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131.
重组干扰素γ的中间试制 总被引:6,自引:0,他引:6
用带有表达质粒PBV220(含有γ干扰素基因)的大肠杆菌DH5α株进行发酵培养,3批中试的菌产量平均为14.1克/L,γ干扰素的表达量平均为1.02±10^9IU/L,收集的菌体经高压匀质破菌后收集包涵体,用7mol/L盐酸胍提取干扰素,此过程中去除78.4%菌体蛋白,而干扰素活性仅损失10.41%,粗制干扰素经复性可使干扰素活性提高405%,比活也有明显提高,3批平均为1.76×10^7IU/m 相似文献
132.
用RT-PCR法从一名抗-HCV阳性献血员血清中扩增到约900bp的DNA片段,经EcoRI酶切后插入pET17Xb表达质粒。SDS-PAGE表明重组质粒在约65kD处有融合蛋白表达,表达蛋白含量约为24%。对其插入片段进行序列分析:核着酸长度为945bp,A:T:G:C比例为18.6:21.9:30.5:29.0,G/C含量占59%,与其它一些HCV殊比较,核着酸同源性Ⅰ型为77.1%.Ⅲ、Ⅳ、Ⅴ、Ⅵ型均<70%.Ⅱ型各株均>90%;氨基酸序列比较的同源性Ⅰ型为857%,Ⅲ、Ⅳ、ⅤⅥ型各株均>70%,Ⅱ型各株均>93%。NS4基因的克隆和表达为其基因和产物作用的进一步研究奠定了基础。 相似文献
133.
水稻染色体标本制备的风油精法 总被引:2,自引:0,他引:2
水稻的染色体较小,不同的染色体在形态上较难区分。常规的压片技术由于很难使染色体分散,且也不能完全排除细胞质的干扰,因而很不适用于水稻染色体核型分析及显带。Kurata 等(1978)采用酶解与火焰干燥技术制备水稻染色体标本,获得清晰的染色体图象,从而成功地进行了水稻染色体的核型分析。陈瑞阳等(1982)参照人类染色体 相似文献
134.
‘Green tides’ are overwhelming the coastline of our blue planet: taking the world’s largest example 总被引:8,自引:0,他引:8
Nai-hao Ye Xiao-wen Zhang Yu-ze Mao Cheng-wei Liang Dong Xu Jian Zou Zhi-meng Zhuang Qing-yin Wang 《Ecological Research》2011,26(3):477-485
A broad spectrum of events that come under the category of green tide are recognized world-wide as a response to elevated
levels of seawater nutrients in coastal areas. Green tides involve a wide diversity of sites, macroalgal species, consequences,
and possible causes. Here we review the effect of natural and man-induced environmental fluctuations on the frequency and
apparent spread of green tides. This article highlights the need for interdisciplinary research aimed at shedding light on
the basic mechanisms governing the occurrence and succession of green algae in coastal seas. This will result in more effective
management and mitigation of the effects of green tides, thus safeguarding the intrinsic and commercial value of coastal marine
ecosystems. 相似文献
135.
In our previous studies, programmed cell death (PCD) was induced in human periodontal ligament (PDL) cells, through activation of caspase-3 and upregulation of CASP5 gene (encoding caspase-5 protein), in response to mechanical stretch loading. The aim of this study is to explore the relationship between the inflammatory caspase, caspase-5, and the apoptotic executioner protein, caspase-3, in human PDL cells. Here, we found that cyclic stretching upregulated the activity and the protein expression level of caspase-3 and -5 and the addition of the caspase-3 inhibitor or caspase-5 inhibitor significantly inhibited the stretch-induced PCD. Meanwhile, the inhibition of caspase-5 inhibited the activation of caspase-3 and vice versa. The result of coimmunoprecipitation also demonstrated that the expression of caspase-3 was immunoprecipitated with caspase-5. Thus, our study revealed that the in vitro application of cyclic stretching induced PCD by activation of caspase-3 and -5 in human PDL cells, and these two caspases could interact with each other after mechanical stretch loading. The study may facilitate further studies on the mechanism of stretch-induced PCD and help us understand the force-related periodontal homeostasis and remodeling better. 相似文献
136.
