Single electron transfer events and dynamical heterogeneity in the small protein azurin from Pseudomonas aeruginosa.

ABSTRACT: Monitoring the fluorescence of single-dye-labeled azurin molecules, we observed the reaction of azurin with hexacyanoferrate under controlled redox potential yielding data on the timing of individual (forward and backward) electron transfer (ET) events. Change-point analysis of the time traces demonstrates significant fluctuations of ET rates and of mid-point potential E ₀. These fluctuations are a signature of dynamical heterogeneity, here observed on a 14 kDa protein, the smallest to date. By correlating changes in forward and backward reaction rates we found that 6% of the observed change events could be explained by a change in midpoint potential, while for 25% a change of the donor-acceptor coupling could explain the data. The remaining 69% are driven by variations i

SUBMITTER: Pradhan B 

PROVIDER: S-EPMC8146731 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature