Linkage of cation binding and folding in human telomeric quadruplex DNA.
Linkage of cation binding and folding in human telomeric quadruplex DNA.
复制标题
DOI：
10.1016/j.bpc.2011.06.012
复制
发表时间：
2011-11
影响因子：
3.8
通讯作者：
Chaires JB
中科院分区：
文献类型：
--
作者：
Gray RD;Chaires JB
DNA四联体的形成需要单价阳离子结合。为了表征阳离子结合化学计量学以及结合和折叠之间的联系，我们对人类端粒序列模型Tel22 （d[A(GGGTTA)3]）进行了KCl滴定，使用荧光指示剂测定[K+]自由和圆二色性，以评估折叠程度。在[K+]free = 5 mM（足够>95%折叠）时，表观结合化学计量为3 K+/Tel22；在[K+]free = 20 mM时，K+/Tel22增加到8 ~ 10 K+/Tel22。热力学分析表明，在[K+]free = 5 mM时，K+结合对Tel22的折叠贡献约为- 4.9 kcal/mol。总的折叠自由能为- 2.4 kcal/mol，表明存在不利于折叠的能量贡献。因此，四重折叠几乎完全由阳离子结合的能量驱动，很少或没有其他弱分子相互作用的贡献。
Formation of DNA quadruplexes requires monovalent cation binding. To characterize the cation binding stoichiometry and linkage between binding and folding, we carried out KCl titrations of Tel22 (d[A(GGGTTA)3]), a model of the human telomere sequence, using a fluorescent indicator to determine [K+]free and circular dichroism to assess the extent of folding. At [K+]free = 5 mM (sufficient for >95% folding), the apparent binding stoichiometry is 3 K+/Tel22; at [K+]free = 20 mM, it increased to 8–10 K+/Tel22. Thermodynamic analysis shows that at [K+]free = 5 mM, K+ binding contributes approximately −4.9 kcal/mol for folding Tel22. The overall folding free energy is −2.4 kcal/mol, indicating that there are energetically unfavorable contributions to folding. Thus, quadruplex folding is driven almost entirely by the energy of cation binding with little or no contribution from other weak molecular interactions.
登录
查看更多内容
影响因子：
14.9
作者：
Lane AN;Chaires JB;Gray RD;Trent JO
通讯作者：
Trent JO
影响因子：
2.9
作者：
Gray, Robert D.;Petraccone, Luigi;Chaires, Jonathan B.
通讯作者：
Chaires, Jonathan B.
影响因子：
3.9
作者：
Galezowska, Elzbieta;Gluszynska, Agata;Juskowiak, Bernard
通讯作者：
Juskowiak, Bernard
影响因子：
14.9
作者：
Gray, Robert D.;Chaires, Jonathan B.
通讯作者：
Chaires, Jonathan B.
影响因子：
15
作者：
Ida, Ramsey;Wu, Gang
通讯作者：
Wu, Gang