Role of β/δ101Gln in regulating the effect of temperature and allosteric effectors on oxygen affinity in woolly mammoth hemoglobin.

ABSTRACT: The oxygen affinity of woolly mammoth hemoglobin (rHb WM) is less affected by temperature change than that of Asian elephant hemoglobin (rHb AE) or human normal adult hemoglobin (Hb A). We report here a biochemical-biophysical study of Hb A, rHb AE, rHb WM, and three rHb WM mutants with amino acid substitutions at β/δ101 (β/δ101Gln→Glu, Lys, or Asp) plus a double and a triple mutant, designed to clarify the role of the β/δ101 residue. The β/δ101Gln residue is important for responding to allosteric effectors, such as phosphate, inositol hexaphosphate (IHP), and chloride. The rHb WM mutants studied generally have higher affinity for oxygen under various conditions of pH, temperature, and salt concentration, and in the presence or absence of organic phosphate, than do rHb WM, rHb AE, and Hb A

SUBMITTER: Yuan Y 

PROVIDER: S-EPMC3946332 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature