---
_id: '15628'
abstract:
- lang: eng
  text: <jats:p>The three-dimensional (3D) crystal structures of the GAF3 domain of
    cyanobacteriochrome Slr1393 (<jats:italic>Synechocystis</jats:italic> PCC6803)
    carrying a phycocyanobilin chromophore could be solved in both 15-<jats:italic>Z</jats:italic>
    dark-adapted state, Pr, λ<jats:sub>max</jats:sub> = 649 nm, and 15-<jats:italic>E</jats:italic>
    photoproduct, Pg, λ<jats:sub>max</jats:sub> = 536 nm (resolution, 1.6 and 1.86
    Å, respectively). The structural data allowed identifying the large spectral shift
    of the Pr-to-Pg conversion as resulting from an out-of-plane rotation of the chromophore’s
    peripheral rings and an outward movement of a short helix formed from a formerly
    unstructured loop. In addition, a third structure (2.1-Å resolution) starting
    from the photoproduct crystals allowed identification of elements that regulate
    the absorption maxima. In this peculiar form, generated during X-ray exposition,
    protein and chromophore conformation still resemble the photoproduct state, except
    for the D-ring already in 15-<jats:italic>Z</jats:italic> configuration and tilted
    out of plane akin the dark state. Due to its formation from the photoproduct,
    it might be considered an early conformational change initiating the parental
    state-recovering photocycle. The high quality and the distinct features of the
    three forms allowed for applying quantum-chemical calculations in the framework
    of multiscale modeling to rationalize the absorption maxima changes. A systematic
    analysis of the PCB chromophore in the presence and absence of the protein environment
    showed that the direct electrostatic effect is negligible on the spectral tuning.
    However, the protein forces the outer pyrrole rings of the chromophore to deviate
    from coplanarity, which is identified as the dominating factor for the color regulation.</jats:p>
article_number: '201910208'
author:
- first_name: Xiuling
  full_name: Xu, Xiuling
  last_name: Xu
- first_name: Astrid
  full_name: Port, Astrid
  last_name: Port
- first_name: Christian
  full_name: Wiebeler, Christian
  last_name: Wiebeler
- first_name: Kai-Hong
  full_name: Zhao, Kai-Hong
  last_name: Zhao
- first_name: Igor
  full_name: Schapiro, Igor
  last_name: Schapiro
- first_name: Wolfgang
  full_name: Gärtner, Wolfgang
  last_name: Gärtner
citation:
  ama: Xu X, Port A, Wiebeler C, Zhao K-H, Schapiro I, Gärtner W. Structural Elements
    Regulating the Photochromicity in a Cyanobacteriochrome. <i>Proceedings of the
    National Academy of Sciences</i>. 2020. doi:<a href="https://doi.org/10.1073/pnas.1910208117">10.1073/pnas.1910208117</a>
  apa: Xu, X., Port, A., Wiebeler, C., Zhao, K.-H., Schapiro, I., &#38; Gärtner, W.
    (2020). Structural Elements Regulating the Photochromicity in a Cyanobacteriochrome.
    <i>Proceedings of the National Academy of Sciences</i>. <a href="https://doi.org/10.1073/pnas.1910208117">https://doi.org/10.1073/pnas.1910208117</a>
  bibtex: '@article{Xu_Port_Wiebeler_Zhao_Schapiro_Gärtner_2020, title={Structural
    Elements Regulating the Photochromicity in a Cyanobacteriochrome}, DOI={<a href="https://doi.org/10.1073/pnas.1910208117">10.1073/pnas.1910208117</a>},
    number={201910208}, journal={Proceedings of the National Academy of Sciences},
    author={Xu, Xiuling and Port, Astrid and Wiebeler, Christian and Zhao, Kai-Hong
    and Schapiro, Igor and Gärtner, Wolfgang}, year={2020} }'
  chicago: Xu, Xiuling, Astrid Port, Christian Wiebeler, Kai-Hong Zhao, Igor Schapiro,
    and Wolfgang Gärtner. “Structural Elements Regulating the Photochromicity in a
    Cyanobacteriochrome.” <i>Proceedings of the National Academy of Sciences</i>,
    2020. <a href="https://doi.org/10.1073/pnas.1910208117">https://doi.org/10.1073/pnas.1910208117</a>.
  ieee: X. Xu, A. Port, C. Wiebeler, K.-H. Zhao, I. Schapiro, and W. Gärtner, “Structural
    Elements Regulating the Photochromicity in a Cyanobacteriochrome,” <i>Proceedings
    of the National Academy of Sciences</i>, 2020.
