Hb Cemenelum [alpha 92 (FG4) Arg-->Trp]: a hemoglobin variant of the alpha 1/beta 2 interface that displays a moderate increase in oxygen affinity.

Hb Cemenelum [alpha 92 (FG4) Arg-->Trp] carries a structural modification at the same position as Hb Chesapeake, a very high oxygen affinity variant. Hb Cemenelum was found in a French diabetic patient with no abnormal hematological features. The purified abnormal hemoglobin, like Hb J Cape Town, another variant of position alpha 92(FG4), displayed only a 1.5- to 2-fold increased oxygen affinity and a reduced cooperativity. This hemoglobin demonstrates that, even for some key residues of the alpha 1/beta 2 interface, the degree at which the functional properties are altered depends upon the specific residue occupying this position.