Laboratorio de Relaxometría y Técnicas Especiales, Grupo de Resonancia Magnética Nuclear, Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG (CONICET), Córdoba (Argentina).
Chemphyschem. 2014 Feb 24;15(3):425-35. doi: 10.1002/cphc.201301051. Epub 2014 Jan 31.
The general applicability of fast field-cycling nuclear magnetic resonance relaxometry in the study of dynamics in lipid bilayers is demonstrated through analysis of binary unilamellar liposomes composed of 1,2-dioleoyl-sn-glycero-3-posphocholine (DOPC) and cholesterol. We extend an evidence-based method to simulating the NMR relaxation response, previously validated for single-component membranes, to evaluate the effect of the sterol molecule on local ordering and dynamics over multiple timescales. The relaxometric results are found to be most consistent with the partitioning of the lipid molecules into affected and unaffected portions, rather than a single averaged phase. Our analysis suggests that up to 25 mol%, each cholesterol molecule orders three DOPC molecules, providing experimental backup to the findings of many molecular dynamics studies. A methodology is established for studying dynamics on multiple timescales in unilamellar membranes of more complex compositions.
通过分析由 1,2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）和胆固醇组成的二元单层脂质体，证明了快速场频核磁共振弛豫法在脂质双层动力学研究中的普遍适用性。我们扩展了一种基于证据的模拟 NMR 弛豫响应的方法，该方法先前已针对单一组分膜进行了验证，以评估甾醇分子对多个时间尺度上局部有序性和动力学的影响。弛豫测量结果与脂质分子分配到受影响和未受影响部分的情况最为一致，而不是单一的平均相。我们的分析表明，每个胆固醇分子最多可以使 25mol%的 DOPC 分子有序化，为许多分子动力学研究的发现提供了实验依据。建立了一种在更复杂组成的单层膜中研究多个时间尺度动力学的方法。
