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OALib Journal期刊

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Phagocytosis by macrophages mediated by receptors for denatured proteins - dependence on tyrosine protein kinases
Hespanhol, M.R.;Mantovani, B.;
Brazilian Journal of Medical and Biological Research , 2002, DOI: 10.1590/S0100-879X2002000300015
Abstract: previous studies have demonstrated that some components of the leukocyte cell membrane, cr3 (mac-1, cd11b/cd18) and p150/95, are able to bind to denatured proteins. thus, it is of interest to know which effector functions of these cells can be triggered by these receptors when they interact with particles or surfaces covered with denatured proteins. in the present study we analyzed their possible role as mediators of phagocytosis of red cells covered with denatured bovine serum albumin (bsa) by mouse peritoneal macrophages. we observed that a) macrophages are able to recognize (bind to) these red cells, b) this interaction can be inhibited by denatured bsa in the fluid phase, c) there is no phagocytosis of these particles by normal macrophages, d) phagocytosis mediated by denatured bsa can be, however, effectively triggered in inflammatory macrophages induced by glycogen or in macrophages activated in vivo with lps, and e) this phagocytic capacity is strongly dependent on the activity of tyrosine protein kinases in its signal transduction pathway, as demonstrated by using three kinds of enzyme inhibitors (genistein, quercetin and herbimycin a).
Restauración en el Inmunoblotting de proteínas de Neisseria meningitidis da?adas por calor y agentes reductores
Estrada,Eric; Ochoa,Rolando; Ferriol,Xenia; García,Ana; Martínez,Juan Carlos; Sotolongo,Franklin;
Vaccimonitor , 2000,
Abstract: five different detergents for restoration of igg antibody binding were studied in the washing steps and in the buffer solution used for the dilution of the conjugate and samples. binding of human serum igg antibodies to outer membrane protein (omp) was detected with class-specific peroxidase-conjugated human antibodies. the positive control reacted with those proteins whose molecular weight corresponded approximately to p1, p3, p4 and p5. proteins of 80 kda, 70 kda and 24 kda and another protein of >150 kda were also recognized. our studies indicated that tween 20 was the best detergent for restoration of omp antigenicity, except for the 150 kda protein. tween 20 achieved a greater number and intensity of bands and a lower background with respect to empigen bb, triton x-100, nonidet np-40 and chaps. the use of detergents affected the antigenicity of the 150 kda protein. washing with tween 20 were the most important steps for restoration of igg antibody binding sites of heat-denatured omps.
MULTIFRACTAL ANALYSIS OF PROTEIN AGGREGATES TO DERIVE PROTEIN-SPECIFIC SIGNATURE
Hrishikesh Mishra, Tapobrata Lahiri*
The IIOAB Journal , 2010,
Abstract: Deriving a property of a protein that is unique to it has well known significance since the study on ab initio model based derivation of protein structure where uniqueness of protein sequence is taken as the source of specificity of protein structure. In this direction, Heat denatured protein aggregates (HDPA) of proteins were studied with an objective to derive some multi-fractal markers specific to constituent protein that may be further utilized to extract information of the seed protein. Since Ordinary microscopic images of aggregates were analyzed to extract Intensity Level-based Multifractal Dimension (ILMFD) features. ILMFD features include four different features, perimeter fractal dimension (ILMFDP), perimeter-area relationship (ILMFDPAR), Area fractal dimension (ILMFDA) and Perimeter-area fractal dimension (ILMFDPA) that were calculated using fractal computations considering perimeter, and area of aggregate images. Feed forward backpropagation network was used to classify the proteins using different ILMFD parameters. It was found that ILMFD features could discriminate the proteins used in our study, that points to their potential to serve as unique property or marker of a protein. Further to validate the results, the outputs from ANN were clustered, and the outputs clustered in the largest cluster were found to significantly improve the result in class decision given by ANN.
Phagocytosis by macrophages mediated by receptors for denatured proteins - dependence on tyrosine protein kinases
Hespanhol M.R.,Mantovani B.
Brazilian Journal of Medical and Biological Research , 2002,
Abstract: Previous studies have demonstrated that some components of the leukocyte cell membrane, CR3 (Mac-1, CD11b/CD18) and p150/95, are able to bind to denatured proteins. Thus, it is of interest to know which effector functions of these cells can be triggered by these receptors when they interact with particles or surfaces covered with denatured proteins. In the present study we analyzed their possible role as mediators of phagocytosis of red cells covered with denatured bovine serum albumin (BSA) by mouse peritoneal macrophages. We observed that a) macrophages are able to recognize (bind to) these red cells, b) this interaction can be inhibited by denatured BSA in the fluid phase, c) there is no phagocytosis of these particles by normal macrophages, d) phagocytosis mediated by denatured BSA can be, however, effectively triggered in inflammatory macrophages induced by glycogen or in macrophages activated in vivo with LPS, and e) this phagocytic capacity is strongly dependent on the activity of tyrosine protein kinases in its signal transduction pathway, as demonstrated by using three kinds of enzyme inhibitors (genistein, quercetin and herbimycin A).
The Probable Structure of “Form IV” (Alkali-Denatured Circular DNA)  [PDF]
Ken Biegeleisen
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1103114
Abstract:
A detailed molecular model for alkali-denatured duplex circular DNA (“Form IV”) is proposed. The illustrative biological example used is the replicative form of fx174, a 5 kb duplex circular chromosome. The model explains all of Form IV’s known and peculiar features. In a sedimentation coefficient vs. pH titration, Form IV begins to appear at pH 12.3, at which point it can be persuasively argued that no further supertwists can be added to the already-highly-supertwisted chromosome. Therefore a new structure must appear. The sedimentation coefficient s then undergoes a massive, but initially reversible increase as the pH is raised further, culminating at pH 12.8 with a 250% increase. This degree of compactness can only be explained by a 4-stranded tetraplex structure, consisting of a pair of duplexes whose base pairs are mutually intercalated. Above pH 12.8, the structural changes become irreversible, suggesting a further conformational change. It is proposed that this involves an axial rotation of the component duplex strands, so that the bases now stack on the outside, and the phosphate groups lie in the core, where they bond ionically by means of salt bridges. When the irreversibly denatured compact structure is neutralized at moderate-to-high salt concentrations, a third novel structure appears, which has a sedimentation coefficient midway between the native 21 s and the denatured 50 s. It is proposed that this is a hybrid structure; part tetraplex, part duplex. To return to a fully-duplex form, it is necessary to both neutralize the solution, and also to greatly reduce the ionic strength, i.e., to the range 0.001-0.01 M. Since the DNA, under those conditions, cannot possibly have normal complementary base-pairing, the duplex structure must either be tautomerically base-paired, or else stabilized solely by base-stacking, with no base-pairing at all.
Refolding of Reduced/Denatured Lysozyme by High Performance Hydrophobic Interaction Chromatography
高效疏水作用色谱法对还原变性溶菌酶的折叠研究

