Seminars & Lectures
|* TITLE||Network topology analysis in Photosystem II core complex|
|* DATE / TIME||2012-09-21, 4 pm|
|* PLACE||503 Conference room, APCTP Headquarters, Pohang|
Part of the functionality of the photosystem II comes from the transfer of energy between chlorophylls. These are connected in to a complex network where the coupling strength is related to both the geometry of the chloroplast (the embedding of the chlorophylls) and their spatial orientation. We investigate how much of the photosystem II in Thermosynechococcus vulcanus that can be explained by the network topology of this network.
We calculate the excitation-energy coupling strength by using Förster energy transfer theory. We use the calculated excitation-energy coupling strength as the basis for constructing a network of possible excitation transfer pathways.
We find that network centrality measures can characterize the role of individual chlorophylls in the excitation-energy transfer network. By using the network-structural measures betweenness centrality, closeness centrality and clustering coefficient, we can predict the different functionality of individual chlorophylls.
Among other things, we can infer that the chlorophyll complex CP47 has the role of a bridge in excitation energy transfer . We can infer that most of chlorophylls in pigment-protein complex CP47 have heightened probability to absorb the energy compared with other chlorophylls. The so-called A-branch special pair in the reaction center is characterized by a high closeness centrality, a high betweenness centrality and a low clustering coefficient. This implies that this component is able to get more energy than other component of special pair.