Hartawan Laksmono

TL;DR: Time resolved experiments on PSII nano/microcrystals from Thermosynechococcus elongatus performed with the recently developed technique of serial femtosecond crystallography provide evidence that PSII undergoes significant conformational changes at the electron acceptor side and at the Mn4CaO5 core of the OEC.

TL;DR: It is demonstrated that femtosecond X-ray laser pulses can be used to probe the structure of liquid water in micrometre-sized droplets that have been evaporatively cooled below TH, and experimental evidence is found for the existence of metastable bulk liquid water down to temperatures of kelvin in the previously largely unexplored no man’s land.

TL;DR: This simultaneous XRD-XES study shows that the PS II crystals are intact during measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation-sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies.

TL;DR: Ammonia, a water analogue, has been used as a marker, as it binds to the Mn4CaO5 cluster in the S2 and S3 states, and this approach, together with a comparison of the native dark and 2F states, is used to discriminate between proposed O–O bond formation mechanisms.

TL;DR: The spectra show that the initial O-O bond formation, coupled to Mn-reduction, does not yet occur within 250 μs after the third flash, and the initial frames in a molecular movie of the structural changes during the catalytic reaction in photosystem II are represented.