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101.
Nanoscale organization of the pathogen receptor DC-SIGN mapped by single-molecule high-resolution fluorescence microscopy. 总被引:3,自引:0,他引:3
Bärbel I. de Bakker Dr. Frank de Lange Dr. Alessandra Cambi Dr. Jeroen P. Korterik Erik M. H. P. van Dijk Dr. Niek F. van Hulst Prof. Carl G. Figdor Prof. Maria F. Garcia‐Parajo Prof. 《Chemphyschem》2007,8(10):1473-1480
DC-SIGN, a C-type lectin exclusively expressed on dendritic cells (DCs), plays an important role in pathogen recognition by binding with high affinity to a large variety of microorganisms. Recent experimental evidence points to a direct relation between the function of DC-SIGN as a viral receptor and its spatial arrangement on the plasma membrane. We have investigated the nanoscale organization of fluorescently labeled DC-SIGN on intact isolated DCs by means of near-field scanning optical microscopy (NSOM) combined with single-molecule detection. Fluorescence spots of different intensity and size have been directly visualized by optical means with a spatial resolution of less than 100 nm. Intensity- and size-distribution histograms of the DC-SIGN fluorescent spots confirm that approximately 80 % of the receptors are organized in nanosized domains randomly distributed on the cell membrane. Intensity-size correlation analysis revealed remarkable heterogeneity in the molecular packing density of the domains. Furthermore, we have mapped the intermolecular organization within a dense cluster by means of sequential NSOM imaging combined with discrete single-molecule photobleaching. In this way we have determined the spatial coordinates of 13 different individual dyes, with a localization accuracy of 6 nm. Our experimental observations are all consistent with an arrangement of DC-SIGN designed to maximize its chances of binding to a wide range of microorganisms. Our data also illustrate the potential of NSOM as an ultrasensitive, high-resolution technique to probe nanometer-scale organization of molecules on the cell membrane. 相似文献
102.
Giampiero Bettinetti Milena Sorrenti Laura Catenacci Franca Ferrari Silvia Rossi Ilaria Salvadeo Paolo Carraro 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):329-332
Triacetyl α-cyclodextrin, triacetyl β-cyclodextrin and triacetyl γ-cyclodextrin were tested as possible hydrophobic carriers
to prolong the release of hydrophilic teicoplanin (TCP). Physical–chemical characterization of individual components, drug-carrier
physical mixtures at 0.5, 0.67 and 0.75 mass fraction of carrier, and the respective interaction products by kneading or evaporative
crystallization under microwave irradiation was carried out using differential scanning calorimetry (DSC) and thermogravimetric
analysis (TGA). In vitro drug release in pH 7.4 phosphate buffer at 37 °C was determined by intrinsic dissolution rate (IDR)
measurements on non disintegrating compressed discs. Solid-state interactions of TCP with triacetyl α-cyclodextrin by evaporative
crystallization and kneading and with triacetyl β-cyclodextrin by evaporative crystallization (probably resulting in carrier
amorphization) were demonstrated. The role of carrier hydrophobicity, carrier mass fraction and preparation method of solid
drug-carrier combinations on solid-state drug-carrier interactions and slowing down of TCP release was assessed. Modulation
of drug release can be achieved using TCP-triacetyl γ-cyclodextrin combinations at 0.5 mass fraction of carrier. 相似文献
103.
104.
We investigate the existence of nontranslation invariant (periodic) density profiles, for systems interacting via translation invariant long-range potentials, as minimizers of local mean field free energy functionals. The existence of a second-order transition from a uniform to a nonuniform density at a specified temperature is proven for a class of model systems. 相似文献
105.
106.
Vladimir Rapić Prof. Dr. Karl Schlögl Brigitte Steinitz 《Monatshefte für Chemie / Chemical Monthly》1977,108(4):767-780
Starting from optically active methylferrocene-- and--carboxylic acids (1 a and1 b) of known absolute configuration and enantiomeric purity about 15 chiral ferrocenes (of each isomeric series— and ) were obtained by suitable ligand transformations. Thereby (almost) all possible chiral combinations of the ligands CH3, COOH (COO–), COOCH3, CN and NH2 (NH3
+) were accessible which are necessary for a potential test of approximations of chirality functions for compounds with basic symmetry C5v. The chiroptical properties of these disubstituted ferrocenes are recorded.Preliminary tests using a shortened Ansatz revealed large discrepancies between calculated () and found [M]D-values. Possible reasons for this failure are discussed.
61. Mitt. über Ferrocenderivate
39. Mitt.:A. Meyer, H. Neudeck undK. Schlögl, Chem. Ber.110, 1403 (1977).
60. Mitt.:V. Rapi, K. Schlögl undB. Steinitz, J. Organometal. Chem.94, 87 (1975). 相似文献
61. Mitt. über Ferrocenderivate
39. Mitt.:A. Meyer, H. Neudeck undK. Schlögl, Chem. Ber.110, 1403 (1977).
60. Mitt.:V. Rapi, K. Schlögl undB. Steinitz, J. Organometal. Chem.94, 87 (1975). 相似文献
107.
108.
Paolo Zatta Tamas KissMario Suwalsky Guy Berthon 《Coordination chemistry reviews》2002,228(2):271-284
Aluminium has been known as a neurotoxic agent to experimental animals since the last century (Arch. Exp. Pharmacol. 40 (1897) 98). However, great interest arose in it bioinorganic chemistry as well biology when it was demonstrated to be the causative agent in pathologies related to the long-term dialysis treatment of uremic subjects with renal failure (Life Chem. 11 (1994) 197), and as a potential etiopathogenic cofactor for several neurodegenerative diseases. The inorganic biochemistry of aluminium is still largely to be discovered. In this review the pro-oxidative property of aluminium toward biological membrane will be presented and its implications in involvement in human pathology will be discussed in an interdisciplinary frame from the bioinorganic point of view. 相似文献
109.
110.
Torsten Küppers Martin Köckerling Prof. Dr. Helge Willner Prof. Dr. 《无机化学与普通化学杂志》2007,633(2):280-284
The new tetracyanoborate K[B(CN)4]·CH3CN was synthesized by dissolution of the solvent‐free K[B(CN)4] in acetonitrile and subsequent careful crystallization. The crystal structure has been determined by single‐crystal X‐ray diffraction. It crystallizes in the orthorhombic space group P212121 with Z = 4. Some comparisons with related structures are made, and the vibrational spectrum is discussed. 相似文献