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1.
Sar1 is a small GTPase involved in COPⅡ vesicle transport. Previous studies showed that H79G mutation of Sar1 can lock Sar1 in its GTP-bound active conformation, stabilize coat assembly, and prevent the disassembly of COP Ⅱ vesicle coats by reducing Sec23/24 GAPstimulated hydrolysis. We show here that the replacement of His79 by glycine induces a large conformation change in switch Ⅱ and results in the lost of hydrogen bond between His79 and its associated nucleophilic water molecule that was hypothesized to reduce the GAP-stimulated hydrolysis during the COP Ⅱ assembly and disassembly. These results confirm that the switch Ⅱ conformation is important for COP Ⅱ disassembly through coat-controlled GTP hydrolysis.  相似文献   

2.
1INTRODUCTIONTheplanttoxin,CrotinIisoneoftheribosomeinactivatingproteins(RIPs)[l3.AccordingtothemolecularmechanismofactiontheRIPscanbedividedintotwokinds[2:.OnebelongstoRNAN-glycosidasewhichisclassifiedastwotypes.TypeIconsistsofasinglepolypeptidechain,forexample,trichosanthinandsaporin-Typellconsistsoftwochains,suchasricinandabrin'ThiskindofRIPshydrolysesasingleN-glycosidicbondbetweenanadenineandriboseatspecificnu-cleotide(A4324)of28SrRNAintheribosomes[3i.ThesecondkindofRIPsbel…  相似文献   

3.
1 INTRODUCTION The tris(ethylenediamine) cobalt (Ⅲ) complex in which there are L and D configurations is one of the very interest cations due to the chirality among research complexes and the characterization of reaction on the ion-pair charge-transfer transitions. It has been mentioned in a lot of examples on the chirality and the structure, such as [L-Co(en)3]- [?Co(edta)]2Cl?0H2O[1], [(+)DCo(en)3]Cl3稨2O[2], [(+)-Co(en)3?-)-Cr(en)3]Cl?.1H2O[3], [()-Co(en)3] (SCN)3[4], [(+)D…  相似文献   

4.
1 INTRODUCTION The coordination chemistry of Pd(Ⅱ) com- plexes with didentate nitrogen coordination ligands has been extensively studied for a few decades[1]. Pd(Ⅱ) trends to bond to the didentate nitrogen in cis-mode and such complexes have potential usage in the emerging area of self-assembly[2]. We will report herein the synthesis and crystal structure of a cis-coordinated mononuclear Pd(Ⅱ) complex with one 1,10-phenanthroline and two THF as ligands, 1. 2 EXPERIMENTAL 2. …  相似文献   

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In the title coordination compound,[Cu(HDPPZC)(SO4)(H2O)]2 (1,HDPPZC=dipyrido[3,2-a:2,3-c]-phenazine-2-carboxylic acid),has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction,elemental analysis and magnetic susceptibility measurement.It crystallizes in triclinic,space group P1 with a=0.69485(6),b=0.76878(4),c=1.76638(13)nm,α=99.437(6),β=94.690(6),γ=95.735(6)o,V=0.92151(12) nm 3,Z=1,Cu2C38 H24 N 8S2O14,Mr=1007.85,Dc= 1.816 g·cm-3,F(000)=510,GOOF=0.988,the final R=0.0580 and wR=0.0689.The structural analyses reveal that complex 1 shows discrete dinuclear clusters,which are further linked by hydrogen bonding and π·π stacking interactions to form a three-dimensional supramolecular compound.Magnetic measurement shows ferromagnetic and antiferromagnetic exchange interactions in the sample.  相似文献   

8.
A binuclear complex [Cu2(phen)2(ip)(Hip)2]·4H2O has been synthesized by the reaction of Cu(CH3COO)2·H2O, phen(1,10-phenanthroline) and isophthalic acid (H2ip) under hydrothermal condition. Elemental analysis, IR spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. Crystal data for this complex: mono- clinic, space group C2/c, a = 19.214(3), b = 10.6973(14), c = 22.567(3) , β = 105.081(2)°, C24H19N2O8Cu, Mr = 526.95, Z = 8, F(000) = 2160, V = 4478.6(10) 3, Dc = 1.563 g/cm3, μ = 1.030 mm-1, –24≤h≤16, –13≤k≤13, –28≤l≤28, R = 0.0369 and wR = 0.0819 for 4615 (Rint = 1.0357) independent reflections and 3290 observed ones (I > 2σ(I)). Structural analysis shows that coordination geometry of Cu(Ⅱ) is a planar square, and the title complex exhibits a 2-D framework supramolecular structure by hydrogen bonds and π-π stacking interactions.  相似文献   

