[Opposite control of O2 affinity for hemoglobin by donors and acceptors]

The effects of electron donors and acceptors on O2 binding by hemoglobin were studied. 2,4-Dinitrophenol, levomycetin and pelargonidine-3,5-diglycoside which act as electron acceptors in free radical reactions, enhance this process. In contrast, N-propylajmalin which is known to be an electron donor in the above reactions, suppresses the O2 binding. Diphosphoglycerate and inositol hexaphosphate, the natural inhibitors of O2 binding, exhibit, similar to N-propylajamlin, the properties of electron donors, the latter being a more potent electron donor than the former.