排序方式: 共有242条查询结果,搜索用时 15 毫秒
11.
12.
Ramziya Kiyamova Olga Kostianets Sergey Malyuchik Valeriy Filonenko Vasiliy Usenko Vadym Gurtovyy Yuliya Khozayenko Stepan Antonuk Lloyd Old Ivan Gout 《Molecular biotechnology》2010,46(2):105-112
Medullary breast carcinoma (MBC) is a relatively rare malignancy with heavy lymphocytic infiltration that despite cytologically
anaplastic features and high mitotic index has more favorable prognosis than other types of breast cancer. Lymphocytic infiltration
of tumors reflects ongoing immune response against tumor antigens which could represent a great interest as potential targets
for cancer immunotherapy. The search for MBC antigens by SEREX methodology has not been successful due to a very high titer
of false positive clones, representing immunoglobulin genes. Here, we describe a novel approach for generating cDNA expression
libraries from MBC tumor samples which are depleted of IgG cDNA clones and, therefore, are suitable for the identification
of novel tumor-associated antigens (TAA) by SEREX approach. Modified methodology allowed us to isolate a panel of known and
novel TAA which are currently under further investigation. 相似文献
13.
PrepMS: TOF MS data graphical preprocessing tool 总被引:1,自引:0,他引:1
Karpievitch YV Hill EG Smolka AJ Morris JS Coombes KR Baggerly KA Almeida JS 《Bioinformatics (Oxford, England)》2007,23(2):264-265
We introduce a simple-to-use graphical tool that enables researchers to easily prepare time-of-flight mass spectrometry data for analysis. For ease of use, the graphical executable provides default parameter settings, experimentally determined to work well in most situations. These values, if desired, can be changed by the user. PrepMS is a stand-alone application made freely available (open source), and is under the General Public License (GPL). Its graphical user interface, default parameter settings, and display plots allow PrepMS to be used effectively for data preprocessing, peak detection and visual data quality assessment. AVAILABILITY: Stand-alone executable files and Matlab toolbox are available for download at: http://sourceforge.net/projects/prepms 相似文献
14.
15.
Dimerization of the major birch pollen allergen Bet v 1 is important for its in vivo IgE-cross-linking potential in mice 总被引:1,自引:0,他引:1
Schöll I Kalkura N Shedziankova Y Bergmann A Verdino P Knittelfelder R Kopp T Hantusch B Betzel C Dierks K Scheiner O Boltz-Nitulescu G Keller W Jensen-Jarolim E 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(10):6645-6650
In type I allergy, the cross-linking of membrane IgE on B lymphocytes and of cytophilic IgE on effector cells by their respective allergens are key events. For cross-linking two IgE molecules, allergens need at least two epitopes. On large molecules, these could be different epitopes in a multivalent, or identical epitopes in a symmetrical, fashion. However, the availability of epitopes may be limited on small allergens such as Bet v 1, the major birch pollen allergen. The present work analyzes whether dimerization is required for the cross-linking capacity of this allergen. In immunoblots, murine monoclonal and polyclonal human Bet v 1-specific Abs detected, besides a Bet v 1 monomer of 17 kDa, a dimer of 34 kDa. In dynamic light scattering, Bet v 1 appeared as dimers and even multimers, but a single condition could be defined where it behaved exclusively monomerically. Small-angle x-ray scattering of the monomeric and dimeric samples resulted in diagrams agreeing with the calculated models. Circular dichroism measurements indicated that the structure of Bet v 1 was preserved under monomeric conditions. Skin tests in Bet v 1-allergic mice were positive with Bet v 1 dimer, but remained negative using the monomer. Furthermore, in contrast to dimeric Bet v 1, the monomer was less capable of activating murine memory B cells for IgE production in vivo. Our data indicate that the presentation of two identical epitopes by dimerized allergens is a precondition for cross-linking of IgE on mast cells and B lymphocytes. 相似文献
16.
