Physical chemical studies of reactions of human hemoglobins
The molecular dissociation of the derivatives, carbonmonoxy-, oxy-, ferro-, and ferri-, of normal adult hemoglobin has been studied at a pH of five. Of these derivatives, ferrohemoglobin is least dissociated while ferrihemoglobin is most extensively dissociated at a given concentration. The apparent dissociation constants have been calculated and related to the acid dissociation of the "theme-linked" acid groups of these derivatives.

Hemoglobins labelled with Carbon-14 have been prepared. Using C14 labels on one hemoglobin, the exchange of molecular subunits has been studied after dissociation of mixtures of normal adult and sickle cell hemoglobins at acid and alkaline pH. Hemoglobin "hybrids", in which one type of subunit is radioactive and the other not, have been formed and isolated. These hybrids have been used in the identification of the polypeptide chain in which the anomaly occurs in sickle cell hemoglobin. This anomaly was found to occur in the [beta] chains. The kinetics of the [alpha] chain exchange between the two hemoglobins has been studied at alkaline pH. Presumptive evidence of the mode of dissociation at this pH has been obtained. Preliminary investigations are reported on the isolation of hemoglobin hybrids in which only the chains are radioactive.

Spectral data for several derivatives of hemoglobin have been related to a recently adopted standard. The use of the ferroversenate ion in forming ferrohemoglobin from oxyhemoglobin is reported.