scholarly journals Structural view of the helicase reveals thatZika virususes a conserved mechanism for unwinding RNA

2018 ◽  
Vol 74 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Lei Li ◽  
Jin Wang ◽  
Zhihui Jia ◽  
Neil Shaw
Keyword(s):  
Hydrogen Bonding ◽  
High Resolution ◽  
Crystal Structures ◽  
Zika Virus ◽  
Healthcare Professionals ◽  
Neurological Complications ◽  
Side Chain ◽  
Hydrogen Bonding Interactions ◽  
Solvent Molecules

Recent studies suggest a link between infection byZika virus(ZIKV) and the development of neurological complications. The lack of ZIKV-specific therapeutics has alarmed healthcare professionals worldwide. Here, crystal structures of apo and AMPPNP- and Mn2+-bound forms of the essential helicase of ZIKV refined to 1.78 and 1.3 Å resolution, respectively, are reported. The structures reveal a conserved trimodular topology of the helicase. ATP and Mn2+are tethered between two RecA-like domains by conserved hydrogen-bonding interactions. The binding of ligands induces the movement of backbone Cα and side-chain atoms. Numerous solvent molecules are observed in the vicinity of the AMPPNP, suggesting a role in catalysis. These high-resolution structures could be useful for the design of inhibitors targeting the helicase of ZIKV for the treatment of infections caused by ZIKV.

The significance of the Cα substituent in the selective inhibition of matrix metalloproteinases 1 and 9

2011 ◽  
Vol 392 (11) ◽  
Author(s):  
Riyad Domingo ◽  
Kelly Chibale ◽  
Edward D. Sturrock
Keyword(s):  
Hydrogen Bonding ◽  
Matrix Metalloproteinases ◽  
Active Sites ◽  
Unsaturated Compound ◽  
Selective Inhibition ◽  
Acid Group ◽  
Side Chain ◽  
Carboxylic Acid Group ◽  
Lead Compounds ◽  
Hydrogen Bonding Interactions

Abstract Matrix metalloproteinases (MMPs) cleave and degrade most components of the extracellular matrix, and unregulated MMP activity has been correlated to cancer and metastasis. Hence there is a burgeoning need to develop inhibitors that bind selectively to structurally similar MMPs. The inhibition profiles of peptidomimetics containing Cα substituents at the α,β unsaturated carbon were evaluated against the recombinant forms of ADAM17, MMP1, and MMP9. The dicarboxylic acid D2 and hydroxamate C2 inhibited MMP9 but not MMP1. The unsaturated compound E2 displayed selective inhibition for MMP1, compared with the saturated precursor C2, with an IC50 value of 3.91 μm. The molecular basis for this selectivity was further investigated by the molecular docking of E2 and D2 into the active sites of MMP1 and MMP9. These data demonstrate hydrogen-bonding interactions between the carbonyl group of the Cα substituent of E2 and the side chain of Asn180 present in the active site of MMP1. Conversely, the docked MMP9-D2 structure shows hydrophobic and hydrogen bonding between the ligand’s morpholine substituent and second carboxylic acid group with Leu187 and an amide, respectively. This study suggests that substituents other than P1′ and P2′ may confer selectivity among MMPs and may aid in the search for novel lead compounds.

scholarly journals A computational study on how structure influences the optical properties in model crystal structures of amyloid fibrils

2017 ◽  
Vol 19 (5) ◽  
pp. 4030-4040 ◽  
Author(s):  
Luca Grisanti ◽  
Dorothea Pinotsi ◽  
Ralph Gebauer ◽  
Gabriele S. Kaminski Schierle ◽  
Ali A. Hassanali
Keyword(s):  
Optical Properties ◽  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Crystal Structures ◽  
Amyloid Fibrils ◽  
Computational Study ◽  
Model Systems ◽  
Hydrogen Bonding Interactions ◽  
Model Crystal ◽  
Different Types

Different types of hydrogen bonding interactions that occur in amyloids model systems and molecular factors that control the susceptibility of the protons to undergo proton transfer and how this couples to the optical properties.

