Binding of Human Hemoglobin and Its Polypeptide Chains with Haptoglobin Coupled to an Agarose Matrix

Abstract
The interactions of human haptoglobin covalently linked to agarose with human Hb and with p-chloromercuribenzoic-acid-treated .alpha. and .beta. chains (.alpha.* and .beta.* chains) were studied by flow chromatography and equilibrium binding. In solid state, haptoglobin maintained the same binding characteristics as in solution, the order of binding affinities being: Hb < .alpha.* chain < .beta.* chain. The study of the binding parameters of the .alpha.* chain showed an heterogeneity of binding sites on the haptoglobin and an average affinity constant Ka of 3.6 .times. 104 l/mol.