The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Klaus Kern - One of the best experts on this subject based on the ideXlab platform.
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exploring the molecular conformation space by soft molecule Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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Exploring the Molecular Conformation Space by Soft Molecule–Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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active conformation control of unfolded proteins by hyperthermal Collision with a metal Surface
Nano Letters, 2014Co-Authors: Gordon Rinke, Stephan Rauschenbach, Klaus Kern, Ludger Harnau, Alyazan Albarghash, Matthias PaulyAbstract:The physical and chemical properties of macromolecules like proteins are strongly dependent on their conformation. The degrees of freedom of their chemical bonds generate a huge conformational space, of which, however, only a small fraction is accessible in thermal equilibrium. Here we show that soft-landing electrospray ion beam deposition (ES-IBD) of unfolded proteins allows to control their conformation. The dynamics and result of the deposition process can be actively steered by selecting the molecular ion beam's charge state or tuning the incident energy. Using these parameters, protein conformations ranging from fully extended to completely compact can be prepared selectively on a Surface, as evidenced on the subnanometer/amino acid resolution level by scanning tunneling microscopy (STM). Supported by molecular dynamics (MD) simulations, our results demonstrate that the final conformation on the Surface is reached through a mechanical deformation during the hyperthermal ion Surface Collision. Our experimental results independently confirm the findings of ion mobility spectrometry (IMS) studies of protein gas phase conformations. Moreover, we establish a new route for the processing of macromolecular materials, with the potential to reach conformations that would be inaccessible otherwise.
Stephan Rauschenbach - One of the best experts on this subject based on the ideXlab platform.
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exploring the molecular conformation space by soft molecule Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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Exploring the Molecular Conformation Space by Soft Molecule–Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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active conformation control of unfolded proteins by hyperthermal Collision with a metal Surface
Nano Letters, 2014Co-Authors: Gordon Rinke, Stephan Rauschenbach, Klaus Kern, Ludger Harnau, Alyazan Albarghash, Matthias PaulyAbstract:The physical and chemical properties of macromolecules like proteins are strongly dependent on their conformation. The degrees of freedom of their chemical bonds generate a huge conformational space, of which, however, only a small fraction is accessible in thermal equilibrium. Here we show that soft-landing electrospray ion beam deposition (ES-IBD) of unfolded proteins allows to control their conformation. The dynamics and result of the deposition process can be actively steered by selecting the molecular ion beam's charge state or tuning the incident energy. Using these parameters, protein conformations ranging from fully extended to completely compact can be prepared selectively on a Surface, as evidenced on the subnanometer/amino acid resolution level by scanning tunneling microscopy (STM). Supported by molecular dynamics (MD) simulations, our results demonstrate that the final conformation on the Surface is reached through a mechanical deformation during the hyperthermal ion Surface Collision. Our experimental results independently confirm the findings of ion mobility spectrometry (IMS) studies of protein gas phase conformations. Moreover, we establish a new route for the processing of macromolecular materials, with the potential to reach conformations that would be inaccessible otherwise.
Peter H Seeberger - One of the best experts on this subject based on the ideXlab platform.
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exploring the molecular conformation space by soft molecule Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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Exploring the Molecular Conformation Space by Soft Molecule–Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
