@article{MuellerBessiRichteretal.2021, author = {M{\"u}ller, Diana and Bessi, Irene and Richter, Christian and Schwalbe, Harald}, title = {The Folding Landscapes of Human Telomeric RNA and DNA G-Quadruplexes are Markedly Different}, series = {Angewandte Chemie International Edition}, volume = {60}, journal = {Angewandte Chemie International Edition}, number = {19}, doi = {10.1002/anie.202100280}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238917}, pages = {10895 -- 10901}, year = {2021}, abstract = {We investigated the folding kinetics of G-quadruplex (G4) structures by comparing the K\(^{+}\)-induced folding of an RNA G4 derived from the human telomeric repeat-containing RNA (TERRA25) with a sequence homologous DNA G4 (wtTel25) using CD spectroscopy and real-time NMR spectroscopy. While DNA G4 folding is biphasic, reveals kinetic partitioning and involves kinetically favoured off-pathway intermediates, RNA G4 folding is faster and monophasic. The differences in kinetics are correlated to the differences in the folded conformations of RNA vs. DNA G4s, in particular with regard to the conformation around the glycosidic torsion angle χ that uniformly adopts anti conformations for RNA G4s and both, syn and anti conformation for DNA G4s. Modified DNA G4s with \(^{19}\)F bound to C2′ in arabino configuration adopt exclusively anti conformations for χ. These fluoro-modified DNA (antiTel25) reveal faster folding kinetics and monomorphic conformations similar to RNA G4s, suggesting the correlation between folding kinetics and pathways with differences in χ angle preferences in DNA and RNA, respectively.}, language = {en} } @article{KernHaagsEggeretal.2023, author = {Kern, Christian S. and Haags, Anja and Egger, Larissa and Yang, Xiaosheng and Kirschner, Hans and Wolff, Susanne and Seyller, Thomas and Gottwald, Alexander and Richter, Mathias and de Giovannini, Umberto and Rubio, Angel and Ramsey, Michael G. and Bocquet, Fran{\c{c}}ois C. and Soubatch, Serguei and Tautz, F. Stefan and Puschnig, Peter and Moser, Simon}, title = {Simple extension of the plane-wave final state in photoemission: bringing understanding to the photon-energy dependence of two-dimensional materials}, series = {Physical Review Research}, volume = {5}, journal = {Physical Review Research}, number = {3}, doi = {10.1103/PhysRevResearch.5.033075}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350330}, year = {2023}, abstract = {Angle-resolved photoemission spectroscopy (ARPES) is a method that measures orbital and band structure contrast through the momentum distribution of photoelectrons. Its simplest interpretation is obtained in the plane-wave approximation, according to which photoelectrons propagate freely to the detector. The photoelectron momentum distribution is then essentially given by the Fourier transform of the real-space orbital. While the plane-wave approximation is remarkably successful in describing the momentum distributions of aromatic compounds, it generally fails to capture kinetic-energy-dependent final-state interference and dichroism effects. Focusing our present study on quasi-freestanding monolayer graphene as the archetypical two-dimensional (2D) material, we observe an exemplary E\(_{kin}\)-dependent modulation of, and a redistribution of spectral weight within, its characteristic horseshoe signature around the \(\bar {K}\) and \(\bar {K´}\) points: both effects indeed cannot be rationalized by the plane-wave final state. Our data are, however, in remarkable agreement with ab initio time-dependent density functional simulations of a freestanding graphene layer and can be explained by a simple extension of the plane-wave final state, permitting the two dipole-allowed partial waves emitted from the C 2p\(_z\) orbitals to scatter in the potential of their immediate surroundings. Exploiting the absolute photon flux calibration of the Metrology Light Source, this scattered-wave approximation allows us to extract E\(_{kin}\)-dependent amplitudes and phases of both partial waves directly from photoemission data. The scattered-wave approximation thus represents a powerful yet intuitive refinement of the plane-wave final state in photoemission of 2D materials and beyond.}, language = {en} } @article{GottschalkRichterZiegleretal.2019, author = {Gottschalk, Michael G. and Richter, Jan and Ziegler, Christiane and Schiele, Miriam A. and Mann, Julia and Geiger, Maximilian J. and Schartner, Christoph and Homola, Gy{\"o}rgy A. and Alpers, Georg W. and B{\"u}chel, Christian and Fehm, Lydia and Fydrich, Thomas and Gerlach, Alexander L. and Gloster, Andrew T. and Helbig-Lang, Sylvia and Kalisch, Raffael and Kircher, Tilo and Lang, Thomas and Lonsdorf, Tina B. and Pan{\´e}-Farr{\´e}, Christiane A. and Str{\"o}hle, Andreas and Weber, Heike and Zwanzger, Peter and Arolt, Volker and Romanos, Marcel and Wittchen, Hans-Ulrich and Hamm, Alfons and Pauli, Paul and Reif, Andreas and Deckert, J{\"u}rgen and Neufang, Susanne and H{\"o}fler, Michael and Domschke, Katharina}, title = {Orexin in the anxiety spectrum: association of a HCRTR1 polymorphism with panic disorder/agoraphobia, CBT treatment response and fear-related intermediate phenotypes}, series = {Translational Psychiatry}, volume = {9}, journal = {Translational Psychiatry}, doi = {10.1038/s41398-019-0415-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227479}, year = {2019}, abstract = {Preclinical studies point to a pivotal role of the orexin 1 (OX1) receptor in arousal and fear learning and therefore suggest the HCRTR1 gene as a prime candidate in panic disorder (PD) with/without agoraphobia (AG), PD/AG treatment response, and PD/AG-related intermediate phenotypes. Here, a multilevel approach was applied to test the non-synonymous HCRTR1 C/T Ile408Val gene variant (rs2271933) for association with PD/AG in two independent case-control samples (total n = 613 cases, 1839 healthy subjects), as an outcome predictor of a six-weeks exposure-based cognitive behavioral therapy (CBT) in PD/AG patients (n = 189), as well as with respect to agoraphobic cognitions (ACQ) (n = 483 patients, n = 2382 healthy subjects), fMRI alerting network activation in healthy subjects (n = 94), and a behavioral avoidance task in PD/AG pre- and post-CBT (n = 271). The HCRTR1 rs2271933 T allele was associated with PD/AG in both samples independently, and in their meta-analysis (p = 4.2 × 10-7), particularly in the female subsample (p = 9.8 × 10-9). T allele carriers displayed a significantly poorer CBT outcome (e.g., Hamilton anxiety rating scale: p = 7.5 × 10-4). The T allele count was linked to higher ACQ sores in PD/AG and healthy subjects, decreased inferior frontal gyrus and increased locus coeruleus activation in the alerting network. Finally, the T allele count was associated with increased pre-CBT exposure avoidance and autonomic arousal as well as decreased post-CBT improvement. In sum, the present results provide converging evidence for an involvement of HCRTR1 gene variation in the etiology of PD/AG and PD/AG-related traits as well as treatment response to CBT, supporting future therapeutic approaches targeting the orexin-related arousal system.}, language = {en} }