The human hemoglobin subunit mu (Hb-mu) has been identified as a potential biomarker for alpha-thalassemia. However, little structural and functional information is available for this subunit. Here, we have overexpressed and purified a double mutant of C49S/C104S Hb-mu and solved its X-ray crystal structure. It adopts a typical protein fold of the globins, similar to that of the alpha-subunit. The structure also reveals that the protein undergoes self-oxidation of Met62 in the heme distal site, producing the form of sulfoxide (Met-SO). The property and function have also been studied by spectr...
