Synthesis and crystal structures of four three-dimensional hybrid materials based on polyoxovanadate bridging macrocyclic copper/nickel complexes

The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′)bis(sparfloxacin-κ2O,O′)manganese(II) dihydrate, [Mn(C8H4O4)(C19H22F2N4O3)2(H2O)0.25]·2H2O or [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O, (I), and bis(sparfloxacin-κ2O,O′)copper(II) benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O3)2](C8H4O4)·2H2O or [Cu(Hspar)2](bdc)·2H2O, (II), are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate). The Mn2+ion in (I) is coordinated by twoO,O′-bidentate Hspar neutral molecules (which exist as zwitterions) and anO,O′-bidentate bdc dianion to generate a distorted MnO6trigonal prism. A very long bond [2.580 (12) Å] from the Mn2+ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II), the Cu2+ion lies on a crystallographic inversion centre and a CuO4square-planar geometry arises from its coordination by twoO,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I) and (II) feature intramolecular N—H...O hydrogen bonds, which closeS(6) rings. In the crystals of both (I) and (II), the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

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Structural Insight into African Swine Fever Virus A179L-Mediated Inhibition of Apoptosis

Journal of Virology ◽

10.1128/jvi.02228-16 ◽

2017 ◽

Vol 91 (6) ◽

Cited By ~ 26

Author(s):

Suresh Banjara ◽

Sofia Caria ◽

Linda K. Dixon ◽

Mark G. Hinds ◽

Marc Kvansakul

Keyword(s):

Crystal Structures ◽

African Swine Fever Virus ◽

Three Dimensional ◽

African Swine Fever ◽

Fever Virus ◽

Structural Basis ◽

Dna Virus ◽

Content Type ◽

Antiapoptotic Proteins ◽

Apoptosis Inhibition

ABSTRACT Programmed cell death is a tightly controlled process critical for the removal of damaged or infected cells. Pro- and antiapoptotic proteins of the Bcl-2 family are pivotal mediators of this process. African swine fever virus (ASFV) is a large DNA virus, the only member of the Asfarviridae family, and harbors A179L, a putative Bcl-2 like protein. A179L has been shown to bind to several proapoptotic Bcl-2 proteins; however, the hierarchy of binding and the structural basis for apoptosis inhibition are currently not understood. We systematically evaluated the ability of A179L to bind proapoptotic Bcl-2 family members and show that A179L is the first antiapoptotic Bcl-2 protein to bind to all major death-inducing mammalian Bcl-2 proteins. We then defined the structural basis for apoptosis inhibition of A179L by determining the crystal structures of A179L bound to both Bid and Bax BH3 motifs. Our findings provide a mechanistic understanding for the potent antiapoptotic activity of A179L by identifying it as the first panprodeath Bcl-2 binder and serve as a platform for more-detailed investigations into the role of A179L during ASFV infection. IMPORTANCE Numerous viruses have acquired strategies to subvert apoptosis by encoding proteins capable of sequestering proapoptotic host proteins. African swine fever virus (ASFV), a large DNA virus and the only member of the Asfarviridae family, encodes the protein A179L, which functions to prevent apoptosis. We show that A179L is unusual among antiapoptotic Bcl-2 proteins in being able to physically bind to all core death-inducing mammalian Bcl-2 proteins. Currently, little is known regarding the molecular interactions between A179L and the proapoptotic Bcl-2 members. Using the crystal structures of A179L bound to two of the identified proapoptotic Bcl-2 proteins, Bid and Bax, we now provide a three-dimensional (3D) view of how A179L sequesters host proapoptotic proteins, which is crucial for subverting premature host cell apoptosis.

