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1.
Tatyana V Ovchinnikova Zakhar O Shenkarev Zoya A Yakimenko Natalia V Svishcheva Andrey A Tagaev Dmitry A Skladnev Alexander S Arseniev 《Journal of peptide science》2003,9(11-12):817-826
Zervamicin IIB is a member of the alpha-aminoisobutyric acid containing peptaibol antibiotics. A new procedure for the biosynthetic preparation of the uniformly 13C- and 15N-enriched peptaibol is described This compound was isolated from the biomass of the fungus-producer Emericellopsis salmosynnemata strain 336 IMI 58330 obtained upon cultivation in the totally 13C, 15N-labelled complete medium. To prepare such a medium the autolysed biomass and the exopolysaccharides of the obligate methylotrophic bacterium Methylobacillus flagellatus KT were used. This microorganism was grown in totally 13C, 15N-labelled minimal medium containing 13C-methanol and 15N-ammonium chloride as the only carbon and nitrogen sources. Preliminary NMR spectroscopic analysis indicated a high extent of isotope incorporation (> 90%) and led to the complete 13C- and 15N-NMR assignment including the stereospecific assignment of Aib residues methyl groups. The observed pattern of the structurally important secondary chemical shifts of 1H(alpha), 13C=O and 13C(alpha) agrees well with the previously determined structure of zervamicin IIB in methanol solution. 相似文献
2.
Milov AD Tsvetkov YD Gorbunova EY Mustaeva LG Ovchinnikova TV Handgraaf JW Raap J 《化学与生物多样性》2007,4(6):1243-1255
Zervamicin is a voltage-gated ion-channel-forming peptide. Channels are generally considered to be formed by first insertion of amphipathic molecules into the phospholipid bilayer, followed by self-assembly of a variable number of transmembrane helices. We have studied the length of the peptide structure to address the question whether this peptide is long enough to span the phospholipid bilayer. The pulsed electron-electron double resonance (PELDOR) spectroscopic technique was used to determine the length of the helical molecule in membrane-mimicking solvents. This was achieved from the distance-related dipole-dipole interaction between spin labels, which were located at both ends of the linear peptide chain. The data were obtained by using samples of frozen glassy solutions of MeOH, MeOH/toluene, and MeOH/CHCl(3). Contributions of inter- and intramolecular interactions of spin labels were separated to analyze the intramolecular interaction and the distance distribution function between the labels. It is shown that the main maximum of the distribution functions is located at a distance of ca. 3.3 nm, and this distance appears to be only slightly dependent on the solvent composition. The distribution function was observed to narrow after addition of either CHCl(3) or toluene to MeOH. This effect is rationalized in terms of a decreased mobility of the terminal amino acid residues. By molecular-dynamics simulations, it was shown that the conformation, corresponding with the predominant distance found by PELDOR, agrees well with the mixed alpha/3(10)-helical that was previously determined by NMR. However, in the case toluene was added to the MeOH solution to further increase the hydrophobicity of the environment of the membrane-active peptide, the distribution function gives rise to a minor fraction (7-8%) with a distance of 4.2 nm. This distance corresponds most likely to the more extended 2(7)-helix structure. 相似文献
3.
B. N. Ivanov V. L. Shmeleva V. I. Ovchinnikova 《Journal of bioenergetics and biomembranes》1985,17(4):239-249
The number of protons released inside the chloroplast thylakoids per electron which is transferred through the electron transport chain (H+/e– ratio) was measured in isolated pea chloroplasts at pH 6.0 under continuous illumination and with methyl viologen as an electron acceptor. At saturating light intensity (200 W · m–2) (strong light) the H+/e– ratio was 3. At low intensity (0.9 W · m–2) (weak light) the H+/e– ratio was 2 with dark-adapted chloroplasts, but it was close to 3 with chloroplasts that were preilluminated with strong light. It is shown that the presence of azide in the reaction mixture leads to errors in the determination of the H+/e– ratio due to underestimation of the initial rate of H+ efflux on switching off the light. To explain the above data, we assume that transformation of the electron transport chain occurs during illumination with strong light, namely, the Q cycle becomes operative. 相似文献
4.
Pavel V. Panteleev Ilia A. Bolosov Sergey V. Balandin Tatiana V. Ovchinnikova 《Journal of peptide science》2015,21(2):105-113
β‐Hairpin antimicrobial peptides are among the most potent peptide antibiotics of animal origin. Arenicins, isolated earlier from marine polychaeta lugworm Arenicola marina, belong to a family of β‐hairpin antimicrobial peptides and display a broad spectrum of biological activities. However, despite being potent antimicrobials, arenicins are partially unapplicable as therapeutics as a result of their relatively high cytotoxicity against mammalian cells. In this study, a template‐based approach was used to create therapeutically valuable analogs of arenicin‐1 and identify amino acid residues important for antibacterial and cytotoxic activities of the peptide. The plasmids encoding recombinant analogs were constructed by mutagenesis technique based on inverse PCR amplification of the whole arenicin‐1 expression plasmid. The analogs were produced as a part of the fusion proteins in Escherichia coli. It was shown that an obvious reduction in hemolytic activity without lose of antimicrobial activity can be achieved by a single amino acid substitution in the non‐polar face of the molecule with hydrophilic residues such as serine and arginine. As the result, the selective analog with 50‐fold improved therapeutic index was developed. The circular dichroism spectra demonstrated that the secondary structure of the analog was similar to the natural arenicin‐1 in water solution and sodium dodecyl sulfate micelles but significantly differed in the presence of dodecylphosphocholine micelles mimicking mammalian membranes. Similarly to arenicin‐1, the designed analog killed bacteria via induction of the membrane damage, assessed using the fluorescent dye SYTOX Green uptake. Our results afford molecular insight into mechanism of antimicrobial action of the designed arenicin analogs and their possible clinical application. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
5.
