Speaker
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)
No
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Dr. Tjaart Kruger, Tjaart.Kruger@up.ac.za, University of Pretoria
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
Diatoms are unicellular marine photosynthetic organisms characterized by their silica shell. Their light harvesting complexes are named fucoxanthin-chlorophyll protein (FCP). Besides efficient absorption and rapid subsequent transfer of photoenergy to the photochemical reaction centre, FCP complexes are also strongly involved in photoprotection, a complex series of events known as non-photochemical quenching (NPQ) by which plants and algae dissipate excess absorbed energy that would otherwise damage the photosystems. Diatoms exhibit considerably stronger NPQ than plants. The diatom Cyclotella meneghiniana possesses two types of light-harvesting complexes, known as FCPa and FCPb, which differ primarily in their protein compositions. In this study we used femtosecond transient absorption spectroscopy to investigate the energy transfer dynamics and thermal energy dissipation pathways in FCPb at the last energy transfer stage. Two different pump energies at 680 nm excitation were used. The effect of the environment surrounding the protein was investigated by comparing the behavior of solubilized FCPb (sFCPb) with that of FCPb incorporated into proteoliposomes (plFCPb), the latter of which serve as a model system for the study of membrane-bound enzymes and transport proteins. The results show that, while the fluorescence of the plFCPb sample is quenched relative to sFCPb, it appears to exhibit less annihilation than sFCPb, suggesting that the proteoliposome samples may be a new model system to study NPQ mechanisms in these complexes.
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
