State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
Amino Acids. 2012 Aug;43(2):557-65. doi: 10.1007/s00726-011-1150-5. Epub 2011 Nov 24.
Steered molecular dynamics simulations are performed to explore the unfolding and refolding processes of CLN025, a 10-residue beta-hairpin. In unfolding process, when CLN025 is pulled along the termini, the force-extension curve goes back and forth between negative and positive values not long after the beginning of simulation. That is so different from what happens in other peptides, where force is positive most of the time. The abnormal phenomenon indicates that electrostatic interaction between the charged termini plays an important role in the stability of the beta-hairpin. In the refolding process, the collapse to beta-hairpin-like conformations is very fast, within only 3.6 ns, which is driven by hydrophobic interactions at the termini, as the hydrophobic cluster involves aromatic rings of Tyr1, Tyr2, Trp9, and Tyr10. Our simulations improve the understanding on the structure and function of this type of miniprotein and will be helpful to further investigate the unfolding and refolding of more complex proteins.
采用导向分子动力学模拟方法研究了 CLN025（一个由 10 个残基组成的β发夹）的展开和折叠过程。在展开过程中，当 CLN025 沿着两端被拉伸时，在模拟开始不久，力-延伸曲线就在负值和正值之间来回波动。这与其他肽的情况非常不同，在其他肽中，力大部分时间都是正值。这种异常现象表明，带电荷的两端之间的静电相互作用对β发夹的稳定性起着重要作用。在折叠过程中，折叠成β发夹样构象非常快，仅需 3.6ns，这是由两端的疏水相互作用驱动的，因为疏水簇涉及 Tyr1、Tyr2、Trp9 和 Tyr10 的芳环。我们的模拟提高了对这种小型蛋白结构和功能的理解，并将有助于进一步研究更复杂蛋白的展开和折叠。
