酸性条件下的DNA构象变化加速DNA变性解链

调控DNA的变性解链过程是DNA扩增与检测的关键步骤。对于传统的热循环DNA扩增策略，由于变温过程中热量分布不均一以及变温速度慢等不利因素，会直接影响DNA变性解链过程，从而降低DNA检测放大的效果、延长检测的时长。因此，探索快速、高效的调控DNA变性解链的方法具有重要的研究意义。本文发展了以胞嘧啶在酸性条件下的质子化反应为基础，通过改变溶液的pH值，来诱导DNA构象在Watson-Crick（WC）碱基对与Hoogsteen（HG）碱基对之间的分子构象转换，从而实现精准、快速、高效的DNA变性解链调控目标。结果表明，相较于传统的温控方法，pH调控方法能显著提高DNA变性的速率约6倍以上。本文发现pH调控方法通过降低双链DNA的反应焓约160 kJ/mol，从而提高双链DNA变性速率和效率。该方法具有用于DNA信号放大与检测等相关应用的潜力。

Low pH Induced DNA Conformational Switch Accelerates DNA Disassociation

DNA denaturation by thermal melting is critical for DNA amplification and detection. However， the uneven heat distribution and temperature change hinders its application in DNA amplification and detection. It's highly desired to explore a fast and efficient approach to regulating DNA degeneration. In this paper， we propose to apply acid， instead of thermal melting， to accelerate the DNA denaturation by regulating DNA conformation quickly and precisely via protonation of cytosine. We find that the thermodynamic properties of DNA highly depend on its molecular conformation. Furthermore， compared with traditional thermal method， pH method significantly increases the rate of DNA denaturation by more than 6 times. We further found that the mechanism of the pH control method to improve DNA denaturation by rapidly decreasing the enthalpy of double-stranded DNA （160 kJ/mol）， and hope that this method can be used in applications of DNA amplification and detection.