Abstract
Femtosecond time-resolved crystallography (TRC) on proteins enables resolving the spatial structure of short-lived photocycle intermediates. An open question is whether confinement and lower hydration of the proteins in the crystalline state affect the light-induced structural transformations. Here, we measured the full photocycle dynamics of a signal transduction protein often used as model system in TRC, Photoactive Yellow Protein (PYP), in the crystalline state and compared those to the dynamics in solution, utilizing electronic and vibrational transient absorption measurements from 100 fs over 12 decades in time. We find that the photocycle kinetics and structural dynamics of PYP in the crystalline form deviate from those in solution from the very first steps following photon absorption. This illustrates that ultrafast TRC results cannot be uncritically extrapolated to in vivo function, and that comparative spectroscopic experiments on proteins in crystalline and solution states can help identify structural intermediates under native conditions.
| Original language | English |
|---|---|
| Article number | 4248 |
| Pages (from-to) | 1-12 |
| Number of pages | 12 |
| Journal | Nature Communications |
| Volume | 11 |
| Issue number | 1 |
| Early online date | 25 Aug 2020 |
| DOIs | |
| Publication status | Published - 1 Dec 2020 |
Funding
This work was supported by the Dutch organization for scientific research NWO, through the divisions of Earth and Life Sciences (ALW) and Chemical Sciences (CW), through an Open Programme grant to M.L.G., Medium Large Investment grants to M.L.G., K.J.H. and J.T.M.K. P.K. and J.T.M.K. were supported by a NWO-VICI grant. The authors would like to thank Dr. S. Yeremenko for reuse of the PYP-TA datasets.