Abstact

The immunoglobulin Kol was the first intact antibody molecule which was characterized by high-resolution X-ray crystallography. Furthermore the complete amino-acid sequence of the heavy (H)-chain is known. Here we report the complete amino-acid sequence of the light (L)-chain of the monoclonal immunoglobulin Kol (IgG1). The polypeptide has an Mr of 22,781, consists of 216 amino acids and due to its structure is of the lambda-type. With the characteristic amino acids threonine, asparagine, threonine, glycine and lysine in positions 101, 114, 116, 154, and 165, respectively the Kol L-chain is of the Mcg isotype. With the proteins Mcg, Mot, Bur, Loc and Mem six myeloma-derived amino-acid sequences of the same isotype are known. The amino-acid sequence of the N-terminal variable part is characteristic of subgroup 1. This contribution completes the primary structure of IgG1 Kol.