9.
A new heteropolymolybdoarsenate [H2N(CH2CH2)2O]10[Mn2(AsVMo9O33)2]·12H2O(1) has been synthesized in aqueous solution and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The crystal is made up of sandwich-type [Mn2(AsVMo9O33)2]10- anions, [H2N(CH2CH2)2O]+ cations and H2O molecules of crystallization. The magnetic properties of 1 have been studied by measuring its magnetic susceptibility in the temperature range of 2.0-300.0 K, indicating the existence of antiferromagnetic interactions.  相似文献   

10.
A novel coordination polymer [Na2Pd(2,6-pydc)2(H2O)6]n (2,6-H2pyde = 2,6-pyri-dinedicarboxylie acid) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinie system, space group P21/c,with a = 11.962(2), b = 6.5552(13), c = 12.673(3) A, β = 91.72(3)°, V= 993.3(3) A3,Z = 2, Mr=590.68, Dc = 1.975 g/cm3,μ=1.059 mm-1, F(000) = 592, the final R = 0.0211 and wR = 0.0454. In the crystal the Pd(Ⅱ) ion adopts a distorted four-coordinated square-planar geometry and bonds to two bidentate 2,6-pyridinedicarboxylate molecules through caronyl oxygen and pyridine nitrogen atoms. The title complex exhibits a novel three-dimensional network structure.  相似文献   

11.
The title compound 5-allyl-2,3-dihydro-9-(2-hydroxy-5-oxocyclopent-1-enyl)-cyclopenta[b]chromen-1(9H)-one monohydrate(C20H18O4.H2O,Mr = 340.36) was synthesized and crystallized.It crystallizes in the triclinic system,space group P with a = 8.5840(17),b = 8.7027(17),c = 11.561(2),α = 89.69(3),β = 74.33(3),γ = 86.13(3)°,V = 829.6(3)3,Z = 2,Dc = 1.363 g/cm3,MoKa radiation(λ = 0.71073 ),F(000) = 360,μ = 0.098 mm-1,the final R = 0.0430 and wR = 0.1008 for 2957 observed reflections with(I > 2σ(I)).X-ray analysis reveals that atoms C(1),C(2),C(3),C(4),C(5) and O(1) on the new pyran ring are coplanar,which is obviously different from the half-chair or boat conformations of other similar compounds.  相似文献   

12.
1INTRODUCT1oNIthasbeenwellknownthatthereactionofcopper(E)saltswithditertiaryphosphinesorarsinesisoftenaconvenientroutetocopper(I)analogues.8-dimethylarsinoquinolinee,3-methylthiopropyldimethylarsineand(o-diphenylarsi-nophenyl)diphenylphosphinesulphideallonlyyieldcopper(I)complexesofthiskindofligandsfromreactioninvolvingcopper(I)salts.Insimilarmanner,copper(I)nitratecomplexesofstoichiometryCu(dppm)(NO,),Cu2(dppe)3(NO,)2,Cu-(dppe),(NO,),andCu(dppe)(NO,)havebeenprepared.ltappearsthatthe…  相似文献   

13.
A novel coordination polymer, [Mn(PDC)H2O]n (1) (H2PDC=pyridine-2,3-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. X-ray single crystal structural analyses revealed that two-dimensional frameworks were formed, and further assembled into a three-dimensional supramolecular structure bridged by PDC ligands. Moreover, the magnetic study of complex 1 shows weak antiferromagnetic interaction between the neighboring Mn(II) centers within the chains and even weak ferromagnetic interactions between the Mn(II) centers in different chains.  相似文献   

14.
The title compound N-(2-ethoxyphenyl)-3-oxobenzo[d]isothiazole-2(3H)-carboxa-mide(C16H14N2O3S,Mr = 314.35) has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.The crystal belongs to triclinic,space group P with a = 4.6395(15),b = 8.689(3),c = 17.917(7),α = 87.763(9),β = 84.625(9),γ = 82.344(9)°,V = 712.4(4)3,Z = 2,Dc = 1.465 Mg·m-3,λ(MoKa) = 0.71073,F(000) = 328,μ(MoKa) = 0.242 mm-1,the final R = 0.038 and wR = 0.089.A total of 3702 unique reflections were collected,of which 2762 with I > 2σ(I) were observed.X-ray analysis revealed that the benzisothiazolone ring and benzene moieties were essentially planar,and three intramolecular hydrogen bonds N(2)-H(2N)…O(1),N(2)-H(2N)…O(3) and C(10)-H(10)…O(2) were observed.The preliminary biologi-cal test showed that the title compound had antifungal and antibacteria activities against Bacillus subtilis(CMCC63003),Aeromonas hydrophila(ATCC7966),Staphylococcus aureus(ATCC6538),Escherichia coli(JM103),Blastomyces albicans,Gloeosporium papaya P.Henn,Colletotrichum gloeosporioides Penz and Botryodiplodia theobromae.  相似文献   

