Evolutionary and functional insights into the mechanism underlying body-size-related adaptation of mammalian hemoglobin.

ABSTRACT: Hemoglobin (Hb) represents a model protein to study molecular adaptation in vertebrates. Although both affinity and cooperativity of oxygen binding to Hb affect tissue oxygen delivery, only the former was thought to determine molecular adaptations of Hb. Here, we suggest that Hb affinity and cooperativity reflect evolutionary and physiological adaptions that optimized tissue oxygen delivery. To test this hypothesis, we derived the relationship between the Hill coefficient and the relative affinity and conformational changes parameters of the Monod-Wymann-Changeux allosteric model and graphed the 'biophysical Hill landscape' describing this relation. We found that mammalian Hb cooperativity values all reside on a ridge of maximum cooperativity along this landscape that allows for both gross

SUBMITTER: Rapp O 

PROVIDER: S-EPMC6812962 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature