Explain the structure of immunoglobulin with suitable diagram.

Explanation

In the 1950s experiements by Porter and Edelman revealed the basic structure of the immunoglobulin.
(ii) An antibody molecules is Y shaped structure that comparies of four polypeptide chains, two identical light chains (L) of molecular weight 25,000 Da (Approximately 214 amino acids ) and two identical heavy chains (H) of molecular weight 50,000 Da (approximately) 450 amino acids).
(iii) The polypeptide chains ar linked together by di- sulphide (S-S) bonds. One light chain is attached to each heavy and two heavy chains are attached to each other to form a Y shaped structure. Hence, an antibody is represented by `H_(2)I_(2)`
(iv) Each chain ( L and H) has two terminals They are C - terminal (Carboxyl) and amino or N- terminal.
(vi) Antibodies responding to different antigens have very different (V) regions but their(C) regions are the same in all antibodies.

(vii) The (C ) regions that forms the stem of the stem of the anitibody monomer determine the antibody class and serve common functions in all antibodies.