Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The IIM are a heterogeneous group of systemic rheumatic diseases which share the common features of chronic muscle weakness and mononuclear cell infiltrates in muscle. A number of classification schemes have been proposed for them, but none takes into consideration the marked immunologic, clinical, and genetic heterogeneity of the various clinical groups. We compared the usefulness of myositis-specific autoantibodies (anti-aminoacyl-tRNA synthetases, anti-SRP, anti-Mi-2 and anti-MAS) to the standard clinical categories (polymyositis, dermatomyositis, overlap myositis, cancer-associated myositis, and inclusion body myositis) in predicting clinical signs and symptoms, HLA types, and prognosis in 212 adult IIM patients. Although patients with inclusion body myositis (n = 26) differed in having significantly more asymmetric and distal weakness, falling, and atrophy than other patients, there were few other significant differences among the other clinical groups. In contrast, autoantibody status defined distinct sets of patients and each patient had only 1 myositis-specific autoantibody. Patients with anti-amino-acyl-tRNA synthetase autoantibodies (n = 47), compared to those without these antibodies, had significantly more frequent arthritis, fever, interstitial lung disease, and "mechanic's hands"; HLA-DRw52; higher mean prednisone dose at survey, higher proportion of patients receiving cytotoxic drugs, and higher death rates. Those with anti-signal recognition particle antibodies (n = 7) had increased palpitations; myalgias; DR5, DRw52; severe, refractory disease; and higher death rates. Patients with anti-Mi-2 antibodies (n = 10) had increased "V-sign" and "shawl-sign" rashes, and cuticular overgrowth; DR7 and DRw53; and a good response to therapy. The 2 patients with anti-MAS antibodies were the only ones with alcoholic rhabdomyolysis preceding myositis; both had insulin-dependent diabetes mellitus, and both had HLA-B60, -C3, -DR4, and -DRw53. These findings suggest that myositis-specific autoantibody status is a more useful guide than clinical group in assessing patients with myositis, and that specific associations of immunogenetics, immune responses, and clinical manifestations occur in IIM. Thus the myositis-specific autoantibodies aid in interpreting the diverse symptoms and signs of myositis patients and in predicting their clinical course and prognosis. We propose, therefore, that an adjunct classification of the IIM, based on the myositis-specific autoantibody status, be incorporated into future studies of their epidemiology, etiology, and therapy.
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PMID:A new approach to the classification of idiopathic inflammatory myopathy: myositis-specific autoantibodies define useful homogeneous patient groups. 165 47

The synthesis of gallophosphate cloverite in the presence of aluminium leads to a partial substitution of Ga by Al. 27Al and 19F magic-angle spinning nuclear magnetic resonance (MAS NMR) studies on this material confirm this substitution. 27Al MAS NMR shows a broad line at 30 ppm which can be attributed to tetrahedrally coordinated Al in the solid. The 19F MAS NMR results are more complex. The spectrum presents five lines between -68 ppm and -95 ppm which can be assigned to fluorine in D4Rs with variable composition in Ga and Al. Two other lines, at -145.6 ppm and -178.2 ppm, may correspond to impurities and to a fluorine atom in a pseudo-sodalite cage environment, respectively.
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PMID:Use of 19F nuclear magnetic resonance spectroscopy for probing substitution of Al for Ga in cloverite. 782 78

High-temperature 33Na MAS NMR experiments up to 873 K for a number of different sodalites (Na8[AlSiO4]6(NO3)2, Na8[AlSiO4]6(NO2)2, Na8[AlSiO4]6I2, Na7.9[AlSiO4]6(SCN)7.9 x 0.5H2O, Na8[AlGeO4]6(NO3)2, and Na7[AlSiO4]6(H3O2) x 4H2O) were carried out. The spectra of the first five sodalites consist of a quadrupolar MAS pattern with different quadrupolar coupling constants. The quadrupolar interaction for the thiocyanate sodalite, the nitrate aluminosilicate, and germanate sodalite decreases strongly passing a coalescence state on heating, while the quadrupolar interaction of the iodide and nitrite sample shows nearly no change. The basic hydrosodalite shows an asymmetric lineshape at room temperature and, between 350 and 370 K, a second line due to the evaporation of cage-water emerges. The linewidth increases with rising temperature. The temperature dependence of the quadrupolar interaction seems to be a function of the sodalite beta-cage expansion. Two conceivable jump mechanisms are proposed for a tetrahedral two-site jump between occupied and unoccupied tetrahedral sites.
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PMID:Influence of sodium ion dynamics on the 23Na quadrupolar interaction in sodalite: a high-temperature 23Na MAS NMR study. 1127 Jul 43

