Pressure-induced structural changes of alanine oligopeptides in aqueous solutions
Pressure-induced structural changes of alanine oligopeptides in aqueous solutions
复制标题
水溶液中丙氨酸寡肽的压力诱导结构变化
DOI：
10.1080/08957959.2019.1584195
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发表时间：
2019
影响因子：
2
通讯作者：
Yukihiro Yoshimura
中科院分区：
文献类型：
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作者：
Takahiro Takekiyo;Minoru Kato;Yukihiro Yoshimura
水溶液中的短丙氨酸（Ala）寡肽具有聚脯氨酸II [PPII;（φ，<$）=（−60°，150°）]和扩展β构象[（φ，<$）=（−150°，150°）]，其构象与蛋白质的变性状态有关。在这项研究中，我们研究了压力引起的构象变化的五-和六-丙氨酸（Ala 5和Ala 6，分别）在水溶液中使用傅里叶变换红外光谱（FTIR）。一个值得注意的观察是，随着压力的增加，在Ala 6中产生了两个位于1620和1690 cm− 1的峰，这两个峰被分配给分子间β折叠。在Ala 5中未观察到这些峰。我们对吸光度变化和频率偏移的分析进一步表明，压力分别是导致Ala 5的PPII → β构象变化和Ala 6的PPII →分子间β-折叠结构变化的原因。这些结果表明，与Ala 6相比，Ala 5在高压下具有不同的构象稳定性。
Short alanine (Ala) oligopeptides in aqueous solution adopt polyproline II [PPII; (φ,ψ) = (−60°, 150°)] and extendedβconformations [(φ,ψ) = (−150°, 150°)], whose conformers are related to the denatured state of proteins. In this study, we investigated pressure-induced conformational changes of penta- and hexa-alanines (Ala5and Ala6, respectively) in aqueous solutions using Fourier-transform infrared (FTIR) spectroscopy. A remarkable observation was that two peaks at 1620 and 1690 cm−1in Ala6assigned to the intermolecular β-sheets were generated with increasing pressure. These peaks were not observed in Ala5. Our analyses of absorbance changes and frequency shifts further suggested that pressure was responsible for the PPII → β conformational change of Ala5, and the PPII → intermolecular β-sheet structure of Ala6, respectively. These results indicated a differing conformational stability of Ala5under high pressure as compared with Ala6.