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91.
Structures and functions of about 700 oligopeptides of various plants are presently known. However, only one polypeptide has
been isolated from grapes and characterized. At the same time, tens of thousands of uncharacterized amino acid sequences have
been revealed in this plant, among which there can also be precursors of oligopeptide regulators. Due to the scientific and
practical importance of innate immunity of agricultural plants, we have undertaken structural and functional investigation
of these sequences to identify new regulatory oligopeptides including antimicrobial agents. For this purpose, we elaborated
a special method of computer analysis enabling comparison of primary structures of putative precursors of grape oligopeptides
with amino acid sequences of known oligopeptides of other plants. Structural similarity served as the basis for prediction
of potential functional properties. As a result, over 20 new structures of antimicrobial and other grape oligopeptides have
been found. 相似文献
92.
Quantum-chemical study of structures, energies, and effective partial charge distribution for several models of the Rieske protein redox center is performed in terms of the B3LYP density functional method in combination with the broken symmetry approach using three different atomic basis sets. The structure of the redox complex optimized in vacuum differs markedly from that inside the protein. This means that the protein matrix imposes some stress on the active site resulting in distortion of its structure. The redox potentials calculated for the real active site structure are in a substantially better agreement with the experiment than those calculated for the idealized structure. This shows an important role of the active site distortion in tuning its redox potential. The reference absolute electrode potential of the standard hydrogen electrode is used that accounts for the correction caused by the water surface potential. Electrostatic calculations are performed in the framework of the polarizable solute model. Two dielectric permittivities of the protein are employed: the optical permittivity for calculation of the intraprotein electric field, and the static permittivity for calculation of the dielectric response energy. Only this approach results in a reasonable agreement of the calculated and experimental redox potentials. 相似文献
93.
Using poly-(ethylene glycol)s of different molecular weights, we probe the channels formed in planar lipid bilayers by epsilon toxin secreted by the anaerobic bacterium Clostridium perfringens. We find that the pore is highly asymmetric. The cutoff size of polymers entering the pore through its opening from the cis side, the side of toxin addition, is ∼500 Da, whereas the cutoff size for the polymers entering from the trans side is ∼2300 Da. Comparing these characteristic molecular weights with those reported earlier for OmpF porin and the α-Hemolysin channel, we estimate the radii of cis and trans openings as 0.4 nm and 1.0 nm, respectively. The simplest geometry corresponding to these findings is that of a truncated cone. The asymmetry of the pore is also confirmed by measurements of the reversal potential at oppositely directed salt gradients. The moderate anionic selectivity of the channel is salted-out more efficiently when the salt concentration is higher at the trans side of the pore. 相似文献
94.
Vaĭner AS Boiarskikh UA Voronina EN Selezneva IA Sinkina TV Lazarev AF Petrova VD Filipenko ML 《Molekuliarnaia biologiia》2010,44(5):816-823
Breast cancer is the most incident cancer among women. We investigated the role of polymorphisms of folate metabolizing genes MTHFR (C677T and A1298C), SHMT1 (C1420T) and MTHFD (G1258A) in genetic susceptibility to this type of cancer. We determined allele and genotype frequencies in case (850 women with sporadic form of breast cancer) and control (810 women) groups. None of these polymorphisms was significantly associated with breast cancer risk. To increase statistical power of our study, we conducted a meta-analysis which included published genotype data and the results of our work. Meta-analysis also revealed no significant association of studied SNPs with breast cancer. 相似文献
95.
