TY  - JOUR
A1  - Leupold, Dieter
A1  - Teuchner, Klaus
A1  - Ehlert, Jürgen
A1  - Irrgang, Klaus-Dieter
A1  - Renger, Gernot
A1  - Lokstein, Heiko
T1  - Stepwise two-photon excited fluorescence from higher excited states of chlorophylls in photosynthetic antenna complexes
Y1  - 2006
UR  - http://www.jbc.org/
U6  - https://doi.org/10.1074/jbc.M600080200
SN  - 0021-9258
ER  - 
TY  - JOUR
A1  - Lokstein, Heiko
A1  - Hoextermann, Ekkehard
A1  - Leupold, Dieter
A1  - Garab, Gyoezoe
A1  - Renger, Gernot
T1  - A tribute : Professor Dr. Paul Hoffmann (March 28, 1931-July 10, 2008), a scientist with a great collaborative spirit
Y1  - 2009
UR  - http://www.springerlink.com/content/100325
U6  - https://doi.org/10.1007/s11120-009-9414-6
SN  - 0166-8595
ER  - 
TY  - JOUR
A1  - Krikunova, Maria
A1  - Lokstein, Heiko
A1  - Leupold, Dieter
A1  - Hiller, Roger G.
A1  - Voigt, B.
T1  - Pigment-pigment interactions in PCP of Amphidinium carterae investigated by nonlinear polarization spectroscopy in the frequency domain
N2  - Peridinin-chlorophyll a-protein (PCP) is a unique antenna complex in dinoflagellates that employs peridinin (a carotenoid) as its main light-harvesting pigment. Strong excitonic interactions between peridinins, as well as between peridinins and chlorophylls (Chls) a, can be expected from the short intermolecular distances revealed by the crystal structure. Different experimental approaches of nonlinear polarization spectroscopy in the frequency domain (NLPF) were used to investigate the various interactions between pigments in PCP of Amphidinium carterae at room temperature. Lineshapes of NLPF spectra indicate strong excitonic interactions between the peridinin's optically allowed S-2 (1Bu(+)) states. A comprehensive subband analysis of the distinct NLPF spectral substructure in the peridinin region allows us to assign peridinin subbands to the two Chls a in PCP having different S-1-state lifetimes. Peridinin subbands at 487, 501, and 535 nm were assigned to the longer-lived Chl, whereas a peridinin subband peaking at 515 nm was detected in both clusters. Certain peridinin(s), obviously corresponding to the subband centered at 487 nm, show(s) specific (possibly Coulombic?) interaction between the optically dark S-1(2A(g)(-)) and/or intramolecular charge- transfer (ICT) state and S-1 of Chl a. The NLPF spectrum, hence, indicates that this peridinin state is approximately isoenergetic or slightly above S-1 of Chl a. A global subband analysis of absorption and NLPF spectra reveals that the Chl a Q(y)-band consists of two subbands ( peaking at 669 and 675 nm and having different lifetimes), confirmed by NLPF spectra recorded at high pump intensities. At the highest applied pump intensities an additional band centered at <= 660 nm appears, suggesting-together with the above results-an assignment to a low-dipole moment S-0-> S-1/ICT transition of peridinin
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Leupold, Dieter
A1  - Lokstein, Heiko
A1  - Scheer, Hugo
T1  - Excitation energy transfer between (bacterio)chlorophylls : the role of excitonic coupling
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Legall, Herbert
A1  - Stiel, Holger
A1  - Beck, Michael
A1  - Leupold, Dieter
A1  - Gruszecki, Wieslaw I.
A1  - Lokstein, Heiko
T1  - Near edge X-ray absorption fine structure spectroscopy (NEXAFS) of pigment-protein complexes : peridinin- chlorophyll a-protein (PCP) of Amphidinium carterae
N2  - Peridinin-chlorophyll a protein (PCP) is a unique water soluble antenna complex that employs the carotenoid peridinin as the main light-harvesting pigment. In the present study the near edge X-ray absorption fine structure (NEXAFS) spectrum of PCP was recorded at the carbon Kedge. Additionally, the NEXAFS spectra of the constituent pigments, chlorophyll a and peridinin, were measured. The energies of the lowest unoccupied molecular levels of these pigments appearing in the carbon NEXAFS spectrum were resolved. Individual contributions of the pigments and the protein to the measured NEXAFS spectrum of PCP were determined using a "building block" approach combining NEXAFS spectra of the pigments and the amino acids constituting the PCP apoprotein. The results suggest that absorption changes of the pigments in the carbon near K-edge region can be resolved following excitation using a suitable visible pump laser pulse. Consequently, it may be possible to study excitation energy transfer processes involving "optically dark" states of carotenoids in pigment-protein complexes by soft X-ray probe optical pump double resonance spectroscopy (XODR).
Y1  - 2007
UR  - http://www.sciencedirect.com/science/journal/0165022X
U6  - https://doi.org/10.1016/j.jbbm.2006.08.005
SN  - 0165-022X
ER  - 
TY  - JOUR
A1  - Gruszecki, Wieslaw I.
A1  - Stiel, H.
A1  - Niedzwiedzki, Dariusz
A1  - Beck, Michael
A1  - Milanowska, J.
A1  - Lokstein, Heiko
A1  - Leupold, Dieter
T1  - Towards elucidating the energy of the first excited singlet state of xanthophyll cycle pigments investigated by x-ray absorption spectroscopy
Y1  - 2005
ER  -