Yuliya V. Kucherenko Shefalee K. Bhavsar Valentin I. Grischenko Uwe R. Fischer Stephan M. Huber Florian Lang 《The Journal of membrane biology》2010,235(3):177-189
Excessive glucose concentrations foster glycation and thus premature aging of erythrocytes. The present study explored whether
glycation-induced erythrocyte aging is paralleled by features of suicidal erythrocyte death or eryptosis, which is characterized
by cell membrane scrambling with subsequent phosphatidylserine exposure at the cell surface and cell shrinkage. Both are triggered
by increases of cytosolic Ca2+ concentration ([Ca2+]i), which may result from activation of Ca2+ permeable cation channels. Glycation was accomplished by exposure to high glucose concentrations (40 and 100 mM), phosphatidylserine
exposure estimated from annexin binding, cell shrinkage from decrease of forward scatter, and [Ca2+]i from Fluo3-fluorescence in analysis via fluorescence-activated cell sorter. Cation channel activity was determined by means
of whole-cell patch clamp. Glycation of total membrane proteins, immunoprecipitated TRPC3/6/7, and immunoprecipitated L-type
Ca2+ channel proteins was estimated by Western blot testing with polyclonal antibodies used against advanced glycation end products.
A 30–48-h exposure of the cells to 40 or 100 mM glucose in Ringer solution (at 37°C) significantly increased glycation of
membrane proteins, hemoglobin (HbA1c), TRPC3/6/7, and L-type Ca2+ channel proteins, enhanced amiloride-sensitive, voltage-independent cation conductance, [Ca2+]i, and phosphatidylserine exposure, and led to significant cell shrinkage. Ca2+ removal and addition of Ca2+ chelator EGTA prevented the glycation-induced phosphatidylserine exposure and cell shrinkage after glycation. Glycation-induced
erythrocyte aging leads to eryptosis, an effect requiring Ca2+ entry from extracellular space. 相似文献
17.
A new microsporidium, Liebermannia patagonica n. gen., n. sp., is described from midgut and gastric caecum epithelial cells of Tristira magellanica, an apterous grasshopper species of southern Patagonia, Argentina. L.patagonica is diplokaryotic, apansporoblastic, homosporous, and polysporoblastic. Transitional (from merogony to sporogony) stages and sporonts of L. patagonica were surrounded by host rough endoplasmic reticulum. The ovocylindrical spores measured 2.9 +/- 0.09 x 1.2 +/- 0.04 microm (fresh, n = 50), and they had an isofilar polar filament of only three coils and a cluster of tubules instead of a classical posterior vacuole. Prevalence was high (up to 80.6%) at the type locality for the four years sampled . Maximum likelihood , neighbor joining, maximum parismony analyses of the small submit rDNA all placed L.patagonica(Accession No. DQ 239917) in one with Orthosomella operophterae. 相似文献
18.
The permeability transition pore (PTP) and the ATP-dependent potassium (mtK-ATP) channel of mitochondria are known to play key roles in mitochondrially mediated apoptosis. We investigated how modulation of the permeability transition pore (PTP) and the ATP-dependent potassium (mtK-ATP) channel, either as single elements or in combination, affects the proapoptotic intracellular calcium ([Ca(2+)](i)) transients and the mitochondrial membrane potential (psi(m)). For this purpose a model was established exploring the [Ca(2+)](i) transients in N2A cells using continuous application of ATP that causes a biphasic [Ca(2+)](i) response. This response was sensitive to endoplasmatic reticulum (ER) Ca(2+) depletion and a smooth ER Ca(2+)-ATPase (SERCA) antagonist. PTP inhibition by cyclosporine A (CsA) or its non-immunosuppressive derivative NIM811 caused an amplification of the secondary [Ca(2+)](i) peak and induced a hyperpolarization of psi(m). Both the putative mtK-ATP channel inhibitor 5-hydroxydecanoate (5-HD) and the opener diazoxide ameliorated the ATP-induced secondary [Ca(2+)](i) peak. The effect of diazoxide was accompanied by a depolarization of psi(m) whereas 5-HD had no effect on psi(m). When diazoxide and CsA or NIM811 were applied together the secondary [Ca(2+)](i) rise did not return to baseline and a not significant hyperpolarization of psi(m) was observed. So, simultaneous inhibition of PTP and activation of the mtK-ATP channel prevents the increased slope of the secondary [Ca(2+)](i) peak induced by CsA (or NIM811) and also the depolarization after diazoxide application. Hence, we propose that modulation of one of these channels leads to functional changes of the other channel by means of Delta[Ca(2+)](i) and Deltapsi(m). 相似文献
19.
