Immunoglobulin Kappa Variable (IgkV)

An Ig molecule is made up of 2 identical heavy chains and 2 identical light chains, either kappa or lambda, joined by disulfide bonds so that each heavy chain is linked to a light chain and the 2 heavy chains are linked together. The kappa and lambda light chains have no apparent functional differences. Each Ig kappa light chain has an N-terminal variable (V) region containing the antigen-binding site and a C-terminal constant (C) region, encoded by a C region gene (IGKC), that provides signaling functions. The kappa light chain V region is encoded by 2 types of genes: V genes and joining (J) genes. Random selection of just 1 gene of each type to assemble a V region accounts for the great diversity of V regions among Ig molecules. The kappa light chain locus on chromosome 2 contains approximately 40 functional V genes, followed by approximately 5 functional J genes.