R. Graham Cooks - One of the best experts on this subject based on the ideXlab platform.
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Ion/Surface reactions and ion soft-landing
Physical Chemistry Chemical Physics, 2005Co-Authors: Bogdan Gologan, Jason R Green, Jormarie Alvarez, Julia Laskin, R. Graham CooksAbstract:Ion/Surface Collision phenomena in the hyperthermal Collision energy regime (1–100 eV) are reviewed, with emphasis on chemical processes associated with the impact of small organic and biological ions at functionalized self-assembled monolayer Surfaces. Inelastic Collisions can lead to excitation of the projectile ion and can result in fragmentation, a process known as Surface-induced dissociation which is useful in chemical analysis using tandem mass spectrometry. Changes in charge can accompany ion/Surface Collisions and those associated with a change in polarity (positive to negative ions or vice versa) are an attractive method for ion structural characterization and isomer differentiation. The Surface-induced charge inversion of nitrobenzene and other substituted aromatics is discussed. Reactive Collisions occurring between gaseous ions and Surfaces depend on the chemical nature of the Collision partners. These reactions can be used for selected chemical modifications of Surfaces as well as for Surface analysis. Particular emphasis is given here to ion soft-landing, another type of ion/Surface interaction, in which the projectile ion is landed intact at the Surface, either as the corresponding neutral molecule or, interestingly but less commonly, in the form of the ion itself. The ion soft-landing experiment allows for preparative mass spectrometry; for example the preparation of pure biological compounds by using the mass spectrometer as a separation device. After separation, the mass-selected ions are collected by soft-landing, at different spatial points in an array. If the experiment is performed using a suitable liquid medium, in the case of some proteins at least, biological activity is retained.
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A multiquadrupole tandem mass spectrometer for the study of ion/Surface Collision processes
Review of Scientific Instruments, 2002Co-Authors: Zheng Ouyang, Jormarie Alvarez, Verena Grill, Christopher H. Doerge, Luca Gianelli, Peter D. Thomas, Henry W. Rohrs, R. Graham CooksAbstract:A compact tandem mass spectrometer containing two quadrupole mass analyzers (Q), two octapole ion guides (o) and a static quadrupole ion beam-bending lens (q) (QoqoQ configuration) has been built for the study of ion/Surface Collisions. Positive or negative ions are generated by either electron impact ionization or chemical ionization, selected by mass-to-charge ratio using the first quadrupole mass analyzer, guided by the first octapole ion guide, bent by a static quadrupole lens through 90°, and then focused onto a Surface at an angle of 45° with reference to the Surface normal. The secondary ions generated from Collisions with the target Surface are collected at an emergent angle of 45°, guided by the second octapole ion guide, mass-analyzed by the second quadrupole mass analyzer, and finally detected. The Collision energy can be varied from 0 to 500 eV. The primary ions can also be made to pass straight through the quadrupole bending lens and then examined by an electron multiplier prior to Surface Collisions. The Surface can be introduced into the ion/Surface Collision region without venting the main chamber. The capabilities of the QoqoQ instrument are demonstrated by a variety of ion/Surface Collisional processes in the 10s of eV laboratory translational energy range. These include Surface-induced dissociation, charge permutation, Surface analysis via chemical sputtering, and selective Surface modification via ion/Surface reactions.
Kelvin Anggara - One of the best experts on this subject based on the ideXlab platform.
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exploring the molecular conformation space by soft molecule Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.
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Exploring the Molecular Conformation Space by Soft Molecule–Surface Collision
Journal of the American Chemical Society, 2020Co-Authors: Kelvin Anggara, Yuntao Zhu, Martina Delbianco, Stephan Rauschenbach, Sabine Abb, Peter H Seeberger, Klaus KernAbstract:Biomolecules function by adopting multiple conformations. Such dynamics are governed by the conformation landscape whose study requires characterization of the ground and excited conformation states. Here, the conformational landscape of a molecule is sampled by exciting an initial gas-phase molecular conformer into diverse conformation states, using soft molecule-Surface Collision (0.5-5.0 eV). The resulting ground and excited molecular conformations, adsorbed on the Surface, are imaged at the single-molecule level. This technique permits the exploration of oligosaccharide conformations, until now, limited by the high flexibility of oligosaccharides and ensemble-averaged analytical methods. As a model for cellulose, cellohexaose chains are observed in two conformational extremes, the typical "extended" chain and the atypical "coiled" chain-the latter identified as the gas-phase conformer preserved on the Surface. Observing conformations between these two extremes reveals the physical properties of cellohexaose, behaving as a rigid ribbon that becomes flexible when twisted. The conformation space of any molecule that can be electrosprayed can now be explored.