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Crystal structures of tricalcium citrates

Powder Diffraction ◽

10.1017/s0885715618000283 ◽

2018 ◽

Vol 33 (2) ◽

pp. 98-107 ◽

Cited By ~ 3

Author(s):

James A. Kaduk

Keyword(s):

Crystal Structures ◽

Density Functional ◽

Three Dimensional ◽

Water Molecules ◽

Calcium Citrate ◽

Powder Diffraction Data ◽

Coordination Polyhedra ◽

X Ray ◽

Calcium Supplements ◽

Dimensional Network

The crystal structures of calcium citrate hexahydrate, calcium citrate tetrahydrate, and anhydrous calcium citrate have been solved using laboratory and synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Both the hexahydrate and tetrahydrate structures are characterized by layers of edge-sharing Ca coordination polyhedra, including triply chelated Ca. An additional isolated Ca is coordinated by water molecules, and two uncoordinated water molecules occur in the hexahydrate structure. The previously reported polymorph of the tetrahydrate contains the same layers, but only two H2O coordinated to the isolated Ca and two uncoordinated water molecules. Anhydrous calcium citrate has a three-dimensional network structure of Ca coordination polyhedra. The new polymorph of calcium citrate tetrahydrate is the major crystalline phase in several commercial calcium supplements.

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The crystal structure of kalsilite, KAlSiO4

Mineralogical Magazine and Journal of the Mineralogical Society ◽

10.1180/minmag.1965.035.272.02 ◽

1965 ◽

Vol 35 (272) ◽

pp. 588-595 ◽

Cited By ~ 34

Author(s):

A. J. Perrotta ◽

J. V. Smith

Keyword(s):

Crystal Structure ◽

Oxygen Atom ◽

Crystal Structures ◽

Bond Angle ◽

Three Dimensional ◽

Full Matrix ◽

Ideal Position ◽

Wide Range ◽

The Ideal

SummaryA full-matrix, three-dimensional refinement of kalsilite, KAlSi04 (hexagonal, a 5·16, c 8.69 Å, P6a), shows that the silicon and aluminium atoms are ordered. The respective tetrahedral distances of 1·61 and 1·74 Å agree with values of 1·61 and 1·75 Å taken to be typical of framework structures. As in nepheline, an oxygen atom is statistically distributed over three sites displaced 0·25 Å from the ideal position on a triad axis. This decreases the bond angle from 180° to 163° in conformity with observations on some other crystal structures. The potassiumoxygen distances of 2·77, 2·93, and 2·99 Å are consistent with the wide range normally found for this weakly bonded atom.

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Crystal structures of the dioxane hemisolvates ofN-(7-bromomethyl-1,8-naphthyridin-2-yl)acetamide and bis[N-(7-dibromomethyl-1,8-naphthyridin-2-yl)acetamide]

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989017012208 ◽

2017 ◽

Vol 73 (10) ◽

pp. 1409-1413 ◽

Cited By ~ 2

Author(s):

Robert Rosin ◽

Wilhelm Seichter ◽

Monika Mazik

Keyword(s):

Hydrogen Bonds ◽

Crystal Structures ◽

Lone Electron Pair ◽

Electron Pair ◽

Three Dimensional ◽

Supramolecular Network ◽

Halogen Bonds ◽

Host Interactions ◽

Compound Ii ◽

Noncovalent Bonding

The syntheses and crystal structures ofN-(7-bromomethyl-1,8-naphthyridin-2-yl)acetamide dioxane hemisolvate, C11H10BrN3O·0.5C4H8O2, (I), and bis[N-(7-dibromomethyl-1,8-naphthyridin-2-yl)acetamide] dioxane hemisolvate, 2C11H9Br2N3O·0.5C4H8O2, (II), are described. The molecules adopt a conformation with the N—H hydrogen pointing towards the lone electron pair of the adjacent naphthyridine N atom. The crystals of (I) are stabilized by a three-dimensional supramolecular network comprising N—H...N, C—H...N and C—H...O hydrogen bonds, as well as C—Br...π halogen bonds. The crystals of compound (II) are stabilized by a three-dimensional supramolecular network comprising N—H...N, C—H...N and C—H...O hydrogen bonds, as well as C—H...π contacts and C—Br...π halogen bonds. The structure of the substituent attached in the 7-position of the naphthyridine skeleton has a fundamental influence on the pattern of intermolecular noncovalent bonding. While the Br atom of (I) participates in weak C—Br...Oguestand C—Br...π contacts, the Br atoms of compound (II) are involved in host–host interactionsviaC—Br...O=C, C—Br...N and C—Br...π bonding.

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