Name: Prof. dr. Rienk van Grondelle Room: s-162 Mail: r.van.grondelle@vu.nl Telephone : +31 20 59 87930 University : VU Amsterdam (website) Department: Biofysica (website) |
The VU-Biophysics research group, started by me in 1988, is the world leading group in the study of the primary processes in photosynthesis using laser- and other spectroscopic tools. There is no group in the world who has contributed so much to our current understanding of the light-harvesting and charge separation processes in photosynthesis. We have successfully applied and further developed ultrafast and other laser-spectroscopic techniques to understand the process of photosynthetic light-harvesting and charge separation on the basis of the underlying physics. In addition to applying state-of-the-art techniques we have developed important new experimental tools such as multi-pulse-, visible-pump-midIR-, stark-, and time-resolved single molecule emission spectroscopy. We are the world leading group in the development and application of global- and target-analysis techniques to analyze complex multi-dimensional data. This has directly led to our successful attempts to understand photosynthetic light-harvesting and charge separation at the level of the intact thylakoid membrane. We made essential contributions to the development of the disordered exciton/Redfield relaxation model that explains the complex phenomenology of photosynthetic light-harvesting. On the basis of these achievements we could recently identify the major component in the process of energy dissipation in photosynthesis. Recently, in the Netherlands a major research program Towards BioSolar Cells was initiated (42 MEuro), partly inspired by this work.
Light-harvesting:
My group has unravelled the physics of photosynthetic excitation energy transfer. Our contributions include the
spectroscopic characterization of bacterial LHs, the first pump probe experiments on bacterial membranes, our
study of the bacterial light-harvesting building block, the report of exciton equilibration, the observation of
exciton-vibrational wave-packets, the measurement of superradiance in bacterial and plant LHs, the
characterization of the energy transfer function of the major plant light-harvesting complex LHCII, of
Photosystem I and the core-antenna and reaction centre of Photosystem II. We developed the disordered exciton
model to understand the spectroscopy of bacterial and plant light-harvesting complexes and reaction centres,
which was extended to include the (modified) Redfield theory to describe exciton relaxation and energy
transfer.We include charge transfer states and the process of charge separation in reaction centres. The ambition is
to extend the model to more complex structures, eventually modelling a plant/bacterial photosynthetic membrane.
We initiated single molecule fluorescence microscopy with the aim to watch dynamic fluctuations of the
emission of single bacterial LHs. We recently extended these experiments to the plant LHs. We have applied a
combination of spectroscopic and various microscopic techniques (electron microscopy, AFM) to investigate the
large scale organization of the photosynthetic membrane. By using polarized light-spectroscopy we could
demonstrate the large scale organization of the RC-LH1 complexes in the membrane of Rb. Sphaeroides. We
were the first to obtain an AFM picture of the membrane of Rb. Sphaeroides. The AFM results together with the
polarized light spectroscopy led to a detailed model for the organization of this photosynthetic membrane.
Light-driven charge separation:
We have made major contributions in understanding the process of primary charge separation, in particular in the
reaction center of Photosystem II. We developed the multimer-model to describe the spectroscopy and charge
separation in the PSII RC. We collected important spectroscopic data to describe charge separation and
fluorescence of the PSII RC. We discovered new pathways for charge separation involving the monomeric
chlorophyll in the active branch. Using visible-pump-midIR-probe, we could prove that charge separation in the
PSII RC is initiated on the accessory Chl in the PSII RC. Based on the Stark effect on PS2RCs we proposed that
more than one charge separation pathway may be operative, dependent on the realization of the disorder.
Carotenoids:
We have identified new electronic excited states in carotenoids incorporated in the light-harvesting antenna
complexes of photosynthetic bacteria. In the spirilloxanthin containing LH1 antenna of the purple bacterium Rs.
Rubrum, following carotenoid excitation a new excited state was discovered, labelled S*, that is a precursor for
very efficient triplet formation. Later we could demonstrate the formation of the same S*-state in the LH2 of
antenna of Rb. Sphaeroides, but in this case S*, apart from forming triplets, also contributed to the high energy
transfer efficiency in these LH-systems. Today, S* is an accepted part of the complexity of carotenoid excited
states, not only in photosynthetic systems but also in artificial photosynthetic constructs.
Non-photochemical quenching:
We showed that in LHCII the most likely site of quenching is the Chl a610-611-612 trimer, where most of the
excitations become localized within 10-20 ps after excitation. This suggests that Chl-to-Car energy transfer occurs
via one of the low-lying electronic states of the lutein carotenoid, that in the structure of LHCII is closely
associated with these three chlorophylls. In covalently-linked Phthalocyanin-Carotenoid dyads, we could
quantitatively demonstrate that the quenching of the Phthalocyanin excited state occurred via the population of the
carotenoid S1 state. Similarly in aggregates of LHCII the Chl excited state decays via a carotenoid excited state,
most likely of lutein 1 in contact with the Chl 610-611-612 trimer. For the first time a molecular mechanism was
identified that quantitatively could explain NPQ. In cyanobacteria, grown under iron stress, the pigment-protein
IsiA accumulates. We showed that IsiA forms strongly quenched aggregates. Using ultrafast spectroscopy and
broadband detection we could show that also in these IsiA-aggregates quenching occurs via the transient
population of a carotenoid excited state.