Experimental and ab initio molecular orbital techniques are developed for study of aluminum species with large quadrupole coupling constants to test structural models for methylaluminoxanes (MAO). The techniques are applied to nitrogen- and oxygen-containing complexes of aluminum and to solid MAO isolated from active commercial MAO preparations. (Aminato)- and (propanolato)aluminum clusters with 3-, 4-, and 6-coordinate aluminum sites are studied with three (27)Al NMR techniques optimized for large (27)Al quadrupole coupling constants: field-swept, frequency-stepped, and high-field MAS NMR. Four-membered (aminato)aluminum complexes with AlN(4) coordination yield slightly smaller C(q) values than similar AlN(2)C(2) sites: 12.2 vs 15.8 MHz. Planar 3-coordinate AlN(2)C sites have the largest C(q) values, 37 MHz. In all cases, molecular orbital calculations of the electric field gradient tensors yields C(q) and eta values that match with experiment, even for a large hexameric (aminato)aluminum cage. A D(3d) symmetry hexaaluminum oxane cluster, postulated as a model for MAO, yields a calculated C(q) of -23.7 MHz, eta = 0.7474, and predicts a spectrum that is too broad to match the field-swept NMR of methylaluminoxane, which shows at least three sites, all with C(q) values greater than 15 MHz but less than 21 MHz. Thus, the proposed hexaaluminum cluster, with its strained four-membered rings, is not a major component of MAO. However, calculations for dimers of the cage complex, either edge-bridged or face-bridged, show a much closer match to experiment. Also, MAO preparations differ, with a gel form of MAO having significantly larger (27)Al C(q) values than a nongel form, a conclusion reached on the basis of (27)Al NMR line widths in field-swept NMR spectra acquired from 13 to 24 T.
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PMID:Structural characterization of MAO and related aluminum complexes. 1. Solid-state (27)Al NMR with comparison to EFG tensors from ab initio molecular orbital calculations. 1172 9

The (31)P MAS NMR spectrum of solid Li(3)P(7)(monoglyme)(3) has been reinvestigated over a wide temperature range (-70 to +77 degrees C) and under conditions of better resolution (Larmor frequency of 162 MHz and spinning rate of approximately 30 kHz) than previously measured (121 MHz and 13 kHz). At low temperatures three spinning sideband (ssb) manifolds are observed: a singlet (centered at -45 ppm relative to 85% H(3)PO(4)) due to the apical atom (A) of the P(7)-cage trianion; a 1 : 1 : 1 triplet (at -110, -117, and -124.5 ppm) due to the negatively charged equatorial (E) atoms, and a one to two doublet (at -161 and -168.5 ppm) due to the basal (B) atoms. These results are consistent with the P(7) cage having nearly, but not perfect, C(3v) symmetry. The compound appears to be well ordered in the solid state with very little structural dispersity. On heating, the NMR lines broaden and eventually coalesce into a single ssb manifold. This behavior is ascribed to bond-shift rearrangement similar to the Cope rearrangement in bullvalene. A MAS 2D exchange experiment and a quantitative analysis of the 1D NMR lineshapes indicate that, unlike in solution where the rearrangement involves a single bond shift at a time, in the solid the process involves a succession of two bond shifts: The first leads to an intermediate species in which the rearranged P(7) cage is inverted, while in the subsequent step a second bond shift takes place that also restores the original orientation of the cage in the lattice. The overall effect of the double bond shift is equivalent to cyclic permutation of the phosphorus atoms within the five member rings of the P(7)-cage. The quantitative analysis of the dynamic lineshapes shows that this cyclic permutation proceeds at a different rate in one ring (k(d)(1)) than in the other two (k(d)(2,3)). The kinetic parameters for these processes are E(a)(1)=18.7 kJ/mol, E(a)(2,3)=58.0 kJ/mol, k(d)(1)(17 degrees C)=k(d)(2,3)(17 degrees C)=10(4) s(-1). No indications for independent threefold molecular jumps of the P(7) cage were found.
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PMID:Bond-shift rearrangement in solid Li(3)P(7)(monoglyme)(3): a (31)P MAS NMR study. 1174 Aug 99

