Malhotra Isha, Babu Sujin B
Out of Equilibrium Group, Department of physics, Indian Institute of Technology, Delhi-110016, India.
J Phys Condens Matter. 2020 Jun 1;32(35). doi: 10.1088/1361-648X/ab8c8e.
Patchy particles are considered to be a good model for protein aggregation. We propose a novel method to generate different structures of glucose isomerase protein such as chains, crystals and bundles by utilising aggregation of two-patch colloidal particles in presence of competing isotropic and anisotropic potential. We calculate the equilibrium phase diagram of two-patch colloidal particles and demonstrates the coexistence of different phases like disordered clusters, chains, crystals and bundles depending on the relative strength of isotropic and anisotropic potential. We also show that the formation of network of bundles is metastable against the formation of thermodynamically favored finite sized bundles along with thermodynamically stable crystals. These bundles appear to be helical in structure similar to that observed in sickle cell hemoglobin. The simulation results show that the method can characterize phase behaviour of glucose isomerase protein, which provides a novel tool to unveil self-assembly mechanism of protein under different conditions.
斑片状颗粒被认为是蛋白质聚集的良好模型。我们提出了一种新方法，通过在存在竞争的各向同性和各向异性势的情况下利用双斑胶体颗粒的聚集来生成葡萄糖异构酶蛋白的不同结构，如链、晶体和束状结构。我们计算了双斑胶体颗粒的平衡相图，并证明了根据各向同性和各向异性势的相对强度，不同相（如无序簇、链、晶体和束状结构）的共存。我们还表明，束状网络的形成相对于沿着热力学稳定晶体形成热力学上有利的有限尺寸束状结构是亚稳的。这些束状结构在结构上似乎是螺旋状的，类似于在镰状细胞血红蛋白中观察到的结构。模拟结果表明，该方法可以表征葡萄糖异构酶蛋白的相行为，这为揭示不同条件下蛋白质的自组装机制提供了一种新工具。
