Quantification of the Binding Tendencies of Cholestyramine I: Effect of Structure and Added Electrolytes on the Binding of Unconjugated and Conjugated Bile-Salt Anions

The binding of conjugated and unconjugated bile salts to cholestyramine from aqueous media was investigated and the data plotted according to the Langmuir adsorption equation. Higher affinity constants were obtained with the dihydroxy rather than the trihydroxy derivatives. Glycine conjugation was found to alter the affinity constants only slightly, whereas conjugation with taurine markedly increased the affinity of cholestyramine for the bile salt. The addition of bicarbonate or chloride anions to the system produced a significant decrease in the extent of binding of the trihydroxy bile-salt anions; the effect being more pronounced in the case of the chloride ion.