biostudies-literatureDavis KMNCRR NIH HHSNIGMS NIH HHS9161-9https://www.ebi.ac.uk/biostudies/studies/S-EPMC3897202biostudies-literatureUnknown117(31)It is well-known that biological samples undergo X-ray-induced degradation. One of the fastest occurring X-ray-induced processes involves redox modifications (reduction or oxidation) of redox-active cofactors in proteins. Here we analyze room-temperature data on the photoreduction of Mn ions in the oxygen-evolving complex (OEC) of photosystem II, one of the most radiation damage-sensitive proteins and a key constituent of natural photosynthesis in plants, green algae, and cyanobacteria. Time-resolved X-ray emission spectroscopy with wavelength-dispersive detection was used to collect data on the progression of X-ray-induced damage. A kinetic model was developed to fit experimental results, and the rate constant for the reduction of OEC Mn(III) and Mn(IV) ions by solvated electrons was deteThe journal of physical chemistry. BKinetic modeling of the X-ray-induced damage to a metalloprotein.PMC3897202P41 RR0077075P41RR007707P41 GM103543R24 GM1110728P41GM103543Henning RWSeidler GTPushkar YDavis KMKosheleva IfalseKinetic modeling of the X-ray-induced damage to a metalloprotein.It is well-known that biological samples undergo X-ray-induced degradation. One of the fastest occurring X-ray-induced processes involves redox modifications (reduction or oxidation) of redox-active cofactors in proteins. Here we analyze room-temperature data on the photoreduction of Mn ions in the oxygen-evolving complex (OEC) of photosystem II, one of the most radiation damage-sensitive proteins and a key constituent of natural photosynthesis in plants, green algae, and cyanobacteria. Time-resolved X-ray emission spectroscopy with wavelength-dispersive detection was used to collect data on the progression of X-ray-induced damage. A kinetic model was developed to fit experimental results, and the rate constant for the reduction of OEC Mn(III) and Mn(IV) ions by solvated electrons was dete2013-01-01T00:00:00Z2013 Aug2025-04-03T23:01:49.253Z2019-03-27T01:20:19ZS-EPMC38972022381580910.1021/jp403654n