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排序方式: 共有377条查询结果,搜索用时 15 毫秒
311.
312.
Ulrike Zeitschel Elisa R. Zanier Katrin Moschke Alperen Serdaroglu Fabio Canneva Stephan von Hörsten Maria‐Grazia De Simoni Gianluigi Forloni Carsten Jäger Elisabeth Kremmer Steffen Roßner Peer‐Hendrik Kuhn 《Aging cell》2016,15(5):953-963
Alzheimer's disease (AD) is histopathologically characterized by neurodegeneration, the formation of intracellular neurofibrillary tangles and extracellular Aβ deposits that derive from proteolytic processing of the amyloid precursor protein (APP). As rodents do not normally develop Aβ pathology, various transgenic animal models of AD were designed to overexpress human APP with mutations favouring its amyloidogenic processing. However, these mouse models display tremendous differences in the spatial and temporal appearance of Aβ deposits, synaptic dysfunction, neurodegeneration and the manifestation of learning deficits which may be caused by age‐related and brain region‐specific differences in APP transgene levels. Consequentially, a comparative temporal and regional analysis of the pathological effects of Aβ in mouse brains is difficult complicating the validation of therapeutic AD treatment strategies in different mouse models. To date, no antibodies are available that properly discriminate endogenous rodent and transgenic human APP in brains of APP‐transgenic animals. Here, we developed and characterized rat monoclonal antibodies by immunohistochemistry and Western blot that detect human but not murine APP in brains of three APP‐transgenic mouse and one APP‐transgenic rat model. We observed remarkable differences in expression levels and brain region‐specific expression of human APP among the investigated transgenic mouse lines. This may explain the differences between APP‐transgenic models mentioned above. Furthermore, we provide compelling evidence that our new antibodies specifically detect endogenous human APP in immunocytochemistry, FACS and immunoprecipitation. Hence, we propose these antibodies as standard tool for monitoring expression of endogenous or transfected APP in human cells and APP expression in transgenic animals. 相似文献
313.
Amadasi A Dall'asta C Ingletto G Pela R Marchelli R Cozzini P 《Bioorganic & medicinal chemistry》2007,15(13):4585-4594
Docking techniques and the HINT (Hydropathic Interaction) program were used to explain interactions of aflatoxin B(1) and ochratoxin A with beta- and gamma-cyclodextrins. The work was aimed at designing a chemosensor to identify very low concentrations of these mycotoxins by exploiting the affinity of the cyclodextrin cavity for many small organic molecules. Actually, the inclusion of the fluorescent portion of these toxins into the cavity may lower the quenching effect of the solvent, thus enhancing the luminescence. HINT is a 'natural' force field, based on experimentally determined LogP(octanol/water) values, that is able to consider both enthalpic and entropic contributions to the binding free energy with an unified approach. HINT is normally applied to predict the DeltaG degrees of binding for protein-ligand, protein-protein, and protein-DNA interactions. The leading forces in biomolecular processes are the same as those involved in organic host-guest inclusion phenomena, therefore we applied this methodology for the first time to cyclodextrin complexes. The results allowed us to explain spectroscopic data in absence of available crystallographic or NMR structural data. 相似文献
314.
Tonelli M Masterson LR Hallenga K Veglia G Markley JL 《Journal of biomolecular NMR》2007,39(3):177-185
We present a highly sensitive pulse sequence, carbonyl carbon label selective 1H–15N HSQC (CCLS-HSQC) for the detection of signals from 1H–15N units involved in 13C′–15N linkages. The CCLS-HSQC pulse sequence utilizes a modified 15N CT evolution period equal to 1/(
) (∼33 ms) to select for 13C′–15N pairs. By collecting CCLS-HSQC and HNCO data for two proteins (8 kDa ubiquitin and 20 kDa HscB) at various temperatures
(5–40°C) in order to vary correlation times, we demonstrate the superiority of the CCLS-HSQC pulse sequence for proteins with
long correlation times (i.e. higher molecular weight). We then show that the CCLS-HSQC experiment yields assignments in the
case of a 41 kDa protein incorporating pairs of 15N- and 13C′-labeled amino acids, where a TROSY 2D-HN(CO) had failed. Although the approach requires that the 1H–15N HSQC cross peaks be observable, it does not require deuteration of the protein. The method is suitable for larger proteins
and is less affected by conformational exchange than HNCO experiments, which require a longer period of transverse 15N magnetization. The method also is tolerant to the partial loss of signal from isotopic dilution (scrambling). This approach
will be applicable to families of proteins that have been resistant to NMR structural and dynamic analysis, such as large
enzymes, and partially folded or unfolded proteins. 相似文献
315.
Fernando Porcelli Doriana Triggiani Bethany A. Buck-Koehntop Larry R. Masterson Gianluigi Veglia 《Journal of biological inorganic chemistry》2009,14(8):1219-1225
We investigated the time dependence of the degradation of three alkyltin derivatives by a nine amino acid linear peptide (I1LGCWCYLR9) containing a CXC motif derived from the primary sequence of stannin, a membrane protein involved in alkyltin toxicity. We
monitored the reaction kinetics using the intrinsic fluorescence of the tryptophan residue in position 5 of the peptide and
found that all of the alkyltins analyzed are progressively degraded to dialkyl derivatives, following a pseudoenzymatic reaction
mechanism. The end point of the reactions is the formation of a covalent complex between the disubstituted alkyltin and the
peptide cysteines. These data agree with the speciation profiles proposed for polysubstituted alkyltins in the environment
and reveal a possible biotic degradation pathway for these toxic compounds. 相似文献
316.
