SDS induced conformational changes in the combining site of anti-trinitrophenyl antibodies. A kinetic study

The conformational stability of the combining sites of high affinity anti-TNP antibodies in the presence of SDS has been investigated by using several novel fluorescent and spectroscopic probes. Kinetic studies employing these probes along with circular dichroism measurements indicate that the binding of SDS monomer to hydrophobic sites on the antibody molecule causes a very rapid increase in the accessibility of the combining site to water. The loss in the ability of these antibodies to bind hapten in SDS solution appears to depend upon much slower conformational transitions; however, the presence of bound homologous hapten is observed to enhance the resistance of the anti-TNP combining site to denaturation by SDS