[Hemoglobins, XXVIII. Phosphate-protein-interaction, gene expression and function: the genetic and allosteric control of the oxygen affinity of the fetal blood (author's transl)].
This work describes possible molecular mechanisms concerning the control of oxygen affinity in fetal blood of mammalia. There is a genetic control of oxygen affinity through a fetal gene: at constant phosphate concentration (Hb less than P2-glycerate) in humans there is a hemoglobin with only five binding sites to 2,3-bisphosphoglycerate, resulting in an increased oxygen affinity. In several species (sheep, cattle, goat) with Met-Leu as the N-terminal group of the beta-chains, the 2,3-bisphosphoglycerate binding sites are deleted in positions beta 1 and beta 2, so that the regulation is phosphate-independent and thus providing a fetal hemoglobin with an increased oxygen affinity. The allosteric control is observed in pigs. In the postembryonal development "adult" hemoglobin with seven contacts (beta-chains) is demonstrated. The increased oxygen affinity is achieved here by a reduced biosynthesis of 2,3-bisphosphoglycerate (Hb greater than P2-glycerate) (Rapoport-Luebering-cycle). The functional control is discussed with respect to the ontogeny of the hemoglobins.
D000494:Allosteric Regulation; D000818:Animals; D002417:Cattle; D005260:Female; D005319:Fetal Hemoglobin; D006041:Goats; D006441:Hemoglobin A; D006801:Humans; D046911:Macromolecular Substances; D010108:Oxyhemoglobins; D011247:Pregnancy; D012756:Sheep; D013045:Species Specificity; D013552:Swine
D046911:Macromolecular Substances; D010108:Oxyhemoglobins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin
Hämoglobine, XXVIII. Phosphat-Protein-Wechselwirkung, Genexpression und Funktion: Genetische und allosterische Kontrolle der Sauerstoffaffinität des foetalen Blutes.