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1.
Rasmus H. Fogh Dick Schipper Rolf Boelens Robert Kaptein 《Journal of biomolecular NMR》1995,5(3):259-270
Summary The 1H, 13C and 15N NMR resonances of serine protease PB92 have been assigned using 3D tripleresonance NMR techniques. With a molecular weight of 27 kDa (269 residues) this protein is one of the largest monomeric proteins assigned so far. The side-chain assignments were based mainly on 3D H(C)CH and 3D (H)CCH COSY and TOCSY experiments. The set of assignments encompasses all backbone carbonyl and CHn carbons, all amide (NH and NH2) nitrogens and 99.2% of the amide and CHn protons. The secondary structure and general topology appear to be identical to those found in the crystal structure of serine protease PB92 [Van der Laan et al. (1992) Protein Eng., 5, 405–411], as judged by chemical shift deviations from random coil values, NH exchange data and analysis of NOEs between backbone NH groups.Abbreviations 2D/3D/4D
two-/three-/four-dimensional
- HSQC
heteronuclear single-quantum coherence
- HMQC
heteronuclear multiple-quantum coherence
- COSY
correlation spectroscopy
- TOCSY
total correlation spectroscopy
- NOE
nuclear Overhauser enhancement (connectivity)
- NOESY
2D NOE spectroscopy
Experiment nomenclature (H(C)CH, etc.) follows the conventions used elsewhere [e.g. Ikura et al. (1990) Biochemistry, 29, 4659–4667]. 相似文献
2.
Siddhartha Sarma Russell J. DiGate Debra L. Banville R. D. Guiles 《Journal of biomolecular NMR》1996,8(2):171-183
Summary Modern multidimensional double- and triple-resonance NMR methods have been applied to assign the backbone and side-chain 13C resonances for both equilibrium conformers of the paramagnetic form of rat liver microsomal cytochrome b
5. The assignment of backbone 13C resonances was used to confirm previous 1H and 15N resonance assignments [Guiles, R.D. et al. (1993) Biochemistry, 32, 8329–8340]. On the basis of short- and medium-range NOEs and backbone 13C chemical shifts, the solution secondary structure of rat cytochrome b
5 has been determined. The striking similarity of backbone 13C resonances for both equilibrium forms strongly suggests that the secondary structures of the two isomers are virtually identical. It has been found that the 13C chemical shifts of both backbone and side-chain atoms are relatively insensitive to paramagnetic effects. The reliability of such methods in anisotropic paramagnetic systems, where large pseudocontact shifts can be observed, is evaluated through calculations of the magnitude of such shifts.Abbreviations DANTE
delays alternating with nutation for tailored excitation
- DEAE
diethylaminoethyl
- DQF-COSY
2D double-quantum-filtered correlation spectroscopy
- EDTA
ethylenediaminetetraacetic acid
- HCCH-TOCSY
3D proton-correlated carbon TOCSY experiment
- HMQC
2D heteronuclear multiple-quantum correlation spectroscopy
- HNCA
3D triple-resonance experiment correlating amide protons, amide nitrogens and alpha carbons
- HNCO
3D triple-resonance experiment correlating amide protons, amide nitrogens and carbonyl carbons
- HNCOCA
3D triple-resonance experiment correlating amide protons, amide nitrogens and alpha carbons via carbonyl carbons
- HOHAHA
2D homonuclear Hartmann-Hahn spectroscopy
- HOHAHA-HMQC
3D HOHAHA relayed HMQC
- HSQC
2D heteronuclear single-quantum correlation spectroscopy
- IPTG
isopropyl thiogalactoside
- NOESY
2D nuclear Overhauser enhancement spectroscopy
- NOESY-HSQC
3D NOESY relayed HSQC
- TOCSY
2D total correlation spectroscopy
- TPPI
time-proportional phase incrementation
- TSP
trimethyl silyl propionate 相似文献
3.
《Nucleosides, nucleotides & nucleic acids》2013,32(4-7):901-902
The seco C-nucleosides 3-(1,2,3,4,5-penta-O-acetyl-D-gluco- and D-galacto-pentitol-1-yl)-1H-1,2,4-triazoles (6 and 7) were obtained in one pot by deamination and dethiolation of 4-amino-3-(D-gluco- and D-galacto-pentitol-1-yl)-5-mercapto-1,2,4-triazoles (1 and 2), respectively, using sodium nitrite in orthophosphoric acid and subsequent acetylation. The structures were confirmed by using 1H, 13C and 2D NMR spectra, DQFCOSY, HMQC and HMBC experiments. The favored conformational structures were deduced from the vicinal coupling constants of the protons. 相似文献
4.
