Article
Distal histidine stabilizes bound O2 and acts as a gate for ligand entry in both subunits of adult human hemoglobin.
The Journal of biological chemistry - 19 Mar 2010
Birukou Ivan, Schweers Rachel L, Olson John S
Abstract excerpt
The role of the distal histidine in regulating ligand binding to adult human hemoglobin (HbA) was re-examined systematically by preparing His(E7) to Gly, Ala, Leu, Gln, Phe, and Trp mutants of both Hb subunits. Rate constants for O(2), CO, and NO binding were measured using rapid mixing and laser...
Topics
- Carbon Monoxide
- Hemoglobins
- Histidine
- Humans
- Hydrogen Bonding
- Imidazoles
- Kinetics
- Ligands
- Mutation
- Nitric Oxide
- Oxygen
- Phenylalanine
- Protein Binding
- Protein Conformation
- Thermodynamics