Modulation of expression and polymerization of hemoglobin Polytaur, a potential blood substitute

► Experimental conditions are defined to obtain a novel cyclic 180 kDa Polytaur hemoglobin trimer. ► Size, oxygen binding properties and low oxidation levels of the trimeric Polytaur are ideally suited for its use as a blood substitute. ► Human alpha hemoglobin-stabilizing protein, a hemoglobin folding chaperone in vivo, resulted in decreased yield and unusual spectroscopic and functional properties.