Hiroyuki Hosokawa Phat Vinh Dip Maria Merkulova Anastasia Bakulina Zhenjie Zhuang Ashok Khatri Xiaoying Jian Shawn M. Keating Stephanie A. Bueler John L. Rubinstein Paul A. Randazzo Dennis A. Ausiello Gerhard Grüber Vladimir Marshansky 《The Journal of biological chemistry》2013,288(8):5896-5913
Previously, we reported an acidification-dependent interaction of the endosomal vacuolar H+-ATPase (V-ATPase) with cytohesin-2, a GDP/GTP exchange factor (GEF), suggesting that it functions as a pH-sensing receptor. Here, we have studied the molecular mechanism of signaling between the V-ATPase, cytohesin-2, and Arf GTP-binding proteins. We found that part of the N-terminal cytosolic tail of the V-ATPase a2-subunit (a2N), corresponding to its first 17 amino acids (a2N(1–17)), potently modulates the enzymatic GDP/GTP exchange activity of cytohesin-2. Moreover, this peptide strongly inhibits GEF activity via direct interaction with the Sec7 domain of cytohesin-2. The structure of a2N(1–17) and its amino acids Phe5, Met10, and Gln14 involved in interaction with Sec7 domain were determined by NMR spectroscopy analysis. In silico docking experiments revealed that part of the V-ATPase formed by its a2N(1–17) epitope competes with the switch 2 region of Arf1 and Arf6 for binding to the Sec7 domain of cytohesin-2. The amino acid sequence alignment and GEF activity studies also uncovered the conserved character of signaling between all four (a1–a4) a-subunit isoforms of mammalian V-ATPase and cytohesin-2. Moreover, the conserved character of this phenomenon was also confirmed in experiments showing binding of mammalian cytohesin-2 to the intact yeast V-ATPase holo-complex. Thus, here we have uncovered an evolutionarily conserved function of the V-ATPase as a novel cytohesin-signaling receptor. 相似文献
137.
Qiuxia Wang Congcong Liu Lili Xu Fangzhou Zhuang Bo Guan Guangcan Lin Chengdong Peng 《Zeitschrift fur angewandte Ichthyologie》2020,36(4):542-544
Parameters of the length-weight relationship (LWR) were estimated for four fish species [Beaufortia szechuanensis (Fang, 1930), Claea dabryi (Sauvage, 1874), Percocypris pingi (Tchang, 1930), and Yunnanilus sichuanensis Ding, 1995] from the Yalong River. Samples were collected seasonally from June 2018 to July 2019, using various fishing gears [set nets (mesh: 1.5 × 2.0 cm), hook, drift gill nets (three mesh sizes: 1.0; 2.0; 3.0 cm) and electro fishing]. Two new maximum standard length were recorded for C. dabryi and P. pingi. 相似文献
138.
139.
用免疫荧光单克隆抗体对脊髓灰质炎病毒抗原表位的分析 总被引:1,自引:0,他引:1
用间接免疫荧光与中和试验筛选出来的抗脊髓灰质炎2型与3型不同毒株的12个单克隆抗体,其中3个仅有免疫荧光活性,9个具有中和与免疫荧光活性。用免疫荧光活性的单克隆抗体进行试验,发现它们在识别特异性抗原表位方面与中和性单克隆抗体相似,显示出株特异的、几个毒株共同特异的或型特异的抗原表位。根据表位分布关系及特征,可以用来鉴别型内毒株的特征、毒株的抗原分析、抗原变异的研究以及疫苗相关病例的鉴别。所得结果与中和性单克抗隆抗体及T1-寡核苷酸指纹图谱分析一致。而免疫荧光单克隆抗体识别抗原表位的活性范围比中和性单克隆抗体更广。另外还发现某些兼有荧光与中和两活性的同一个单克隆抗体,用不同方法(IF与NT)进行试验时,与相同毒株出现不同表位反应,这点是值得引起注意需待进一步证实的重要问题。 相似文献
140.