caa a22 4500 445889926 CHVBK 20180317145612.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s11120-011-9689-2 doi (NATIONALLICENCE)springer-10.1007/s11120-011-9689-2 Calculation of chromophore excited state energy shifts in response to molecular dynamics of pigment-protein complexes [Elektronische Daten] [Serguei Vassiliev, Abdullah Mahboob, Doug Bruce] The absorption and energy transfer properties of photosynthetic pigments are strongly influenced by their local environment or "site.” Local electrostatic fields vary in time with protein and chromophore molecular movement and thus transiently influence the excited state transition properties of individual chromophores. Site-specific information is experimentally inaccessible in many light-harvesting pigment-proteins due to multiple chromophores with overlapping spectra. Full quantum mechanical calculations of each chromophores excited state properties are too computationally demanding to efficiently calculate the changing excitation energies along a molecular dynamics trajectory in a pigment-protein complex. A simplified calculation of electrostatic interactions with each chromophores ground to excited state transition, the so-called charge density coupling (CDC) for site energy, CDC, has previously been developed to address this problem. We compared CDC to more rigorous quantum chemical calculations to determine its accuracy in computing excited state energy shifts and their fluctuations within a molecular dynamics simulation of the bacteriochlorophyll containing light-harvesting Fenna-Mathews-Olson (FMO) protein. In most cases CDC calculations differed from quantum mechanical (QM) calculations in predicting both excited state energy and its fluctuations. The discrepancies arose from the inability of CDC to account for the differing effects of charge on ground and excited state electron orbitals. Results of our study show that QM calculations are indispensible for site energy computations and the quantification of contributions from different parts of the system to the overall site energy shift. We suggest an extension of QM/MM methodology of site energy shift calculations capable of accounting for long-range electrostatic potential contributions from the whole system, including solvent and ions. Springer Science+Business Media B.V., 2011 Bacteriochlorophyll nationallicence FMO protein nationallicence Excited state energies nationallicence Molecular dynamics nationallicence BChl : Bacteriochlorophyll nationallicence FMO : Fenna-Mathews-Olson complex nationallicence PS : Photosystem nationallicence CDC : Charge density coupling nationallicence TDC : Transition density cube nationallicence TrEsp : Transition charge from electrostatic potential nationallicence PBQC : Poisson-Boltzmann quantum chemistry nationallicence TD-DFT : Time-dependent density functional theory nationallicence QM : Quantum mechanics nationallicence MD : Molecular dynamics nationallicence HOMO : Highest occupied molecular orbital nationallicence LUMO : Lowest unoccupied molecular orbital nationallicence Vassiliev Serguei Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut Mahboob Abdullah Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut Bruce Doug Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut Photosynthesis Research Springer Netherlands 110/1(2011-10-01), 25-38 0166-8595 110:1<25 2011 110 11120 https://doi.org/10.1007/s11120-011-9689-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11120-011-9689-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vassiliev Serguei Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut NATIONALLICENCE 700 1- Mahboob Abdullah Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut NATIONALLICENCE 700 1- Bruce Doug Department of Biology, Brock University, 500 Glenridge Avenue, L2S 3A1, St. Catharines, ON, Canada aut NATIONALLICENCE 773 0- Photosynthesis Research Springer Netherlands 110/1(2011-10-01), 25-38 0166-8595 110:1<25 2011 110 11120 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer