Molecular evolution and structure-function relationships of gene products from extinct and extant mammalian species

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Directly linking external environmental conditions with cellular metabolic processes, vertebrate hemoglobins are exquisitely tailored to balance the uptake of oxygen at the lungs and its delivery to the tissues. While the heme groups (the loci for oxygen binding) of all hemoglobins are identical, the globin composition can vary substantially between species. Seemingly small changes in the amino acid composition, resulting from base substitutions with the DNA of the globin chains, can have profound effects on the protein's oxygen-binding characteristics and sensitivity to temperature. These alterations have undoubtedly played a key role in the ability of mammals to occupy a diverse range of habitats, yet little is known regarding their precise molecular mechanisms and mode of evolution. This application is for funds to support novel research on hemoglobins from extinct and extant mammals specialized to life in arctic, semi-aquatic and subterranean environments, focusing specifically on the oxygen binding characteristics of these respiratory proteins in response to temperature and other red cell ligands (carbon dioxide, protons, chloride ions and certain organic phosphates).