王彦,耿信笃
色谱 , 2003,
Abstract: 首次用高效疏水相互作用色谱(HPHIC)研究了还原变性溶菌酶(Lys)的复性。对还原变性Lys在3种疏水性不同的色谱柱上的复性情况进行了考察,发现还原变性Lys在疏水性最弱的XDM-GM1型色谱柱上的复性效率最高,当Lys质量浓度为2.0g/L时,其复性效率可达到94.6%。
Refolding of reduced/denatured RNase A on the hydrophobic liquid-solid interface
还原变性核糖核酸酶在疏水性液-固界面上的复性

BI Jing,BAI Quan,WANG Jun,WANG Lili,
毕晶
,白泉,王军,王骊丽

色谱 , 2010,
Abstract: The renaturation of the reduced/denatured RNase A on the hydrophobic liquid-solid interface was investigated using hydrophobic interaction chromatography (HIC). The effects of urea concentrations, the ratios of reduced and oxidized glutathiones (GSH and GSSG), the pH of mobile phase and protein concentrations on the refolding efficiency and mass recovery of the reduced/denatured RNase A were investigated in detail. The results indicated that the reduced/denatured RNase A can be refolded completely under the optimized conditions of pH 8.0, 2.0 mol/L urea and the concentration ratio of GSH/GSSG of 8:1 in mobile phase. When the denatured protein was at the concentration of 5.0 mg/mL, the bioactivity efficiency and mass recoveries were 98.0% and 61.9% for 8.0 mol/L urea-denatured RNase A, respectively; and 100.1% and 66.8% for 7.0 mol/L guanidine hydrochloride (GuaHCl)-denatured RNase A, respectively. It proves that HIC is a powerful tool and new approach for protein refolding.
Comparison of different DNA extraction methods for activated sludge
活性污泥总DNA提取方法的比较