Yoshihito Ueno Shinji Ishihara Yasutomo Ito Yukio Kitade 《Nucleosides, nucleotides & nucleic acids》2013,32(4-6):475-487
The synthesis and properties of oligonucleotides (ONs) containing 9-(2,3,4-trihydroxybutyl)adenine, A C2 and A C3, are described. The ON containing A C2 involves the 3′ → 4′ and 3′ → 5′ phosphodiester linkages in the strand, whereas that containing A C3 possesses the 3′ → 4′ and 2′ → 5′ phosphodiester linkages. It was found that incorporation of the analogs, A C2 or A C3, into ONs significantly reduces the thermal and thermodynamic stabilities of the ON/DNA duplexes, but does not largely decrease the thermal and thermodynamic stabilities of the ON/RNA duplexes as compared with the case of the ON/DNA duplexes. It was revealed that the base recognition ability of A C2 is greater than that of A C3 in the ON/RNA duplexes. 相似文献
5.
Daniella Braz Parente Fernando Fernandes Paiva Jaime Araújo Oliveira Neto Lilian Machado-Silva Fatima Aparecida Ferreira Figueiredo Valeria Lanzoni Carlos Frederico Ferreira Campos Pedro Emmanuel Alvarenga Americano do Brasil Marilia de Brito Gomes Renata de Mello Perez Rosana Souza Rodrigues 《PloS one》2015,10(5)
ObjectiveTo evaluate the capability of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) to assess steatohepatitis and fibrosis determined by histopathology in type 2 diabetic patients.MethodsFifty-nine type 2 diabetic patients (49 women, 10 men; mean age, 54 ± 9 years) were submitted to liver biopsy for the evaluation of non-alcoholic fatty liver disease (NAFLD) and underwent DWI on a 3.0T MR system using 10 b values. Institutional approval and patient consent were obtained. Pure molecular-based (D), perfusion-related (D*), and vascular fraction (f) were calculated using a double exponential model and least squares curve fitting. D, D*, and f were compared between patients with and without steatohepatitis and between patients with and without fibrosis. The variables were compared by using the Ranksum test and Student t-test.ResultsSteatohepatitis was observed in 22 patients and fibrosis in 16 patients. A lower D median (0.70 s/mm2 vs. 0.83 s/mm2, p<0.05) and a lower D* median (34.39 s/mm2 vs. 45.23 s/mm2, p<0.05) were observed among those with steatohepatitis. A lower D median (0.70 s/mm2 vs. 0.82 s/mm2, p<0.05) and a lower D* median (35.01 s/mm2 vs. 44.76 s/mm2, p=0.05) were also observed among those with fibrosis.ConclusionIVIM-DWI has the potential to aid in the characterization of steatohepatitis and fibrosis. 相似文献
6.
Abstract Conformational analysis and 1H NMR spectral assignments have been carried out using COSY and RELAY methods for a series of related oligoribonucleotides including two pen- tamers with 5′-dangling bases. Intraresidue long-range five bond scalar coupling was observed between pyrimidine H5 and H1′ protons in the COSY-45 spectra and this feature was useful for both assignment purposes and conformational analysis. The ribose ring conformations were predominantly C3′-endo with the C2′-endo population increasing at the 3′-terminus. The 5′-dangling bases were not stacked efficiently, exhibiting lower % C3′-endo values than their 3′-nearest neighbors. Backbone torsion angle populations, β′, γ+, ε′, were determined using ′H-′H, ′H-31P, and 13C-31P coupling constants. From β′ and γ+ populations the U3-G4 step in CAUG was found to be less efficiently stacked than the C1-A2 and A2-U3 steps. This observation in solution is consistent with the fiber diffraction A-RNA model (S. Arnott, D.W.L. Hukins, S.D. Dover, W. Fuller and A.R. Hodgson, J. Mol. Biol. 81, 107-122, 1973) which also predicts poor stacking in a U-G dinucleotide. The ε′ populations were >65% for all C3′- O3′ bonds and consistent with a right-handed A-RNA helix. 相似文献
7.
