Amino-acid sequence of an allotype b4 light chain from a rabbit antibody to streptococcal carbohydrate.

The complete amino-acid sequence was determined for a rabbit-antibody light chain of allotype b4. The light chain was recovered from approximately 20 g of homogeneous antibody to group C streptococcal carbohydrate, which was obtained from an immunized rabbit. Several enzymic digestions were used to obtain the overlapping peptides necessary for the sequence determination. The L chain has 210 amino-acid residues, as determined by sequence analysis, and a molecular mass of 23,060 daltons. This antibody light chain contains seven half-cystine residues characteristic of the (kappa)B light-chain class. The amino-terminal sequence was determined to be Ala-Asp-Ile-Val-Met, indicating that the chain belongs to the V(kappa)I subgroup.