Fraenza Carla C, Anoardo Esteban
Laboratorio de Relaxometría y Técnicas Especiales (LaRTE), Grupo de Resonancia Magnética Nuclear, Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG - CONICET, Ciudad Universitaria X5000HUA, Córdoba, Argentina.
Laboratorio de Relaxometría y Técnicas Especiales (LaRTE), Grupo de Resonancia Magnética Nuclear, Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG - CONICET, Ciudad Universitaria X5000HUA, Córdoba, Argentina.
Biophys Chem. 2017 Sep;228:38-46. doi: 10.1016/j.bpc.2017.06.007. Epub 2017 Jun 27.
We study the molecular dynamics of lipids in binary large unilamellar liposomes suspended in DO composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or soy phosphatidylcholine (SPC) additivated with different percentiles of sodium deoxycholate (SDC). We use the fast field-cycling proton NMR relaxometry technique over a wide timescale and at diverse temperatures. A model previously validated in different formulations is here employed for the relaxometric analysis of elastic vesicles. A new dynamical regime is observed for the first time in additivated DMPC and additivated/non-additivated SPC liposomes. This surprising feature is discussed in terms of vesicle shape fluctuations, enhanced elasticity and lipid & additive diffusion within the membrane. The continuum elastic theory is revisited for a better understanding of recent experiments and those here presented. We address the point of deformability measurements across rigid permeable barriers versus measurements of the bending elastic modulus in free-standing vesicles.
我们研究了悬浮在重水（DO）中的二元大单层脂质体中脂质的分子动力学，这些脂质体由添加了不同百分比脱氧胆酸钠（SDC）的1,2 - 二肉豆蔻酰 - sn - 甘油 - 3 - 磷酸胆碱（DMPC）或大豆磷脂酰胆碱（SPC）组成。我们在很宽的时间尺度和不同温度下使用快速场循环质子核磁共振弛豫测量技术。一个先前在不同配方中得到验证的模型在此用于弹性囊泡的弛豫分析。首次在添加了SDC的DMPC脂质体以及添加了/未添加SDC的SPC脂质体中观察到一种新的动力学状态。从囊泡形状波动、增强的弹性以及膜内脂质和添加剂的扩散方面讨论了这一惊人特征。为了更好地理解近期实验以及本文所展示的实验，我们重新审视了连续弹性理论。我们讨论了跨刚性渗透屏障的可变形性测量与独立囊泡弯曲弹性模量测量的问题。
