The Primary Structure of a Rat κ Bence Jones Protein: Phylogenetic Relationships of V- and C-Region Genes

Abstract

Abstract The complete amino acid sequence of a LOU rat κ Bence Jones protein, S211, is presented. The availability of such a sequence makes it possible to re-evaluate the phylogenetic relationships of V- and C-region genes. The data suggest that V- and C-genes, and also V-genes between themselves, have evolved at different rates. The Vκ1-gene seems to have been preserved during evolution and its products could be identified in three other species. The differences between these Vκ1 like sequences and a human Vκ1 representative sequence are similar and fall inside the range of inter-subgroup differences. On the other hand, the comparison of Cκ-regions from four different species agrees with their recognized phylogenetic relationships. Evidence is presented which suggests that two substitutions within the C-region of the S211 κ-chain are unrelated to allotypes and presumably represent somatic events or are evidence for multiple isotypes of rat Cκ-region.