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Publié par | heinrich-heine-universitat_dusseldorf |
Publié le | 01 janvier 2008 |
Nombre de lectures | 37 |
Poids de l'ouvrage | 7 Mo |
Extrait
ON THE MECHANISMS
OF NONPHOTOCHEMICAL QUENCHING
IN PLANTS AND DIATOMS
Inaugural‐Dissertation
zur
Erlangung des Doktorgrades der
Mathematisch‐Naturwissenschaftlichen Fakultät
der Heinrich‐Heine‐Universität Düsseldorf
vorgelegt von
Yuliya Miloslavina
aus Valujki
November 2008 Aus dem Max‐Planck‐Institut für Bioanorganische Chemie Gedruckt mit der Genehmigung der Mathematisch‐Naturwissenschaftlichen Fakultät der Heinrich‐Heine‐Universität Düsseldorf Referent: Prof. Dr. A.R. Holzwarth Koreferent: Prof. Dr. K. Kleinermans Tag der mündlichen Prüfung: 28. November 2008
Life is a miracle
For my dear parents and for you,
with gratitudeTABLE OF CONTENTS
SUMMARY ...................................................................................................................................................................8 ZUSAMMENFASSUNG ................. 11 ABBREVIATIONS AND SYMBOLS............................................................. 14
CHAPTER 1. INTRODUCTION INTO PHOTOSYNTHESIS .................................................... 17 PIGMENTS ...................................................................................................................................................... 18
Chlorophylls ......................................................................................................................................... 18
Carotenoids ........... 19
Binding of pigments.......................................................................................................................... 21 THYLAKOID MEMBRANE IN HIGHER PLANTS ............................................................................................. 21 PHOTOSYSTEM I ............................................................................................................................................ 23 PHOTOSYSTEM II ........................................................................... 25
Photosystem II core .......................................................................................................................... 25
PS II supercompex ............................................................................................................................. 26
PS II kinetics ......................................................................................................................................... 28
Exciton/radical pair equilibrium model .................................................................................. 28
Other models ......... 29
CHAPTER 2. INTRODUCTION INTO NONPHOTOCHEMICAL QUENCHING
PROCESSES ........ 31 ΔPH ................................................................................................................................................................ 33 XANTHOPHYLL CYCLE .................................................................... 33 PSBS PROTEIN ................................................................................. 35 MAJOR LIGHT‐HARVESTING ANTENNA OF PS II (LHC II) ..................................................................... 36 MINOR LIGHT‐HARVESTING COMPLEXES ................................................................................................... 38 PRESENT HYPOTHESES FOR THE QE QUENCHING MECHANISM .............................................................. 3 9
Zeaxanthin as a direct quencher ................................................................................................. 39
PsbS as a direct quencher .............................................................................................................. 39
Minor antenna as the site of qE ................................................................................................... 40
Conformational change in LHC II ............................................................................................... 40
PS II RC is the site of qE ................................................................................................................... 41 NON‐PHOTOCHEMICAL QUENCHING IN DIATOMS ..................................................................................... 41
CHAPTER 3. MAIN AIMS OF THE THESIS ............................................................................... 45 SUMMARY OF OPEN QUESTIONS .................................................................................................................. 48 5CHAPTER 4. MATERIALS AND METHODS .............................................................................. 49 SINGLE PHOTON TIMING ............................................................................................................................. 49
The principle of single photon timing ........................................................................................ 49
Laser system ......................................................................................................................................... 52
Detection electronics ........................................................................................................................ 52
Data analysis ......... 53 PREPARATION AND CHARACTERIZATION OF SAMPLES ............................................................................ 57
PS II core particles from cyanobacteria ................................................................................... 57
PS II enriched membranes (BBYs) .............................................................................................. 58
LHC II trimers and aggregates ..................................................................................................... 59
Arabidopsis thaliana plants ........................................................................................................... 60
Fluorescence kinetics ........................................................................................................................ 62
Diatoms ................................................................................................................................................... 64
CHAPTER 5. CHARGE SEPARATION KINETICS IN PHOTOSYSTEM II CORE
PARTICLES ......... 67 RESULTS ........................................................................................................................................................ 67
Fluorescence decay kinetics ........................................................................................................... 67
Kinetic Modeling ................................................................................................................................. 69 DISCUSSION ...................... 72
Kinetic model ......... 72
Traplimit versus transfertothetrap limit ........................................................................... 75 CONCLUSIONS ............................................................................................................................................... 77
CHAPTER 6. ENERGY TRANSFER AND CHARGE SEPARATION KINETICS IN
PHOTOSYSTEM II ENRICHED MEMBRANE PARTICLES ..................................................... 79 RESULTS ........................................................................................................................................................ 79
Fluor