  mla: Xu, Xiuling, et al. “Structural Elements Regulating the Photochromicity in
    a Cyanobacteriochrome.” <i>Proceedings of the National Academy of Sciences</i>,
    201910208, 2020, doi:<a href="https://doi.org/10.1073/pnas.1910208117">10.1073/pnas.1910208117</a>.
  short: X. Xu, A. Port, C. Wiebeler, K.-H. Zhao, I. Schapiro, W. Gärtner, Proceedings
    of the National Academy of Sciences (2020).
date_created: 2020-01-23T08:16:24Z
date_updated: 2022-01-06T06:52:30Z
doi: 10.1073/pnas.1910208117
language:
- iso: eng
project:
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: Proceedings of the National Academy of Sciences
publication_identifier:
  issn:
  - 0027-8424
  - 1091-6490
publication_status: published
status: public
title: Structural Elements Regulating the Photochromicity in a Cyanobacteriochrome
type: journal_article
user_id: '40778'
year: '2020'
...
---
_id: '23626'
abstract:
- lang: eng
  text: <jats:p>Interfaces of room temperature ionic liquids (RTILs) are important
    for both applications and basic science and are therefore intensely studied. However,
    the evolution of their interface structure with the cation’s alkyl chain length
    n from Coulomb to van der Waals interaction domination has not yet been studied
    for even a single broad homologous RTIL series. We present here such a study of
    the liquid–air interface for <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML"
    overflow="scroll"><m:mrow><m:mpadded width="+1.7pt"><m:mi>n</m:mi></m:mpadded><m:mo>=</m:mo><m:mrow><m:mpadded
    width="+1.7pt"><m:mn>2</m:mn></m:mpadded><m:mtext>to</m:mtext><m:mo> </m:mo><m:mn>22</m:mn></m:mrow></m:mrow></m:math></jats:inline-formula>,
    using angstrom-resolution X-ray methods. For <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML"
    overflow="scroll"><m:mrow><m:mpadded width="+1.7pt"><m:mi>n</m:mi></m:mpadded><m:mo
    mathvariant="bold">&lt;</m:mo><m:mn>6</m:mn></m:mrow></m:math></jats:inline-formula>,
    a typical “simple liquid” monotonic surface-normal electron density profile <jats:inline-formula><m:math
    xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mrow><m:msub><m:mi>ρ</m:mi><m:mi>e</m:mi></m:msub><m:mrow><m:mo
    stretchy="false">(</m:mo><m:mi>z</m:mi><m:mo stretchy="false">)</m:mo></m:mrow></m:mrow></m:math></jats:inline-formula>
    is obtained, like those of water and organic solvents. For <jats:inline-formula><m:math
    xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"><m:mrow><m:mpadded
    width="+1.7pt"><m:mi>n</m:mi></m:mpadded><m:mo mathvariant="bold">&gt;</m:mo><m:mn>6</m:mn></m:mrow></m:math></jats:inline-formula>,
    increasingly more pronounced nanoscale self-segregation of the molecules’ charged
    moieties and apolar chains yields surface layering with alternating regions of
    headgroups and chains. The layering decays into the bulk over a few, to a few
    tens, of nanometers. The layering periods and decay lengths, their linear n dependence,
    and slopes are discussed within two models, one with partial-chain interdigitation
    and the other with liquid-like chains. No surface-parallel long-range order is
    found within the surface layer. For <jats:inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML"
    overflow="scroll"><m:mrow><m:mpadded width="+1.7pt"><m:mi>n</m:mi></m:mpadded><m:mo>=</m:mo><m:mn>22</m:mn></m:mrow></m:math></jats:inline-formula>,
    a different surface phase is observed above melting. Our results also impact general
    liquid-phase issues like supramolecular self-aggregation and bulk–surface structure
    relations.</jats:p>
author:
- first_name: Julia
  full_name: Haddad, Julia
  last_name: Haddad
- first_name: Diego
  full_name: Pontoni, Diego
  last_name: Pontoni
- first_name: Bridget M.
  full_name: Murphy, Bridget M.
  last_name: Murphy
- first_name: Sven
  full_name: Festersen, Sven
  last_name: Festersen
- first_name: Benjamin
  full_name: Runge, Benjamin
  last_name: Runge
- first_name: Olaf M.
  full_name: Magnussen, Olaf M.
  last_name: Magnussen
- first_name: Hans-Georg
  full_name: Steinrück, Hans-Georg
  id: '84268'
  last_name: Steinrück
  orcid: 0000-0001-6373-0877
- first_name: Harald
  full_name: Reichert, Harald
  last_name: Reichert
- first_name: Benjamin M.
  full_name: Ocko, Benjamin M.
  last_name: Ocko
- first_name: Moshe
  full_name: Deutsch, Moshe
  last_name: Deutsch
citation:
  ama: Haddad J, Pontoni D, Murphy BM, et al. Surface structure evolution in a homologous
    series of ionic liquids. <i>Proceedings of the National Academy of Sciences</i>.
