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  1. Article ; Online: Direct detection of coupled proton and electron transfers in human manganese superoxide dismutase

    Jahaun Azadmanesh / William E. Lutz / Leighton Coates / Kevin L. Weiss / Gloria E. O. Borgstahl

    Nature Communications, Vol 12, Iss 1, Pp 1-

    2021  Volume 12

    Abstract: Human manganese superoxide dismutase (MnSOD) is an oxidoreductase that uses concerted proton and electron transfers to reduce the levels of superoxide radicals in mitochondria, but mechanistic insights into this process are limited. Here, the authors ... ...

    Abstract Human manganese superoxide dismutase (MnSOD) is an oxidoreductase that uses concerted proton and electron transfers to reduce the levels of superoxide radicals in mitochondria, but mechanistic insights into this process are limited. Here, the authors report neutron crystal structures of Mn3+SOD and Mn2+SOD, revealing changes in the protonation states of key residues in the enzyme active site during the redox cycle.
    Keywords Science ; Q
    Language English
    Publishing date 2021-04-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Room-temperature photo-induced martensitic transformation in a protein crystal. Corrigendum

    Steven Dajnowicz / Patricia S. Langan / Kevin L. Weiss / Ilia N. Ivanov / Andrey Kovalevsky

    IUCrJ, Vol 6, Iss 4, Pp 781-

    2019  Volume 781

    Abstract: The article by Dajnowicz et al. [IUCrJ (2019). 6, 619–629] is withdrawn. ...

    Abstract The article by Dajnowicz et al. [IUCrJ (2019). 6, 619–629] is withdrawn.
    Keywords martensitic transformations ; reversibly switchable fluorescent proteins ; fluorescence ; tetramerization ; isomerization ; chromophore deprotonation ; UV–vis absorption spectroscopy ; room-temperature X-ray photocrystallography ; Science ; Q
    Language English
    Publishing date 2019-07-01T00:00:00Z
    Publisher International Union of Crystallography
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Room-temperature photo-induced martensitic transformation in a protein crystal

    Steven Dajnowicz / Patricia S. Langan / Kevin L. Weiss / Ilia N. Ivanov / Andrey Kovalevsky

    IUCrJ, Vol 6, Iss 4, Pp 619-

    2019  Volume 629

    Abstract: Martensitic transformations are the first-order crystal-to-crystal phase transitions that occur mostly in materials such as steel, alloys and ceramics, thus having many technological applications. These phase transitions are rarely observed in molecular ... ...

    Abstract Martensitic transformations are the first-order crystal-to-crystal phase transitions that occur mostly in materials such as steel, alloys and ceramics, thus having many technological applications. These phase transitions are rarely observed in molecular crystals and have not been detected in protein crystals. Reversibly switchable fluorescent proteins are widely used in biotechnology, including super-resolution molecular imaging, and hold promise as candidate biomaterials for future high-tech applications. Here, we report on a reversibly switchable fluorescent protein, Tetdron, whose crystals undergo a photo-induced martensitic transformation at room temperature. Room-temperature X-ray crystallography demonstrates that at equilibrium Tetdron chromophores are all in the trans configuration, with an ∼1:1 mixture of their protonated and deprotonated forms. Irradiation of a Tetdron crystal with 400 nm light induces a martensitic transformation, which results in Tetdron tetramerization at room temperature revealed by X-ray photocrystallography. Crystal and solution spectroscopic measurements provide evidence that the photo-induced martensitic phase transition is coupled with the chromophore deprotonation, but no trans–cis isomerization is detected in the structure of an irradiated crystal. It is hypothesized that protein dynamics assists in the light-induced proton transfer from the chromophore to the bulk solvent and in the ensuing martensitic phase transition. The unique properties of Tetdron may be useful in developing novel biomaterials for optogenetics, data storage and nanotechnology.
    Keywords martensitic transformations ; reversibly switchable fluorescent proteins ; fluorescence ; tetramerization ; isomerization ; chromophore deprotonation ; UV–vis absorption spectroscopy ; room-temperature X-ray photocrystallography ; Science ; Q
    Language English
    Publishing date 2019-07-01T00:00:00Z
    Publisher International Union of Crystallography
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Substrate Binding Stiffens Aspartate Aminotransferase by Altering the Enzyme Picosecond Vibrational Dynamics

