Index >>Immunity >> Disulphide Bonds

Disulphide Bonds

Immunoglobulin molecules contain interchain and intrachain disulphide (-S-S-) bonds. lnterchain disulphide bonds are of two types, HH bonds connecting the two heavy chains and HL bonds connecting a heavy and a light chain. Interchain disulphide bonds have a stabilizing role, but are not essential.

Some IgA and IgD molecules do not have HL disulphide bonds. Interchain disulphide  bonds are essential for conferring the particular structure, immunoglobulin. Each variable region and each of the domains of the constant region has one intrachain disulphide bond, i.e. each 110 amino acid residue region contains one bond. The two sulphur atoms are separated by about 50-60 amino acid residues.