Physicochemical and Phylogenetic Approaches shed light on the Complete 2/2 Hemoglobins Family Classification and Characterization

BUSTAMANTE, JUAN PABLO; BOECHI, LEONARDO; RADUSKY, LEANDRO; ESTRIN, DARÍO; TEN HAVE, ARJEN; MARTÍ, MARCELO ADRIÁN

Congreso; 18th International Conference on Oxygen-Binding and Sensing Proteins; 2014

The globin family of heme proteins offer a large, diverse and thoroughly studied set of proteins, whose function is tightly related to small ligand (mainly O2 but also NO, CO, and H2S) affinity and reactivity. Usually, those displaying high O2 affinity function as O2-redox related enzymes, like NO dioxygenase function of Mycobacterium tuberculosis 2/2 HbN. Moderate affinity globins usually act as oxygen carriers, like mammalian myoglobin, while low O2 affinity globins are NO or CO sensors, like soluble guanylate cyclase. Assuming that the protein function is coded in the structure through the determination of its chemical properties, we present a study aimed to classifying and characterizing the whole 2/2 Hbs family, assigning to each protein thus a putative O2 affinity based on ligand entry and stabilization. In this work we employed a combined bioinformatics, physicochemical and phylogenetic approaches to describe and assign key 2/2 Hbs features that in turn determine O2 affinity. Our results confirm previous classifications and include a complete description of the divergence of different subgroups at the molecular level.