Synthesis and crystal structures of some bis(3-methyl-1H-indol-2-yl)(salicyl)methanes

2019 ◽  
Vol 75 (1) ◽  
pp. 65-69
Author(s):  
Wyatt Cole ◽  
Stephanie L. Hemmingson ◽  
Audrey C. Eisenberg ◽  
Catherine A. Ulman ◽  
Joseph M. Tanski ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Dimethyl Sulfoxide ◽  
Crystal Structures ◽  
Double Layer ◽  
Acid Catalysis ◽  
Double Layers ◽  
One Dimensional ◽  
Salicylaldehyde Derivatives ◽  
Central Carbon ◽  
Solvent Molecules

Four 2,2′-bisindolylmethanes (BIMs), a useful class of polyindolyl species joined to a central carbon, were synthesized using salicylaldehyde derivatives and simple acid catalysis; these are 2-[bis(3-methyl-1H-indol-2-yl)methyl]-6-methylphenol, (IIa), 2-[bis(3-methyl-1H-indol-2-yl)methyl]-4,6-dichlorophenol, (IIb), 2-[bis(3-methyl-1H-indol-2-yl)methyl]-4-nitrophenol, (IIc), and 2-[bis(3-methyl-1H-indol-2-yl)methyl]-4,6-di-tert-butylphenol, (IId). BIMs (IIa) and (IIb) were characterized crystallographically as the dimethyl sulfoxide (DMSO) disolvates, i.e. C26H24N2O·2C2H6OS and C25H20Cl2N2O·2C2H6OS, respectively. Both form strikingly similar one-dimensional hydrogen-bonding chain motifs with the DMSO solvent molecules. BIM (IIa) packs into double layers of chains whose orientations alternate every double layer, while (IIb) forms more simply packed chains along the a axis. BIM (IIa) has a remarkably long c axis.

scholarly journals Crystal structures ofN′-aminopyridine-2-carboximidamide andN′-{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide

2017 ◽  
Vol 73 (7) ◽  
pp. 1021-1025
Author(s):  
Francois Eya'ane Meva ◽  
Timothy John Prior ◽  
David John Evans ◽  
Emmanuel Roland Mang
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Dimensional Chain ◽  
Two Dimensional ◽  
One Dimensional ◽  
Bond Lengths ◽  
Hydrogen Bonding Interactions ◽  
Hydrogen Bonding Network

The crystal structures ofN′-aminopyridine-2-carboximidamide (C6H8N4),1, andN′-{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide (C13H13N5),2, are described. The non-H atoms in compound1are nearly planar (r.m.s. deviation from planarity = 0.0108 Å), while2is twisted about the central N—N bond by 17.8 (2)°. Both molecules are linked by intermolecular N—H...N hydrogen-bonding interactions;1forms a two-dimensional hydrogen-bonding network and for2the network is a one-dimensional chain. The bond lengths of these molecules are similar to those in other literature reports of azine and diimine systems.

scholarly journals Crystal Structures of Four Novel Thiophene/Phenyl-piperidine Hybrid Chalcones

2014 ◽  
Vol 70 (a1) ◽  
pp. C1020-C1020
Author(s):  
Masood Parvez ◽  
Muhammad Bakhtiar ◽  
Muhammad Baqir ◽  
Muhammad Zia-ur-Rehman
Keyword(s):  
Hydrogen Bonding ◽  
Pharmaceutical Industry ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Drug Targets ◽  
Important Class ◽  
Hydrogen Bonding Interactions ◽  
Benzene Rings ◽  
Type C

Chalcones constitute an important class of bioactive drug targets in the pharmaceutical industry that includes anti-ulcerative drug sofalcone. In continuation of our work, the crystal structures of four closely related 1-phenyl-piperidine based chalcones will be presented. I: C19 H21NOS, MW = 311.43, T = 173(2) K, λ = 0.71073 Å, Orthorhombic, P b c a, a = 10.1045(4), b = 10.5358(4), c = 30.6337(12) Å, V = 3261.2(2) Å3, Z = 8, Dc = 1.269 Mg/m3, F (000) = 1328, R [I>2σ(I)] = 0.059. II: C18H19NOS, MW = 297.40, T = 173(2) K, λ = 1.54178 Å, Orthorhombic, P b c a, a = 8.9236(2), b = 11.0227(2), c = 30.8168(6) Å, V = 3031.21(11) Å3 Z = 8, Dc = 1.303 Mg/m3, F (000) = 1264, R [I>2σ(I)] = 0.035. III: C18H19NOS, MW = 297.40, T = 173(2) K, λ = 1.54178 Å, Orthorhombic, P b c a, a = 8.82990(10), b = 11.0061(2), c = 31.2106(5) Å, V = 3033.13(8) Å3, Z = 8, Dc = 1.303 Mg/m3, F (000) = 1264, R [I>2σ(I)] = 0.048. IV: C18H18ClNOS, MW = 331.84, T = 173(2) K, λ = 0.71073 Å, Monoclinic, P 21/c, a = 14.1037(4), b = 11.3153(3), c = 10.1290(2) Å, β = 101.1367(14)0, V = 1586.02(7) Å3, Z = 4, Dc = 1.390 Mg/m3, F (000) = 696, R [I>2σ(I)] = 0.038. The crystals of I, II and III are isomorphous. In all structures, the piperidine rings are in chair conformations, thiophene rings are essentially planar and the C=C bonds in the prop-2-en-1-one fragment adopt E-conformation. All crystal structures are devoid of any classical hydrogen bonds. However, non-classical hydrogen bonding interactions of the type C---H...O in compounds II, III and IV link the molecules into chains extended along the b-axis. Moreover, C---H...Cg interactions involving thiophene rings in I and III and benzene ring in IV and π...π interactions between benzene rings lying about inversion centers are present in II and III.

