Murgia Sergio, Lampis Sandrina, Angius Rossella, Berti Debora, Monduzzi Maura
Dipartimento di Scienze Chimiche, Cagliari University and CSGI, SS 554 Bivio Sestu, 09042 Monserrato (CA), Italy.
J Phys Chem B. 2009 Jul 9;113(27):9205-15. doi: 10.1021/jp9035474.
The entrapment of AMP, GMP, CMP, and UMP nucleotides along with two different AMP-based nucleolipids (hydrophobically functionalized nucleotides) inside the liquid crystalline phases of the monoolein/water system is investigated through optical microscopy, small-angle X-ray diffraction (SAXRD), and nuclear magnetic resonance (NMR) techniques. As ascertained mainly through (31)P NMR experiments, when included within the cubic phase, the various nucleotides undergo a slow hydrolysis of the sugar-phosphate ester bond, induced by specific interactions at the monoolein-water interface. Upon aging, the degradation of the nucleotides causes a cubic-to-hexagonal phase transition. Differently, neither hydrolysis nor alterations of the monoolein self-assembly are observed when the nucleotides are included as lipid derivatives within the cubic liquid crystalline phase. A model that explains both the hydrolysis and the consequent phase transition is presented.
通过光学显微镜、小角X射线衍射（SAXRD）和核磁共振（NMR）技术，研究了单油酸甘油酯/水体系液晶相中AMP、GMP、CMP和UMP核苷酸以及两种不同的基于AMP的核脂质（疏水功能化核苷酸）的包封情况。主要通过³¹P NMR实验确定，当各种核苷酸包含在立方相中时，由于在单油酸甘油酯-水界面的特定相互作用，糖磷酸酯键会发生缓慢水解。随着时间推移，核苷酸的降解会导致立方相到六方相的转变。不同的是，当核苷酸作为脂质衍生物包含在立方液晶相中时，未观察到单油酸甘油酯自组装的水解或变化。本文提出了一个解释水解及随之发生的相变的模型。
