Jakob Schauss

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Benjamin P. Fingerhut

Ludwig-Maximilians-Universität München

Thomas Elsaesser

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Achintya Kundu

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Claus Ropers

University of Göttingen

Armin Feist

Max Planck Institute for Dynamics and Self-Organization

Sascha Schäfer

University of Regensburg

K. E. Echternkamp

University of Göttingen

Sergey V. Yalunin

Max Planck Institute for Dynamics and Self-Organization

Eva M. Bruening

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Torsten Siebert

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Cooperative Institutions

University of Göttingen

Max Planck Institute for Multidisciplinary Sciences

Max Planck Institute for Dynamics and Self-Organization

Carl von Ossietzky Universität Oldenburg

Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy

Max Planck Institute for Biophysical Chemistry

Intelligent Transport Systems Niedersachsen

Wigner Research Centre for Physics

ELI-HU Research and Development Non-Profit

Lockheed Martin (United States)

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Contact Ion Pairs of Phosphate Groups in Water: Two-Dimensional Infrared Spectroscopy of Dimethyl Phosphate and ab Initio Simulations

The Journal of Physical Chemistry Letters (2019)

Jakob Schauss Achintya Kundu Benjamin P. Fingerhut Thomas Elsaesser

The interaction of phosphate groups with ions in an aqueous environment has a strong impact on the structure and folding processes of DNA and RNA. The dynamic variety of ionic arrangements, including both contact pairs and water separated ions, and the molecular coupling mechanisms are far from being understood. In a combined experimental and theoretical approach, we address the properties of contact ion pairs of the prototypical system dimethyl phosphate with Na+, Ca2+, and Mg2+ ions in water. Linear and femtosecond two-dimensional infrared (2D-IR) spectroscopy of the asymmetric (PO2)- stretching vibration separates and characterizes the different species via their blue-shifted vibrational signatures and 2D-IR line shapes. Phosphate-magnesium contact pairs stand out as the most compact geometry while the contact pairs with Ca2+ and Na+ display a wider structural variation. Microscopic density functional theory simulations rationalize the observed frequency shifts and reveal distinct differences between the contact geometries.

Folding (DSP implementation)

10.1021/acs.jpclett.9b02157

Cite

Citations (26)

Aqueous Contact Ion Pairs of Phosphate Groups with Na⁺, Ca²⁺ and Mg²⁺ – Structural Discrimination by Femtosecond Infrared Spectroscopy and Molecular Dynamics Simulations

Zeitschrift für Physikalische Chemie (2020)

Benjamin P. Fingerhut Jakob Schauss Achintya Kundu Thomas Elsaesser

Abstract The extent of contact and solvent shared ion pairs of phosphate groups with Na + , Ca 2+ and Mg 2+ ions in aqueous environment and their relevance for the stability of polyanionic DNA and RNA structures is highly debated. Employing the asymmetric phosphate stretching vibration of dimethyl phosphate (DMP), a model system of the sugar-phosphate backbone of DNA and RNA, we present linear infrared, femtosecond infrared pump-probe and absorptive 2D-IR spectra that report on contact ion pair formation via the presence of blue shifted spectral signatures. Compared to the linear infrared spectra, the nonlinear spectra reveal contact ion pairs with increased sensitivity because the spectra accentuate differences in peak frequency, transition dipole moment strength, and excited state lifetime. The experimental results are corroborated by long time scale MD simulations, benchmarked by density functional simulations on phosphate-ion-water clusters. The microscopic interpretation reveals subtle structural differences of ion pairs formed by the phosphate group and the ions Na + , Ca 2+ and Mg 2+ . Intricate properties of the solvation shell around the phosphate group and the ion are essential to explain the experimental observations. The present work addresses a challenging to probe topic with the help of a model system and establishes new experimental data of contact ion pair formation, thereby underlining the potential of nonlinear 2D-IR spectroscopy as an analytical probe of phosphate-ion interactions in complex biological systems.

Solvation shell

10.1515/zpch-2020-1614

Cite

Citations (7)

Electron-Light Interaction in Optical Near-Fields studied by Ultrafast Transmission Electron Microscopy

Armin Feist K. E. Echternkamp Jakob Schauss Sergey V. Yalunin Sascha Schäfer

Photon-induced scattering of swift electrons with confined light is studied by ultrafast transmission electron microscopy (UTEM) and employed to locally map optical near-fields. Fluence-dependent kinetic energy spectra reveal quantum coherent scattering features.

