Showing papers by "Charles DeLisi published in 1976"

Some Physical Chemical Aspects of Receptor-Ligand Interactions

Abstract: Quantitative evaluations of a variety of binding reactions of interest to immunologists have usually assumed that the reactants are homogeneously dispersed in solution for purposes of calculation. In fact, many of these reactions involve cell-bound “receptors” which are present at exceedingly high local concentrations on discrete particles. We describe how such a distribution can influence the experimentally measured binding constants. We also briefly consider the additional complexities introduced when multipoint attachment between the ligand and cell-bound receptors is possible, and discuss the possible biological implications.

Hemolytic Plaque Inhibition: The Physical Chemical Limits on Its Use As an Affinity Assay

Abstract: An analysis of the fundamental physical chemical limits of hemolytic plaque inhibition as a method for obtaining thermodynamic and kinetic information is presented. It is shown that inhibition curve characteristics will be sensitive functions of reaction affinities only when the antibody inhibitor and antibody red blood cell reaction mechanisms are related in certain ways. It is further shown that conditions which are most sensititive to IgG affinity changes will generally not be the best for detecting changes in IgM affinity. The apparently conflicting reports on IgM maturation are completely explicable in terms of experimental requirements imposed by physical chemical characteristics of the reaction. Experiments in which maturation is observed are found to conform to the most sensitive conditions of the assay, whereas those in which it is not observed are found to conform to relatively insensitive conditions, and would therefore be capable of registering changes only when affinity shifts are large.

Hinge and Valence Effects on Antibody Binding Properties

Abstract: Since the characterization of bond formation between large molecules must be phenomenological, a quantitative description of the reaction must be in terms of thermodynamic parameters; in particular, free energies and equilibrium constants. In addition, however, because an antigen is large compared to an antibody combining site and its structural features highly heterogeneous, a complete description of the interaction will require specification of a set of free energies.