Ming-Jen Cheng Ming-Der Wu Ih-Sheng Chen Min Tseng Gwo-Fang Yuan 《Phytochemistry letters》2011,4(3):372-376
One new cyclohex-2-enone derivative, purpureusone (1), together with seven known compounds (2–8) were isolated from the n-BuOH-soluble fraction of the 95% EtOH extract of the red yeast rice fermented with the yellow mutant of the fungus Monascus purpureus BCRC 38038. Their structures were characterized by direct interpretation of their spectroscopic methods, including 1D NMR (1H, 13C NMR, DEPT), 2D NMR (COSY, NOESY, HSQC and HMBC), and HRESIMS. Purpureusone (1) contains a cyclohex-2-enone skeleton connected with one γ-lactone ring, one octanoyl, and 2-oxopentyl side chains. Some isolates were evaluated for their antifungal effect against Candida albicans and Saccharomyces cerevisiae using a TLC bioautographic method. Compound 1 showed antifungal inhibitory activity in vitro. 相似文献
8.
Abstract A conformational analysis of the A, B, C and D DNA forms was made in order to establish molecular models presenting a good agreement with experimental data obtained from fiber X-ray, infrared linear dichroism and 31P NMR. The proposed models have been refined and do present good stereochemistry and optimized H-bond distances between bases associated with the Watson-Crick pairing. The DNA conformations proposed are a left handed double helix for the C form and right handed helices for A, B and D. Relations to conformational transitions between these forms are discussed. 相似文献
9.
Daniel E. Morrison Fatiah Issa Mohan Bhadbhade Ludwig Groebler Paul K. Witting Michael Kassiou Peter J. Rutledge Louis M. Rendina 《Journal of biological inorganic chemistry》2010,15(8):1305-1318
The preparation of boronated triaryl and tetraaryl phosphonium salts of the type [PPh3CH2R]Br [R is 4-boronophenyl (1), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-yl)phenyl (2), 3-boronophenyl (3), 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-yl)phenyl (4), 2-boronophenyl (5), 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-yl)phenyl (6), and closo-1,2-carboran-1-yl (7)] is described. These compounds were prepared by the reaction of triphenylphosphine with benzylic bromides or 1-bromomethyl-closo-1,2-carborane in acetonitrile solution at 85 °C. The zwitterionic nido-7,8-carborane derivative PPh3CH2C2B9H11 (8) was prepared by treatment of 7 with cesium fluoride in refluxing ethanol. All compounds were fully characterized by multinuclear (1H, 11B, 13C, and 31P) 1D- and 2D-NMR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis, and single-crystal X-ray
structures were determined for compounds 1, 3, 7, and 8. The cytotoxicities and boron uptake of selected derivatives were investigated in vitro using human glioblastoma (T98G) and
canine kidney tubule (MDCK II) cells. The zwitterionic species 8 was found to be the least cytotoxic agent while also delivering the greatest amount of boron to the T98G cells, peaking at
9.15 ± 2.65 μg B/mg protein. 相似文献
10.
《Nucleosides, nucleotides & nucleic acids》2013,32(11):2061-2076
Abstract A modified nitrogen and sulfur glycosylation reaction involving benzothiazole benzoxazole and pyridine nucleoside bases with furanose and pyranose sugars are described. Conformational analysis has been studied by homo- and heteronuclear two-dimensional NMR methods (2D DFQ-COSY, HMQC and HMBC). The N and S sites of glycosylation were determined from the 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments. All the deprotected nucleosides were tested for their potential antitumor activity. 相似文献
11.
