Human λ-chain sequence variations and serologic associations

Abstract In an examination of 67 human λ-chains, two were found with constant region variatoins of a type not previously noted. One had two substitutions noted for the first tiem, a serine instead of lysine at position 133 and a glutamine for lysien at 190. The other protein had a previously detected glutamic acid instead of lysine ar residue 160 but a threonine instead of lysine at 167. None of these appears to be no correlation of the St and 111 V λ serologic factors with Mcg-type proteins. One of 12 λ-chains derived from patients with an IgD paraproteimia was found to be of the Mcg type.