Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA.
Phys Chem Chem Phys. 2022 Jan 19;24(3):1553-1568. doi: 10.1039/d1cp04205j.
Reconstituted photosynthetic proteins which are activated upon exposure to solar energy hold enormous potential for powering future solid state devices and solar cells. The functionality and integration of these proteins into such devices has been successfully enabled by lipid-like peptides. Yet, a fundamental understanding of the organization of these peptides with respect to the photosynthetic proteins and themselves remains unknown and is critical for guiding the design of such light-activated devices. This study investigates the relative organization of one such peptide sequence VK (V: valine and K: lysine) within assemblies. Given the expansive spatiotemporal scales associated with this study, a hybrid coarse-grained (CG) model which captures the structure, conformation and aggregation of the peptide is adopted. The CG model uses a combination of iterative Boltzmann inversion and force matching to provide insight into the relative organization of VK in assemblies. The CG model reproduces the structure of a VK peptide sequence along with its all atom (AA) solvation structure. The relative organization of multiple peptides in an assembly, as captured by CG simulations, is in agreement with corresponding results from AA simulations. Also, a backmapping procedure reintroduces the AA details of the peptides within the aggregates captured by the CG model to demonstrate the relative organization of the peptides. Furthermore, a large number of peptides self-assemble into an elongated micelle in the CG simulation, which is consistent with experimental findings. The coarse-graining procedure is tested for transferability to longer peptide sequences, and hence can be extended to other amphiphilic peptide sequences.
在太阳能的激发下重新形成的光合作用蛋白在为未来的固态设备和太阳能电池提供动力方面具有巨大的潜力。通过类脂肽，可以成功地实现这些蛋白质在这些设备中的功能和集成。然而，这些肽与光合作用蛋白本身的组织方式的基本理解仍然未知，这对于指导这种光激活设备的设计至关重要。本研究调查了 VK（V：缬氨酸和 K：赖氨酸）这样的肽序列在组装体中的相对组织情况。鉴于这项研究涉及广泛的时空尺度，因此采用了一种混合粗粒化（CG）模型来捕获肽的结构、构象和聚集。CG 模型结合迭代玻尔兹曼反演和力匹配，深入了解 VK 在组装体中的相对组织情况。CG 模型再现了 VK 肽序列的结构及其全原子（AA）溶剂化结构。CG 模拟中捕获的组装体中多个肽的相对组织与 AA 模拟的相应结果一致。此外，回溯映射过程重新引入了 CG 模型中捕获的聚集体中肽的 AA 细节，以展示肽的相对组织情况。此外，大量肽在 CG 模拟中自组装成一个长形胶束，这与实验结果一致。粗粒化过程经过测试可转移到更长的肽序列，因此可以扩展到其他两亲肽序列。
