The members here are composed of the immunoglobulin (Ig) light chain, kappa type, variable (V) domain. This group contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda, each composed of a constant domain (CL) and a variable domain (VL). There are five types of heavy chains (alpha, gamma, delta, epsilon, and mu), which determines the type of immunoglobulin formed: IgA, IgG, IgD, IgE, and IgM, respectively. In higher vertebrates, there are two types of light chain, designated kappa and lambda, which seem to be functionally identical, and can associate with any of the heavy chains.
Structure:2ADG; Mus musculus monoclonal anti-Cd4 antibody Q425, IgV light and heavy chain heterodimer interface, contacts based on 3.5 A distance.
Structure:2ADG; Mus musculus monoclonal anti-Cd4 antibody Q425, Fab light and heavy chain interface (including constant domains of Fab), contacts based on 3.5 A distance.
Comment:Dimerization of Ig domains from different chains is common, but not found in all members.