I have published in total 435 scientific papers in peer-reviewed scientific journals, amongst which Nature, Proc.Natl Acad Sci USA, Biophys. J, J. Phys Chem, Biochemistry, etc. Among them a few highly cited reviews (BBA 94, J Phys Chem 99). In total this work has attracted more than 15000 citations and consequently belongs to the best cited research in biophysics. I am the co-author of three frequently used textbooks, two on Environmental Physics, the third on Photosynthetic Excitons. Since 1999 I have received 141 invitations to speak on international conferences (amongst which 9 Gordon conferences) and international workshops. Since 99 I have given 44 invited colloquia all over the globe. Since 1999 I have attracted M 8.6 from various sources (NWO, EU, HFSP) to fund my research. In 2001 I was elected as a member of the Royal Netherlands Academy of Arts and Sciences, in 2005 I obtained a honorary doctorate from the University in Lund (Sweden), in 2006 I was elected as a foreign member of the Lithuanian Academy of Sciences and in 2007 I was selected for a Chaire Blaise Pascal, Ile de France. In 2009 I was appointed as Academy Professor , by the Royal Netherlands Academy of Arts and Sciences. I am on the editorial board of 6 journals in my area of science and an associate editor of Photosynthesis Research. My research group is the major partner in the VU-Lasercenter, a European Access facility, part of Laserlab Europe which recently became the Amsterdam Institute for Laserscience and Biomedical Photonics.
In total 52 students graduated under my supervision, while since 99 29 post docs have successfully worked with me. Seventeen of those PhD/Postdocs now hold a professor position at a university in the Netherlands (5), Switzerland (1), India (1), Canada (3), Russia (1), Poland (1), USA (2), Italy (1), Finland (1) and Lithuania (1). Twenty-three are active in scientific research (University, Research Institute, Industry), ten have a career in medical/clinical physics in the Netherlands, five found a position as a teacher in physics/chemistry. The others found jobs in commerce, government, science policy, arts etc.
About ten years ago I started to collaborate with prof K.J. Hellingwerf in the area of photoactive proteins. This research has been highly successful and the VU-Biophysics group is viewed as one of the key players in this area. More recently I have initiated projects in the field of biomedical imaging with lasers.
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25 years of photosynthesis research |
De Groene Amsterdammer |
Radio 5 |
130x Looking Further |
ERC Advanced Grant |
Academy Professor Prize |
How to survive 2050 |
Harvesting light: 25 years of photosynthesis research at Biophysics VU Amsterdam On December 6 Rienk van Grondelle will celebrate his 63rd birthday. But more important to Rienk is that he is now more than 25 years professor in Biophysics at the VU University Amsterdam. On these two occasions we are organizing a symposium on Thursday December 6 and Friday December 7, 2012. Go to www.harvestinglight.org Interview with De Groene Amsterdammer (dutch) - The 10 biggest breakthroughs in science 89 Dutch beta-scientists discuss the most important developments in their field, the breakthroughs that they expect, and the value of their science to the society. Go to the interview with De Groene Amsterdammer Radio 5 (dutch) - Hoe?Zo!Wetenschapscafé Fotosynthese is de motor van moeder aarde. Door dit proces beter te begrijpen kunnen we misschien wel van de natuur afkijken hoe we een effectieve zonnecel kunnen maken. Biofysicus Rienk van Grondelle houdt zich als KNAW Akademiehoogleraar al jarenlang bezig met dit complexe proces. Go to Hoe?Zo!Wetenschapscafé 130x Looking Further To celebrate VU University Amsterdam's 130th anniversary, we present a special book: 130x Looking Further. In this book, we look further into the future, and deeper into the essential values of our university. It isa book in which we reflect on the values that lie at the very heart of our academic and societal endeavours. Go to 130x Looking Further (page 12-17) ERC Advanced Grant Prof. Rienk van Grondelle received an ERC Advanced Grant of almost 3 million euro, which will fund his research into the role chlorophyll-binding proteins play in determining the success of photosynthesis. See also: Prestigious ERC Advanced Grant to Professor of Biophysics Rienk van Grondelle See also: ERC Advanced Grants for Laserlab researchers Academy Professor Prize Rienk van Grondelle has been awarded an Academy Professorship for his outstanding contributions to the understanding of the first stage in photosynthesis. He has very successfully approached this field of research from a biophysical perspective, and has established one of the leading research groups in the world in this field. More specifically, Grondelle's unique contribution has been to carry out pioneering research at the junction of biology, physics, and chemistry. By using new laser-based technology, Rienk van Grondelle's group was the first to highlight the very rapid molecular process by which plants harvest as much sunlight as possible without suffering damage as a result. The pigment that absorbs the light appears to transfer excessive energy to another pigment, where it is converted into warmth and disappears without causing any damage. See also: Academy Professorships Programme 2009 See also: Rienk van Grondelle Akademieprof (Dutch) See also: Lichtbrandstof (Dutch) |
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