dc.contributor.author
Shelaev, Ivan
dc.contributor.author
Gorka, Michael
dc.contributor.author
Savitsky, Anton
dc.contributor.author
Kurashov, Vasily
dc.contributor.author
Mamedov, Mahir
dc.contributor.author
Gostev, Fedor
dc.contributor.author
Möbius, Klaus
dc.contributor.author
Nadtochenko, Victor
dc.contributor.author
Golbeck, John
dc.contributor.author
Semenov, Alexey
dc.date.accessioned
2019-08-28T13:02:42Z
dc.date.available
2019-08-28T13:02:42Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/25376
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-4081
dc.description.abstract
The effect of dehydration on the kinetics of forward electron transfer (ET) has been studied in cyanobacterial photosystem I (PS I) complexes in a trehalose glassy matrix by time-resolved optical and EPR spectroscopies in the 100 fs to 1 ms time domain. The kinetics of the flash-induced absorption changes in the subnanosecond time domain due to primary and secondary charge separation steps were monitored by pump–probe laser spectroscopy with 20-fs low-energy pump pulses centered at 720 nm. The back-reaction kinetics of P700 were measured by high-field time-resolved EPR spectroscopy and the forward kinetics of A∙−1A/A∙−1B→FX by time-resolved optical spectroscopy at 480 nm. The kinetics of the primary ET reactions to form the primary P∙+700A∙−0 and the secondary P∙+700A∙−1 ion radical pairs were not affected by dehydration in the trehalose matrix, while the yield of the P∙+700A∙−1 was decreased by ~20%. Forward ET from the phylloquinone molecules in the A∙−1A and A∙−1B sites to the iron–sulfur cluster FX slowed from ~220 ns and ~20 ns in solution to ~13 μs and ~80 ns, respectively. However, as shown by EPR spectroscopy, the ~15 μs kinetic phase also contains a small contribution from the recombination between A∙−1B and P∙+700. These data reveal that the initial ET reactions from P700 to secondary phylloquinone acceptors in the A- and B-branches of cofactors (A1A and A1B) remain unaffected whereas ET beyond A1A and A1B is slowed or prevented by constrained protein dynamics due to the dry trehalose glass matrix.
en
dc.format.extent
21 Seiten
dc.rights.uri
http://www.fu-berlin.de/sites/refubium/rechtliches/Nutzungsbedingungen
dc.subject
electron transfer
en
dc.subject
optical spectroscopy
en
dc.subject
photosystem I
en
dc.subject
trehalose matrix
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
dc.title
Effect of Dehydrated Trehalose Matrix on the Kinetics of Forward Electron Transfer Reactions in Photosystem I
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1515/zpch-2016-0860
dcterms.bibliographicCitation.journaltitle
Zeitschrift für physikalische Chemie
dcterms.bibliographicCitation.number
2
dcterms.bibliographicCitation.pagestart
325
dcterms.bibliographicCitation.pageend
345
dcterms.bibliographicCitation.volume
231
dcterms.bibliographicCitation.url
https://doi.org/10.1515/zpch-2016-0860
refubium.affiliation
Physik
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.issn
0942-9352
dcterms.isPartOf.eissn
2196-7156