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介绍了纳米电化学DNA生物传感器的基本概念和分类,并介绍了用于DNA标记的纳米粒子的六种类型及其三大检测方法,在此基础上对纳米电化学DNA生物传感器在基因检测、疾病诊断、DNA检测等方面的最新进展进行了综述与讨论。 相似文献
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近几年来,酶传感器、免疫传感器及微生物传感器等发展较为成熟,而DNA生物传感器的研究相对较少.文章从核酸杂交的原理出发介绍了DNA生物传感器的工作原理,举例说明了电化学、光学和声学等几种典型的DNA生物传感器,指出了其固有的优缺点,肯定了DNA传感器发展前景. 相似文献
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阵列生物传感器技术作为一种高通量、快速、选择性高和集成化的分析技术,已在基因组学和蛋白质组学的研究和药物筛选、环境分析,食品分析,临床诊断等领域中得到广泛的应用.阵列生物传感器主要有阵列光学生物传感器和阵列电化学生物传感器.阵列电化学生物传感器是将生物分子识别物质如酶、抗原/抗体、DNA等固定在阵列电极上,以阵列中每根电极产生的电化学信号作为检测信号的电化学分析器件.阵列电化学生物传感器以灵敏度高、分析速度快、选择性好、易于微型化和集成化以及仪器价格低廉等特点受到了研究工作者的极大关注.本文简单介绍了阵列电化学生物传感器的原理和特点,重点评述了2005年以来阵列电化学生物传感器在单组份检测和多组份同时检测两方面的研究进展,简单讨论了阵列电化学生物传感器研究中存在的问题. 相似文献
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DNA传感器是基于DNA分子相互作用原理设计而成的一种新型的检测技术,具有快速,简单等优点,在基因分析及其他应用领域已显示出越来越重要的价值.分子信标是一种具有发卡式结构的寡核苷酸,由于其能够很好地识别单碱基错配序列,基于发卡式DNA的传感器较传统的单链DNA传感器有更好的检测特异性,目前得到广泛的研究.本文介绍了DNA生物传感器及分子信标的有关原理,并着重介绍了发卡式DNA的结构及其在DNA生物传感器中的应用. 相似文献
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Capping DNA with DNA 总被引:13,自引:0,他引:13
Twelve classes of deoxyribozymes that promote an ATP-dependent "self-capping" reaction were isolated by in vitro selection from a random-sequence pool of DNA. Each deoxyribozyme catalyzes the transfer of the AMP moiety of ATP to its 5'-terminal phosphate group, thereby forming a 5',5'-pyrophosphate linkage. An identical DNA adenylate structure is generated by the T4 DNA ligase during enzymatic DNA ligation. A 41-nucleotide class 1 deoxyribozyme requires Cu(2+) as a cofactor and adopts a structure that recognizes both the adenine and triphosphate moieties of ATP or dATP. The catalytic efficiency for this DNA, measured at 10(4) M(-1) x min(-1) using either ATP or dATP as substrate, is similar to other catalytic nucleic acids that use small substrates. Chemical probing and site-directed mutagenesis implicate the formation of guanine quartets as critical components of the active structure. The observation of ATP-dependent "self-charging" by DNA suggests that DNA could be made to perform the reactions typically associated with DNA cloning, but without the assistance of protein enzymes. 相似文献
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Eukaryotic DNA polymerases in DNA replication and DNA repair 总被引:16,自引:0,他引:16
Peter M. J. Burgers 《Chromosoma》1998,107(4):218-227
DNA polymerases carry out a large variety of synthetic transactions during DNA replication, DNA recombination and DNA repair.
Substrates for DNA polymerases vary from single nucleotide gaps to kilobase size gaps and from relatively simple gapped structures
to complex replication forks in which two strands need to be replicated simultaneously. Consequently, one would expect the
cell to have developed a well-defined set of DNA polymerases with each one uniquely adapted for a specific pathway. And to
some degree this turns out to be the case. However, in addition we seem to find a large degree of cross-functionality of DNA
polymerases in these different pathways. DNA polymerase α is almost exclusively required for the initiation of DNA replication
and the priming of Okazaki fragments during elongation. In most organisms no specific repair role beyond that of checkpoint
control has been assigned to this enzyme. DNA polymerase δ functions as a dimer and, therefore, may be responsible for both
leading and lagging strand DNA replication. In addition, this enzyme is required for mismatch repair and, together with DNA
polymerase ζ, for mutagenesis. The function of DNA polymerase ɛ in DNA replication may be restricted to that of Okazaki fragment
maturation. In contrast, either polymerase δ or ɛ suffices for the repair of UV-induced damage. The role of DNA polymerase
β in base-excision repair is well established for mammalian systems, but in yeast, DNA polymerase δ appears to fullfill that
function.
