Amino Terminal Sequences of Heavy and Light Chains of Chicken Anti-Dinitrophenyl Antibody

Abstract

Based on their amino terminal sequences human κ and λ light (L) chains form several subgroups (1–3). The L chains of the immunoglobulins of other animal species have been classified as homologues of the κ and/or λ classes (4). The κ class has been characterized as having a free (unblocked) amino terminus and a carboxyl terminal half cystine residue, whereas the λ class has been considered generally to have a blocked amino terminus, usually pyrrolidone carboxylic acid, and a penultimate half cystine residue at the carboxyl terminus (4, 5). Based on these criteria, Hood et al. (4) suggested that the chicken L chain was a κ type. Although the L chain from normal chicken IgG has an unblocked N-terminal amino acid (4, 6), we reported that the first 17 residues appeared to fit better in the N-terminal sequence of human λ rather than κ chains (6).