| 1. |
- Liu, Haibin, et al.
(författare)
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Asymmetric oxidation of sulfides with hydrogen peroxide catalyzed by a vanadium complex of a new chiral NOO-ligand
- 2009
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Ingår i: Catalysis communications. - : Elsevier BV. - 1566-7367 .- 1873-3905. ; 11:4, s. 294-297
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Tidskriftsartikel (refereegranskat)abstract
- A new chiral NOO-tridentate ligand (8R)-2-(2-hydroxyphenyl)-4-methyl-5,6,7.8-tetrahydro-quinolin-8-ol (1) bearing a rigid tetrahydroquinoline framework was prepared and applied in the vanadium-catalyzed asymmetric oxidation of aryl methyl sulfides with H2O2 as oxidant. Less toxic acetone was found to be the proper solvent for the enantioselective oxidation of sulfides. Under the optimal condition, the asymmetric oxidation of aryl methyl sulfides in acetone catalyzed by VO(acac)(2)/1 at 0 degrees C gives good to high yields (80-95%) of sulfoxides with enantioselectivity up to 77% ee.
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| 2. |
- Chi, Zhi-Hong, et al.
(författare)
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Zinc transporter 7 is located in the cis-Golgi apparatus of mouse choroid epithelial cells.
- 2006
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Ingår i: Neuroreport. - : Ovid Technologies (Wolters Kluwer Health). - 0959-4965. ; 17:17, s. 1807-11
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Tidskriftsartikel (refereegranskat)abstract
- The cellular localization of zinc transporter 7 protein in the mouse choroid plexus was examined in this study. Zinc transporter 7 immunoreactive cells were detected in the third, lateral, and fourth ventricles of CD-1 mouse brain. Distinct zinc transporter 7 immunoreactivity was concentrated in the perinuclear regions of the positive cells. The results from zinc autometallography showed that zinc-positive grains were also predominantly located in the perinuclear areas. Ultrastructural localization showed that zinc transporter 7 immunostaining was predominantly present in the membrane and cisternae of the cis-Golgi networks and some vesicle compartments. The results support the notion that zinc transporter 7 may participate in the transport of the cytoplasmic zinc into the Golgi apparatus, and may be involved in local packaging of zinc-binding proteins in the mouse choroid plexus.
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| 3. |
- Gao, Hui-Ling, et al.
(författare)
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Expression of zinc transporter ZnT7 in mouse superior cervical ganglion.
- 2008
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Ingår i: Autonomic neuroscience : basic & clinical. - : Elsevier BV. - 1566-0702. ; 140:1-2, s. 59-65
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Tidskriftsartikel (refereegranskat)abstract
- The superior cervical ganglion (SCG) neurons contain a considerable amount of zinc ions, but little is known about the zinc homeostasis in the SCG. It is known that zinc transporter 7 (ZnT7, Slc30a7), a member of the Slc30 ZnT family, is involved in mobilizing zinc ions from the cytoplasm into the Golgi apparatus. In the present study, we examined the expression and localization of ZnT7 and labile zinc ions in the mouse SCG using immunohistochemistry, Western blot and in vivo zinc selenium autometallography (AMG). Our immunohistochemical analysis revealed that the ZnT7 immunoreactivity in the SCG neurons was predominately present in the perinuclear region of the neurons, suggesting an affiliation to the Golgi apparatus. The Western blot results verified that ZnT7 protein was expressed in the mouse SCGs. The AMG reaction product was shown to have a similar distribution as ZnT7 immunoreactivity. These observations support the notion that ZnT7 may participate in zinc transport, storage, and incorporation of zinc into zinc-binding proteins in the Golgi apparatus of mouse SCG neurons.
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| 4. |
- Graslund, S, et al.
(författare)
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Protein production and purification
- 2008
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Ingår i: Nature methods. - : Springer Science and Business Media LLC. - 1548-7105 .- 1548-7091. ; 5:2, s. 135-146
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Tian, Yu-Peng, et al.
(författare)
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Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
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Tidskriftsartikel (refereegranskat)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
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| 6. |
- Wang, Hui, et al.
(författare)
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Attenuation of phagocytosis of xenogeneic cells by manipulating CD47.
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 109:2, s. 836-42
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Tidskriftsartikel (refereegranskat)abstract
- Signal regulatory protein alpha (SIRPalpha) is a critical immune inhibitory receptor on macrophages, and its interaction with CD47, a ligand for SIRPalpha, prevents autologous phagocytosis. We hypothesized that interspecies incompatibility of CD47 may contribute to the rejection of xenogeneic cells by macrophages. Here, we show that pig CD47 does not interact with mouse SIPRalpha. Similar to CD47-/- mouse cells, porcine red blood cells (RBCs) failed to induce SIRPalpha tyrosine phosphorylation in mouse macrophages. Blocking SIRPalpha with antimouse SIRPalpha mAb (P84) significantly enhanced the phagocytosis of CD47+/+ mouse cells, but did not affect the engulfment of porcine or CD47-/- mouse cells by mouse macrophages. CD47-deficient mice, whose macrophages do not phagocytose CD47-/- mouse cells, showed markedly delayed clearance of porcine RBCs compared with wild-type mouse recipients. Furthermore, mouse CD47 expression on porcine cells markedly reduced their phagocytosis by mouse macrophages both in vitro and in vivo. These results indicate that interspecies incompatibility of CD47 contributes significantly to phagocytosis of xenogeneic cells by macrophages and suggest that genetic manipulation of donor CD47 to improve its interaction with the recipient SIRPalpha may provide a novel approach to prevent phagocyte-mediated xenograft rejection.
