Ig heavy chain variable region Light – Other Categories

Peptide derived from the variable region on the heavy chain of immunoglobulin (Ig) which is part of the fragment antigen binding (Fab) fragment of antibodies. Ig or antibodies are made up of two heavy and two light chains both of which have a constant region and a variable region. The variable region, the antigen binding site, is composed of three complementarity determining regions (CDRs) from the variable heavy chain and three CDRs from the variable light chains. The amino acid sequences of the variable region differ between each antibody allowing Ig to bind to specific antigens. The variable regions are encoded by a variety of V, D and J gene segments. During somatic recombination different combinations from the V, D and J varieties can be joined together. Consequently this gives rise to a diverse variable region. The Ig heavy chain can be classed as being either: IgM, IgG, IgA, IgD or IgE each of which change the function of the antibody.