scholarly journals Crystal structures of three complexes of zinc chloride with tri-tert-butylphosphane

2016 ◽  
Vol 72 (1) ◽  
pp. 35-39 ◽  
Author(s):  
Aaron D. Finke ◽  
Danielle L. Gray ◽  
Jeffrey S. Moore
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Zinc Chloride ◽  
Chloride Complex ◽  
Lewis Base ◽  
Ambient Conditions ◽  
Hydrogen Bonding Interactions ◽  
Complex Forms ◽  
Cl Atoms

Under anhydrous conditions and in the absence of a Lewis-base solvent, a zinc chloride complex with tri-tert-butylphosphane as the μ-bridged dimer is formed,viz.di-μ-chlorido-bis[chloridobis(tri-tert-butylphosphane)zinc], [ZnCl4(C12H27P)2], (1), which features a nearly square-shaped (ZnCl)2cyclic core and whose Cl atoms interact weakly with C—H groups on the phosphane ligand. In the presence of THF, monomeric dichlorido(tetrahydrofuran-κO)(tri-tert-butylphosphane-κP)zinc, [ZnCl2(C4H8O)(C12H27P)] or [P(tBu3)(THF)ZnCl2], (2), is formed. This slightly distorted tetrahedral Zn complex has weak C—H...Cl interactions between the Cl atoms and phosphane and THF C—H groups. Under ambient conditions, the hydrolysed complex tri-tert-butylphosphonium aquatrichloridozincate 1,2-dichloroethane monosolvate, (C12H28P)[ZnCl3(H2O)]·C2H4Cl2or [HPtBu3]+[(H2O)ZnCl3]−·C2H4Cl2, (3), is formed. This complex forms chains of [(H2O)ZnCl3]−anions from hydrogen-bonding interactions between the water H atoms and Cl atoms that propagate along thebaxis.

scholarly journals (η6-Benzene)(carbonato-κ2O,O′)[dicyclohexyl(naphthalen-1-ylmethyl)phosphane-κP]ruthenium(II) chloroform trisolvate

2014 ◽  
Vol 70 (7) ◽  
pp. m272-m273
Author(s):  
Saravanan Gowrisankar ◽  
Helfried Neumann ◽  
Anke Spannenberg ◽  
Matthias Beller
Keyword(s):  
Hydrogen Bonding ◽  
Metal Complex ◽  
Room Temperature ◽  
Crystal Packing ◽  
The Other ◽  
Asymmetric Unit ◽  
Carbonate Group ◽  
Acta Cryst ◽  
Hydrogen Bonding Interactions ◽  
Solvent Molecules

The title compound, [Ru(CO3)(η6-C6H6){(C6H11)2P(CH2C10H7)}]·3CHCl3, was synthesized by carbonation of [RuCl2(η6-C6H6){(C6H11)2P(CH2C10H7)}] with NaHCO3in methanol at room temperature. The RuIIatom is surrounded by a benzene ligand, a chelating carbonate group and a phosphane ligand in a piano-stool configuration. The crystal packing is consolidated by C—H...O and C—H...Cl hydrogen-bonding interactions between adjacent metal complexes and between the complexes and the solvent molecules. The asymmetric unit contains one metal complex and three chloroform solvent molecules of which only one was modelled. The estimated diffraction contributions of the other two strongly disordered chloroform solvent molecules were substracted from the observed diffraction data using the SQUEEZE procedure inPLATON[Spek (2009).Acta Cryst.D65, 148–155].

