Antibody bonding

The reversible dissociation of antigen-antibody bonds by nonaqueous solvents such as dioxane may prove of considerable practical use in procedures for the isolation and purification of specific antibodies (cf. Singer et al., 1960). 

Xia Z, Goldsmith HL, and van de Ven TG. Flow-induced detachment of red Mood cells adhering to surfaces by lecific antigen-antibody bonds. Biophys J 1994 66 1222-1230. 

Feng, W. Geng, X. Studies on silica-bonded monoclonal antibody packing material for separation of recombinant interferon by high performance immunoafflnity chromatography. Biomed.Chromatogr., 1993, 7, 317-320 [column was anti-interferon monoclonal antibody bonded to silica gradient]... 

A good fit between antigenic sites and antibody-combining sites creates as environment for the intermolecular attractive forces to be created and limits the chances of repulsive forces. The strength of the single antigen/antibody bond is the affinity that reflects the summation of the attractive and repulsive forces. 

In Fig. 7 there is shown the predicted effect of variation of the hapten-antibody bond-strength constant K. ... 

Fig. 7.—Calculated dependence of amount of antigen-antibody precipitate on hapten-antibody bond-strength constant K, for Atotai - Bwtai = 25, K = Vz. s = 1.

The forces responsible for combination and attraction of antigen and antibody molecules may be classified as electronic van der Waals attraction, Coulomb attraction, attraction of electric dipoles or multipoles, formation of hydrogen bonds, etc. The specificity of interaction of antigen and antibody molecules arises from their structural complementariness, which permits close contact of the molecules over sufficient area for these weak forces to co-operate in forming a strong antigen-antibody bond. 

Isolated soybean Glycine max Merr L. cv Clay) seed-coat halves and cotyledons were treated with [ H](S)ABA (0.38 jaCi, 69 jaCi/nmol). The [ H](S)ABA was recovered from [ H](R/S)ABA (Amersham) using immunoaffinity chromatography with monoclonal antibodies bonded to Affigel-10 (Bio-Rad). The [ H](S)ABA was applied in 20 /il of 40 mM MES buffer (pH 6.0) to the adaxial surface of the cotyledons or the interior surface of seed coats. Both seed parts were placed on moistened filter paper in Petri dishes and incubated in the dark for the duration of the experiment. 

The greatest selectivity of detection, however, has been achieved by covering piezoelectric sensor surfaces with biological antibodies. Roederer and Bastiaans obtained quantitative sensor response to the presence of human IgG dissolved in both buffer and diluted blood serum (70). The sensor was a quartz SAW device which had the antibody anti-human IgG covalently bonded to its surface. Selectivity was exhibited because response to the protein IgG was obtained in the presence of an excess of other blood serum proteins. In later work the limit of detection of an antibody-bonded SAW device was found to be 2 ng of antigen (82). 

---