Haemoglobin (Hb) is chemically best considered as a duplex of globin heterodimers. The main adult haemoglobin (HbA) is composed of two alpha (α) and two beta (β) chains assembled in two αβ dimers (α1β1 and α2β2), while foetal haemoglobin (HbF) is composed of two alpha-gamma (αγ) dimers. Their main function is to transport oxygen from the lungs to tissues, but it also specifically interacts with three other gases, carbon dioxide, carbon monoxide and nitric oxide. [excerpt]peer-reviewe