Ion exchange of the sodium hydro sodalites [Na3(H2O)4]2-[Al3Si3O12]2 [Na4(H3O2)]2[Al3Si3O12]2 and [Na4(OH)]2[Al3Si3O12]2 with aqueous Pb(NO3)2 solutions yielded, whichever reactant sodalite phase was used, the same lead hydro sodalite, [Pb2(OH)-(H2O)3]2[Al3Si3O12]2. Thus, in the case of the non-basic reactant [Na3(H2O)4]2-[Al3Si3O12]2 an overexchange occurs with respect to the number of nonframework cationic charges. Rietveld structure refinement of the lead hydro sodalite based on powder X-ray diffraction data (cubic, a = 9.070 A, room temperature, space group P43n) revealed that the two lead cations within each polyhedral sodalite cage form an orientationally disordered dinuclear [Pb2(micro-OH)(micro-H2O)(H2O)2]3+ complex. Due to additional lead framework oxygen bonds the coordination environment of each metal cation (CN 3+3) is approximately spherical, and clearly the lead 6s electron lone pair is stereochemically inactive. This is also suggested by the absence of a small peak at 13.025 keV, attributed in other Pb2+-O compounds to an electronic 2p-6s transition, in the PbL3 edge XANES spectrum. 1H MAS NMR and FTIR spectra show that the hydrogen atoms of the aqua hydroxo complex (which could not be determined in the Rietveld analysis) are involved in hydrogen bonds of various strengths.
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PMID:Lead hydro sodalite [Pb2(OH)(H2O)3]2[Al3Si3O12]2: synthesis and structure determination by combining X-ray rietveld refinement, 1H MAS NMR FTIR and XANES spectroscopy. 1193 Nov 9

PX(4) (+)[Al(OR)(4)](-) (X=I: 1 a, X=Br: 1 b) was prepared from X(2), PX(3), and Ag[Al(OR)(4)] [R=C(CF(3))(3)] in CH(2)Cl(2) at -30 degrees C in 69-86 % yield. P(2)X(5) (+) salts were prepared from 2 PX(3) and Ag[Al(OR)(4)] in CH(2)Cl(2) at -30 degrees C yielding almost quantitatively P(2)X(5) (+)[Al(OR)(4)](-) (X=I: 3 a, X=Br: 3 b). The phosphorus-rich P(5)X(2) (+) salts arose from the reaction of cold (-78 degrees C) mixtures of PX(3), P(4), and Ag[Al(OR)(4)] giving P(5)X(2) (+)[Al(OR)(4)](-) (X=I: 4 a, X=Br: 4 b) with a C(2v)-symmetric P(5) cage. Silver salt metathesis presumably generated unstable PX(2) (+) cations from PX(3) and Ag[Al(OR)(4)] (X=Br, I) that acted as electrophilic carbene analogues and inserted into the Xbond;X (Pbond;X/Pbond;P) bond of X(2) (PX(3)/P(4)) leading to the highly electrophilic and CH(2)Cl(2)-soluble PX(4) (+) (P(2)X(5) (+)/P(5)X(2) (+)) salts. Reactions that aimed to synthesize P(2)I(3) (+) from P(2)I(4) and Ag[Al(OR)(4)] instead led to anion decomposition and the formation of P(2)I(5)(CS(2))(+)[(RO)(3)Al-F-Al(OR)(3)](-) (5). All salts were characterized by variable-temperature solution NMR studies (3 b also by (31)P MAS NMR), Raman and/or IR spectroscopy as well as X-ray crystallography (with the exception of 4 a). The thermochemical volumes of the Pbond;X cations are 121 (PBr(4) (+)), 161 (PI(4) (+)), 194 (P(2)Br(5) (+)), 271 (P(2)I(5) (+)), and 180 A(3) (P(5)Br(2) (+)). The observed reactions were fully accounted for by thermochemical calculations based on (RI-)MP2/TZVPP ab initio results and COSMO solvation enthalpy calculations (CH(2)Cl(2) solution). The enthalpies of formation of the gaseous Pbond;X cations were derived as +764 (PI(4) (+)), +617 (PBr(4) (+)), +749 (P(2)I(5) (+)), +579 (P(2)Br(5) (+)), +762 (P(5)I(2) (+)), and +705 kJ mol(-1) (P(5)Br(2) (+)). The insertion of the intermediately prepared carbene analogue PX(2) (+) cations into the respective bonds were calculated, at the (RI-)MP2/TZVPP level, to be exergonic at 298 K in CH(2)Cl(2) by Delta(r)G(CH(2)Cl(2))=-133.5 (PI(4) (+)), -183.9 (PBr(4) (+)), -106.5 (P(2)I(5) (+)), -81.5 (P(2)Br(5) (+)), -113.2 (P(5)I(2) (+)), and -114.5 kJ mol(-1) (P(5)Br(2) (+)).
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PMID:PX4+, P2X5+, and P5X2+ (X=Br, I) salts of the superweak Al(OR)4- anion [R=C(CF3)3]. 1235 36

