Fig. 4: General biochemical and redox properties of globins and delivery strategies.
From: Controlled oxygen delivery to power tissue regeneration
a The oligomeric state and heme coordination properties of all four human globins. The X-ray crystal structure of tetrameric hemoglobin (Hb) displays the b1 subunit as a ribbon structure, while the entire structure of monomeric myoglobin (Mb) is shown as a ribbon, positioned relative to Hb b1. The coordinated heme is highlighted in cyan in both structures. b Structural properties of five-coordinate heme-bound Fe(II) (Hb and Mb) binding to oxygen. In the deoxy conformation, Fe(II) sits out of plane from the tetradentate heme. Oxygen binding facilitates shift to stable, tetrahedral geometry in oxyhemoglobin. c oxygen binding properties of Hb and Mb. Hb exhibits cooperative binding as the oligomers transition from T-state to R-state after one oxygen binds. Mb exhibits hyperbolic binding because it functions as a monomer. d Redox properties of oxygen coordination to heme. e Strategies adopted to modify or delivery globins for use as an artificial blood supply. Figure created with BioRender.com, released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license.
