Figure 2.
Characterization of cow CD23 binding to sugars in a solid-phase binding assay. A, binding competition assays in which immobilized CRD was probed with horseradish peroxidase, as reporter ligand, at concentrations well below saturation binding. Under these conditions, the relative KI values for competing monosaccharide and oligosaccharide ligands closely approximate KD values. Solid bars, KI values for various sugars relative to the KI for mannose. Error bars, S.D. for three or more assays for each sugar. Absolute KI values are indicated at the top of each bar. B, comparison of binding of α-methyl mannoside and Man9GlcNAc2 oligosaccharide. An example of a competition assay is shown. The average ratio of the affinities for five assays was 240 ± 50. C, pH dependence of binding was determined using the same solid-phase assay format.