Antibody-hapten interactions

HAp coatings, 14 105 HapMap project, 20 839 Hapten-antibody interactions, 9 64 Haptic sensor, for skin conditions, 3 749 Harcros antifoam, commercial defoamer, 3 24 It... 

W8. Wehmeyer, K. R., Halsall, H. B., and Heineman, W. R., Electrochemical investigation of hapten. Antibody interactions by differential pulse polarography. Clin. Chem. 28, 1968-1972 (1982). 

Understanding of hapten-antibody interaction would benefit from physical-chemical study of binding (x-ray, NMR, etc.), with the realization that for most molecules there will be many possible antibody combining site structures. 

Hapten antibody interaction of N=36 ortho-, meta- and para-substituted benzoic acids [K relative to K of unsubstituted compound), was correlated with following parameter combinations B° and... 

Specific, rapid, and high-affinity recognition of antigens by antibodies is essential for the host s immune system to respond to invasion by foreign cells and pathogens. Pecht and Lancet have presented a cogent analysis of antibody interactions with haptens, and the interested reader will find their examination of the kinetics and thermodynamics to be particularly lucid. Briefly, for the simple one-step binding scheme. 

First, an inert ligand is desirable because it allows the investigator to perform important preliminary experiments with ease. Binding measurements and assays of biological activity are straightforward and unusual experiments that might not be feasible with a chemically reactive molecule can be done. For example, photolabile molecules may be used as haptens for antibody production and the hapten-immunoglobulin interaction subsequently explored (Fleet et al., 1969). 

Association Constants of Antigen-Antibody, Hapten-Antibody and Ligand-Lectin Interactions... 

Conditions and abbreviations pH 7.5 antiserum, As43 RO, percentage of phenoxide species Klff, affinity constant of the antibody-hapten-BSA interaction relative to the affinity of the antibody for hapten 5-BSA conjugate n.a., not available [891. 

Primary antigen-antibody interactions can be used to quantitate both antigens and haptens. Methods exploiting primary interactions have been developed for both antigen-hapten and antibody quantitation. These methods involve combining... 

Homogeneous, AM assays pose different requirements. Here, the enzyme should be easily conjugated near the active site without altering its activity. The reaction of hapten- or antigen-labeled enzyme with antibody should affect strongly the enzyme activity, e.g., through steric inhibition of the substrate at the catalytic site. The requirements for optimal ionic conditions and temperature for both enzyme activity and antigen-antibody interaction should be compatible. 

The binding forces are electrostatic attractions between sites with opposite charges such as -NH3 carried by a lysine residue and a carboxylate, van der Waals forces, and hydrogen bonds. It is predicted that the first two types of bonds, which increase rapidly as the distances decrease, will be all the more efficient as the complementarity is better. The expression hydrophobic interactions is used because an exact fit drives away water molecules present close to the hydrophobic residues such as valine, leucine, isoleucine, etc. This concept, developed further in Chapter 11, implies that a decrease in surface contact with water is in itself a stabilizing factor. All these forces are reversible. When the hapten-antibody complex in solution is introduced into a dialysis bag, only the hapten can cross over the membrane, and its elimination from the interior bag causes complete dissociation of the complex through equilibrium displacement. 

Immunoassay techniques are based on the antigen-antibody interaction. These techniques involve a competitive reaction between antigen molecules of the target molecules and labeled antigen molecules for a limited number of antibodies. Enzyme-linked immunosorbent assays (ELISA) in which antibodies are immobilized on a solid phase are the most popular for pesticide detection. As pesticides are small molecules, in order to synthesize antibodies, pesticide derivatives (haptens) must be synthesized and coupled to carrier proteins. ... 

Structure-activity relationships in immunochemistry [21, 335, 396, 725 — 728] reveal the importance of steric interactions in the QSAR of hapten-antibody (32) interactions (eq. 150) [396, 725] eq. 151 could be derived for the 50% inhibition of complement by benzylpyridinium ions (33) [727]. 

Binding constants for the interaction of antibodies with antigens show a wide variation. Anti-carbohydrate antibodies have K values of the order of 10 M whilst polypeptide and certain hapten antibodies have K values approaching M (e.g. anti-gastrin, anti-fluorescein) (13, 14). 

The shape of the interaction area between lysozyme and the CDR loops of the antibody is easily distinguished from the hapten-binding crevice. The interaction extends over a large area with maximum dimensions of about 20 X 30 A (Figure 15.15). The interaction surface is irregular but relatively flat, with small protuberances and depressions that are complementary in the antigen and the antibody. Residues from all six CDR loops contribute to the... 

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