    2018;115:E1100-E1107. doi:<a href="https://doi.org/10.1073/pnas.1716418115">10.1073/pnas.1716418115</a>
  apa: Haddad, J., Pontoni, D., Murphy, B. M., Festersen, S., Runge, B., Magnussen,
    O. M., Steinrück, H.-G., Reichert, H., Ocko, B. M., &#38; Deutsch, M. (2018).
    Surface structure evolution in a homologous series of ionic liquids. <i>Proceedings
    of the National Academy of Sciences</i>, <i>115</i>, E1100–E1107. <a href="https://doi.org/10.1073/pnas.1716418115">https://doi.org/10.1073/pnas.1716418115</a>
  bibtex: '@article{Haddad_Pontoni_Murphy_Festersen_Runge_Magnussen_Steinrück_Reichert_Ocko_Deutsch_2018,
    title={Surface structure evolution in a homologous series of ionic liquids}, volume={115},
    DOI={<a href="https://doi.org/10.1073/pnas.1716418115">10.1073/pnas.1716418115</a>},
    journal={Proceedings of the National Academy of Sciences}, author={Haddad, Julia
    and Pontoni, Diego and Murphy, Bridget M. and Festersen, Sven and Runge, Benjamin
    and Magnussen, Olaf M. and Steinrück, Hans-Georg and Reichert, Harald and Ocko,
    Benjamin M. and Deutsch, Moshe}, year={2018}, pages={E1100–E1107} }'
  chicago: 'Haddad, Julia, Diego Pontoni, Bridget M. Murphy, Sven Festersen, Benjamin
    Runge, Olaf M. Magnussen, Hans-Georg Steinrück, Harald Reichert, Benjamin M. Ocko,
    and Moshe Deutsch. “Surface Structure Evolution in a Homologous Series of Ionic
    Liquids.” <i>Proceedings of the National Academy of Sciences</i> 115 (2018): E1100–1107.
    <a href="https://doi.org/10.1073/pnas.1716418115">https://doi.org/10.1073/pnas.1716418115</a>.'
  ieee: 'J. Haddad <i>et al.</i>, “Surface structure evolution in a homologous series
    of ionic liquids,” <i>Proceedings of the National Academy of Sciences</i>, vol.
    115, pp. E1100–E1107, 2018, doi: <a href="https://doi.org/10.1073/pnas.1716418115">10.1073/pnas.1716418115</a>.'
  mla: Haddad, Julia, et al. “Surface Structure Evolution in a Homologous Series of
    Ionic Liquids.” <i>Proceedings of the National Academy of Sciences</i>, vol. 115,
    2018, pp. E1100–07, doi:<a href="https://doi.org/10.1073/pnas.1716418115">10.1073/pnas.1716418115</a>.
  short: J. Haddad, D. Pontoni, B.M. Murphy, S. Festersen, B. Runge, O.M. Magnussen,
    H.-G. Steinrück, H. Reichert, B.M. Ocko, M. Deutsch, Proceedings of the National
    Academy of Sciences 115 (2018) E1100–E1107.
date_created: 2021-09-01T09:47:27Z
date_updated: 2022-01-06T06:55:57Z
department:
- _id: '633'
doi: 10.1073/pnas.1716418115
intvolume: '       115'
language:
- iso: eng
page: E1100-E1107
publication: Proceedings of the National Academy of Sciences
publication_identifier:
  issn:
  - 0027-8424
  - 1091-6490
publication_status: published
status: public
title: Surface structure evolution in a homologous series of ionic liquids
type: journal_article
user_id: '84268'
volume: 115
year: '2018'
...
---
_id: '41838'
abstract:
- lang: eng
  text: "<jats:title>Significance</jats:title>\r\n          <jats:p>The hierarchical
    assembly pathway of the cytoskeletal protein vimentin may be responsible for the
    astonishing mechanical properties of the emerging filaments, such as high flexibility
    and extensibility, and thus play a key role in cellular mechanics. A two-step
    assembly mechanism, involving a lateral and a subsequent elongational step, has
    been established; however, the elongational step could not be followed in solution.
