Question

draw , label, and discuss a basic antibody structure

Answer 1

Antibody or immunoglobulin is a Y shaped heterodimer composed of 4 polypeptide chains: 2 light chains and 2 heavy chains.

All 4 H and L chains are bound to each other by disulfide bonds, and by noncovelent interactions such as salt linkages, hydrogen bonds, and hydrophobic bonds.

Chains have 2 ends:an aminoterminal end and carboxyterminal end.

There are 5 classes of H chain and 2 classes of L chain

Any antibody contains only one type of light chain and one type of heavy chain..

Based on constant region of heavy chains, antibody has been classified into 5 types: IgG,IgA, IgM, IgD, IgE

Each H and L chain comprises of two regions: variable region and constant region.

Hinge region: it is the junction formed between constant region of heavy chains of IgG, IgA and IgD. It is absent in IgE and IgM. This region is rich in proline and cysteine. The hinge region is quite flexible, helps the antibody reaching towards antigen.