《Phytomedicine》2014,21(12):1717-1724
BackgroundThe lichen compound (+)-protolichesterinic acid (+)-PA, isolated from Iceland moss, has anti-proliferative effects on several cancer cell lines. The chemical structure of (+)-PA is similar to a known fatty acid synthase (FASN) inhibitor C75.AimsTo test whether the anti-proliferative activity of (+)-PA is associated with effects on FASN and HER2 (human epidermal growth factor receptor 2) and major signalling pathways. Synergism between (+)-PA and lapatinib, a HER2 active drug, was also evaluated.Materials and methodsPure compound was isolated by preparative high-performance liquid chromatography (HPLC) and purity of (+)-PA analyzed by analytical HPLC. Cell viability was assessed using Crystal violet staining. FASN and HER2 expression was estimated by immunofluorescence. The Meso Scale Discovery (MSD)® assay was used to measure activation of ERK1/2 and AKT. Synergism was estimated by the CalcuSyn software.ResultsTreatment with (+)-PA increased FASN expression in SK-BR-3 cells, which overexpress FASN and HER2, implying a compensatory response to inhibition of FASN activity. HER2 expression was decreased suggesting secondary downregulation. ERK1/2 and AKT signalling pathways were inhibited, probably due to reduced levels of HER2. No effects were observed in T-47D cells. Synergism between (+)-PA and lapatinib was observed in the SK-BR-3 cells.ConclusionResults suggest that the primary effect of (+)-PA is inhibition of FASN activity. Synergistic effects with lapatinib were seen only in SK-BR-3 cells, and not T-47D cells, further supporting the notion that (+)-PA acts by inhibiting FASN with secondary effects on HER2 expression and signalling. (+)-PA could therefore be a suitable agent for further testing, alone or in combination treatment against HER2-overexpressing breast cancer. 相似文献
12.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(4):472-479
A new series of pyrazolo[3,4-d]pyrimidine-6-one derivatives (2a–2j) were prepared by using the Biginelli multicomponent cyclocondensation of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one (1a), different aromatic aldehydes, and urea with a catalytic amount of HCl at reflux temperature. These compounds were characterized by IR, 1H NMR, 13C NMR, and Mass spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 2b, 2i, and 2j with IC50 values of 0.37 µM, 0.04 µM, and 0.06 µM, respectively, exhibited better antiamoebic activity than the standard drug metronidazole (IC50?=?1.33 µM). The toxicological studies of these compounds on human breast cancer MCF-7 cell line showed that the compounds 2b, 2i, and 2j exhibited >80% viability at the concentration range of 1.56–50 µM. 相似文献
13.
Khodayar Gholivand Ahlam Madani Alizadegan Azam Anaraki Firooz Khosro Khajeh Hossein Naderi-manesh Hamidreza Bijanzadeh 《Journal of enzyme inhibition and medicinal chemistry》2013,28(1):105-111
Carbacylamidophosphates with the general formula RC(O)NHP(O)R1R2 constitute organophosphorus compounds that are used as insecticides, pesticides and ureas inhibitors. In this work, we studied the inhibition potency of CCl3C(O)NHP(O)Cl21, CHCl2C(O)NHP(O)Cl22, CH2ClC(O)NHP(O)Cl23 and CF3C(O)NHP(O)Cl24, which are the major intermediates for carbacylamidophosphates synthesis towards human erythrocyte acetylcholinesterase (hAChe) activity using Ellman's modified kinetic method. Unexpectedly, it was observed that they were not only hydrolytically unstable but also inhibited hAChE in a similar manner to that produced by organophosphorus insecticides. Enzymatic data, bimolecular inhibition rate constants (ki) and IC50 values for inhibition of hAChE demonstrated that they are irreversible inhibitors and the inhibition potency of compound 2 (IC50 = 88 μM) was the greatest in comparison with compounds 1, 3 and 4. Also the electropositivity of the phosphorus atom and the hydrophobicity of the compounds demonstrated that these two factors play an additional effect and different role in the inhibitory activity of these compounds. Hydrolytic stability of the compounds was determined by 31P NMR monitoring of the loss of the parent molecules with D2O as a function of time. This study considers antiacetylcholinesterase activity according to the structural and the electronic aspects of compounds 1–4, according to IR, 1H, 13C and 31P NMR spectral data. 相似文献
14.
William H. Gmeiner Alan Skradis Richard T. Pon Jinqian Liu 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):1577-1578
Abstract The effects of cytarabine on the structural and thermodynamic properties of an Okazaki fragment were investigated using UV hyperchromicity and 2D 1H NMR. Cytarabine significantly decreased the stability of this model Okazaki fragment, decreasing the melting temperature from 46.8 °C to 42.4 °C at 1.33 × 10?5M. Cytarabine also markedly increased the bend angle of the Okazaki fragment duplex from 20° to 42°. Changes to the structures and stabilities of Okazaki fragments may cause the biological effects of cytarabine. 相似文献
15.
C. A.G. Haasnoot U. K. Pandit C. Kruk C. W. Hilbers 《Journal of biomolecular structure & dynamics》2013,31(2):449-467
Abstract 1H-NMR spectra of bleomycin A2 recorded at 500 MHz in D2O and H2O at 24°C and 3°C were investigated. Resonances of the individual spin systems were identified by using two-dimensional correlated spectroscopy (COSY), two-dimensional spin echo correlated spectroscopy (SECSY) and by the application of two-dimensional Nuclear Overhauser Effect spectroscopy (NOESY). Employment of these techniques allowed the assignment of 13 exchangeable and 59 non-exchangeable protons in the 1H NMR spectrum of bleomycin A2. By means of 2D NOE spectroscopy also interresidual connectivities could be observed. Comparison of the NOESY spectra at 3°C and 24°C suggest that at low temperatures the central part of the bleomycin A2 molecule tends to adopt an extended conformation. 相似文献
16.
