Amino acid sequence of rabbit pneumococcal antibody I. Light-chain cysteine-containing peptides

Abstract

Rabbit light chains of the b4 allotype from anti-pneumococcal antibodies of restricted heterogeneity and non-immune immunoglobulins were subjected to tryptic, cyanogen bromide, and limited acid hydrolysis. The resultant peptides were sequenced using either the manual or automated Edman degradation. Sequences were aligned either by overlap or by homology with human light-chain data. Rabbit κB light chains have three intrachain disulfide bonds. Three half-cystines were located at positions 23, 134, and 194, homologous with the positions of half-cystines in human light chains, which possess only two intrachain disulfide bonds (23-88 and 134-194). Frangione and Lamm (1970, FEBS (Fed. Eur. Biochem. Soc.) Lett. 11, 339) isolated a peptide from rabbit light chains containing half-cystine-88 by homology with human light chains. We located the two additional half-cystines at position 171 in the constant region and in the variable region between positions 40 and 85. This confirms the presence of a disulfide bond between the constant and variable domains which we had previously postulated. A Val-Leu interchange at position 174 indicates that there are at least two b4 allotype constant-region sequences.SCOPUS: ar.jinfo:eu-repo/semantics/publishe