The double-stranded ladder-like structure of poly[[bis(μ2-acetato-κ2O:O′)bis(acetato-κO)bis(μ-4,4′-bipyridine-κ2N:N′)dicopper(II)] 4-nitrophenol disolvate tetrahydrate]

2013 ◽  
Vol 69 (10) ◽  
pp. 1100-1103
Author(s):  
Sizwe J. Zamisa ◽  
Patrick Ndungu ◽  
Bernard Omondi
Keyword(s):  
Hydrogen Bonding ◽  
Coordination Polymer ◽  
Title Compound ◽  
Basal Plane ◽  
Copper Acetate ◽  
Water Solvent ◽  
Hydrogen Bonding Interactions ◽  
Complex Forms ◽  
Solvent Molecules ◽  
Unit Cell Length

The reaction of 4,4′-bipyridine with copper acetate in the presence of 4-nitrophenol led to the formation of the title compound, {[Cu(CH3COO)2(C10H8N2)]·C6H5NO3·2H2O}n. The complex forms a double-stranded ladder-like coordination polymer extending along thebaxis. The double-stranded polymers are separated by 4-nitrophenol and water solvent molecules. The two CuIIcentres of the centrosymmetric Cu2O2ladder rungs have square-pyramidal coordination environments, which are formed by two acetate O atoms and two 4,4′-bipyridine N atoms in the basal plane and another acetate O atom at the apex. The ladder-like double strands are separated from each other by one unit-cell length along thecaxis, and are connected by the water and 4-nitrophenol molecules through a series of O—H...O and C—H...O hydrogen-bonding interactions and two unique intermolecular π–π interactions.

scholarly journals Crystal structures of chlorido[dihydroxybis(1-iminoethoxy)]arsanido-κ3 N,As,N′]platinum(II) and of a polymorph of chlorido[dihydroxybis(1-iminopropoxy)arsanido-κ3 N,As,N′]platinum(II)

2020 ◽  
Vol 76 (2) ◽  
pp. 180-185
Author(s):  
Nina R. Marogoa ◽  
D.V. Kama ◽  
Hendrik G. Visser ◽  
M. Schutte-Smith
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Donor Ligands ◽  
Intermolecular Hydrogen Bonding ◽  
Π Interactions ◽  
Hydrogen Bonding Interactions ◽  
Oxygen Donor ◽  
Dimensional Network

Each central platinum(II) atom in the crystal structures of chlorido[dihydroxybis(1-iminoethoxy)arsanido-κ3 N,As,N′]platinum(II), [Pt(C4H10AsN2O4)Cl] (1), and of chlorido[dihydroxybis(1-iminopropoxy)arsanido-κ3 N,As,N′]platinum(II), [Pt(C6H14AsN2O4)Cl] (2), is coordinated by two nitrogen donor atoms, a chlorido ligand and to arsenic, which, in turn, is coordinated by two oxygen donor ligands, two hydroxyl ligands and the platinum(II) atom. The square-planar and trigonal–bipyramidal coordination environments around platinum and arsenic, respectively, are significantly distorted with the largest outliers being 173.90 (13) and 106.98 (14)° for platinum and arsenic in (1), and 173.20 (14)° and 94.20 (9)° for (2), respectively. One intramolecular and four classical intermolecular hydrogen-bonding interactions are observed in the crystal structure of (1), which give rise to an infinite three-dimensional network. A similar situation (one intramolecular and four classical intermolecular hydrogen-bonding interactions) is observed in the crystal structure of (2). Various π-interactions are present in (1) between the platinum(II) atom and the centroid of one of the five-membered rings formed by Pt, As, C, N, O with a distance of 3.7225 (7) Å, and between the centroids of five-membered (Pt, As, C, N, O) rings of neighbouring molecules with distances of 3.7456 (4) and 3.7960 (6) Å. Likewise, weak π-interactions are observed in (2) between the platinum(II) atom and the centroid of one of the five-membered rings formed by Pt, As, C, N, O with a distance of 3.8213 (2) Å, as well as between the Cl atom and the centroid of a symmetry-related five-membered ring with a distance of 3.8252 (12) Å. Differences between (2) and the reported polymorph [Miodragović et al. (2013). Angew. Chem. Int. Ed. 52, 10749–10752] are discussed.

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