Microcin J25 uptake: His5 of the MccJ25 lariat ring is involved in interaction with the inner membrane MccJ25 transporter protein SbmA
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
de Cristóbal RE Solbiati JO Zenoff AM Vincent PA Salomón RA Yuzenkova J Severinov K Farías RN 《Journal of bacteriology》2006,188(9):3324-3328
Escherichia coli microcin J25 (MccJ25) is a plasmid-encoded antibiotic peptide consisting of 21 L-amino acid residues (G1-G-A-G-H5-V-P-E-Y-F10-V-G-I-G-T15-P-I-S-F-Y20-G). E. coli RNA polymerase (RNAP) is the intracellular target of MccJ25. MccJ25 enters cells after binding to specific membrane transporters: FhuA in the outer membrane and SbmA in the inner membrane. Here, we studied MccJ25 mutants carrying a substitution of His5 by Lys, Arg, or Ala. The inhibitory effects on cellular growth and in vitro RNAP activity were determined for each mutant microcin. The results show that all mutants inhibited RNAP in vitro. However, the mutants were defective in their ability to inhibit cellular growth. Experiments in which the FhuA protein was bypassed showed that substitutions of MccJ25 His5 affected the SbmA-dependent transport. Our results thus suggest that MccJ25 His5 located in the lariat ring is involved, directly or indirectly, in specific interaction with SbmA and is not required for MccJ25 inhibition of RNAP. 相似文献
20.
Nagy G Szabó M Unnep R Káli G Miloslavina Y Lambrev PH Zsiros O Porcar L Timmins P Rosta L Garab G 《Photosynthesis research》2012,111(1-2):71-79
Diatoms possess effective photoprotection mechanisms, which may involve reorganizations in the photosynthetic machinery. We have shown earlier, by using circular dichroism (CD) spectroscopy, that in Phaeodactylum tricornutum the pigment-protein complexes are arranged into chiral macrodomains, which have been proposed to be associated with the multilamellar organization of the thylakoid membranes and shown to be capable of undergoing light-induced reversible reorganizations (Szabó et al. Photosynth Res 95:237, 2008). Recently, by using small-angle neutron scattering (SANS) on the same algal cells we have determined the repeat distances and revealed reversible light-induced reorganizations in the lamellar order of thylakoids (Nagy et al. Biochem J 436:225, 2011). In this study, we show that in moderately heat-treated samples, the weakening of the lamellar order is accompanied by the diminishment of the psi-type CD signal associated with the long-range chiral order of the chromophores (psi, polymer or salt-induced). Further, we show that the light-induced reversible increase in the psi-type CD is associated with swelling in the membrane system, with magnitudes larger in high light than in low light. In contrast, shrinkage of the membrane system, induced by sorbitol, brings about a decrease in the psi-type CD signal; this shrinkage also diminishes the non-photochemical quenching capability of the cells. These data shed light on the origin of the psi-type CD signal, and confirm that both CD spectroscopy and SANS provide valuable information on the macro-organization of the thylakoid membranes and their dynamic properties; these parameters are evidently of interest with regard to the photoprotection in whole algal cells. 相似文献