Kocharova NA Ovchinnikova OG Torzewska A Shashkov AS Knirel YA Rozalski A 《Carbohydrate research》2007,342(3-4):665-670
An oligosaccharide that corresponds to the repeating unit of the O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O36. Structural studies of the oligosaccharide and O-deacylated lipopolysaccharide were performed using sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, and H-detected (1)H,(13)C HSQC and HMBC experiments. It was found that the O-polysaccharide is built up of linear trisaccharide repeating units containing 2-acetamido-2-deoxyglucose, 6-deoxy-l-talose (l-6dTal), and 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) and has the following structure. [structure: see text] 相似文献
6.
Blinova MI Kalmykova NV Iudintseva NM Kuz'minykh EV Iurlova NA Ovchinnikova OA Potokin IL 《Tsitologiia》2002,44(8):788-791
Data on the influence of the black yeast melanin (3 samples) on the in vitro differentiation of human keratinocytes are presented. The effect of melanins was estimated by the morphological state of keratinocytes using electron microscopy. The obtained differences in the state of the formed multilayer keratinocyte sheets depended on the melanin sample. 相似文献
7.
Zaitseva L. G. Ovchinnikova T. V. Vodovozova E. L. Molotkovsky Yul. G. Polyakov N. B. Titov M. I. Esipov S. E. Grinkevich V. A. 《Russian Journal of Bioorganic Chemistry》2002,28(5):371-384
The subunits of the F0 membrane sector of bovine heart mitochondrial H+-ATPase that contact the lipids of the mitochondrial inner membrane were identified with the use of specially synthesized proteoliposomes that contained active mitochondrial H+-ATPase and a photoreactive lipid, which was 1-acyl-2-[12-[di-azocyclopentadiene-2-carbonylamino)-[12-14C]dodecanoyl]-sn-glycero-3-phosphocholine, 1-acyl-2-[11-([125I]diazoiodocyclopentadiene-2-carbonyloxy)undecanoyl]-sn-glycero-3-phosphocholine, or 1-acyl-2-[12-(diazocyclopentadiene-2-carbonylamino)dodecanoyl]-sn-glycero-3-phosphocholine, where acyl is a mixture of the residues of palmitic (70%) and stearic (30%) acids. An analysis of the cross-linked products obtained upon the UV-irradiation of these proteoliposomes indicated that subunits c and a of the F0 membrane sector contact the lipids. The crosslinked products were identified by SDS-PAGE and MALDI mass spectrometry. 相似文献
8.
Milov AD Tsvetkov YD Gorbunova EY Mustaeva LG Ovchinnikova TV Raap J 《Biopolymers》2002,64(6):328-336
In this article, the pulsed double electron-electron resonance in electron spin-echo (PELDOR) technique is applied to study the self-aggregation of spin-labeled zervamicin IIA, a hexadecapeptide antibiotic of fungal origin, which is known to form ion channels in a phospholipid double layer. Measurements of the ion channel forming properties and the antibiotic activity of the analog indicate that replacement of the C-terminal phenylalaninol by the amino-2,2,6,6-tetramethylpiperidinyloxy (TEMPO) residue does not influence the biophysical and biological properties. The dipole-dipole interaction between the spin labels of the fully biologically active peptide analog was studied in frozen (77 K) glassy solutions in different ratios of toluene-methanol. The spin-labeled zervamicin IIA molecules were shown to form aggregates. An average distance between the spin labels in the aggregates was estimated to be in the range of 25-35 A (depending on the solvent composition), indicating that the amphiphilic helical peptide molecules are oriented in an antiparallel fashion. Increasing of methanol content in the solution results in a loosening of the aggregate structure. It was shown that the fraction of aggregated zervamicin IIA molecules is less than 44-67% depending on the solvent composition. The general usefulness of the method to obtain structural long-range information in a range of several tens of angstroms is demonstrated by comparison with the peptide cluster of trichogin GA IV. 相似文献
9.
Vladimirova NM Sautkina EN Ovchinnikova TV Potapenko NA 《Biochemistry. Biokhimii?a》2002,67(4):503-509
Functionally active Na2+,K2+-ATPase isozymes containing three types of the catalytic subunits (1, 2, and 3) were obtained from calf brain by two methods: selective removal of contaminating proteins according to Jorgensen (1974) and selective solubilization of the enzyme with subsequent reformation of the membrane structure according to Esmann (1988). All preparations were characterized with respect to ouabain-inhibition constants. The presence of the cytoskeleton protein tubulin (3 isoform) in the high-molecular-weight complex of Na2+,K2+-ATPase 31 isozyme from brain stem axolemma and the junction between Na2+,K2+-ATPase 3 subunit and tubulin 3 subunit are shown for the first time. 相似文献
10.