Hydrophobic distal pocket affects NO-heme geminate recombination dynamics in dehaloperoxidase and H64V myoglobin

The recombination dynamics of NO with dehaloperoxidase (DHP) from Amphitrite ornata following photolysis are measured by femtosecond time-resolved absorption spectroscopy. The analysis of ligand recombination in photolyzed DHP-NO and H64V Mb-NO has provided evidence for the vital role of the distal histidine in stabilizing the NO ligand in the docking site, which provides a barrier to recombination that is modulated by protein dynamics and temperature.