标题： 通过多系算法研究螺旋-线圈转变的热力学 显示英文标题

标题： Thermodynamics of helix-coil transitions studied by multicanonical algorithms

摘要： 热力学中螺旋-线圈转变在氨基酸同源寡聚体中的研究是通过最近提出的多规范算法进行的。 考虑了长度为10的三种特征氨基酸，丙氨酸（螺旋形成者），缬氨酸（螺旋中性）和甘氨酸（螺旋破坏者）。 对于丙氨酸，还考虑了其他长度（15和20），以检查长度依赖性。 从一次完全随机初始构象的多规范生产运行中，我们获得了最低能量构象和各种热力学量（平均螺旋度，Zimm-Bragg$s$和$\sigma$参数，螺旋态和线圈态之间的自由能差异等） 作为温度的函数。 结果证实了丙氨酸是螺旋形成者，缬氨酸是螺旋中性，甘氨酸是螺旋破坏者。 显示英文摘要

摘要： Thermodynamics of helix-coil transitions in amino-acid homo-oligomers are studied by the recently proposed multicanonical algorithms. Homo-oligomers of length 10 are considered for three characteristic amino acids, alanine (helix former), valine (helix indifferent), and glycine (helix breaker). For alanine other lengths (15 and 20) are also considered in order to examine the length dependence. From one multicanonical production run with completely random initial conformations, we have obtained the lowest-energy conformations and various thermodynamic quantities (average helicity, Zimm-Bragg $s$ and $\sigma$ parameters, free energy differences between helix and coil states, etc.) as functions of temperature. The results confirm the fact that alanine is helix-forming, valine is helix-indifferent, and glycine is helix-breaking.