| Popis: |
Single molecule time traces (from fluorescence or force spectroscopy, nanopores, ion channels, etc.) provide unique information on the kinetic state sequence of the system under study.However, single molecule Foerster resonance energy transfer (smFRET) data is often used to uncover equilibrium distributions only, leaving the kinetic information unexploited. This is because of experimental limitations associated with smFRET, such as photo-bleaching, inter-fluorophore variation and the limited time window. Therefore, analysis tools beyond dwell-time histograms are required for smFRET time traces.Here we present a new maximum likelihood-based approach custom-tailored for experimental smFRET data. Our analysis tool handles multiple input traces, experimental inter-fluorophore variation, truly hidden states, and performs unbiased model selection. We demonstrate the robustness of rate determination and model selection on the basis of experimental and simulated data.Finally, we solve the kinetic state model for the complex conformational dynamics of the heat shock protein Hsp90 with unprecedented accuracy. This reveals novel insights into the effects of drug candidates, nucleotides and co-chaperones on Hsp90's kinetics. |
