Energy transfer within pc trimers of mastigocladus laminosus studied by picosecond time-resolved transient absorption spectroscopy

Schneider, Siegfried; Geiselhart, P.; Siebzehnrübl, S.; Fischer, Richard W.; Scheer, Hugo

doi:10.1515/znc-1988-1-213

Cited by 14 publications

(6 citation statements)

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“…The decrease in the lifetimes with increasing aggregation can be understood from the increased number of possible acceptor molecules for each donor in the higher aggregates. Kinetics in full agreement with these data was observed by picosecond absorption for monomers and trimers of C-PC (Sandstrom et al 1988a;Gillbro et al 1987;Schneider et al 1988). The anisotropy relaxation closely followed the isotropic lifetimes.…”

Section: C-phycocyanin and Allophycocyaninsupporting

confidence: 71%

Applications of ultrafast laser spectroscopy for the study of biological systems

Holzwarth

1989

Quart. Rev. Biophys.

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The discovery of mode-locked laser operation now nearly two decades ago has started a development which enables researchers to probe the dynamics of ultrafast physical and chemical processes at the molecular level on shorter and shorter time scales. Naturally the first applications were in the fields of photophysics and photochemistry where it was then possible for the first time to probe electronic and vibrational relaxation processes on a sub-nanosecond timescale. The development went from lasers producing pulses of many picoseconds to the shortest pulses which are at present just a few femtoseconds long. Soon after their discovery ultrashort pulses were applied also to biological systems which has revealed a wealth of information contributing to our understanding of a broadrange of biological processes on the molecular level.It is the aim of this review to discuss the recent advances and point out some future trends in the study of ultrafast processes in biological systems using laser techniques. The emphasis will be mainly on new results obtained during the last 5 or 6 years. The term ultrafast means that I shall restrict myself to sub-nanosecond processes with a few exceptions.

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Section: C-phycocyanin and Allophycocyaninsupporting

confidence: 71%

Applications of ultrafast laser spectroscopy for the study of biological systems

Holzwarth

1989

Quart. Rev. Biophys.

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“…This is qualitatively expected since the number of possible pairwise energy transfer paths increases in parallel. Similar energy transfer lifetimes, although varying considerably with detection wavelengths, were subsequently reported also from picosecond transient absorption measurements (Sandstrom et al 1988a, Schneider et al, 1988, , from analysis of the DAS and application of the appropriate kinetic model based on the X-ray structure, assigned the shortest lifetimes, ranging from 50 ps iti monomers to 10 ps in hexamers, to the energy transfer from the group of/9155 chromophores to the two other groups. The ^155 chromophores have the shortest wavelength in absorption and were thus termed sensitizing (s) chromophores.…”

Section: Energy Transfer Kinetics and Mechanismssupporting

confidence: 68%

Structure‐function relationships and energy transfer in phycobiliprotein antennae

Holzwarth

1991

Physiologia Plantarum

106

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The present understanding of how interactions between chromophore and protein as well as between chromophore and chromophore in different aggregation states influence the spectral and excited state kinetic properties of phycobiliprotein antenna pigments is discussed. Properties of isolated phycobiliproteins from both cyanobacteria and red algae as well as from cryptophytes and of intact phycobilisomes are covered. The experimental results are discussed in terms of general principles for chromophore coupling and energy transfer. Some controversial topics in this field are outlined.

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“…This is much faster than the reported experimental values of 20 to 36 ps from fluorescence relaxation [22,25] or the values of 21 to 48 ps from absorption transient measurements [23,26,27]. In fact, the calculated fast relaxation times are at [26] or beyond [24] the expected limits of time resolution for the experimental results reported to date [24,26].…”

Section: (Aft ) 3-trimermentioning

confidence: 70%

Excitation transfer in C-phycocyanin. Förster transfer rate and exciton calculations based on new crystal structure data for C-phycocyanins from Agmenellum quadruplicatum and Mastigocladus laminosus

Sauer

Scheer²

1988

Biochimica et Biophysica Acta (BBA) - Bioenergetics

127

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F~rs:er mechanlsm; ExcitonCalculations of excitation tra~er rates among the chr,mmphores of C-phycocyanin using the F6rster inductive resonance transfer mechanism have been carried out using the new coordinates for the pesition and ovlentation of the dn-omophores (Schirmer, T., Bode, W. and Hubor, R. (1967) J. Mol. Biol. 196, 677-69b'). Several of the rate constants are significantly altered from the results of oor calculations using the previously published emmlinates (Sauer, K., Scheer, H. and Sauer, P. (1987) Photochem. Photoblol. 46, 427-4d0). Ill partiolllar, for the (a/~)3-trimers of Mastigoclmtm/am/Iosm or for the (al0)3-trimels or the (~8)¢hexamers of Agmn~,llmn ~adr~icatm~ the new calculations predict excited state relaxation components with exponential time constants shorter than 1 ps. In fact, some of the interactions are so strong that exeiton coupling is probably the relevant mechanism of interaction. The largest exciton energy is calculated to be about 56 an -I, for the imeracfion betweea the adjacent a84 and ~84 ehromophores of neighboring monomer units within the (a~)3.triaters or (aB)¢hexamers. An energy transfer model invoking a combination of pairwlse exciton formation followed by slower Fc~rster transfer steps is described. that transfer excitation to it with an efficiency of 95~ or greater and in a time that is much shorter than the lifetime (a few nanoseconds) of the excited state in the absence of trapping [1]. A model, known as the Pebble Mosaic Model, was developed to describe this excitation transfer process [2]. It is based on the knowledge that most photosynthetic pigments (chromophores) occur in welldefined associations with proteins and that these pigment proteins occur in organized arrays with respect to the embedded reaction centers in photosynthetically active membranes [3]. In the Pebble Mosaic Model excitation is considered to appear in collective excited states (excitons) that encompass all of the chromophores that interact with 0005-2728/88/$03.50

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Energy transfer within pc trimers of mastigocladus laminosus studied by picosecond time-resolved transient absorption spectroscopy

Cited by 14 publications

References 0 publications

Applications of ultrafast laser spectroscopy for the study of biological systems

Applications of ultrafast laser spectroscopy for the study of biological systems

Structure‐function relationships and energy transfer in phycobiliprotein antennae

Excitation transfer in C-phycocyanin. Förster transfer rate and exciton calculations based on new crystal structure data for C-phycocyanins from Agmenellum quadruplicatum and Mastigocladus laminosus

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