    Steven Dajnowicz / Yongqiang Cheng / Luke L. Daemen / Kevin L. Weiss / Oksana Gerlits / Timothy C. Mueser / Andrey Kovalevsky

    ACS Omega, Vol 5, Iss 30, Pp 18787-

    2020  Volume 18797

    Keywords Chemistry ; QD1-999
    Language English
    Publishing date 2020-07-01T00:00:00Z
    Publisher American Chemical Society
    Document type Article ; Online
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  5. Article ; Online: Structural plasticity of the selectivity filter in a nonselective ion channel

    Raktim N. Roy / Kitty Hendriks / Wojciech Kopec / Saeid Abdolvand / Kevin L. Weiss / Bert L. de Groot / Adam Lange / Han Sun / Leighton Coates

    IUCrJ, Vol 8, Iss 3, Pp 421-

    2021  Volume 430

    Abstract: The sodium potassium ion channel (NaK) is a nonselective ion channel that conducts both sodium and potassium across the cellular membrane. A new crystallographic structure of NaK reveals conformational differences in the residues that make up the ... ...

    Abstract The sodium potassium ion channel (NaK) is a nonselective ion channel that conducts both sodium and potassium across the cellular membrane. A new crystallographic structure of NaK reveals conformational differences in the residues that make up the selectivity filter between the four subunits that form the ion channel and the inner helix of the ion channel. The crystallographic structure also identifies a side-entry, ion-conduction pathway for Na+ permeation that is unique to NaK. NMR studies and molecular dynamics simulations confirmed the dynamical nature of the top part of the selectivity filter and the inner helix in NaK as also observed in the crystal structure. Taken together, these results indicate that the structural plasticity of the selectivity filter combined with the dynamics of the inner helix of NaK are vital for the efficient conduction of different ions through the non-selective ion channel of NaK.
    Keywords ion channels ; membrane proteins ; x-ray crystallography ; solid-state nmr ; molecular dynamics ; Science ; Q
    Subject code 572
    Language English
    Publishing date 2021-05-01T00:00:00Z
    Publisher International Union of Crystallography
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Covalent narlaprevir- and boceprevir-derived hybrid inhibitors of SARS-CoV-2 main protease

    Daniel W. Kneller / Hui Li / Gwyndalyn Phillips / Kevin L. Weiss / Qiu Zhang / Mark A. Arnould / Colleen B. Jonsson / Surekha Surendranathan / Jyothi Parvathareddy / Matthew P. Blakeley / Leighton Coates / John M. Louis / Peter V. Bonnesen / Andrey Kovalevsky

    Nature Communications, Vol 13, Iss 1, Pp 1-

    2022  Volume 11

    Abstract: Three covalent hybrid inhibitors of SARS-CoV-2 main protease (Mpro) have been designed and compared to Pfizer’s nirmatrelvir (PF-07321332), providing atomic and thermodynamic details of their binding to the enzyme, and antiviral potency. ...

    Abstract Three covalent hybrid inhibitors of SARS-CoV-2 main protease (Mpro) have been designed and compared to Pfizer’s nirmatrelvir (PF-07321332), providing atomic and thermodynamic details of their binding to the enzyme, and antiviral potency.
    Keywords Science ; Q
    Language English
    Publishing date 2022-04-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
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  7. Article ; Online: The structure of a potassium-selective ion channel reveals a hydrophobic gate regulating ion permeation

    Patricia S. Langan / Venu Gopal Vandavasi / Wojciech Kopec / Brendan Sullivan / Pavel V. Afonne / Kevin L. Weiss / Bert L. de Groot / Leighton Coates

    IUCrJ, Vol 7, Iss 5, Pp 835-

    2020  Volume 843

    Abstract: Protein dynamics are essential to function. One example of this is the various gating mechanisms within ion channels, which are transmembrane proteins that act as gateways into the cell. Typical ion channels switch between an open and closed state via a ... ...

