Hemoglobin Djelfa beta98 (FG 5) Val leads to Ala: isolation and functional properties of the heme saturated form

Hemoglobin Djelfa beta98 (FG 5) Val leads to Ala is a neutrally substituted unstable hemoglobin, exhibiting the same gross features as hemoglobin Köln beta98 (FG 5) Val leads to Met. In addition to the presence of a deheminized fraction, a heme saturated abnormal hemoglobin was visualized and isolated by high resolution electrofocusing. By functional studies of the fully heminized form, a slightly increased oxygen affinity, an impairment of heme-heme interaction and a decreased response to organic phosphates were demonstrated. These functional perturbations point out the importance of the beta98 invariant valyl residue, in the quaternary contacts. They can account for the poor oxygen delivery of erythrocytes.