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1.
Grape thaumatin-like proteins (TLPs) play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H and H2/4MBT are VVTL1), and having different unfolding temperatures (56 vs. 62°C), with protein F2/4JRU being heat unstable and forming haze, while I/4L5H does not. These differences in properties are attributable to the conformation of a single loop and the amino acid composition of its flanking regions. 相似文献
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Efficient extraction of RNA from mammalian tissue 总被引:10,自引:0,他引:10
Marsha L. Frazier Wendy Mars Dagne L. Florine Richard A. Montagna Grady F. Saunders 《Molecular and cellular biochemistry》1983,56(2):113-122
RNA extraction from mammalian tissue has been compared using the different deproteinizing agents: a) guanidine-HCl, b) guanidinium-thiocyanate, c) buffer-saturated phenol, or d) buffer-saturated phenol followed by a proteinase K digestion of the aqueous phase. Both solid tissues (first, second, and third trimester fetal bovine pancreas), and human white blood cell populations were studied. Degradation, as seen in citric acid-urea agarose gels, and the ability to serve as templates for cell-free protein synthesis were used as criteria to assess the efficiency of the different methods. We conclude that employing buffer-saturated phenol with proteinase K digestion is a superior method for consistent extraction of relatively undegraded RNA in quantitative amounts from mammalian tissue. 相似文献
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Gianfranco Di Matteo Giovanni Romeo Guido Di Prisco 《Archives of biochemistry and biophysics》1980,200(1):55-60
A study on the response of the stability and activity of crystalline ox liver nuclear and mitochondrial glutamate dehydrogenases to temperature variations has been carried out. The thermodynamic properties of the heat inactivation process and of the reaction with the substrates glutamate and α-ketoglutarate have been investigated. The heat inactivation of nuclear glutamate dehydrogenase proceeds at a faster rate than that of the mitochondrial enzyme in the temperature range 40–51 °C; the enthalpy of activation of the inactivation process is higher and the entropy is almost double, compared to the values of mitochondrial glutamate dehydrogenase. The effect of temperature on the maximal velocity shows that, with both glutamate and α-ketoglutarate, the enthalpy of activation with nuclear glutamate dehydrogenase is double and the decrease in entropy almost half of the values of the mitochondrial enzyme. The variation of the apparent Km with temperature shows a decrease of the affinity of both enzymes for glutamate, with no major difference in the thermodynamic properties of the reaction. With α-ketoglutarate, on the other hand, the affinity of nuclear glutamate dehydrogenase decreased, whereas that of the mitochondrial enzyme increased with temperature. The process is therefore exothermic with the former enzyme, endothermic with the latter; furthermore, it occurs with a decrease in enthropy with nuclear glutamate dehydrogenase, but with a large increase with the mitochondrial enzyme. The studies on the effect of temperature on the activity were carried out in the range 20–44 °C. 相似文献
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Cutolo M Capellino S Montagna P Ghiorzo P Sulli A Villaggio B 《Arthritis research & therapy》2005,7(5):R1124-R1132
Sex hormones seem to modulate the immune/inflammatory responses by different mechanisms in female and male rheumatoid arthritis
patients. The effects of 17β-oestradiol and of testosterone were tested on the cultured human monocytic/macrophage cell line
(THP-1) activated with IFN-γ in order to investigate their role in cell proliferation and apoptosis. Activated human THP-1
cells were cultured in the presence of 17β-oestradiol and testosterone (final concentration, 10 nM). The evaluation of markers
of cell proliferation included the NF-κB DNA-binding assay, the NF-κB inhibition complex, the proliferating cell nuclear antigen
expression and the methyl-tetrazolium salt test. Apoptosis was detected by the annexin V-propidium assay and by the cleaved
poly-ADP ribose polymerase expression. Specific methods included flow analysis cytometry scatter analysis, immunocytochemistry
and western blot analysis. Cell growth inhibition and increased apoptosis were observed in testosterone-treated THP-1 cells.
Increased poly-ADP ribose polymerase-cleaved expression and decreased proliferating cell nuclear antigen expression, as well
as an increase of IκB-α and a decrease of the IκB-α phosphorylated form (ser 32), were found in testosterone-treated THP-1
cells. However, the NF-κB DNA binding was found increased in 17β-oestradiol-treated THP-1 cells. The treatment with staurosporine
(enhancer of apoptosis) induced decreased NF-κB DNA binding in all conditions, but particularly in testosterone-treated THP-1
cells. Treatment of THP-1 by sex hormones was found to influence cell proliferation and apoptosis. Androgens were found to
increase the apoptosis, and oestrogens showed a protective trend on cell death – both acting as modulators of the NF-κB complex. 相似文献
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Shiping Liu Eline D. Lorenzen Matteo Fumagalli Bo Li Kelley Harris Zijun Xiong Long Zhou Thorfinn Sand Korneliussen Mehmet Somel Courtney Babbitt Greg Wray Jianwen Li Weiming He Zhuo Wang Wenjing Fu Xueyan Xiang Claire C. Morgan Aoife Doherty Mary J. O’Connell James O. McInerney Erik W. Born Love Dalén Rune Dietz Ludovic Orlando Christian Sonne Guojie Zhang Rasmus Nielsen Eske Willerslev Jun Wang 《Cell》2014