317.
Neuroprotective mesenchymal stem cells are endowed with a potent antioxidant effect in vivo 总被引:2,自引:0,他引:2
318.
Gabriele Albertin Stefano Antoniutti Gianluigi Zanardo 《Inorganica chimica acta》2010,363(3):605-4201
Mixed-ligand complexes [ReBr(CO)2(CNR)nL3−n] (1-4) [R = 4-CH3OC6H4, 4-CH3C6H4, C(CH3)3; L = P(OEt)3, PPh(OEt)2; n = 1, 2] were prepared by allowing carbonyl compounds [ReBr(CO)4L] and [ReBr(CO)3L2] to react with an excess of isocyanide. Treatment of these bromocomplexes [ReBr(CO)2(CNR)nL3−n] with SnCl2 · 2H2O yielded the trichlorostannyl derivatives [Re(SnCl3)(CO)2(CNR)nL3−n] (5-8). Trihydridestannyl complexes [Re(SnH3)(CO)2(CNR)nL3−n] (9-12) were prepared by allowing trichlorostannyl compounds 5-8 to react with NaBH4 in ethanol. The trimethylstannyl derivative [Re(SnMe3)(CO)2(CNC6H4-4-CH3){PPh(OEt)2}2] (13b) was also prepared by treating [Re(SnCl3)(CO)2(CNC6H4-4-CH3){PPh(OEt)2}2] with an excess of MgBrMe in diethylether. Reaction of the tin trihydride complexes [Re(SnH3)(CO)2(CNR)nL3−n] (9-12) with CO2 (1 atm) led to dinuclear OH-bridging bis(formate) derivatives [Re{Sn(OC(H)O)2(μ-OH)}(CO)2(CNR)nL3−n]2 (14, 15). The complexes were characterised spectroscopically (IR, 1H, 31P, 13C, 119Sn NMR) and by X-ray crystal structure determination of [Re(SnH3)(CO)2{CNC(CH3)3}{PPh(OEt)2}2] (10b). 相似文献
319.
Gianluigi Bacchetta Salvatore Brullo Mauro Casti Gian Pietro Giusso del Galdo 《Nordic Journal of Botany》2010,28(2):137-173
A taxonomic revision of the populations belonging to the Dianthus sylvestris Wulfen group (Caryophyllaceae) occurring in central and southern Italy, Sardinia and Sicily has been made. This group is represented in the surveyed territories by 17 morphologically and ecologically well differentiated species: Dianthus arrosti C. Presl, D. siculus C. Presl, D. graminifolius C. Presl, D. cyathophorus Moris, D. gasparrinii Guss., D. longicaulis Ten., D. virgatus Pasquale, D. tarentinus Lacaita, D. morisianus Vals., D. japygicus Bianco & Brullo, D. sardous Bacch., Brullo, Casti & Giusso, D. busambrae Soldano & F. Conti, D. brachycalyx Huet sp. nov., D. oliastrae sp. nov., D. insularis sp. nov., D. genargenteus sp. nov. and D. ichnusae sp. nov. Besides, two new subspecies are recognized within D. ichnusae (subsp. ichnusae and subsp. toddei). This taxonomical treatment is supported by a multivariate analysis based on 25 morphological characters and 1 phenological character. Each of the taxa is described and illustrated. In addition, notes on nomenclature, ecology, chorology, taxonomical relationships and conservation status are given. Lectotypes are designated for those taxa that are based on material from the investigated territories. 相似文献
320.
Hepatocellular carcinoma (HCC) is the most common primary liver cancer and one of the most frequent types of cancer worldwide. It normally develops in patients with chronic liver disease, especially cirrhosis, although some cases without an apparent underlying liver disease have been reported. The pathogenesis of HCC is multi-factorial and complex. Hepatitis viruses are the main factors favoring the development of HCC. In fact, chronic inflammation associated with hepatitis C or B virus infection can lead to progressive liver fibrosis, cirrhosis and ultimately HCC. Chronic inflammation and liver fibrosis cause a continuous remodeling of the extracellular matrix (ECM), a dynamic process that involves several molecules including integrins and matrix processing enzymes. An increasing body of evidence indicates that ADAMs are involved in promoting tumor formation and progression of HCC. A Disintegrin And Metalloproteases (ADAMs) are a group of proteins belonging to the zinc protease superfamily. ADAMs are usually transmembrane proteins that contain disintegrin and metalloprotease domains and are, therefore, able to carry out both cell adhesion and protease activities. Soluble isoforms of ADAMs have also been discovered and characterized. In this review, we focus on the contribution of ADAM proteins to HCC tumorigenesis and cancer progression. The potential role of ADAMs as key modulators of tumor–stroma interactions during tumor progression, by means of the activities of their constituent domains, is also discussed. 相似文献