论文标题
了解分子内离子对相互作用在构象稳定性中的作用
Understanding the role of intramolecular ion-pair interactions in conformational stability using an ab initio thermodynamic cycle
论文作者
论文摘要
分子内离子对相互作用产生许多分子的形状和功能。通过适当的取向，这些相互作用克服了空间因素，并负责几种肽的紧凑结构。在这项研究中，我们提出了基于等电和炼金术突变的热力学循环，以估计分子内离子对相互作用能量。我们确定了具有共同离子对组合的26个基准分子的这些能量，并将它们与使用分子内对称性的扰动理论获得的结果进行了比较。对于具有较长接头的系统，使用两种方法在真空期使用两种方法评估的离子对能均偏离不到2.5％。基于密度功能理论的热力学循环促进了具有连续/微覆盖模型的模型三肽中盐桥相互作用的计算，四个大肽：1EJG（crambin），1bdk（bradykinin），1l2y，1l2y（1l2y）（1l2y（1l2y）（一种与色氨酸笼中的微蛋白）（来自色氨酸笼子）和1sco（cor）和1sco（scor）（1So）（scorpion and 1so）（scorpion and scorpion and scorpion and scorpion ancxin and soxin and soxin and soxin and soxin and soxin and soxin and soxin a soxin and soxin a sosexin。
Intramolecular ion-pair interactions yield shape and functionality to many molecules. With proper orientation, these interactions overcome steric factors and are responsible for the compact structures of several peptides. In this study, we present a thermodynamic cycle based on isoelectronic and alchemical mutation to estimate intramolecular ion-pair interaction energy. We determine these energies for 26 benchmark molecules with common ion-pair combinations and compare them with results obtained using intramolecular symmetry-adapted perturbation theory. For systems with long linkers, the ion-pair energies evaluated using both approaches deviate by less than 2.5% in vacuum phase. The thermodynamic cycle based on density functional theory facilitates calculations of salt-bridge interactions in model tripeptides with continuum/microsolvation modeling, and four large peptides: 1EJG (crambin), 1BDK (bradykinin), 1L2Y (a mini-protein with a tryptophan cage), and 1SCO (a toxin from the scorpion venom).
