CMSP Webinar (Atomistic Simulation Seminar Series) 05 Oct 11:00 CET, Prof. Tjaart Krüger

[CMSP Seminars Secretariat]

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CMSP Webinar (Atomistic Simulation Seminar Series)
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** * * Wednesday**, 5 October 2022, 11:00**CET* * **
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/Zoom registration link/: 
https://zoom.us/meeting/register/tJcvdOCtrz8uGNOOWXka0xuyKqDd9L6X2UfZ**

Speaker: ***Tjaart Krüger *(University of Pretoria, South Africa)

Title: *Single-molecule spectroscopy of photosynthetic light-harvesting 
complexes

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Abstracts:
Photosynthetic light-harvesting complexes have to balance two vital 
functions: efficient light harvesting and efficient energy dissipation. 
The former occurs under low levels of solar radiation, during which the 
absorbed photoenergy is converted into chemical energy with near-unity 
quantum efficiency. The latter, finely tuned photoprotective function 
serves to safely remove excess absorbed energy to limit photodamage. The 
nature of both functions is a subject of intense research. The 
light-harvesting proteins commonly coordinate numerous chromophores in a 
dense arrangement, resulting in complex, coupled energy-transfer 
mechanisms. Consequently, transitions between the light-harvesting and 
photoprotective functions often involve only subtle protein 
conformational changes, i.e., the population equilibrium between 
different conformational states of light-harvesting proteins is often 
very sensitive to the protein’s local environment. Single-molecule 
spectroscopy uniquely allows one to monitor protein functional switches 
in real time, to explore the protein conformational landscapes, and to 
unravel the underlying photophysical processes. In this webinar I will 
show how the intrinsic disorder of photosynthetic proteins is regulated 
by their local environments, allowing them to switch between different 
light-harvesting and photoprotective states. The unstable equilibrium 
between different functional states can be finely tuned by the incident 
photon flux1, pH2, chromophore arrangement3, and interaction with 
accessory proteins4. Examples of environmentally controlled 
conformational switching, as assessed by single-molecule spectroscopy, 
will be given for light-harvesting complexes of plants, cyanobacteria, 
and diatoms.
/References/
/1.    Gwizdala et al. J Am Chem Soc 138 (36): 11616-11622 (2016).//
//2.    Krüger et al. Biophys J 102: 2669–2676 (2012).//
//3.    Krüger et al. Proc Natl Acad Sci USA, 108:13516-13521 (2011); 
Krüger et al. Proc Natl Acad Sci USA 114: E11063-E11071 (2017).//
//4.    Gwizdala et al. J Phys Chem Lett 9:2426-2432 (2018)./

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CMSP Seminars support:OnlineCMSP at ictp.it  

CMSP, Condensed Matter & Statistical Physics Section
http://www.ictp.it/research/cmsp.aspx

The Abdus Salam International Centre for Theoretical Physics
https://www.ictp.it/

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CMSP, Condensed Matter & Statistical Physics Section
http://www.ictp.it/research/cmsp.aspx

The Abdus Salam International Centre for Theoretical Physics
https://www.ictp.it/

CMSP Seminars support:OnlineCMSP at ictp.it  
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