The Active Site Loop Modulates the Reorganization Energy of Blue Copper Proteins by Controlling the Dynamic Interplay with Solvent.
Understanding the factors governing the rate of electron transfer processes in proteins is crucial not only to a deeper understanding of redox processes in living organisms but also for the design of efficient devices featuring biological molecules. Here, molecular dynamics simulations performed on native azurin and four chimeric cupredoxins allow for the calculation of the reorganization energy and of structure-related quantities that were used to clarify the molecular determinants to the dynamics/function relationship in blue copper proteins. We find that the dynamics of the small, metal-binding loop region controls the outer-sphere reorganization energy not only by determining the exposure of the active site to solvent but also through the modulation of the redox-dependent rearrangement of the whole protein scaffold and of the surrounding water molecules.
Licia
L
Paltrinieri
Marco
M
Borsari
Antonio
A
Ranieri
Gianantonio
G
Battistuzzi
¶CNR-Nano Institute of Nanoscience, via Campi 213/A, 41125 Modena, Italy.
Stefano
S
Corni
¶CNR-Nano Institute of Nanoscience, via Campi 213/A, 41125 Modena, Italy.
Carlo Augusto
CA
Bortolotti
azurin; electron transfer; molecular dynamics; reorganization energy; solvent