Electron scattering

10.1364/cleo_qels.2015.fth1e.3

Cite

Citations (0)

Vibrational Dynamics and Couplings of the Hydrated RNA Backbone: A Two-Dimensional Infrared Study

The Journal of Physical Chemistry Letters (2018)

Eva M. Bruening Jakob Schauss Torsten Siebert Benjamin P. Fingerhut Thomas Elsaesser

The equilibrium structure of the RNA sugar-phosphate backbone and its hydration shell is distinctly different from hydrated DNA. Applying femtosecond two-dimensional infrared (2D-IR) spectroscopy in a range from 950 to 1300 cm-1, we elucidate the character, dynamics, and couplings of backbone modes of a double-stranded RNA A-helix geometry in its aqueous environment. The 2D-IR spectra display a greater number of backbone modes than for DNA, with distinctly different lineshapes of diagonal peaks. Phosphate-ribose interactions and local hydration structures are reflected in the complex coupling pattern of RNA modes. Interactions with the fluctuating water shell give rise to spectral diffusion on a 300 fs time scale, leading to a quasi-homogeneous line shape of the symmetric (PO2)- stretching mode of the strongly hydrated phosphate groups. The RNA results are benchmarked by 2D-IR spectra of DNA oligomers in water and analyzed by molecular dynamics and quantum mechanical molecular mechanics simulations.

Dynamics

Two-dimensional infrared spectroscopy

10.1021/acs.jpclett.7b03314

Cite

Citations (28)

Phosphate–Magnesium Ion Interactions in Water Probed by Ultrafast Two-Dimensional Infrared Spectroscopy

The Journal of Physical Chemistry Letters (2019)

Jakob Schauss Fabian Dahms Benjamin P. Fingerhut Thomas Elsaesser

Electric interactions between ions and ionic molecular groups in aqueous solution play a fundamental role in chemistry and biology. While Mg2+ ions are known to strongly affect the structure and folding dynamics of biomolecules, the relevance of different solvation geometries and the underlying interactions are mainly unresolved. We study dynamics and couplings between the hydrated Mg2+ and the dimethylphosphate anion, an established model system for the DNA and RNA backbone. The asymmetric (PO2-) stretching vibration serves as a sensitive noninvasive probe of phosphate-ion interactions. Femtosecond two-dimensional infrared (2D-IR) spectroscopy directly maps Mg2+ ions in contact with the phosphate groups via a distinct blue-shifted signature in the 2D spectrum. Data for different Mg2+ concentrations are analyzed by microscopic density functional theory modeling of cluster geometries and associated spectroscopic features, providing spatial assignments of the observed 2D-IR signatures. Phosphate-ion interactions arising from electrostatic Coulomb forces and exchange repulsion are the predominant origin of the observed frequency shifts.

Biomolecule

10.1021/acs.jpclett.8b03568

Cite

Citations (20)

Change of Hydration Patterns upon RNA Melting Probed by Excitations of Phosphate Backbone Vibrations

The Journal of Physical Chemistry B (2020)

Achintya Kundu Jakob Schauss Benjamin P. Fingerhut Thomas Elsaesser

The water hydration shell has decisive impact on the structural and functional properties of RNA. Changes of RNA structure upon melting and in biochemical processes are accompanied by a change of hydration patterns, a process which is barely characterized. To discern hydration geometries around the backbone phosphate groups of an RNA double helix at the molecular level, we combine two-dimensional infrared spectroscopy of phosphate vibrations with theoretical simulations. There are three distinct coexisting hydration motifs of the RNA A-helix, an ordered chain-like arrangement of water molecules with links between neighboring phosphate groups, separate local hydration shells of up to six water molecules, and hydrated phosphate/counterion contact pairs. RNA disordering upon melting is connected with a transition from predominant ordered water structures to local hydration shells around phosphate units. Structural fluctuations are dominated by librational water motions occurring on a 300 fs time scale, without exchange between hydration motifs.

