Shaanxi University of Science and Technology, School of food and Biological Engineering, Xian 710016, China; Neijiang Vocational and Technical College, Department of Agricultural Technology, Neijiang 641000, China.
Shaanxi University of Science and Technology, School of food and Biological Engineering, Xian 710016, China.
Int J Biol Macromol. 2020 Jul 15;155:91-102. doi: 10.1016/j.ijbiomac.2020.03.190. Epub 2020 Mar 26.
Starch is an important resource in nature, and HHP (high hydrostatic pressure) is one of the most important physical modification technologies. In this study, molecular dynamics simulation was used to explore the interchain interaction and the changes of molecule conformations of amylopectin and double-amylose helix at atomic level in different pressure. The results shown that, firstly, high pressure increased the content of 4C1 chair conformation, decreased the RMSD (root mean square deviations) and RMSF (root mean square fluctuation), made molecules more stable. Secondly, high pressure increased the interchain VDW (Van der Waals) and electrostatic forces, then caused the decreases of the interchain distances and surface area of both amylopectin and double-amylose, made molecules more compact. Thirdly, high pressure decreased the intramolecular hydrogen bonds, increased the molecule-solvent hydrogen bonds. These findings can explain some existing experimental phenomena from the atomic level, meanwhile, it may also provide importance reference value for using of HHP in starch processing and the studies of starch granule structure.
淀粉是自然界中一种重要的资源，而超高压（high hydrostatic pressure，HHP）是最重要的物理改性技术之一。在本研究中，我们使用分子动力学模拟从原子水平探索了不同压力下支链淀粉和双螺旋淀粉分子构象的链间相互作用和变化。结果表明：首先，高压增加了 4C1 椅式构象的含量，降低了均方根偏差（root mean square deviations，RMSD）和均方根波动（root mean square fluctuation，RMSF），使分子更加稳定。其次，高压增加了链间范德华（Van der Waals）和静电力，导致支链淀粉和双螺旋淀粉的链间距离和表面积减小，使分子更加紧凑。第三，高压降低了分子内氢键的数量，增加了分子-溶剂氢键。这些发现可以从原子水平解释一些现有的实验现象，同时，也可能为 HHP 在淀粉加工和淀粉颗粒结构研究中的应用提供重要的参考价值。