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| 7. |
- Wang, Hui, et al.
(författare)
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Lack of CD47 on nonhematopoietic cells induces split macrophage tolerance to CD47null cells
- 2007
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National academy of sciences. - 0027-8424 .- 1091-6490. ; 104:34, s. 13744-13749
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Tidskriftsartikel (refereegranskat)abstract
- Macrophages recognize CD47 as a marker of "self" and phagocytose CD47null hematopoietic cells. Using CD47 chimera models, here, we show that the phagocytic activity of macrophages against CD47null hematopoietic cells is conferred by CD47 expression on nonhematopoietic cells, and this "education" process is hematopoietic cell-independent. Macrophages in the chimeras where nonhematopoietic cells express CD47 phagocytose CD47null cells, whereas those in the chimeras lacking CD47 on nonhematopoietic cells are tolerant to CD47null cells. However, macrophages in the latter chimeras retain phagocytic activity against CD47null RBCs, demonstrating a split macrophage tolerance to CD47null hematopoietic cells. The findings highlight the potential importance of nonhematopoietic cells in the regulation of macrophage function, and suggest a previously uncharacterized mechanism of macrophage tolerance.
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| 8. |
- Wang, Lin, et al.
(författare)
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Synthesis and high pressure induced amorphization of C60 nanosheets
- 2007
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 91:10, s. 103112-
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Tidskriftsartikel (refereegranskat)abstract
- C-60 nanosheets with thicknesses in the nanometer range were synthesized by a simple method. Compared to bulk C-60, the lattice of the nanosheets is expanded by about 0.4%. In situ Raman spectroscopy and energy-dispersive x-ray diffraction under high pressures have been employed to study the structure of the nanosheets. The studies indicate that the bulk modulus of the C-60 nanosheets is significantly larger than that of bulk C-60. The C-60 cages in nanosheets can persist at pressures over 30 GPa, 3 GPa higher than for bulk C-60. These results suggest that C-60 crystals in even small size will be a potential candidate of superhard materials.
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| 9. |
- Zhang, Xiang, et al.
(författare)
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Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group
- 2008
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Ingår i: Applied organometallic chemistry. - : Wiley. - 0268-2605 .- 1099-0739. ; 22:10, s. 592-597
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Tidskriftsartikel (refereegranskat)abstract
- Chiral pyrrolidine SalenMn(III) complexes with an anchored functional group at the N-aza-substituent in the pyrrolidine backbone were synthesized, and used as catalysts for asymmetric epoxidation of substituted chromenes. The complex 1 with an anchored imidazole as acceptor could effectively catalyze epoxidation of substituted chromenes in the absence of expensive additive 4-phenyl pyridine N-oxide (PPNO) by the coordination of the anchored organic base to the central manganese ion. Complexes 2 and 3 with a quaternary ammonium salt unit at the Naza-substituent in the pyrrolidine backbone displayed higher activities than Jacobsen catalyst and the analogous complex 4 without anchored functional group in the aforementioned reaction.
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| 10. |
- Chumnarnsilpa, Sakesit, 1967-, et al.
(författare)
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Calcium ion exchange in crystalline gelsolin
- 2006
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Ingår i: Journal of Molecular Biology. - England : Academic Press. - 0022-2836 .- 1089-8638. ; 357:3, s. 773-782
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Tidskriftsartikel (refereegranskat)abstract
- Gelsolin is a calcium and pH-sensitive modulator of actin filament length. Here, we use X-ray crystallography to examine the extraction and exchange of calcium ions from their binding sites in different crystalline forms of the activated N and C-terminal halves of gelsolin, G1-G3 and G4-G6, respectively. We demonstrate that the combination of calcium and low pH activating conditions do not induce conformational changes in G4-G6 beyond those elicited by calcium alone. EGTA is able to remove calcium ions bound to the type I and type II metal ion-binding sites in G4-G6. Constrained by crystal contacts and stabilized by interdomain interaction surfaces, the gross structure of calcium-depleted G4-G6 remains that of the activated form. However, high-resolution details of changes in the ion-binding sites may represent the initial steps toward restoration of the arrangement of domains found in the calcium-free inactive form of gelsolin in solution. Furthermore, bathing crystals with the trivalent calcium ion mimic, Tb3+, results in anomalous scattering data that permit unequivocal localization of terbium ions in each of the proposed type I and type II ion-binding sites of both halves of gelsolin. In contrast to predictions based on solution studies, we find that no calcium ion is immune to exchange.
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