通过核糖及其二聚体对膜的透
1NASA Ames Research Center, Mail Stop 229-1, Moffett Field, California 94035, USA.
Journal of the American Chemical Society
|July 23, 2009
概括
里波斯的穿越细胞膜的速度要比阿拉比诺斯或西洛斯快得多. 分子模拟显示,这是由于核糖的独特的分子内相互作用,有助于生命早期的发展.
科学领域:
- 生物物理学的生物物理.
- 生命的起源 研究 研究 研究
- 计算化学计算化学
背景情况:
- 与其二聚体,阿拉比诺斯和西洛斯相比,利博具有显著更高的膜透性.
- 这种差异表明,一种潜在的机制可以为原始细胞提供偏好的核糖,这对于早期的生化过程至关重要.
- 这些透性差异的潜在分子原因在很大程度上仍然无法解释.
研究的目的:
- 阐明阿尔多托菌的差异膜透性背后的分子机制.
- 研究糖的结构和相互作用在膜运输中的作用.
- 评估对生命起源和对核糖的偏好选择的影响.
主要方法:
- 用分子动力学模拟来建模糖与脂质双层的相互作用.
- 进行了自由能量计算,以量化糖透的能量障碍.
- 计算了水/六甲甘分区系数,以评估疏水性,并与透性相关.
主要成果:
- 通过膜转移核糖的自由能量比阿拉比诺斯或西洛斯低1.5 - 2千卡/mol.
- 计算的透系数与实验数据密切匹配.
- 透主要通过β-pyranose形式发生, furanose形式起到较小的作用.
- 强大的分子内键在核糖中,在非极地环境中稳定,有助于其增强的透性.
结论:
- 阿尔多托的差异性膜透性是由分子内相互作用和构造稳定性的变化解释的.
- 里的独特性质使其在原始膜上有优越的运输.
- 这些发现支持了核糖在生命起源中的中心作用的假设.
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