Abstract
The interaction of bivalent 2,4-dinitrophenyl (DNP)‡ haptens with rabbit anti-DNP antibody has been studied in the analytical ultracentrifuge. Two series of bivalent haptens have been used, a relatively water insoluble series and a water soluble series. The water insoluble haptens contain an unbranched, aliphatic hydrocarbon chain connecting the two amines to which the DNP groups are bonded. The water soluble series is similar but contains one or two carboxyl groups attached to the intervening chain. With the longer water insoluble haptens the interactions with antibody are slow; some of these haptens required about 2 weeks for complete interaction with the antibody combining sites. Moreover, dimer, trimer and larger polymers of antibody are formed after mixing with the longer water insoluble bivalent haptens. However, the larger polymers of antibody are not stable since with the passage of time they eventually disproportionate to form antibody dimers. In contrast, with the water soluble series, the reactions go to completion immediately and only antibody monomers and dimers are seen. With the water insoluble haptens, the addition of an excess of bivalent hapten causes only a little breakdown of the complexes formed between the antibody molecules. A two-fold excess of water soluble bivalent hapten, on the other hand, causes about 50 per cent of the dimer to dissociate to form fully-saturated antibody monomers. Both the complexes formed with water insoluble and water soluble bivalent haptens will dissociate upon addition of the univalent water soluble hapten DNP-glycine. Finally, measurement of the ratios of hapten to antibody for the sedimentinf monomer and dimer species yield values of two bivalent haptens for the saturated antibody monomer and also two bivalent haptens for the antibody dimer. These values are consistent with the fully-saturated ‘open’ monomer and the ‘closed’ circular dimer species.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
