Light absorption can trigger biologically relevant protein conformational changes. The light-induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ‘proteinquake’ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations with a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.
|Numero di pagine||6|
|Stato di pubblicazione||Published - 2015|
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)
Cottone, G., Levantino, M., Cupane, A., Schirò, G., Lemke, H. T., Zhu, D., Glownia, J. M., Ihee, H., Chollet, M., & Cammarata, M. (2015). Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser. Nature Communications, 6.