    Here, we show direct in situ observation and modeling of the elongation reaction
    of the filaments on the relevant length and time scales, using time-resolved,
    multiangle static and dynamic light scattering. We thus achieve sufficient spatio-temporal
    resolution without the need of labeling, staining, or adsorption to substrates.</jats:p>"
author:
- first_name: Carlos G.
  full_name: Lopez, Carlos G.
  last_name: Lopez
- first_name: Oliva
  full_name: Saldanha, Oliva
  last_name: Saldanha
- first_name: Klaus
  full_name: Huber, Klaus
  id: '237'
  last_name: Huber
- first_name: Sarah
  full_name: Köster, Sarah
  last_name: Köster
citation:
  ama: 'Lopez CG, Saldanha O, Huber K, Köster S. Lateral association and elongation
    of vimentin intermediate filament proteins: A time-resolved light-scattering study.
    <i>Proceedings of the National Academy of Sciences</i>. 2016;113(40):11152-11157.
    doi:<a href="https://doi.org/10.1073/pnas.1606372113">10.1073/pnas.1606372113</a>'
  apa: 'Lopez, C. G., Saldanha, O., Huber, K., &#38; Köster, S. (2016). Lateral association
    and elongation of vimentin intermediate filament proteins: A time-resolved light-scattering
    study. <i>Proceedings of the National Academy of Sciences</i>, <i>113</i>(40),
    11152–11157. <a href="https://doi.org/10.1073/pnas.1606372113">https://doi.org/10.1073/pnas.1606372113</a>'
  bibtex: '@article{Lopez_Saldanha_Huber_Köster_2016, title={Lateral association and
    elongation of vimentin intermediate filament proteins: A time-resolved light-scattering
    study}, volume={113}, DOI={<a href="https://doi.org/10.1073/pnas.1606372113">10.1073/pnas.1606372113</a>},
    number={40}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings
    of the National Academy of Sciences}, author={Lopez, Carlos G. and Saldanha, Oliva
    and Huber, Klaus and Köster, Sarah}, year={2016}, pages={11152–11157} }'
  chicago: 'Lopez, Carlos G., Oliva Saldanha, Klaus Huber, and Sarah Köster. “Lateral
    Association and Elongation of Vimentin Intermediate Filament Proteins: A Time-Resolved
    Light-Scattering Study.” <i>Proceedings of the National Academy of Sciences</i>
    113, no. 40 (2016): 11152–57. <a href="https://doi.org/10.1073/pnas.1606372113">https://doi.org/10.1073/pnas.1606372113</a>.'
  ieee: 'C. G. Lopez, O. Saldanha, K. Huber, and S. Köster, “Lateral association and
    elongation of vimentin intermediate filament proteins: A time-resolved light-scattering
    study,” <i>Proceedings of the National Academy of Sciences</i>, vol. 113, no.
    40, pp. 11152–11157, 2016, doi: <a href="https://doi.org/10.1073/pnas.1606372113">10.1073/pnas.1606372113</a>.'
  mla: 'Lopez, Carlos G., et al. “Lateral Association and Elongation of Vimentin Intermediate
    Filament Proteins: A Time-Resolved Light-Scattering Study.” <i>Proceedings of
    the National Academy of Sciences</i>, vol. 113, no. 40, Proceedings of the National
    Academy of Sciences, 2016, pp. 11152–57, doi:<a href="https://doi.org/10.1073/pnas.1606372113">10.1073/pnas.1606372113</a>.'
  short: C.G. Lopez, O. Saldanha, K. Huber, S. Köster, Proceedings of the National
    Academy of Sciences 113 (2016) 11152–11157.
date_created: 2023-02-06T12:49:36Z
date_updated: 2023-02-06T12:49:55Z
department:
- _id: '314'
doi: 10.1073/pnas.1606372113
intvolume: '       113'
issue: '40'
keyword:
- Multidisciplinary
language:
- iso: eng
page: 11152-11157
publication: Proceedings of the National Academy of Sciences
publication_identifier:
  issn:
  - 0027-8424
  - 1091-6490
publication_status: published
publisher: Proceedings of the National Academy of Sciences
status: public
title: 'Lateral association and elongation of vimentin intermediate filament proteins:
  A time-resolved light-scattering study'
type: journal_article
user_id: '237'
volume: 113
year: '2016'
...