Helix (gastropod)

Solvation shell

10.1021/acs.jpcb.0c01474

Cite

Citations (7)

Ultrafast Transmission Electron Microscopy with nanoscale Photoemitters

Microscopy and Microanalysis (2015)

Armin Feist K. E. Echternkamp Jakob Schauss Sergey V. Yalunin Sascha Schäfer

Journal Article Ultrafast Transmission Electron Microscopy with nanoscale Photoemitters Get access Armin Feist, Armin Feist 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Katharina E Echternkamp, Katharina E Echternkamp 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Jakob Schauss, Jakob Schauss 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Sergey V Yalunin, Sergey V Yalunin 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Sascha Schafer, Sascha Schafer 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Claus Ropers Claus Ropers 4th Physical Institute- Solids and Nanostructures, University of Gottingen, 37077 Gottingen, Germany Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 21, Issue S3, 1 August 2015, Pages 1203–1204, https://doi.org/10.1017/S1431927615006807 Published: 23 September 2015

10.1017/s1431927615006807

Cite

Citations (2)

Magnesium Contact Ions Stabilize the Tertiary Structure of Transfer RNA: Electrostatics Mapped by Two-Dimensional Infrared Spectra and Theoretical Simulations

The Journal of Physical Chemistry B (2020)

Jakob Schauss Achintya Kundu Benjamin P. Fingerhut Thomas Elsaesser

Ions interacting with hydrated RNA play a central role in defining its secondary and tertiary structure. While spatial arrangements of ions, water molecules, and phosphate groups have been inferred from X-ray studies, the role of electrostatic and other noncovalent interactions in stabilizing compact folded RNA structures is not fully understood at the molecular level. Here, we demonstrate that contact ion pairs of magnesium (Mg2+) and phosphate groups embedded in local water shells stabilize the tertiary equilibrium structure of transfer RNA (tRNA). Employing dialyzed tRNAPhe from yeast and tRNA from Escherichia coli, we follow the population of Mg2+ sites close to phosphate groups of the ribose-phosphodiester backbone step by step, combining linear and nonlinear infrared spectroscopy of phosphate vibrations with molecular dynamics simulations and ab initio vibrational frequency calculations. The formation of up to six Mg2+/phosphate contact pairs per tRNA and local field-induced reorientations of water molecules balance the phosphate-phosphate repulsion in nonhelical parts of tRNA, thus stabilizing the folded structure electrostatically. Such geometries display limited sub-picosecond fluctuations in the arrangement of water molecules and ion residence times longer than 1 {\mu}s. At higher Mg2+ excess, the number of contact ion pairs per tRNA saturates around 6 and weakly interacting ions prevail. Our results suggest a predominance of contact ion pairs over long-range coupling of the ion atmosphere and the biomolecule in defining and stabilizing the tertiary structure of tRNA.

Electrostatics

10.1021/acs.jpcb.0c08966

Cite

Citations (29)

Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam

Ultramicroscopy (2016)

Armin Feist Nora Bach Nara Rubiano da Silva Thomas Danz Marcel Möller

We present the development of the first ultrafast transmission electron microscope (UTEM) driven by localized photoemission from a field emitter cathode. We describe the implementation of the instrument, the photoemitter concept and the quantitative electron beam parameters achieved. Establishing a new source for ultrafast TEM, the Göttingen UTEM employs nano-localized linear photoemission from a Schottky emitter, which enables operation with freely tunable temporal structure, from continuous wave to femtosecond pulsed mode. Using this emission mechanism, we achieve record pulse properties in ultrafast electron microscopy of 9 Å focused beam diameter, 200 fs pulse duration and 0.6 eV energy width. We illustrate the possibility to conduct ultrafast imaging, diffraction, holography and spectroscopy with this instrument and also discuss opportunities to harness quantum coherent interactions between intense laser fields and free-electron beams.

Pulse duration

10.1016/j.ultramic.2016.12.005

Cite

Citations (364)

Structural Discrimination of Phosphate Contact Ion Pairs in Water by Femtosecond 2D-IR Spectroscopy

The 22nd International Conference on Ultrafast Phenomena 2020 (2020)

Achintya Kundu Jakob Schauss Benjamin P. Fingerhut Thomas Elsaesser

The distinct structures of contact ion pairs in water are identified. Nonlinear infrared (IR) spectroscopy and theoretical calculations allow for the separation and assignment of spectral features and interactions.

10.1364/up.2020.m4b.9

Cite

Citations (1)