Poster Presentation 2014 International Biophysics Congress

Tuneable light harvesting and folding of a photosynthetic antennae protein - insights into photoprotection (#401)

Alistair J. Laos 1 2 3 , Paul M.G. Curmi 2 , Pall Thordarson 1 3
  1. School of Chemistry, The University of New South Wales, Sydney, NSW, Australia
  2. School of Physics, The University of New South Wales (UNSW), Sydney, Australia
  3. ARC Centre of Excellence in Coherent Bio-Nano Science and Technology, The University of New South Wales, Sydney, NSW, Australia

The ability to mimic photosynthetic processes would lead to an abundance of energy and support environmental sustainability. This study has attempted to further understanding of the light harvesting and photoprotection mechanisms of some of our earliest photosynthetic ancestors, cryptophyte algae. It has been shown that the cryptophyte light harvesting antennae complex PE545 is able to transfer energy via an ultrafast mechanism known as quantum coherence that cannot be accounted for by the Förster model[1,2,3]. Whether or not quantum coherence leads to greater efficiencies in light harvesting remains under debate, and further what role it may play in photosynthesis remains to be elucidated. Interestingly, cryptophyte algae evolved to no longer use the highly ordered, stromal located phycobilisome superstructure of their red algae ancestors. Rather, utilizing water soluble proteins located in the lumen space, an area normally reserved for water splitting and the biochemistry of photosynthetic machinery including proton pumping by ATPase. This raises two fundamental questions; why evolve from the highly ordered and efficient phycobilisome superstructure to seemingly unordered PE545 proteins located in the lumen? Further D

This work investigates the effect of pH on the light harvesting and protein structure of PE545, revealing a possible photoprotection mechanism for cryptophyte algae.

  1. Collini, E., et al. Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature. Nature 463, 644–647 (2010).
  2. Laos, A. J., Curmi, P. M. G. & Thordarson, P. Quantum Coherence and its Impact on Biomimetic Light-Harvesting. Aust. J. Chem 67, 729-73 (2014).
  3. Harrop, S. J., et al. Single-residue insertion switches the quaternary structure and exciton states of cryptophyte light-harvesting proteins. PNAS 111, E2666-E2675 (2014).