Simulation of static and MAS NMR spectra obtained at high field (B(0) = 14.08 T) and high spinning frequency (up to nu(rot) = 22 kHz) allows the determination of 35Cl quadrupolar parameters for various cubane-shaped, cage-like and cyclic Al-O-P clusters; the role of OH...Cl contacts is emphasized.
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PMID:35Cl quadrupolar constants obtained by solid-state NMR: study of chlorinated Al-O-P clusters, involving OH...Cl hydrogen bonds. 1263 29

The rational synthesis of an octahedral coordination capsule in which the triangular faces are covered by single ligands is described herein. Starting with tris(2-hydroxybenzylidene)triaminoguanidinium chloride [H(6)L]Cl, we observed an oxidative cyclization of this ligand in the presence of PPh(4) (+) ions resulting in the complex [Pd(H(2)L')(PPh(3))] (1). The use of 5,5-diethylbarbiturate (bar(2-)) as a bridging ligand in the presence of [Co(en)(3)](3+) (en=ethylenediamine) leads to the formation of a rectangular box with the formula (Et(4)N)(6)[[Co[(PdCl)(Pd)L](2)(mu-bar)](2)] (2). The analysis of the architecture of compounds 1 and 2 enables the development of a self-assembly strategy for the synthesis of an octahedral coordination cage 3 with the formula Na(4)(Et(3)NH)(12)[(Pd(3)L)(8)[mu-(bar)](12)].x H(2)O. Compound 3 was characterized by (13)C-MAS-NMR spectroscopy and single-crystal structure analysis.
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PMID:Rational design of the first closed coordination capsule with octahedral outer shape. 1511 9

Oxidation of Me(6)M(2) (M = Ge, Sn) and Me(4)Pb with the CB(11)Me(12)(*) radical in alkane solvents produced the insoluble salts Me(3)M(+)CB(11)Me(12)(-), characterized by CP-MAS NMR and EXAFS. The cations interact with methyl groups of CB(11)Me(12)(-) with coordination strength increasing from Pb to Ge. Density functional theory (DFT) calculations for the isolated ion pairs, Me(3)M(+)CB(11)Me(12)(-) (M = Ge, Sn), revealed three isomers with the cation above methyl 2, 7, or 12, and not above a BB edge or a BBB triangle. The interaction has a considerable covalent component, with the cation attempting to perform a backside S(E)2 substitution on the methyl carbon. In a fourth less favorable isomer the cation is near methyl 1, inclined toward methyl 2, and interacts with hydrogens. DFT atomic charge distributions and plots of the electrostatic potential on the surface of spheres centered at the CB(11)H(12)(-) and CB(11)Me(12)(-) icosahedra display the effects of uneven charge distribution within the anion and contradict the common belief that the negative charge of the cage anion is concentrated primarily on the cage boron atoms 7-12; in CB(11)Me(12)(-), roughly half is on the cage carbon and the rest on methyls 7-12.
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PMID:Metal cation-methyl interactions in CB11Me12(-) salts of Me3Ge+, Me3Sn+, and Me3Pb+. 1538 38


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