Is there a Root effect in Xenopus hemoglobin?
The reaction of Xenopus hemoglobin with oxygen and carbon monoxide has been reinvestigated over the pH range 8.5-6.0, in the absence and presence of organic phosphates (2,3-diphosphoglycerate or inositol hexakisphosphate), to establish if the tetramer can be stabilized in a T-quaternary state by protons and polyphosphate; the equilibrium and kinetic data indicate that Xenopus hemoglobin does exhibit a Root effect. These new results are discussed with reference to those reported by Bridges et al. [(1985) Resp. Physiol. 61, 125-136] on Xenopus blood and, more generally, to the molecular definition and the structural basis of the Root effect as an extreme form of the Bohr effect.
D019794:2,3-Diphosphoglycerate; D000818:Animals; D002248:Carbon Monoxide / Q000097:blood*; D004163:Diphosphoglyceric Acids / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood*; D010833:Phytic Acid / Q000494:pharmacology; D014982:Xenopus laevis / Q000097:blood*
D004163:Diphosphoglyceric Acids; D006454:Hemoglobins; D019794:2,3-Diphosphoglycerate; D010833:Phytic Acid; D002248:Carbon Monoxide; D010100:Oxygen