    Abstract Protein dynamics are essential to function. One example of this is the various gating mechanisms within ion channels, which are transmembrane proteins that act as gateways into the cell. Typical ion channels switch between an open and closed state via a conformational transition which is often triggered by an external stimulus, such as ligand binding or pH and voltage differences. The atomic resolution structure of a potassium-selective ion channel named NaK2K has allowed us to observe that a hydrophobic residue at the bottom of the selectivity filter, Phe92, appears in dual conformations. One of the two conformations of Phe92 restricts the diameter of the exit pore around the selectivity filter, limiting ion flow through the channel, while the other conformation of Phe92 provides a larger-diameter exit pore from the selectivity filter. Thus, it can be concluded that Phe92 acts as a hydrophobic gate, regulating the flow of ions through the selectivity filter.
    Keywords potassium ion channels ; gating ; x-ray crystallography ; conformational transitions ; Science ; Q
    Language English
    Publishing date 2020-09-01T00:00:00Z
    Publisher International Union of Crystallography
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: The structure of Toho1 β‐lactamase in complex with penicillin reveals the role of Tyr105 in substrate recognition

    Patricia S. Langan / Venu Gopal Vandavasi / Kevin L. Weiss / Jonathan B. Cooper / Stephan L. Ginell / Leighton Coates

    FEBS Open Bio, Vol 6, Iss 12, Pp 1170-

    2016  Volume 1177

    Abstract: The role of the conserved residue Tyr105 in class A β‐lactamases has been the subject of investigation using both structural studies and saturation mutagenesis. Both have shown that while it does not need to be strictly conserved for activity, it is ... ...

    Abstract The role of the conserved residue Tyr105 in class A β‐lactamases has been the subject of investigation using both structural studies and saturation mutagenesis. Both have shown that while it does not need to be strictly conserved for activity, it is important for substrate recognition. With this in mind we determined the crystal structure of Toho1 β‐lactamase at 15 K to 1.10 Å resolution in complex with penicillin. As expected a ring‐opened penicillin molecule bound to Ser70 the catalytic nucleophile, can clearly be seen in electron density in the active site. In addition to the trapped penicillin, however, are two additional intact ring‐closed penicillin molecules, captured by the enzyme through noncovalent interactions at the edge of the active site.
    Keywords antibiotic resistance ; antibiotics ; enzyme ; enzyme structure ; X‐ray crystallography ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2016-12-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
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  9. Article ; Online: Anomalous X-ray diffraction studies of ion transport in K+ channels

    Patricia S. Langan / Venu Gopal Vandavasi / Kevin L. Weiss / Pavel V. Afonine / Kamel el Omari / Ramona Duman / Armin Wagner / Leighton Coates

    Nature Communications, Vol 9, Iss 1, Pp 1-

    2018  Volume 5

    Abstract: The number of K+ occupied binding sites in the selectivity filter of potassium ion channels is still under debate. Here, the authors collect diffraction data on the K+ selective NaK channel NaK2K at a wavelength of 3.35 Å, close to the K absorption edge, ...

    Abstract The number of K+ occupied binding sites in the selectivity filter of potassium ion channels is still under debate. Here, the authors collect diffraction data on the K+ selective NaK channel NaK2K at a wavelength of 3.35 Å, close to the K absorption edge, revealing that all four binding sites in the selectivity filter are fully occupied by K+ ions.
    Keywords Science ; Q
    Language English
    Publishing date 2018-10-01T00:00:00Z
    Publisher Nature Portfolio
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  10. Article ; Online: Anomalous X-ray diffraction studies of ion transport in K+ channels

    Patricia S. Langan / Venu Gopal Vandavasi / Kevin L. Weiss / Pavel V. Afonine / Kamel el Omari / Ramona Duman / Armin Wagner / Leighton Coates

    Nature Communications, Vol 9, Iss 1, Pp 1-

    2018  Volume 5

    Abstract: The number of K+ occupied binding sites in the selectivity filter of potassium ion channels is still under debate. Here, the authors collect diffraction data on the K+ selective NaK channel NaK2K at a wavelength of 3.35 Å, close to the K absorption edge, ...

    Abstract The number of K+ occupied binding sites in the selectivity filter of potassium ion channels is still under debate. Here, the authors collect diffraction data on the K+ selective NaK channel NaK2K at a wavelength of 3.35 Å, close to the K absorption edge, revealing that all four binding sites in the selectivity filter are fully occupied by K+ ions.
    Keywords Science ; Q
    Language English
    Publishing date 2018-10-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
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