Influence of Zinc Ions on the Geminal and Bimolecular Stages of the Horse-Myoglobin Oxygenation
Abstract
The kinetics of nanosecond geminal recombination and bimolar association of molecular oxygen with the horse-heart myoglobin has been investigated by laser flash photolysis. The influence of Zn(II) ions on the dioxygenation and rebonding of myoglobin to a ligand has been considered. The kinetics of the geminal recombination was analyzed within the framework of the model of four states with a side path of ligand motion in the protein matrix. It is shown that an increase in the affinity of myoglobin to O2 in the presence of Zn(II) ions is predominantly caused by an increase in the rate constant of recombination of molecular oxygen from the primary intraprotein site.
- Publication:
-
Journal of Applied Spectroscopy
- Pub Date:
- September 2005
- DOI:
- 10.1007/s10812-005-0141-2
- Bibcode:
- 2005JApSp..72..735L
- Keywords:
-
- myoglobin;
- molecular oxygen;
- geminal and bimolecular recombination;
- zinc ion