(4mt) Determining the Paratope of the Monoclonal Antibody

Antibody is the main molecule to neutralize the antigen from attack. It is secreted from B-cell after immune activation. Structurally, there are four peptide chains, two light chains and two heavy chains, linked with disulfide bonds. On the N-termini of the peptides, there are the variable regions involving the antigen binding. The domain complementary to epitope on antigen in antibody is paratope. Usually, the paratopes are various because the B-cell activation with diverse epitopes generation from different antigen processes.

Among the polymorphic antibody, the potency on antigen binding is quite uneven. For producing the antibody efficiently in vitro, the gene recombinant technique is applied. The recombinant antibody are designed according to the amino acid sequences of paratope in the nature immunoglobin with the high efficacy. Therefore, the paratope need be identified.

With the degradation of monoclonal antibody with pepsin, the Fab was obtained from the purification with protein L. Then, the Fab was subjected to MALDI-TOF for measurement of the molecular weight. And the peptide sequences of paratope on Fab were determined with protein technique. Then, the high potency recombinant antibody can be manufactured on the primary structure of paratope.