Determination of microscopic rate constants for CO binding and migration in myoglobin encapsulated in silica gels.
CO rebinding kinetics after nanosecond photolysis of myoglobin encapsulated in wet silica gels exhibits an enhanced geminate phase that allows the determination of the microscopic rate constants and the activation barriers for distinct ligand docking sites inside the protein matrix. Using a maximum entropy method, we demonstrate that the geminate phase can be well-described by a biphasic lifetime distribution, reflecting rebinding from the distal and proximal sites. Microscopic rates and activation barriers were estimated using a four-state model.
Sottini
Silvia
S
Dipartimento di Fisica, Università degli Studi di Parma, Parco Area delle Scienze 7/A, Università degli Studi di Parma, Parco Area delle Scienze 23/A, 43100 Parma, Italy.
Abbruzzetti
Stefania
S
Viappiani
Cristiano
C
Ronda
Luca
L
Mozzarelli
Andrea
A
D002248:Carbon Monoxide / Q000737:chemistry*; D003627:Data Interpretation, Statistical; D019277:Entropy; D007700:Kinetics; D008024:Ligands; D009211:Myoglobin / Q000737:chemistry*; D010782:Photolysis; D011485:Protein Binding; D058428:Silica Gel; D012822:Silicon Dioxide; D013696:Temperature
D008024:Ligands; D009211:Myoglobin; D058428:Silica Gel; D012822:Silicon Dioxide; D002248:Carbon Monoxide