Uphill energy transfer in LH2-containing purple bacteria at room temperature

DC FieldValueLanguage
dc.contributor.authorTrissl, HW
dc.contributor.authorLaw, CJ
dc.contributor.authorCogdell, RJ
dc.date.accessioned2021-12-23T16:09:41Z-
dc.date.available2021-12-23T16:09:41Z-
dc.date.issued1999
dc.identifier.issn00052728
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/8934-
dc.description.abstractUphill energy transfer in the LH2-containing purple bacteria Rhodopseudomonas acidophila, Rhodopseudomonas palustris, Rhodobacter sphaeroides, Chromatium vinosum and Chromatium purpuratum was studied by stationary fluorescence spectroscopy at room temperature upon selective excitation of the B800 pigments of LH2 and the B880 pigments of LH1 at 803 nm and 900 nm, respectively. The resulting fluorescence spectra differed significantly at wavelengths shorter than the fluorescence maximum but agreed at longer wavelengths. The absorption spectra of the species studied were decomposed into five bands at approx. 800, 820, 830, 850 and 880 nm using the shapes of the absorption spectra of the LH1-RC only species Rhodospirillum rubrum and the isolated B800-850 complex from Rps. acidophila strain 10050 as guide spectra. This allowed a quantification of the number of pigments in each pigment group and, consequently, the antenna size of the photosynthetic unit assuming 36 bacteriochlorophyll a molecules in an LH1-RC complex. In most of the LH2-containing purple bacterial strains the number of LH2 rings per LH1-RC was less than the idealized number of eight (Papiz et al., Trends Plant Sci. 1 (1996) 198-206), which was achieved only by C. purpuratum. Uphill energy transfer was assayed by comparing the theoretical fluorescence spectrum obtained from a Boltzmann equilibrium with the measured fluorescence spectrum obtained by 900 nm excitation. The good match of both spectra in all the purple bacteria studied indicates that uphill energy transfer occurs practically up to its thermodynamically maximal possible extent, All strains studied contained a small fraction of either poorly connected or unconnected LH2 complexes as indicated by higher fluorescence yields from the peripheral complexes than predicted by thermal equilibration or kinetic modeling. This impedes generally the quantitative analysis of blue-excited fluorescence spectra. (C) 1999 Elsevier Science B.V. All rights reserved.
dc.language.isoen
dc.publisherELSEVIER SCIENCE BV
dc.relation.ispartofBIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
dc.subjectantenna size
dc.subjectBiochemistry & Molecular Biology
dc.subjectBiophysics
dc.subjectCHROMATIUM-TEPIDUM
dc.subjectEXCITATION-ENERGY
dc.subjectfluorescence yield
dc.subjectISOLATED B800-850
dc.subjectLH2
dc.subjectLIGHT-HARVESTING COMPLEX
dc.subjectPERIPHERAL ANTENNA
dc.subjectperipheral light harvesting complex
dc.subjectPHOTOSYNTHETIC BACTERIA
dc.subjectPIGMENT-PROTEIN COMPLEXES
dc.subjectpurple bacterium
dc.subjectRHODOBACTER-SPHAEROIDES
dc.subjectRHODOPSEUDOMONAS-ACIDOPHILA
dc.subjectRHODOSPIRILLUM-RUBRUM
dc.titleUphill energy transfer in LH2-containing purple bacteria at room temperature
dc.typejournal article
dc.identifier.doi10.1016/S0005-2728(99)00056-0
dc.identifier.isiISI:000081478500007
dc.description.volume1412
dc.description.issue2
dc.description.startpage149
dc.description.endpage172
dc.contributor.researcheridE-7174-2011
dc.publisher.placePO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
dcterms.isPartOf.abbreviationBiochim. Biophys. Acta-Bioenerg.
dcterms.oaStatusBronze
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