Distribution and respiratory properties of sheep hemoglobins A and B containing the II alphaHis chain

We recently reported the discovery of a second α chain, differing from the common α chain by the replacement 113 (or 114) Leucine→Histidine, in the hemoglobin of several domestic sheep. The ratio of the common α chain, here called αeu,* to the variant one, here called IIαHis, was either about 1.8:1 or about 4:1.In this study, the distribution of the IIαHis chain in 217 sheep from 8 domestic breeds was investigated: the IIαHis chain is present in 30% of animals from different breeds.Oxygen equilibrium determination showed no differences in the oxygen affinity, the Bohr effect and the heme-heme interaction of Hb A (α2,β2A) and Hb B (α2β2B), each containing one of the three possible α chain phenotypes.