Roles of Fe-Histidine bonds in stability of hemoglobin: Recognition of protein flexibility by Q Sepharose.

ABSTRACT: Using various mutants, we investigated to date the roles of the Fe-histidine (F8) bonds in cooperative O₂ binding of human hemoglobin (Hb) and differences in roles between α- and β-subunits in the α₂β₂ tetramer. An Hb variant with a mutation in the heme cavity exhibited an unexpected feature. When the β mutant rHb (βH92G), in which the proximal histidine (His F8) of the β-subunit is replaced by glycine (Gly), was subjected to ion-exchange chromatography (Q Sepharose column) and eluted with an NaCl concentration gradient in the presence of imidazole, yielded two large peaks, whereas the corresponding α-mutant, rHb (αH87G), gave a single peak similar to Hb A. The β-mutant rHb proteins under each peak had identical isoelectric points according to isoelectric f

SUBMITTER: Nagatomo S 

PROVIDER: S-EPMC8390899 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature