@unpublished{WohlgemuthMitric2020, author = {Wohlgemuth, Matthias and Mitric, Roland}, title = {Excitation energy transport in DNA modelled by multi-chromophoric field-induced surface hopping}, series = {Physical Chemistry Chemical Physics}, journal = {Physical Chemistry Chemical Physics}, edition = {submitted version}, doi = {10.1039/D0CP02255A}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-209467}, year = {2020}, abstract = {Absorption of ultraviolet light is known as a major source of carcinogenic mutations of DNA. The underlying processes of excitation energy dissipation are yet not fully understood. In this work we provide a new and generally applicable route for studying the excitation energy transport in multi-chromophoric complexes at an atomistic level. The surface-hopping approach in the frame of the extended Frenkel exciton model combined with QM/MM techniques allowed us to simulate the photodynamics of the alternating (dAdT)10 : (dAdT)10 double-stranded DNA. In accordance with recent experiments, we find that the excited state decay is multiexponential, involving a long and a short component which are due to two distinct mechanisms: formation of long-lived delocalized excitonic and charge transfer states vs. ultrafast decaying localized states resembling those of the bare nucleobases. Our simulations explain all stages of the ultrafast photodynamics including initial photoexcitation, dynamical evolution out of the Franck-Condon region, excimer formation and nonradiative relaxation to the ground state.}, language = {en} } @article{WohlgemuthMiyazakiTsukadaetal.2017, author = {Wohlgemuth, Matthias and Miyazaki, Mitsuhiko and Tsukada, Kohei and Weiler, Martin and Dopfer, Otto and Fujii, Masaaki and Mitrić, Roland}, title = {Deciphering environment effects in peptide bond solvation dynamics by experiment and theory}, series = {Physical Chemistry Chemical Physics}, volume = {19}, journal = {Physical Chemistry Chemical Physics}, number = {33}, doi = {10.1039/C7CP03992A}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159647}, pages = {22564-22572}, year = {2017}, abstract = {Most proteins work in aqueous solution and the interaction with water strongly affects their structure and function. However, experimentally the motion of a specific single water molecule is difficult to trace by conventional methods, because they average over the heterogeneous solvation structure of bulk water surrounding the protein. Here, we provide a detailed atomistic picture of the water rearrangement dynamics around the -CONH- peptide linkage in the two model systems formanilide and acetanilide, which simply differ by the presence of a methyl group at the peptide linkage. The combination of picosecond pump-probe time-resolved infrared spectroscopy and molecular dynamics simulations demonstrates that the solvation dynamics at the molecular level is strongly influenced by this small structural difference. The effective timescales for solvent migration triggered by ionization are mainly controlled by the efficiency of the kinetic energy redistribution rather than the shape of the potential energy surface. This approach provides a fundamental understanding of protein hydration and may help to design functional molecules in solution with tailored properties.}, language = {en} } @article{WohlgemuthMitric2016, author = {Wohlgemuth, Matthias and Mitric, Roland}, title = {Photochemical Chiral Symmetry Breaking in Alanine}, series = {Journal of Physical Chemistry A}, volume = {45}, journal = {Journal of Physical Chemistry A}, number = {120}, doi = {10.1021/acs.jpca.6b07611}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158557}, pages = {8976-8982}, year = {2016}, abstract = {We introduce a general theoretical approach for the simulation of photochemical dynamics under the influence of circularly polarized light to explore the possibility of generating enantiomeric enrichment through polarized-light-selective photochemistry. The method is applied to the simulation of the photolysis of alanine, a prototype chiral amino acid. We show that a systematic enantiomeric enrichment can be obtained depending on the helicity of the circularly polarized light that induces the excited-state photochemistry of alanine. By analyzing the patterns of the photoinduced fragmentation of alanine we find an inducible enantiomeric enrichment up to 1.7\%, which is also in good correspondence to the experimental findings. Our method is generally applicable to complex systems and might serve to systematically explore the photochemical origin of homochirality.}, language = {en} } @unpublished{WohlgemuthMiyazakiTsukadaetal.2017, author = {Wohlgemuth, Matthias and Miyazaki, Mitsuhiko and Tsukada, Kohei and Weiler, Martin and Dopfer, Otto and Fujii, Masaaki and Mitrić, Roland}, title = {Deciphering environment effects in peptide bond solvation dynamics by experiment and theory}, series = {Physical Chemistry Chemical Physics}, journal = {Physical Chemistry Chemical Physics}, doi = {10.1039/C7CP03992A}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159483}, year = {2017}, abstract = {Most proteins work in aqueous solution and the interaction with water strongly affects their structure and function. However, experimentally the motion of a specific single water molecule is difficult to trace by conventional methods, because they average over the heterogeneous solvation structure of bulk water surrounding the protein. Here, we provide a detailed atomistic picture of the water rearrangement dynamics around the -CONH- peptide linkage in the two model systems formanilide and acetanilide, which simply differ by the presence of a methyl group at the peptide linkage. The combination of picosecond pump-probe time-resolved infrared spectroscopy and molecular dynamics simulations demonstrates that the solvation dynamics at the molecular level is strongly influenced by this small structural difference. The effective timescales for solvent migration triggered by ionization are mainly controlled by the efficiency of the kinetic energy redistribution rather than the shape of the potential energy surface. This approach provides a fundamental understanding of protein hydration and may help to design functional molecules in solution with tailored properties.}, language = {en} } @article{WildgruberAschenbrennerWendorffetal.2016, author = {Wildgruber, Moritz and Aschenbrenner, Teresa and Wendorff, Heiko and Czubba, Maria and Glinzer, Almut and Haller, Bernhard and Schiemann, Matthias and Zimmermann, Alexander and Berger, Hermann and Eckstein, Hans-Henning and Meier, Reinhard and Wohlgemuth, Walter A. and Libby, Peter and Zernecke, Alma}, title = {The "Intermediate" CD14\(^{++}\)CD16\(^{+}\) monocyte subset increases in severe peripheral artery disease in humans}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {39483}, doi = {10.1038/srep39483}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167476}, year = {2016}, abstract = {Monocytes are key players in atherosclerotic. Human monocytes display a considerable heterogeneity and at least three subsets can be distinguished. While the role of monocyte subset heterogeneity has already been well investigated in coronary artery disease (CAD), the knowledge about monocytes and their heterogeneity in peripheral artery occlusive disease (PAOD) still is limited. Therefore, we aimed to investigate monocyte subset heterogeneity in patients with PAOD. Peripheral blood was obtained from 143 patients suffering from PAOD (Rutherford stage I to VI) and three monocyte subsets were identified by flow cytometry: CD14\(^{++}\)CD16\(^{-}\) classical monocytes, CD14\(^{+}\)CD16\(^{++}\) non-classical monocytes and CD14\(^{++}\)CD16\(^{+}\) intermediate monocytes. Additionally the expression of distinct surface markers (CD106, CD162 and myeloperoxidase MPO) was analyzed. Proportions of CD14\(^{++}\)CD16\(^{+}\) intermediate monocyte levels were significantly increased in advanced stages of PAOD, while classical and non-classical monocytes displayed no such trend. Moreover, CD162 and MPO expression increased significantly in intermediate monocyte subsets in advanced disease stages. Likewise, increased CD162 and MPO expression was noted in CD14\(^{++}\)CD16\(^{-}\) classical monocytes. These data suggest substantial dynamics in monocyte subset distributions and phenotypes in different stages of PAOD, which can either serve as biomarkers or as potential therapeutic targets to decrease the inflammatory burden in advanced stages of atherosclerosis.}, language = {en} }