Received: 20 April 1998 / Accepted: 8 May 1998 相似文献
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DNA topoisomerases and DNA repair 总被引:5,自引:0,他引:5
C S Downes R T Johnson 《BioEssays : news and reviews in molecular, cellular and developmental biology》1988,8(6):179-184
DNA topoisomerases are enzymes that can modify, and may regulate, the topological state of DNA through concerted breaking and rejoining of the DNA strands. They have been believed to be directly involved in DNA excision repair, and perhaps to be required for the control of repair as well. The vicissitudes of this hypothesis provide a noteworthy example of the dangers of interpreting cellular phenomena without genetic information and vice versa. 相似文献
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D M Lilley 《Biochemical Society transactions》1986,14(2):211-213
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《Cell cycle (Georgetown, Tex.)》2013,12(9):1339-1340
Comment on: Witz G, et al. Proc Natl Acad Sci USA 2011; 108:3608-11. 相似文献
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Hans V. Westerhoff Mary H. O’Dea Anthony Maxwell Martin Gellert 《Cell biochemistry and biophysics》1988,12(1):157-181
Using purified DNA gyrase to supercoil circular plasmid pBR322 DNA, we examined how the linking number attained at the steady
state (‘static head’) varies with the concentrations of ATP and ADP, both in the absence and presence of spermidine. In the
absence of spermidine at total adenine nucleotide concentrations between 0.35 and 1.4 mM, the static-head linking number was independent of the sum concentration of ATP and ADP, but depended strongly on the ratio
of their concentrations. We established that the same linking number was attained independent of the direction from which
the steady state was approached. The decrease in linking number at static head is more extensive when spermidine is present
in the incubation, but remains a function of the [ATP]-to-[ADP] ratio.
These results are discussed in terms of various kinetic schemes for DNA gyrase. We present one kinetic scheme that accounts
for the experimental observations. According to this scheme our experimental results imply that there is significant slip
in DNA gyrase when spermidine is absent. It is possible that spermidine acts through adjustment of the degree of coupling
of DNA gyrase. 相似文献
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DNA杂交与DNA指纹技术 总被引:1,自引:0,他引:1
Southern印迹杂交和DNA指纹技术在分子生物学研究以及疾病的诊断、亲缘关系鉴定、犯罪分子确认等过程中发挥了重要作用。回顾了2种技术的发明、发展历程和在生命科学研究中的作用,并探讨了可能的发展方向,从中可以从一个侧面了解分子生物学的发展历程和体会科学家的智慧在科学技术发展中所起的重要作用。 相似文献
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DNA supercoiling inhibits DNA knotting 总被引:1,自引:1,他引:0
Despite the fact that in living cells DNA molecules are long and highly crowded, they are rarely knotted. DNA knotting interferes with the normal functioning of the DNA and, therefore, molecular mechanisms evolved that maintain the knotting and catenation level below that which would be achieved if the DNA segments could pass randomly through each other. Biochemical experiments with torsionally relaxed DNA demonstrated earlier that type II DNA topoisomerases that permit inter- and intramolecular passages between segments of DNA molecules use the energy of ATP hydrolysis to select passages that lead to unknotting rather than to the formation of knots. Using numerical simulations, we identify here another mechanism by which topoisomerases can keep the knotting level low. We observe that DNA supercoiling, such as found in bacterial cells, creates a situation where intramolecular passages leading to knotting are opposed by the free-energy change connected to transitions from unknotted to knotted circular DNA molecules. 相似文献
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The DNAs of wheat and rye plants with rye B chromosomes have been compared with wheat, rye and oats DNAs by DNA/DNA hybridisation. The presence of DNA from B chromosomes made no significant difference to the proportion of repeated sequence DNA. The repeated sequence fractions of these cereal DNAs were quantitatively divided into eight different groups on the basis of the amount of DNA/DNA hybridisation occurring between the different DNAs. Rye A and B chromosomes contained similar proportions of three of the groups. These results, together with estimates of the thermal stabilities of all the renatured DNA duplexes suggest that rye B chromosome DNA is very similar to rye A chromosome DNA in the proportion and heterogeneity of its repeated sequences. 相似文献