Functional Properties of Human Hemoglobin Treated with 5,5′‐Dithiobis, 3,3′‐Nitrobenzoic Acid

The reaction of 5,5′‐dithiobis, 3,3′‐nitrobenzoic acid with hemoglobin and isolated chains has been studied and the functional properties of the derivatives have been determined. The oxygen affinity of treated hemoglobin, both at low and high salt concentration is higher than that of normal hemoglobin under the same conditions with no substantial change in heme‐heme interaction; the Bohr effect is somewhat reduced in the alkaline range, but is increased in the acid range. The treated β‐chains show enchanced oxygen affinity with respect to normal chains. Treated hemoglobin shows also, in comparison with normal hemoglobin, significant changes in the kinetics of CO binding and O2dissociation.