Novel glycosidic gossypol analogs, 7,7′-gossypol diglucoside tetraacetate GS1, 6,7′-gossypol diglucoside tetraacetate GS2, 7,7′-gossypol diglycoside GS1′, 6,7′-gossypol diglycoside GS2′ were obtained by the ultrasound-assisted reaction of the potassium salt of gossypol with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide under PTC conditions and were fully characterized by 1D NMR (1H NMR, 13C NMR, DEPT, 1D NOE), 2D NMR (HMBC, HMQC), FTIR, HRMS and HPLC. The anticancer activities, cytotoxic effects as well as anti-trypanosomal activities of these novel glycosidic gossypols were explored and suggest that gossypol glycosides could be used to develop new candidates for anticancer drugs and anti-trypanosomal agents. 相似文献
17.
Pooja Singh Deepak Singh Kapkoti Nandan Singh Rashi Tewari Dharmendra Saikia Prasant Kumar Rout 《Biocatalysis and Biotransformation》2019,37(4):304-309
The microbial transformation of artemisinic acid (1) using cell culture of endophytic fungus Trichothecium roseum was investigated. Previously, we have reported two major metabolites, 3β-hydroxyartemisinic acid (2) and 3β,15-dihydroxyartemisinic acid (3) from the biotransformation of artemisinic acid by the fungus T. roseum CIMAPN1. Here in the present paper, we obtained a new minor compound 4 (5.2% in yield) along with compounds 2 and 3 through scale-up of biotransformation process of artemisinic acid using the same fungus. The structure of compound 4 was established as 3-oxoartemisinic acid on the basis of its IR, ESI-MS, HRMS, 1?D (1H and 13C, DEPT), and 2?D (COSY, HSQC, HMBC) NMR spectral data analysis. The possible reaction mechanism of the formation of 3-oxoartemisinic acid from artemisinic acid was proposed. Furthermore, all the three metabolites along with the artemisinic acid were evaluated for their antifungal activity against the three fungal strains Candida albicans (ATCC 14053), Candida albicans clinical isolates and Candida kefyr (ATCC 204093). 3-Oxoartemisinic acid was the most active (4 to 16 times more potent than artemisinic acid) with MIC ranges from 125 to 500?µg/mL among all tested compounds. This study suggested that the artemisinic acid molecule has a great potential to be exploited for further biotransformation by the different fungi and can produce chemically diverse molecules with better biological activity. 相似文献
18.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1896-1901
Rubralactone (1), rubralides A, B and C (2–4), rubramin (5), and 2-formyl-3,5-dihydroxy-4-methylbenzoic acid (6), were isolated from Penicillium rubrum, and their structures established by spectroscopic methods including 2D NMR. The effects on plant growth of 1–6 were examined using the lettuce seedling bioassay. Compound 1 promoted root growth. Compounds 2, 3 and 5 inhibited the growth of lettuce seedlings, but 4 and 6 did not have any inhibitory effect on their growth. 相似文献
19.
《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):1669-1672
Abstract It was found by 1H, 13C and 15N NMR study that substitution of 4,9-dihydro-4, 6-dimethyl-9-oxo-3-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl) imidazo [1,2-a]purine (wyosine triacetate, 1) at C2 position with electronegative groups CH3O and C6H5CH2O results in a noticeable electron distribution disturbance in the “left-hand” imidazole ring and a significant increase in the North conformer population of the sugar moiety. 相似文献
20.
《Journal of receptor and signal transduction research》2013,33(5):439-449
AbstractBenzodipyrazoles have been previously evaluated for their in vitro CDK2 inhibitory activity. In the current investigation, we identified a six-feature common pharmacophore model (AADDRR.33) which is predicted to be responsible for CDK2 inhibition. An efficient 3D QSAR (r2?=?0.98 and q2?=?0.82) model was also constructed by employing PLS regression analysis. From the molecular docking studies, we examined the binding patterns of compound 7aa with the target protein and also calculated the binding energy using MM-GBSA calculations. Three hydrogen bonds with Lys 33, Glu 81, and Leu 83 are conserved even after 1000?ps run in a molecular dynamics simulation. We identified the slight displacement in bond lengths and the conformational changes occurred during the dynamics. The results also elucidated the protein residue–ligand interaction fractions which clearly explained the involvement of non-H-bond interactions. 相似文献