Chromosome mapping of three common markers, ie major and 5S rRNA genes (rDNA) and telomeric repeats, and conventional chromosome
bandings were applied to two sibling species, Apodemus sylvaticus Linnaeus, 1758 and A. flavicollis Melchior, 1834, to further investigate intra- and interspecific karyological differentiation in the genus Apodemus. A slight variation of the rDNA-patterns was detected between the two Apodemus species. In both of them, the major NORs were located on autosome pairs 8, 11, 12 and 22, while the two other rDNA sites
detected on chromosomes 7 and 21 were variable in, respectively, A. sylvaticus and A. flavicollis. Several tiny rDNA sites were present on the sex chromosomes in both species, but their incidence was lower in A. flavicollis. Single 5S rDNA chromosomal sites were conserved on chromosome pair 20. No interstitial sites of telomeric repeats were present
in either species. In the Sicilian population of A. sylvaticus, the constitutive heterochromatin pattern corresponded to the “sylvaticus-E1” cytotype, while A. flavicollis had a species-specific pattern restricted to centromeres of all chromosomes. The results are discussed in relation to cytogenetic
data available for the genus, with emphasis on the Sylvaemus group/subgenus. 相似文献
96.
Chloe Robins Yue Liu Wen Fan Duc M. Duong Jacob Meigs Nadia V. Harerimana Ekaterina S. Gerasimov Eric B. Dammer David J. Cutler Thomas G. Beach Eric M. Reiman Philip L. De Jager David A. Bennett James J. Lah Aliza P. Wingo Allan I. Levey Nicholas T. Seyfried Thomas S. Wingo 《American journal of human genetics》2021,108(3):400-410
97.
Stephen R. Foster Ekaterina I. Galanzha Daniel C. Totten Helen Beneš Robert J. Shmookler Reis Vladimir P. Zharov 《Journal of biophotonics》2014,7(7):465-473
In biomedical applications, nanoparticles have demonstrated the potential to eradicate abnormal cells in small localized pathological zones associated with cancer or infections. Here, we introduce a method for nanotechnology‐based photothermal (PT) killing of whole organisms considered harmful to humans or the environment. We demonstrate that laser‐induced thermal, and accompanying nano‐ and microbubble phenomena, can injure or kill C. elegans and mosquitoes fed carbon nanotubes, gold nanospheres, gold nanoshells, or magnetic nanoparticles at laser energies that are safe for humans. In addition, a photoacoustic (PA) effect was used to control nanoparticle delivery. Through the integration of this technique with molecular targeting, nanoparticle clustering, magnetic capturing and spectral sharpening of PA and PT plasmonic resonances, our laser‐based PA‐PT nano‐theranostic platform can be applied to detection and the physical destruction of small organisms and carriers of pathogens, such as malaria vectors, spiders, bed bugs, fleas, ants, locusts, grasshoppers, phytophagous mites, or other arthropod pests, irrespective of their resistance to conventional treatments. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
98.
Singh BN Hayes GR Lucas JJ Sommer U Viseux N Mirgorodskaya E Trifonova RT Sassi RR Costello CE Fichorova RN 《Glycoconjugate journal》2009,26(1):3-17
Trichomonas vaginalis causes the most common non-viral sexually transmitted infection linked to increased risk of premature birth, cervical cancer
and HIV. This study defines molecular domains of the parasite surface glycoconjugate lipophosphoglycan (LPG) with distinct
functions in the host immunoinflammatory response. The ceramide phospho-inositol glycan core (CPI-GC) released by mild acid
had Mr of ∼8,700 Da determined by MALDI-TOF MS. Rha, GlcN, Gal and Xyl and small amounts of GalN and Glc were found in CPI-GC.
N-acetyllactosamine repeats were identified by endo-β-galactosidase treatment followed by MALDI-MS and MS/MS and capLC/ESI-MS/MS analyses. Mild acid hydrolysis led to products
rich in internal deoxyhexose residues. The CPI-GC induced chemokine production, NF-κB and extracellular signal-regulated kinase
(ERK)1/2 activation in human cervicovaginal epithelial cells, but neither the released saccharide components nor the lipid-devoid
LPG showed these activities. These results suggest a dominant role for CPI-GC in the pathogenic epithelial response to trichomoniasis. 相似文献
99.
100.