超螺旋

超螺旋PGEM-1重组质粒的提取、纯化与鉴定

The Extraction , Purification and Identification of Superhelix pGEM - Recombined Plasmid

所得纯化物以1%琼脂糖凝胶电泳鉴定超螺旋质粒的含量。

The level of purified superhelix plasmids were measured by 1 % agarose gel electrophoresis .

质粒DNA超螺旋构象的激光喇曼光谱研究

Laser Raman spectral analysis of superhelical spatial conformation on plasmid DNA

发酵培养中葡萄糖对超螺旋质粒DNA产量的影响

Effect of Glucose on Supercoiled Plasmid DNA Production in Fermentation Process

其次研究了优化培养基下影响超螺旋质粒DNA产量的各参数变化规律。

Factors influencing the production of supercoiled plasmid DNA were studied .

产毒性大肠杆菌CFA/Ⅰ基因表达与DNA超螺旋状态的关系

Study on relation between DNA supercoiling and cfa / I gene expression

弹性竿模型下超螺旋DNA分子的构象研究

A study on conformations of DNA chain under the elastic rod model

病毒核酸为双链DNA，存在超螺旋型、环型和线型三种形态，G＋C的含量为45%。

G + C of viral DNA was 45 % .

超螺旋化对于质粒DNA在转录水平上的表达是必需的。

Supercoiling is necessary for the expression of recombinant plasmid DNA at transcription level .

用超螺旋双股DNA直接序列分析程序，简化了DNA序列分析工作。

The sequencing procedure was simplified by using supercoiled double strand DNA as template .

DNA旋转酶是类型Ⅱ拓扑异构酶的一种，也是唯一能够引入负超螺旋的拓扑异构酶。

DNA gyrase is the only topoisomerase that is able to introduce negative supercoils into DNA .

本文首先研究了含有不同质量浓度葡萄糖的发酵培养基对超螺旋质粒DNA产量的影响。

In this paper the influence of glucose on the production of supercoiled plasmid DNA in the fermentation process is presented .

DNA链之间可能存在非共价相互作用以维持这种结构。螺线管型结构可能是水溶液中的超螺旋DNA分子普遍的存在形式。

Some of noncovalent interactions between the coils of DNA double strand may be involved in the solenoidal structure of DNA .

超螺旋质粒DNA在热变性后冷却即快速复性方面与染色体DNA不同。

Unlike chromosomal DNA , plasmid is supercoiled in structure , which renatures rapidly after heat denaturation followed by quick cooling .

基因组为闭合环状双链超螺旋DNA，由大约8000对碱基组成；

The genome is a double stranded , covalently closed , circular , supercoiled DNA molecule , approximately 8000 base pairs in size .

DNA回旋酶是细菌特有的一种拓扑异构酶，它能够利用ATP水解的能量将共价闭合环状DNA转变为负超螺旋DNA，从而维持细菌体内正常的超螺旋水平。

DNA gyrase is an essential bacterial topoisomerase that catalyzes the ATP dependent negative supercoiling of double stranded closed circular DNA .

经NI柱纯化的蛋白，在金属催化氧化系统中，具有保护超螺旋质粒不被氧自由基降解的能力。

The purified protein was shown to have a protective effect against plasmid DNA cleavage by reactive oxygen species .

结果表明：以碱裂液中质粒DNA为计算基准的得率为56.61%、超螺旋质粒DNA的电泳纯度100%。

The final yield of plasmid DNA from the broth after alkaline lysis is 56.61 % , and its purity determined by agarose electrophoresis is almost 100 % .

He－Ne激光辐照后的质粒超螺旋双链DNA存活率剂量曲线不同于紫外线和氮离子束。

Dose - effect curve of scDNA survival rate by He - Ne laser radiation differ from that by ultraviolet and N + ion beam .

Polyd（GC）在负超螺旋下形成的Z-DNA

Formation of Z-DNA in Poly d ( GC ) in the Presence of Negatively Supercoil

髓核是由大约120kb的双链DNA分子和与其密切相关的碱性蛋白所组成，碱性蛋白同DNA紧密结合以维持其复杂有序的超螺旋结构，并且能够增强杆状病毒DNA的感染性；

Core of the virus is composed of supercoiled dsDNA genome proximately 120 kb in size and related basic proteins which couple with the genome DNA to maintain its complexity and enhance its infectivity .

二甲亚砜之前有报道称可以帮助以染色质或超螺旋结构的质粒为模板的RNA的体外转录。它的机制被认为是二甲亚砜改变了DNA模板的结构。

Dimethylsulfoxide was previously reported to facilitate in vitro transcription of RNA from chromatin and supercoiled plasmid , with the underlying mechanism being attributed to the alteration of the template structure .

纯化蛋白经SDS-PAGE电泳与westernblot鉴定后，对pUC19质粒进行超螺旋dsDNA裂解研究。

The purified protein was identified with SDS-PAGE and Western blot analysis and was used to cleave supercoiled dsDNA .

详细介绍外部控制器的设计方法，并在此基础上对PID算法、一阶滑模算法、二阶超螺旋算法等控制策略进行了仿真对比。

The paper also introduces the design method of external controller . The Comparative simulation is carried out by the control strategy included PID algorithm 、 first-order algorithm and second-order sliding mode algorithm .

研究还发现等离子体能使DNA构象能转变：从超螺旋构象转变为线性和开环构象，这将有利于提高转基因育种时的成功率，等离子体在转基因技术中的应用前景广阔。

The study also found out that plasma could cause some changes to the conformation of DNA : from the supercoiled structure into the linearized and open circular structure , which would improve the success rate of transformation frequency .

目的研究乙型肝炎病毒（HBV）C蛋白羧基端短小的干扰RNA（siRNA）对HBV超螺旋双链闭环DNA（cccDNA）水平的影响。

Objective To study the effect of hepatitis B virus ( HBV ) C protein C-terminal small interference RNA ( siRNA ) on reduction of HBV covalently closed circular DNA ( cccDNA ) level .

SAP对核糖体RNA和超螺旋DNA的这种切割作用具有不可修复性，可以称之为DNA（RNA）糖苷酶/脱嘌呤裂解酶，这种酶活性也许是SAP抗病毒、抗肿瘤的主要作用机制之一。

So SAP is a kind of DNA ( RNA ) glycosidase / depurination cleavage enzyme as it can effect on the RNA and DNA cleavage beyond retrieve . This kind of enzyme activity may be one of mechanism of anti-virus and anti-tumor effects .

晶体蛋白基因的转录调控与其超螺旋构形的关系

Involvement of superhelical structure in controlling the regulatory transcription of crystallin gene

第7、8、11、12号染色体的长臂则是典型而均匀的超螺旋结构。

The q-arms of chromosome 7,8,11 , and 12 are all typical uniform super-soleniods .

此结果表明碱基受损，主链断裂，超螺旋结构部分解旋。

The results show bases damaging , strandline breaking , supercoiled structure relaxing partly .