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1.
以携有结合转座子Tn916的EnterococcusfaecalisJH2-2为供体,脱卤脱亚硫酸菌HSS1为受体,在厌氧条件下,通过滤膜杂交,结合转移,将Tn916转并插入到受体菌的染色体上,其转移频率为:1.1*10^-7-3*10^-8。  相似文献   

2.
重组葡激酶的分离纯化   总被引:2,自引:0,他引:2  
在构建出高表达,高活性的葡激酶工程菌株的基础上,对表达产物进行了分离纯化研究。经离子交换纯化后,纯度达85%-90%,回收率为50%-60%,经凝胶过滤后,纯度达99%以上,回收率为60%,经SDS-PAGE测定,相对分子质量为15.5*10^3,比活为1.0*10^5,N端氨基酸序列与献报道的相符。  相似文献   

3.
以0.1mol/LNH4Cl溶液为介质,用2.5次微分伏安法测定了丙二醛,线性范围为1.0*10^-6至1.0*10^-3mol/L,检测限达1.0*10^-7mol/L。并测定了细胞培养液介质中新生SD大鼠室肌细胞样品的丙二醛。  相似文献   

4.
对重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)高效表达克隆pZW.GM的表达产物进行了纯化,并对纯化的GM-CSF进行了N端氨基酸序列分析。人GM-CSF基因表达产物在大肠杆菌中以不溶性包涵体形式存在,经过超声破菌、包涵体抽提、凝胶过滤层析、复性、离子交换一系列化步骤,终产物纯度达99%,按蛋白总量计算回收率达10%,比活性达1×10^7u/mg蛋白质。通过测定纯化人GM-CSF的N端1  相似文献   

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重组人白细胞介素-2(rhIL-2)基因表达产物在大肠杆菌中以不溶性包涵体形式存在,经过菌体发酵和收集、超声破菌、包涵体抽提、稀释透析初步复性、反相高压液相色谱纯化,终产物纯度大于99%。反相高压液相色谱不仅可以纯化rhIL-2,且使产物的总活性提高7.9-9倍,比活性提高14 ̄18倍,达到1.5×10^7u/mg蛋白质,蛋白得率为50% ̄56%。结果表明,反相高压液相色谱具有纯化和显提高rhH  相似文献   

6.
由基因工程大肠杆菌表达的重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)以包涵体的形式存在于细胞中,通过破菌、洗涤获得包涵体,再经过溶解、凝胶过滤、复性、疏水和离子交换柱导析得到了均一的产品,经高压液相和SDS-PAGE电泳测定纯度均大于98%,rhGM-CSF的比活为3.2×10^7IU/mg,纯化获得的rhGM-CSF为一酸性蛋白,等电点约为5.2,NH2-末端有20个氨基酸序列测定结果  相似文献   

7.
亲和层析纯化HepG2细胞分泌的PAI—1   总被引:1,自引:0,他引:1  
本文报道用抗PAI-1单克隆抗体(McAb)亲和层析建立了纯化PAI-1的简便方法。经免疫亲和层析,Sephacryl S200凝胶过滤,从HepG2细胞培液中分离到糖基化和非糖基化两种形式的PAI-1,回收率为84%,PAI-1比活性为6.1×10^4IU/mg。糖基化PAI-1分子量为50kD,比活性5.8×10^4IU/mg。非糖基化PAI-1分子量43kD,占总PAI-130%,仍具有PA  相似文献   

8.
用眼动测量方法,对字频为4*10^-3至1.6*10^-5范围内笔画数为4至14的常用汉字进行识别实验,结果表明,汉字识别时间与笔画数无关,而是存在识别时间随字频减小而增大的字频效应,  相似文献   

9.
甘薯叶片蔗糖酶的分离纯化及其部分性质   总被引:11,自引:0,他引:11  
纯化酶经聚丙烯酰胺凝胶电泳显示单一蛋白带,SDS-PAGE显示一条蛋白带,其亚基分子量为39.8kD。用Sephacryl S-200凝胶过滤测得全酶的分子量为79.4kD,该酶由两个相同亚基组成。其表观Km为12mmol/L,Vmax为99.5mg还原糖mg^-1protein h^-1。  相似文献   

10.
采用一种新闻子交换介质Express-IonC(简称IonC)使鼠神经生长因子(mNGF)能得到规模纯化。以鼠颌下腺为原料,匀浆后,经Express-IonC纯化得单一组分的mNGF,用SDS-PAGE测定其相对分子质量约为13.7×10^3,比活约2.3×10^5U/mg。结果表明IonC可替代CM-52,且更适于工因子的规模化生产。  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

13.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

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Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.  相似文献   

20.
Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8+ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8+ T cells are involved in the pathogenesis of RE.  相似文献   

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