论文标题
用量子计算机对稀有构象过渡进行采样
Sampling Rare Conformational Transitions with a Quantum Computer
论文作者
论文摘要
自发的结构重排在复杂生物分子系统的组织和功能中起着核心作用。原则上,基于物理学的计算机模拟(例如分子动力学(MD))使我们能够以原子分辨率研究这些热活化过程。但是,罕见的构象转变在本质上很难使用MD进行研究,因为必须投资大量的计算资源来模拟亚稳态状态的热波动。诸如过渡路径采样之类的路径采样方法具有将可用的计算能力集中在亚稳态状态之间罕见的随机转变上的巨大希望。在这些方法中,出色的局限性之一是生成以低计算成本访问构象空间区域的路径。为了克服这些问题,我们引入了一种严格的方法,该方法集成了机器学习算法和MD模拟,该模拟在具有绝热量子计算的经典计算机上实施。首先,使用功能积分方法,我们基于用机器学习生成的一小部分分子构型来得出系统动力学的严格低分辨率表示。然后,使用量子退火机探索这种低分辨率理论的过渡路径集合,而无需引入非物理偏置力来引导系统的动力学。使用D-Wave量子计算机,我们通过在最新的原子描述中模拟基准构象过渡来验证我们的方案。我们表明,量子计算步骤生成不相关的轨迹,从而促进了配置空间中过渡区域的采样。我们的结果为MD模拟提供了一个新的范式,以整合机器学习和量子计算。
Spontaneous structural rearrangements play a central role in the organization and function of complex biomolecular systems. In principle, physics-based computer simulations like Molecular Dynamics (MD) enable us to investigate these thermally activated processes with an atomic level of resolution. However, rare conformational transitions are intrinsically hard to investigate with MD, because an exponentially large fraction of computational resources must be invested to simulate thermal fluctuations in metastable states. Path sampling methods like Transition Path Sampling hold the great promise of focusing the available computational power on sampling the rare stochastic transition between metastable states. In these approaches, one of the outstanding limitations is to generate paths that visit significantly different regions of the conformational space at a low computational cost. To overcome these problems we introduce a rigorous approach that integrates a machine learning algorithm and MD simulations implemented on a classical computer with adiabatic quantum computing. First, using functional integral methods, we derive a rigorous low-resolution representation of the system's dynamics, based on a small set of molecular configurations generated with machine learning. Then, a quantum annealing machine is employed to explore the transition path ensemble of this low-resolution theory, without introducing un-physical biasing forces to steer the system's dynamics. Using the D-Wave quantum computer, we validate our scheme by simulating a benchmark conformational transition in a state-of-the-art atomistic description. We show that the quantum computing step generates uncorrelated trajectories, thus facilitating the sampling of the transition region in configuration space. Our results provide a new paradigm for MD simulations to integrate machine learning and quantum computing.