15.
The title compound(C26H18N4O4) has been synthesized via a three-component reaction and it was characterized by means of IR and 1H NMR.Its crystal and molecular structures were determined by X-ray diffractometry.It belongs to the triclinic system,space group P1 with a = 7.7288(15),b = 11.168(2),c = 12.645(3) ,α = 107.02(3),β = 90.85(3),γ = 101.93(3)°,V = 1017.9(3) 3,Mr = 450.44,Z = 2,Dc = 1.470 g/cm3,λ = 1.54178 ,μ = 0.836 mm-1,F(000) = 468,the final R = 0.0488 and wR = 0.1180.A total of 11903 reflections were collected,of which 3642 were independent(Rint = 0.0377) and 3025 were observed with I > 2σ(I).  相似文献   

16.
A new dinuclear copper complex, [Cu(C9H11N3)Cl2]2 (C18H22Cl4Cu2N6), has been synthe- sized and characterized by X-ray structure determination. It crystallizes in the triclinic P1 space group with a = 7.526(3), b = 9.473(4), c = 9.535(3) , α = 117.214(10), β = 108.251(9), γ = 91.560(6)o, V = 562.3(4) 3, Z = 1, Mr = 591.30, F(000) = 298, Dc = 1.746 g/cm3, μ(MoKα) = 2.385 mm-1, the final R = 0.0577 and wR = 0.1248 for 2188 unique reflections with 1629 observed ones (I > 2σ(I)). In the title complex, each copper(II) atom is located at the center of a distorted trigonal bipyramid of five coordination atoms (two nitrogen and three chlorine atoms). Two copper(II) atoms were bridged by two chlorine anions (Cl(2) and Cl(2a)) to form a Cu(II)-Cu(II) binuclear entity with the distance between two copper(II) atoms of 3.398 .  相似文献   

17.
A new nickel(II) coordination complex [Ni(phen)3]·(m-nitrobenzoic acid)2·(H2O) was synthesized by self-assembly of m-nitrobenzoic acid, 1,10-phenanthroline and nickelous per- chlorate. It crystallizes in the monoclinic system, space group C2/c, with a = 2.4596(6), b = 1.2124(3), c = 1.9824(5) nm, β = 97.088(5)o, V = 5.866(3) nm3, Dc = 1.474 g/cm3, Z = 4, Mr = 1301.82, μ(MoKα) = 0.417 mm-1 F(000) = 2688, R = 0.0493 and wR = 0.1025. Structural deter- mination indicates that the nickel(II) ion is coordinated with six nitrogen atoms from three phens, giving a distorted octahedral coordination geometry. The cyclic voltametric analysis shows that the electron transfer in the electrode reaction is irreversible.  相似文献   

18.
HU Jiu-Rong  LIANG Fu-Pei   《结构化学》2007,26(7):793-796
A novel complex [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O (Fc = (η5-C5H5)Fe(η5-C5H4), 2,2′-bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187(4), b = 21.7155(13), c = 19.7411(12) (A), α = 90, β = 97.7420(10), γ = 90°, C64H58Fe4Zn2N4O11, Mr = 1413.28, V = 2896.4(3) (A)3, Dc = 1.620 g/cm3, Z = 2, F(000) = 1444, μ(MoKα) = 1.857 mm-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections (I > 2σ(I)). Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2′-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.  相似文献   

19.
Synthesis and Crystal Structure of [{Cd(hmbdc)(H_2O)_3}·2H_2O]_n   总被引:1,自引:0,他引:1  
A novel coordination polymer [{Cd(hmbdc)(H2O)3}·2H2O]n (hmbdc = 5-hydroxy- isophthalic acid) has been synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 9.599(3), b = 18.699(5), c = 7.557(2) , β = 108.198(4)°, V = 1288.6(6) 3, Z = 4, Mr = 382.60, Dc = 1.972 g/cm3, F(000) = 760, μ = 1.740, the final R = 0.0555 and wR = 0.0995 for 1732 observed reflections with I > 2σ(I). The structural analysis shows that the intermolecular hydrogen bonds and π-π interactions result in a three-dimensional supramolecular framework.  相似文献   

20.
1 INTRODUCTION The metal-organic coordination polymers have proved to be promising in developing new mate- rials[1]. It is crucial to select or synthesize the suita- ble bridging organic ligand. Some simple rigid li- gands are skillfully employed[2~4].…  相似文献   

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