title: Why are there two kinds of chain in tetrameric hemoglobins?
abstract: It is shown that the mean allosteric free energy G0(34,12) measures cooperative dioxygen binding in tetrameric hemoglobins. For human hemoglobin G0(34,12) is slightly temperature enhanced between 10 and 35 degrees C. This remarkable thermal behaviour depends on the presence in Hb of two functionally non-equivalent chains. It is proposed that this made the existence of alpha 2 beta 2 hemoglobins biologically advantageous.
mesh_terms: D000495:Allosteric Site; D004734:Energy Metabolism; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D008956:Models, Chemical; D010100:Oxygen / Q000097:blood; D013816:Thermodynamics
chemical_list: D006454:Hemoglobins; D046911:Macromolecular Substances; D010100:Oxygen