scholarly journals 1.45 Å resolution structure of SRPN18 from the malaria vectorAnopheles gambiae

2016 ◽  
Vol 72 (12) ◽  
pp. 853-862 ◽  
Author(s):  
David A. Meekins ◽  
Xin Zhang ◽  
Kevin P. Battaile ◽  
Scott Lovell ◽  
Kristin Michel
Keyword(s):  
Crystal Structure ◽  
Wound Healing ◽  
Anopheles Gambiae ◽  
Protease Inhibitors ◽  
Malaria Vector ◽  
Physiological Responses ◽  
Asymmetric Unit ◽  
Protease Inhibition ◽  
Reactive Center ◽  
Resolution Structure

Serine protease inhibitors (serpins) in insects function within development, wound healing and immunity. The genome of the African malaria vector,Anopheles gambiae, encodes 23 distinct serpin proteins, several of which are implicated in disease-relevant physiological responses.A. gambiaeserpin 18 (SRPN18) was previously categorized as non-inhibitory based on the sequence of its reactive-center loop (RCL), a region responsible for targeting and initiating protease inhibition. The crystal structure ofA. gambiaeSRPN18 was determined to a resolution of 1.45 Å, including nearly the entire RCL in one of the two molecules in the asymmetric unit. The structure reveals that the SRPN18 RCL is extremely short and constricted, a feature associated with noncanonical inhibitors or non-inhibitory serpin superfamily members. Furthermore, the SRPN18 RCL does not contain a suitable protease target site and contains a large number of prolines. The SRPN18 structure therefore reveals a unique RCL architecture among the highly conserved serpin fold.

scholarly journals Crystal structure of acetylcholinesterase catalytic subunits of the malaria vector Anopheles gambiae

2017 ◽  
Vol 25 (4) ◽  
pp. 721-724 ◽  
Author(s):  
Qian Han ◽  
Dawn M. Wong ◽  
Howard Robinson ◽  
Haizhen Ding ◽  
Polo C. H. Lam ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Anopheles Gambiae ◽  
Malaria Vector ◽  
Catalytic Subunits

Alkyl-chain disorder in tetraisohexylammonium bromide

2012 ◽  
Vol 68 (4) ◽  
pp. o152-o155 ◽  
Author(s):  
Malcolm A. Kelland ◽  
Amber L. Thompson
Keyword(s):  
Crystal Structure ◽  
Crystal Growth ◽  
Alkyl Chain ◽  
Growth Inhibitor ◽  
Ammonium Cation ◽  
Asymmetric Unit ◽  
Bromide Anion ◽  
Alkyl Chains ◽  
Hydrate Crystal ◽  
Structure Ii Clathrate Hydrate

Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C24H52N+·Br−, is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space groupP3221, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains. At 250 K, all four isohexyl chains are disordered. In an effort to reduce the disorder in the alkyl chains, the crystal was thermally cycled, but the disorder remained, indicating that it is dynamic in nature.

2,4-Diamino-6-phenyl-1,3,5-triazin-1-ium nitrate: intriguing crystal structure with high Z′/Z′′ and hydrogen bond numbers and Hirshfeld surface analysis of intermolecular interactions

CrystEngComm ◽  
2021 ◽  
Author(s):  
Nicoleta Caimac ◽  
Elena Melnic ◽  
Diana Chisca ◽  
Marina S. Fonari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Surface Analysis ◽  
Intermolecular Interactions ◽  
Title Compound ◽  
Ionic Species ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Asymmetric Unit ◽  
Space Group

The title compound crystallises in the triclinic centrosymmetric space group P1̄ with an intriguing high number of crystallographically unique binary salt-like adducts (Z′ = 8) and a total number of ionic species (Z′′ = 16) in the asymmetric unit.

scholarly journals Unravelling population structure heterogeneity within the genome of the malaria vector Anopheles gambiae

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Melina Campos ◽  
Luisa D. P. Rona ◽  
Katie Willis ◽  
George K. Christophides ◽  
Robert M. MacCallum
Keyword(s):  
Population Structure ◽  
Anopheles Gambiae ◽  
Malaria Vector ◽  
Mosquito Species ◽  
Gene Clusters ◽  
Selective Sweeps ◽  
Structure Heterogeneity ◽  
Genomic Studies ◽  
Time Required ◽  
Genomic Regions

Abstract Background Whole genome re-sequencing provides powerful data for population genomic studies, allowing robust inferences of population structure, gene flow and evolutionary history. For the major malaria vector in Africa, Anopheles gambiae, other genetic aspects such as selection and adaptation are also important. In the present study, we explore population genetic variation from genome-wide sequencing of 765 An. gambiae and An. coluzzii specimens collected from across Africa. We used t-SNE, a recently popularized dimensionality reduction method, to create a 2D-map of An. gambiae and An. coluzzii genes that reflect their population structure similarities. Results The map allows intuitive navigation among genes distributed throughout the so-called “mainland” and numerous surrounding “island-like” gene clusters. These gene clusters of various sizes correspond predominantly to low recombination genomic regions such as inversions and centromeres, and also to recent selective sweeps. Because this mosquito species complex has been studied extensively, we were able to support our interpretations with previously published findings. Several novel observations and hypotheses are also made, including selective sweeps and a multi-locus selection event in Guinea-Bissau, a known intense hybridization zone between An. gambiae and An. coluzzii. Conclusions Our results present a rich dataset that could be utilized in functional investigations aiming to shed light onto An. gambiae s.l genome evolution and eventual speciation. In addition, the methodology presented here can be used to further characterize other species not so well studied as An. gambiae, shortening the time required to progress from field sampling to the identification of genes and genomic regions under unique evolutionary processes.

scholarly journals Powder study of 3-azabicyclo[3.3.1]nonane-2,4-dione form 2

2006 ◽  
Vol 62 (7) ◽  
pp. o3046-o3048 ◽  
Author(s):  
Ashley T Hulme ◽  
Philippe Fernandes ◽  
Alastair Florence ◽  
Andrea Johnston ◽  
Kenneth Shankland
Keyword(s):  
Crystal Structure ◽  
Simulated Annealing ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Title Compound ◽  
Variable Temperature ◽  
Polycrystalline Sample ◽  
Asymmetric Unit ◽  
X Ray ◽  
Compound C

A polycrystalline sample of a new polymorph of the title compound, C8H11NO2, was produced during a variable-temperature X-ray powder diffraction study. The crystal structure was solved at 1.67 Å resolution by simulated annealing from laboratory powder data collected at 250 K. Subsequent Rietveld refinement yielded an R wp of 0.070 to 1.54 Å resolution. The structure contains two molecules in the asymmetric unit, which form a C 2 2(8) chain motif via N—H...O hydrogen bonds.

The effect of partial methylation of the glycine amino group on crystal structure inN,N-dimethylglycine and its hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecules ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Partial Methylation ◽  
Space Groups ◽  
Carboxylate Groups ◽  
Anhydrous Compound ◽  
Additional Hydrogen

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.

2,4,6-Trimethylpyridine-3,5-dicarbonitrile

2006 ◽  
Vol 62 (7) ◽  
pp. o2765-o2767
Author(s):  
Hong-Li Wang ◽  
Bin Zhang ◽  
Yi Dai
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Asymmetric Unit ◽  
Compound C ◽  
Hydrogen Bonding Interactions

The title compound, C10H9N3, is essently planar, except for the methyl H atoms. The asymmetric unit consists of two molecules. In the crystal structure, weak intramolecular C—H...N hydrogen-bonding interactions occur, linking the molecules into chains propagating along the a axis.

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