Ding Man,Li Lu,Zou Li,Wen Donghui,Tang Xiaoyan,
丁嫚
,李璐,邹莉,温东辉,唐孝炎

环境工程学报 , 2009,
Abstract: Using activated sludge sample,which was collected from an experimental MBR treating pharmacy wastewater,several DNA extraction methods were evaluated.DNA extraction includes two steps of cell lysis and DNA purification.Firstly,seven cell lysis methods,including bead mill homogenization,freeze-thawing,SDS-based method,etc.Sencondly,two purifircation methods,phenol/chloroform purification and agarose gel purification were compared.The results showed that SDS-based method and phenol/chloroform purification wer...
DIVERSITY ANALYSIS OF MICROBIAL COMMUNITY AND Fe-HYDROGENASE GENES OF FERMENTATIVE MIXED CULTURE FROM INTERTIDAL SLUDGE
潮间带污泥中厌氧发酵产氢混合菌群组成与Fe-氢酶基因多样性分析

LIU Hong-Yan,WANG Guang-Ce,ZHU Da-Ling,PAN Guang-Hua,
刘洪艳
,王广策,朱大玲,潘光华

海洋与湖沼 , 2012,
Abstract: Sludge sample, collected from intertidal zone of a bathing beach in Tianjin, was pretreated by heat-shock method for enrichment of hydrogen-producing microbial community. The hydrogen production and indicators of hydrogen production (OD600, pH and ORP values) were measured. The results showed that the efficiency of hydrogen production of the heat-shock pretreated sludge was 0.41mol H2/mol glucose. At the end of fermentation, 16S rRNA gene and Fe-hydrogenase gene of the mixed culture were PCR amplified and analyzed by DGGE (denaturing gradient gel electrophoresis) respectively. For 16S rRNA gene six special bands were obtained. The sequencing results showed that the dominate bacterium of the mixed culture belong to Clostridium sp.. Heat-shock pretreatment was favorable to enrich the most known hydrogen-producing bacterium, i.e. Clostridium sp.. As for the Fe-hydrogenase gene of Clostridium three operational taxonomical units (OUTs) were obtained. The segments of Fe-hydrogenase gene were cloned and sequenced. NCBI blast result indicates that the segments of Fe-hydrogenase gene were 79% and 98% identical to that of Clostridium roseum and Clostridium perfringens respectively. The analysis about composition of microbial community and diversity of Fe-hydrogenase gene contribute to enlarge the resource of hydrogen-producing bacteria group.
CLONING AND SEQUENCE OF Fe-HYDROGENASE GENES OF CLOSTRIDIUM SP. FROM MANGROVE OOZE
红树林混合发酵产氢菌群中梭菌属Fe-氢酶基因(hydA)的克隆及序列分析

ZHU Da-Ling,WANG Guang-Ce,PAN Guang-Hua,QIAO Hong-Jin,CAI Jin-Ling,
朱大玲
,王广策,潘光华,乔洪金,才金玲

海洋与湖沼 , 2009,
Abstract: 采用间歇产气试验方法对红树林淤泥中的混合菌群进行产氢菌群富集,并对混合产氢菌群发酵产氢过程中发酵液的pH值和氧化还原电位(ORP)的变化进行分析.此外,在产氢速率最高时段,发酵液中菌群经过常规的基因组提取,分别采用通用的梭菌属Fe-氢酶基因和16S rRNA基因引物进行PCR扩增,扩增产物经变性梯度凝胶电泳(DGGE)分析.结果发现产氢菌群中至少有6种,而Fe-氢酶基因只含有一种.将Fe-氢酶基因的扩增片段切胶纯化之后,经PCR重新扩增、纯化,克隆测序.NCBI序列比对结果表明,该片段序列与产气荚膜梭菌Fe-氢酶基因的序列相似性达99%.根据已知产气英膜梭菌Fe-氢酶基因序列设计引物,经两轮PCR扩增获得Fe-氢酶基因全序列.混合菌群中Fe-氢酶基因GenBank数据库的登录号为EU590683.此外,采用Bioedit和Mega2软件构建了Fe-氢酶的NJ系统进化树,结果表明该Fe-氢酶基因与产气荚膜梭菌(Clostridium perfringens)聚为一类.推测的氨基酸序列与产气英膜梭菌的相应序列相似性达97%-99%.PfamHMM结构域查找结果发现,此氢酶含有五个结构域,分别为1个2Fe-2S铁硫簇结合区域、2个4Fe-4S结合区域、Fe-氢酶大亚基和Fe-氢酶小亚基.
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