Force-induced melting of the DNA double helix - 1. Thermodynamic analysis
Force-induced melting of the DNA double helix - 1. Thermodynamic analysis
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DOI：
10.1016/s0006-3495(01)76067-5
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发表时间：
2001-02-01
影响因子：
3.4
通讯作者：
Bloomfield, VA
中科院分区：
文献类型：
--
作者：
Rouzina, I;Bloomfield, VA
当施加拉伸力时，单个B-DNA分子高度协同地延长到几乎是其轮廓长度的两倍，这被解释为力诱导DNA熔化。这种解释是基于实验和计算的拉伸轮廓之间的相似性，当熔化的力依赖于力的自由能直接从双链和单链DNA的实验力-拉伸曲线获得时。超拉伸相变的高度协同性与熔融解释是一致的。镍DNA承受比转变中点更大的力的能力被解释为熔化转变的一维性质的结果，这导致熔化和未熔化的DNA交替区域，甚至远远高于熔化中点。我们讨论了力诱导熔化与其他作者提出的从B到S转变的关系，最近测量到的施加在单链DNA模板上的力对T7DNA聚合酶活性的影响是通过类似于7pN的弱力优先稳定双链DNA来解释的。
The highly cooperative elongation of a single B-DNA molecule to almost twice its contour length upon application of a stretching force is interpreted as force-induced DNA melting. This interpretation is based on the similarity between experimental and calculated stretching profiles, when the force-dependent free energy of melting is obtained directly from the experimental force versus extension curves of double- and single-stranded DNA. The high cooperativity of the overstretching transition is consistent with a melting interpretation. The ability of nicked DNA to withstand forces greater than that at the transition midpoint is explained as a result of the one-dimensional nature of the melting transition, which leads to alternating zones of melted and unmelted DNA even substantially above the melting midpoint. We discuss the relationship between force-induced melting and the B-to-S transition suggested by other authors, The recently measured effect on T7 DNA polymerase activity of the force applied to a ssDNA template is interpreted in terms of preferential stabilization of dsDNA by weak forces similar to7 pN,