Alteration of heme axial ligands in hemoglobin by organic solvents analyzed by CD, FTIR and XANES techniques - Sorbonne Université Access content directly
Journal Articles Biochemistry Year : 1991

Alteration of heme axial ligands in hemoglobin by organic solvents analyzed by CD, FTIR and XANES techniques

Abstract

The effects of mixed solvents on the ligand binding site in hemoglobin have been investigated though three spectroscopic techniques. Two classes of organic solvents (amides and alcohols) known to increase or decrease the hemoglobin affinity have been choosen for this study. The analysis of the iron CO stretching band shows that the ligand binding sites of aC0 and PCO subunits inside the a2& hemoglobin tetramer exhibit multiple conformations. From the circular dichroism and X-ray absorption near-edge structure data, it appears that no core deformation or heme reorientation occur with the affinity changes. The iron-ligand average bond angle is the sole parameter that depends on the external solvent. Since cosolvents seem to affect the dynamics rather than the hindrance of the heme cavity, we suggest that the protein affinity could be associated with a hierarchy of subtle dynamic states.

Dates and versions

hal-04559148 , version 1 (25-04-2024)

Identifiers

Cite

Christian Zentz, Said El Antri, Serge Pin, Robert Cortes, Alain Massat, et al.. Alteration of heme axial ligands in hemoglobin by organic solvents analyzed by CD, FTIR and XANES techniques. Biochemistry, 1991, 30 (11), pp.2804-2810. ⟨10.1021/bi00225a010⟩. ⟨hal-04559148⟩
3 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More