Ultrafast optical spectroscopy of the electron transfer and protein dynamics in photosystem II [Elektronische Ressource] / vorgelegt von Malwina Szczepaniak

Malwina

Sujets

• Biologie

Informations

• Publié par: heinrich-heine-universitat_dusseldorf
• Publié le: 01 janvier 2009
• Nombre de lectures: 35
• Langue: Deutsch
• Poids de l'ouvrage: 10 Mo

Extrait

Ultrafast optical spectroscopy of the electron transfer
and protein dynamics in Photosystem II






Inaugural-Dissertation



zur Erlangung des Doktorgrades
der Mathematisch-Naturwissenschaftlichen Fakultät
der Heinrich-Heine-Universität Düsseldorf


vorgelegt von

Malwina Szczepaniak
aus Kościan






Düsseldorf/Mülheim an der Ruhr, December 2008
aus dem Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der
Ruhr



























Gedruckt mit der Genehmigung der
Mathematisch-Naturwissenschaftlichen Fakultät der
Heinrich-Heine-Universität Düsseldorf




Referent: Prof. Dr. Alfred R. Holzwarth
Koreferent: Prof. Georg Pretzler

Tag der mündlichen Prüfung: 28.01.2009
Contents

1 INTRODUCTION ...................................................................................................................................... 5
1.1 Photosynthesis ............................................................................................................................ 5
1.2 Photosynthetic complexes........................................................................................................... 6
1.3 Photosystem II core complex...................................................................................................... 7
1.3.1 PSII structure .................................................................................................................... 8
1.3.2 Processes in PSII............................................................................................................. 11
1.3.3 Energy trapping in PSII .................................................................................................. 12
1.3.4 Protein dynamics 13
1.4 Goals of the work...................................................................................................................... 14
2 MATERIALS AND METHODS 17
2.1 Experimental techniques........................................................................................................... 17
2.1.1 Time-correlated single photon counting (TCSPC).......................................................... 17
2.1.2 Synchroscan streak camera (SC)..................................................................................... 19
2.1.3 Excitation conditions for the time-resolved fluorescence measurements........................ 22
2.1.4 Chlorophyll a fluorescence induction ............................................................................. 23
2.2 Sample treatment ...................................................................................................................... 24
2.3 Data analysis............................................................................................................................. 26
2.3.1 Global analysis................................................................................................................ 26
2.3.2 Target analysis 26
2.3.3 Average lifetime of fluorescence 29
2.3.4 Calculation of the standard free energy.......................................................................... 29
3 CHARGE SEPARATION KINETICS IN INTACT PHOTOSYSTEM II CORE PARTICLES IS
TRAP-LIMITED. A PICOSECOND FLUORESCENCE STUDY...................................................... 31
3.1 Introduction............................................................................................................................... 31
3.2 Materials and methods.............................................................................................................. 33
3.3 Results....... 34
3.4 Kinetic modeling....................................................................................................................... 36
3.5 Discussion.. 38
3.6 Supporting materials................................................................................................................. 44
4 CHARGE SEPARATION, STABILIZATION, AND PROTEIN RELAXATION IN
PHOTOSYSTEM II PARTICLES WITH CLOSED REACTION CENTER .................................... 49
4.1 Introduction............................................................................................................................... 49
4.2 Materials and methods.............................................................................................................. 51
4.3 Results....... 53
4.4 Discussion.. 57
4.5 Conclusions 64
5 THE ROLE OF TYRD IN THE ELECTRON TRANSFER KINETICS IN PHOTOSYSTEM II... 65
5.1 Introduction 65
5.2 Materials and methods 67
5.3 Results....... 68
5.4 Discussion.. 72
5.5 Conclusions 76
5.6 Supporting materials................................................................................................................. 77

1
6 A PHOTOPROTECTION MECHANISM INVOLVING THE D BRANCH IN PHOTOSYSTEM 2
II CORES WITH CLOSED REACTION CENTERS...........................................................................81
6.1 Introduction...............................................................................................................................81
6.2 Materials and methods ..............................................................................................................84
6.3 Results........85
6.4 Discussion..87
7 PHOTOSYSTEM II CORE COMPLEXES WITH OPEN RC REVISITED – STREAK CAMERA
DATA..........................93
7.1 Introduction93
7.2 Materials and methods94
7.3 Results and discussion...............................................................................................................95
7.4 Conclusions98
8 CONCLUSIONS .......................................................................................................................................99
8.1 Energy and electron transfer processes .....................................................................................99
8.2 Protein dynamics.....................................................................................................................102
8.3 Charge separation mechanism in PSII with reduced Q .........................................................103 A
8.4 Photoprotection mechanism involves Chl triplet quenching by β-carotene ............................104
9 SUMMARY..............107
10 ZUSAMMENFASSUNG ........................................................................................................................109
REFERENCES................111
LIST OF PUBLICATIONS...........................................................................................................................117
ACKNOWLEDGMENTS .............................................................................................................................119


2 Abbreviations

β-DM n-dodecyl-β-D-maltoside
Car β-carotene
Chl chlorophyll
CS charge separation
CP chlorophyll-binding protein
cyt cytochrome
DAS decay-associated (emission) spectrum
DCM 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran
DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea
Phe or F phenylalanine
EET excitation energy transfer
ET electron transfer
EPR electron paramagnetic resonance
FeCN K [Fe(CN) ] 3 6
FTIR Fourier-transform infrared spectroscopy
FWHM full-width at half-maximum
IRF instrument response function (=PR)
MES 2-(N-morpholino)ethanesulfonic acid
MnCa manganese cluster 4
OD optical density
OEC oxygen-evolving complex
OPO optical parametric oscillator
Pheo pheophytin a
PQ pool plastoquinone pool
PSI Photosystem I
PSII Photosystem II
Q primary quinone electron acceptor A
Q secondary quinone electron acceptor B
PR prompt response (= IRF)
RC reaction center
RP radical pair
SAES species-associated (emission) spectrum
SC streak camera
SPT single photon timing
TCSPC time-correlated single photon counting
T. elongatus Thermosynechococcus elongatus
TMH transmembrane helix
Tyr or Y tyrosine
TyrD Tyrosine D of PSII (D2-Y160)
TyrZ Tyrosine Z of PSII (D1-Y161)
WT wild type


3
1 Introduction
1.1 Photosynthesis
Photosynthesis is one of the most important biological processes. Plants, algae and
photosynthetic bacteria convert the relatively easily accessible solar energy into chemical
energy in the form of organic compounds (for a review on photosynthesis see (1), or the
following books: (2;3) and many others, as well as the information present also in the Internet:
(4)). Oxygenic photosynthetic organisms have the ability to utilize carbon dioxide, release
molecular oxygen and produce carbohydrates from CO and H O. The most general equation 2 2
describing oxygenic photosynthesis can be written in the form:
light CO + H O ⎯⎯→⎯ O + [CH O] (1.1) 2 2 2 2
Photo-induced water splitting together with the associated electron and proton
transport step