Interaction of human hemoglobin with haptoglobin studied by the method of oxygen saturation curves

Abstract

Two types of hemoglobin-haptoglobin complexes were studied which had been prepared by mixing together the two components in a different order. The oxygen saturation curves have shown that hemoglobin was bound in these complexes either in the form of tetramers or in the form of noncooperative dimers. The investigation of the interaction of deoxyhemoglobin with haptoglobin demonstrated that these two proteins do not bind to one another; the corresponding oxygen saturation curve was the same as the curve obtained with hemoglobin alone. In contrast, haptoglobin interfered with the saturation curves of deoxyhemoglobin containing an allosteric effector