Amino-acid Sequence at the C-terminus of Guinea-pig κ Chains obtained from anti-DNP Antibodies

Abstract

THERE are two types of guinea-pig light chains, originally identified by their different antigenic determinants¹. By means of specific precipitation with appropriate antisera the major type was found to account for two-thirds of normal light chains, and the minor type for the rest. But the ratio of major to minor differed from the normal in several purified antibodies, the extreme case being anti-dinitrophenyl-bovine gamma globulin (DNP-BGG) antibodies which contained almost exclusively the major type of light chains^2–3. The major and minor types of guinea-pig light chains were provisionally termed χ and λ pending chemical evidence of homologies to human χ and λ chains. Recently, Hood et al.⁴ reported the sequences of the C-terminal tryptic peptides obtained from the normal light chains of several vertebrate species. Their data also showed that the two types of guinea-pig light chains were normally present in a ratio of about 2:1, and, furthermore, that the major type (C-terminal sequence Ser-Glu-Cys) was homologous to human χ and the minor type to λ chains.