Tau could protect DNA double helix structure
Tau could protect DNA double helix structure
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DOI：
10.1016/s1570-9639(02)00538-1
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发表时间：
2003-02-21
影响因子：
3.2
通讯作者：
He, RQ
中科院分区：
文献类型：
--
作者：
Hua, Q;He, RQ
增色效应已被用于检测tau蛋白对双链DNA向单链DNA转变的影响。结果表明，tau使小牛胸腺DNA的熔解温度从67 ℃提高到81 ℃，使质粒的熔解温度从75 ℃提高到85 ℃。在动力学上，与tau孵育的DNA在260 nm处的吸光度的增加速率明显慢于在热变性期间用作对照的DNA和DNA/牛血清白蛋白。相比之下，当样品立即从热条件转移到室温时，tau的DNA吸光度降低速率比对照组快。结果表明，tau蛋白能有效地抑制DNA的热变性，并能促进DNA的复性。圆二色性光谱结果表明，加入tau后，DNA双螺旋的构象几乎没有变化。此外，tau还显示出保护DNA免受羟基自由基（（OH）-O-.）的能力，在体外攻击，这意味着tau作为DNA保护分子的自由基的功能。(C)2002爱思唯尔科技有限公司。保留所有权利。
The hyperchromic effect has been used to detect the effect of tau on the transition of double-stranded DNA to single-stranded DNA. It was shown that tau increased the melting temperature of calf thymus DNA from 67 to 81 degreesC and that of plasmid from 75 to 85 degreesC. Kinetically, rates of increase in absorbance at 260 nm of DNA incubated with tau were markedly slower than those of DNA and DNA/bovine serum albumin used as controls during thermal denaturation. In contrast, rates of decrease in the DNA absorbance with tau were faster than those of controls when samples were immediately transferred from thermal conditions to room temperature. It revealed that tau prevented DNA from thermal denaturation, and improved renaturation of DNA. Circular dichroic spectra results indicated that there were little detectable conformational changes in DNA double helix when tau was added. Furthermore, tau showed its ability to protect DNA from hydroxyl radical ((OH)-O-.),attacking in vitro, implying that tau functions as a DNA-protecting molecule to the radical. (C) 2002 Elsevier Science B.V. All rights reserved.