Abstract

Incorporation of Homo-Bi-Functional Spacer via Hydrazone and Diimide Bond between Hapten-Protein Conjugate

Tulsidas Shrivastav, Professor, National Institute of Health & Family Welfare

The conjugation process involves the linkage of two or more molecules to form a novel complex having the combined properties of its individual components. The conjugation technique is dependent on two interrelated chemical reactions: the reactive functional groups present on various cross-linking or derivatizing reagents and the functional groups present on the target molecule to be conjugated. The ability to couple one molecule to another has caused the birth of billion-dollar industries serving research, diagnostics, and therapeutic markets. Without the development of conjugation chemistry to produce conjugated molecules, much of the life science research, as we know it today, would have been impossible.

In the present study coupling of hapten to protein through homo-bi-functional spacer via hydrazone and diimide bond is described. Carbohydrate moieties of protein/enzyme were first oxidized by sodium metaperiodate to generate reactive aldehyde group in protein/enzyme followed by addition of excess amount of adipic acid dihydrazide (ADH), a homobifunctional cross linker to form hydrazone bond through a reaction between aldehyde group of enzyme and hydrazide group of adipic acid dihydrazide. The protein/enzymes adipic acid dihydrazide (protein/enzymes-ADH) complex is utilized for preparing hapten- protein/enzyme conjugate through diimide bond formation. The method described for introduction of spacer between hapten andprotein/enzymes conjugate is very simple.