results, taken together with the previous demonstration of both γ and α chains in the same plasma cell, support the conclusion that during plasma cell differentiation a “switch” may occur which alters the expression of the CH gene although the expression of the VL, CL, and VH genes remains unchanged.

[学科分类] 生物科学（综合）