Antibody association constants

Thus, if theantibody has a high affinity for the antigen, it has a high association constant. Typical association constants range from lO to 10 ° L/mol, and as high as 10 L/mol for some monoclonal antibodies. 

The definition of an association constant for an antibody—antigen reaction can become more complex if the antibody—antigen reaction iavolves a multivalent antigen, as is the case when a polyclonal antisemm is used for detection of an antigen. This type of multivalent binding is termed avidity and is defined by the equation ... 

The palytoxin-anti-palytoxin reaction is unique in that its binding increases with increasing temperature (Figure 4). The apparent association constant of the palytoxin to anti-palytoxin was 4.9 x 10 M at 0 C and 1.1 x 10 M" at 35 C, suggesting that H2O must be displaced from some of palytoxin s epitopes before they can bind to their antibody combining sites. 

Busch et al. studied the applicability of CZE to the examination of hapten-antibody complex formation (11). The catalytic antibodies examined have been used to accelerate a Diels-Alder reaction. Association constants of two hapten-antibody complexes were investigated and compared to the ELISA method. The samples contained buffer, hapten, and antibody. The constants obtained with CZE are a factor of 3-5 larger than those found with the ELISA method. The free-hapten concentration is measured directly this allows confirmation of the stoichiometric model. Because of the poor concentration sensitivity of UV detection, the application of an extended optical path length such as a bubble cell is necessary to obtain reliable binding parameters. 

An example of an immunoassay is the enzyme-linked immunosorbent assay (ELISA), which uses 96-well plates with antibodies bound on the sides of the wells. The characteristic of interest is the binding constant for the immunoreaction, which is defined as the association constant between antibody and antigen. It is important to generate a good antibody with strong binding. 

Usually, antibodies feature association constants of 10-4 to 104 M-1 and specificities which can surpass those of enzymes. The two greatest differences between enzymes and antibodies are ... 

Two different sequential saturation assays are modified from the ELISA25 to determine association constants of antibody with lysozymes. In both assays, a constant antibody concentration is incubated with varying concentrations of lysozyme until equilibrium is reached. The time necessary must be determined empirically for each antibody for the antibody HyHEL-10, this was determined to be at least 16 hr,26 and all incubations were performed for 16-24 hr. At the end of the incubation, an aliquot of the mixture is treated with an excess of reagents to sample free (unbound) antibody combining sites by incubating with labeled or solid-phase coupled... 

The ideal column of immunoaffinity chromatography would be made using monoclonal anti-immunoglobulin antibodies. These might be selected for their appropriate epitope affinity, specificity, and association constant to release the monoclonal antibody under defined gentle, nondenaturing conditions. 

Antigen Injected (mg) Average Intrinsic Association Constants for Binding of c-DNP-Lysine to Anti-DNP Antibodies ... 

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

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