---
_id: '23487'
abstract:
- lang: eng
  text: Optical 2D Fourier transform spectroscopy (2DFTS) provides insight into the
    many-body interactions in direct gap semiconductors by separating the contributions
    to the coherent nonlinear optical response. We demonstrate these features of optical
    2DFTS by studying the heavy-hole and light-hole excitonic resonances in a gallium
    arsenide quantum well at low temperature. Varying the polarization of the incident
    beams exploits selection rules to achieve further separation. Calculations using
    a full many-body theory agree well with experimental results and unambiguously
    demonstrate the dominance of many-body physics.
author:
- first_name: T.
  full_name: Zhang, T.
  last_name: Zhang
- first_name: I.
  full_name: Kuznetsova, I.
  last_name: Kuznetsova
- first_name: Torsten
  full_name: Meier, Torsten
  id: '344'
  last_name: Meier
  orcid: 0000-0001-8864-2072
- first_name: X.
  full_name: Li, X.
  last_name: Li
- first_name: R. P.
  full_name: Mirin, R. P.
  last_name: Mirin
- first_name: P.
  full_name: Thomas, P.
  last_name: Thomas
- first_name: S. T.
  full_name: Cundiff, S. T.
  last_name: Cundiff
citation:
  ama: Zhang T, Kuznetsova I, Meier T, et al. Polarization-dependent optical 2D Fourier
    transform spectroscopy of semiconductors. <i>Proceedings of the National Academy
    of Sciences (PNAS)</i>. 2007;104(36):14227-14232. doi:<a href="https://doi.org/10.1073/pnas.0701273104">10.1073/pnas.0701273104</a>
  apa: Zhang, T., Kuznetsova, I., Meier, T., Li, X., Mirin, R. P., Thomas, P., &#38;
    Cundiff, S. T. (2007). Polarization-dependent optical 2D Fourier transform spectroscopy
    of semiconductors. <i>Proceedings of the National Academy of Sciences (PNAS)</i>,
    <i>104</i>(36), 14227–14232. <a href="https://doi.org/10.1073/pnas.0701273104">https://doi.org/10.1073/pnas.0701273104</a>
  bibtex: '@article{Zhang_Kuznetsova_Meier_Li_Mirin_Thomas_Cundiff_2007, title={Polarization-dependent
    optical 2D Fourier transform spectroscopy of semiconductors}, volume={104}, DOI={<a
    href="https://doi.org/10.1073/pnas.0701273104">10.1073/pnas.0701273104</a>}, number={36},
    journal={Proceedings of the National Academy of Sciences (PNAS)}, author={Zhang,
    T. and Kuznetsova, I. and Meier, Torsten and Li, X. and Mirin, R. P. and Thomas,
    P. and Cundiff, S. T.}, year={2007}, pages={14227–14232} }'
  chicago: 'Zhang, T., I. Kuznetsova, Torsten Meier, X. Li, R. P. Mirin, P. Thomas,
    and S. T. Cundiff. “Polarization-Dependent Optical 2D Fourier Transform Spectroscopy
    of Semiconductors.” <i>Proceedings of the National Academy of Sciences (PNAS)</i>
    104, no. 36 (2007): 14227–32. <a href="https://doi.org/10.1073/pnas.0701273104">https://doi.org/10.1073/pnas.0701273104</a>.'
  ieee: 'T. Zhang <i>et al.</i>, “Polarization-dependent optical 2D Fourier transform
    spectroscopy of semiconductors,” <i>Proceedings of the National Academy of Sciences
    (PNAS)</i>, vol. 104, no. 36, pp. 14227–14232, 2007, doi: <a href="https://doi.org/10.1073/pnas.0701273104">10.1073/pnas.0701273104</a>.'
  mla: Zhang, T., et al. “Polarization-Dependent Optical 2D Fourier Transform Spectroscopy
    of Semiconductors.” <i>Proceedings of the National Academy of Sciences (PNAS)</i>,
    vol. 104, no. 36, 2007, pp. 14227–32, doi:<a href="https://doi.org/10.1073/pnas.0701273104">10.1073/pnas.0701273104</a>.
  short: T. Zhang, I. Kuznetsova, T. Meier, X. Li, R.P. Mirin, P. Thomas, S.T. Cundiff,
    Proceedings of the National Academy of Sciences (PNAS) 104 (2007) 14227–14232.
date_created: 2021-08-24T09:08:25Z
date_updated: 2023-04-21T22:45:08Z
department:
- _id: '15'
- _id: '170'
- _id: '293'
- _id: '230'
doi: 10.1073/pnas.0701273104
intvolume: '       104'
issue: '36'
language:
- iso: eng
page: 14227-14232
publication: Proceedings of the National Academy of Sciences (PNAS)
publication_identifier:
  issn:
  - 0027-8424
  - 1091-6490
publication_status: published
status: public
title: Polarization-dependent optical 2D Fourier transform spectroscopy of semiconductors
type: journal_article
user_id: '49063'
volume: 104
year: '2007'
...