论文标题
通过与延伸，收缩，扭曲和超串联相关的统计相互作用粒子对分子链的张力和扭矩的机械响应
Mechanical response to tension and torque of molecular chains via statistically interacting particles associated with extension, contraction, twist, and supercoiling
论文作者
论文摘要
以前引入的张力下的聚合链的统计机械分析的方法扩展到包括扭矩。在这种分析方法的框架内，单体或整个单体之间单个键对张力和扭矩的组合的响应涉及（热或机械）激活携带统计相互作用的粒子的特定混合物，这些粒子携带量子的延伸或收缩或扭曲或超套量的统计相互作用的颗粒。该方法在增加复杂性的应用中被阐明，能够描述扭曲手性与plectonemic手性之间的转化。控制变量是力，延伸，扭矩或连锁（扭曲和扭曲的组合）。在受控张力和扭矩下，双链DNA相关的两种应用和有希望的有望在两种应用中证明了这种方法的多功能性。一种应用描述了（天然）b-DNA，（内部）S-DNA和（彻底）P-DNA之间的构象转换，该构象转换符合实验数据。另一个应用程序描述了扭曲的链条和超螺旋链之间的转换如何适应屈曲过渡中的链接变化和多长度的变化。
A methodology for the statistical mechanical analysis of polymeric chains under tension introduced previously is extended to include torque. The response of individual bonds between monomers or of entire groups of monomers to a combination of tension and torque involves, in the framework of this method of analysis, the (thermal or mechanical) activation of a specific mix of statistically interacting particles carrying quanta of extension or contraction and quanta of twist or supercoiling. The methodology, which is elucidated in applications of increasing complexity, is capable of describing the conversion between twist chirality and plectonemic chirality in quasistatic processes. The control variables are force or extension and torque or linkage (a combination of twist and writhe). The versatility of this approach is demonstrated in two applications relevant and promising for double-stranded DNA under controlled tension and torque. One application describes conformational transformations between (native) B-DNA, (underwound) S-DNA, and (overwound) P-DNA in accord with experimental data. The other application describes how the conversion between a twisted chain and a supercoiled chain accommodates variations of linkage and excess length in a buckling transition.
