Villa Alessandra, Mark Alan E, Saracino Gloria A A, Cosentino Ugo, Pitea Demetrio, Moro Giorgio, Salmona Mario
Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
J Phys Chem B. 2006 Jan 26;110(3):1423-8. doi: 10.1021/jp052722o.
Extensive molecular dynamic simulations (approximately 240 ns) have been used to investigate the conformational behavior of PrP106-126 prion peptide in four different environments (water, dimethyl sulfoxide, hexane, and trifluoroethanol) and under both neutral and acidic conditions. The conformational polymorphism of PrP106-126 in solution observed in the simulations supports the role of this fragment in the structural transition of the native to the abnormal form of prion protein in response to changes in the local environmental conditions. The peptide in solution is primarily unstructured. The simulations show an increased presence of helical structure in an apolar solvent, in agreement with the results from circular dichroism spectroscopy. In water solution, beta-sheet elements were observed between residues 108-112 and either residues 115-121 or 121-126. An alpha-beta transition was observed under neutral conditions. In DMSO, the peptide adopted an extended conformation, in agreement with nuclear magnetic resonance experiments.
广泛的分子动力学模拟（约240纳秒）已被用于研究PrP106 - 126朊病毒肽在四种不同环境（水、二甲基亚砜、己烷和三氟乙醇）以及中性和酸性条件下的构象行为。模拟中观察到的PrP106 - 126在溶液中的构象多态性支持了该片段在朊病毒蛋白从天然形式向异常形式的结构转变中，响应局部环境条件变化所起的作用。溶液中的肽主要是无结构的。模拟显示在非极性溶剂中螺旋结构的存在增加，这与圆二色光谱的结果一致。在水溶液中，在残基108 - 112与残基115 - 121或121 - 126之间观察到β - 折叠元件。在中性条件下观察到α - β转变。在二甲基亚砜中，该肽呈现伸展构象，这与核磁共振实验结果一致。
