Search results for "Crystal structure"
showing 10 items of 15036 documents
The Crystal Structure of Gurmarin, a Sweet Taste–Suppressing Protein: Identification of the Amino Acid Residues Essential for Inhibition
2018
International audience; Gurmarin is a highly specific sweet-taste suppressing protein in rodents that is isolated from the Indian plant Gymnemasylvestre. Gurmarin consists of 35 amino acid residues containing three intramolecular disulfide bridges that form a cystine knot. Here, we report the crystal structure of gurmarin at a 1.45 Å resolution and compare it with previously reported NMR solution structures. The atomic structure at this resolution allowed us to identify a very flexible region consisting of hydrophobic residues. Some of these amino acid residues had been identified as a putative binding site for the rat sweet taste receptor in a previous study. By combining alanine-scanning …
Determinants for Tight and Selective Binding of a Medicinal Dicarbene Gold(I) Complex to a Telomeric DNA G-Quadruplex: a Joint ESI MS and XRD Investi…
2016
International audience; The dicarbene gold(I) complex [Au(9-methylcaffein-8-ylidene)(2)]BF4 is an exceptional organometallic compound of profound interest as a prospective anticancer agent. This gold(I) complex was previously reported to be highly cytotoxic toward various cancer cell lines invitro and behaves as a selective G-quadruplex stabilizer. Interactions of the gold complex with various telomeric DNA models have been analyzed by a combined ESI MS and X-ray diffraction (XRD) approach. ESI MS measurements confirmed formation of stable adducts between the intact gold(I) complex and Tel 23 DNA sequence. The crystal structure of the adduct formed between [Au(9-methylcaffein-8-ylidene)(2)]…
Vibrational and Molecular Properties of Mg2+ Binding and Ion Selectivity in the Magnesium Channel MgtE
2018
Magnesium ions (Mg2+) are crucial for various biological processes. A bacterial Mg2+ channel, MgtE, tightly regulates the intracellular Mg2+ concentration. Previous X-ray crystal structures showed that MgtE forms a dimeric structure composed of a total of 10 transmembrane α helices forming a central pore, and intracellular soluble domains constituting a Mg2+ sensor. The ion selectivity for Mg2+ over Ca2+ resides at a central cavity in the transmembrane pore of MgtE, involving a conserved aspartate residue (Asp432) from each monomer. Here, we applied ion-exchange-induced difference FTIR spectroscopy to analyze the interactions between MgtE and divalent cations, Mg2+ and Ca2+. Using site-dire…
Pb2+complexes of small-cavity azamacrocyclic ligands: thermodynamic and kinetic studies
2017
The synthesis, acid-base behavior and Pb2+ coordination chemistry of the new aza-scorpiand like ligand 5-[2-(N-2-fluorenyl)ethylamino]-2,5,8-triaza[9]-2,6-pyridinophane (L1) have been studied by potentiometry, NMR and spectrofluorimetric titrations, and the results are compared with those obtained for the related compounds L2, lacking the fluorenyl group, and L3, the macrocycle lacking the pendant arm. The crystal structures obtained for complexes [PbL1][PbL1Cl](NO3)Cl2·4H2O (1) and [PbL3](ClO4)2 (2) reveal that the metal ion is located over the plane defined by the nitrogen atoms of the macrocyclic core due to its inability to accommodate the large Pb2+ ion in the macrocyclic cavity. For L…
Preparation and molecular structures of N′-(2-heteroarylmethylidene)-3-(3-pyridyl)acrylohydrazides
2018
Abstract The crystal and molecular structures of N′-(2-furylmethylidene)-3-(3-pyridyl)acrylohydrazide and N′-(2-thienylmethylidene)-3-(3-pyridyl)acrylohydrazide are reported, and the influence of the type of the heteroatom on the aromaticity of the aromatic rings is discussed. Both molecules are nearly planar. The geometry of the acrylohydrazide arrangement is comparable to that of homologous compounds. Density functional theory (DFT) calculations were performed in order to analyze the changes in the geometry of the studied compounds in the crystalline state and for the isolated molecule. The most significant changes were observed in the values of the N–N and C–N bond lengths. The harmonic …
Crystal structure, Hirshfeld analysis and molecular docking with the vascular endothelial growth factor receptor-2 of (3Z)-5-fluoro-3-(hydroxyimino)i…
2017
The reaction between 5-fluoroisatin and hydroxylamine hydrochloride in acidic ethanol yields the title compound, C8H5FN2O2, whose molecular structure matches the asymmetric unit and is nearly planar with an r.m.s. deviation for the mean plane through all non-H atoms of 0.0363 Å. In the crystal, the molecules are linked by N—H...N, N—H...O and O—H...O hydrogen-bonding interactions into a two-dimensional network along the (100) plane, forming rings withR22(8) andR12(5) graph-set motifs. The crystal packing also features weak π–π interactions along the [100] direction [centroid-to-centroid distance 3.9860 (5) Å]. Additionally, the Hirshfeld surface analysis indicates that the major contributio…
Crystal structure of (3E)-5-nitro-3-(2-phenylhydrazinylidene)-1H-indol-2(3H)-one
2017
The reaction between 5-nitroisatin and phenylhydrazine in acidic ethanol yields the title compound, C14H10N4O3, whose molecular structure deviates slightly from a planar geometry (r.m.s. deviation = 0.065 Å for the mean plane through all non-H atoms). An intramolecular N—H...O hydrogen bond is present, forming a ring of graph-set motifS(6). In the crystal, molecules are linked by N—H...O and C—H...O hydrogen-bonding interactions into a two-dimensional network along (120), and rings of graph-set motifR22(8),R22(26) andR44(32) are observed. Additionally, a Hirshfeld surface analysis suggests that the molecules are stacked along [100] through C=O...Cginteractions and indicates that the most im…
1-(Pyridin-4-yl)-3-(2,4,6-trichlorophenyl)benz[4,5]imidazo[1,2-d][1,2,4]triazin-4(3H)-one
2016
In the title compound, C20H10Cl3N5O, the 13-membered ring system makes dihedral angles of 78.64 (9)° with the trichlorophenyl ring and 62.60 (10)° with the pyridine ring. The crystal packing is dominated by π–π interactions between the 13-membered ring systems [centroid–centroid distance = 3.6655 (11)°].
CCDC 2211279: Experimental Crystal Structure Determination
2023
Related Article: Anssi Peuronen, Anni Taponen, Elina Kalenius, Ari Lehtonen, Manu Lahtinen|2023|Angew.Chem.,Int.Ed.|62|e202215689|doi:10.1002/anie.202215689
CCDC 289303: Experimental Crystal Structure Determination
2007
Related Article: K.Laihia, A.Valkonen, E.Kolehmainen, A.Antonov, D.Zhukov, I.Fedosov, V.Nikiforov|2006|J.Mol.Struct.|800|100|doi:10.1016/j.molstruc.2006.03.095