Force-induced melting of a short DNA double helix
Force-induced melting of a short DNA double helix
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DOI：
10.1007/s002490000107
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发表时间：
2001-01-01
影响因子：
2
通讯作者：
Williams, PM
中科院分区：
文献类型：
--
作者：
Pope, LH;Davies, MC;Williams, PM
DNA的动力学行为对许多细胞过程至关重要。对转录和复制至关重要的一个主要特征是双链体“解链”的能力。它最近已被证明，动态力光谱提供有关生物分子解离的能量学信息。我们已经采用这种技术来研究单个十二核苷酸分子的解结合。为了将双链体分离成单链DNA，在一定的加载速率范围内需要17至40 pN的力。熔化力对加载速率的依赖性的解释表明，断裂的能垒在9和13千卡摩尔（-1）之间的高度和位于0.58 nm的中间结构状态。热熔融研究表明，在解离之前，寡核苷酸经历了一个转变，需要7和11千卡摩尔（-1）之间的能量。通过结合动态力谱和热熔融的研究，我们显示了一个能源景观的衍生解离12聚体双链体。直到最近，这种类型的信息只能通过计算分析获得。此外，力谱数据允许双链体形成和熔化的动力学的估计。
The dynamic behaviour of DNA is of fundamental importance to many cellular processes. One principal characteristic, central to transcription and replication, is the ability of the duplex to "melt". It has recently been shown that dynamic force spectroscopy provides information about the energetics of biomolecular dissociation. We have employed this technique to investigate the unbinding of single dodecanucleotide molecules. To separate the duplex to single-stranded DNA, forces ranging from 17 to 40 pN were required over a range of loading rates. Interpretation of the dependence of melting force on loading rate revealed that the energy barrier to rupture is between 9 and 13 kcal mol(-1) in height and situated 0.58 nm from an intermediate structural state. Thermal melting studies show that, prior to dissociation, the oligonucleotide underwent a transition which required between 7 and II kcal mol(-1) in energy. Through combined dynamic force spectroscopy and thermal melting studies we show the derivation of an energy landscape to dissociate a 12-mer duplex. Until very recently, this type of information was only accessible by computational analysis. Additionally, the force spectroscopy data allow an estimation of the kinetics of duplex formation and melting.