Characterization of the hemoglobins of the adult brushtailed possum, Trichosurus vulpecula (Kerr) reveals non-genetic heterogeneity

The hemoglobins contained within the red blood cells of the adult brushtail possum exhibited cooperative (n = 2.6) oxygen binding curves with an associated p50 of 38 mm Hg at pH 7.4 and a large Bohr effect (− 0.60). Stripped hemolysate showed a Bohr effect of − 0.27, and was sensitive to added DPG (K = 56 μmol L− 1), ATP (K = 130 μmol L− 1), and chloride ions. Four isoforms of hemoglobin were identified using isoelectric focusing. Mass spectrometry indicated that all four isoforms most likely represent the same gene products which have differentially undergone post-translational deamidation and glutathionylation. The oxygen binding characteristics of three isolated isohemoglobins have been determined.