Bunow M R, Levin I W
Biochim Biophys Acta. 1977 Nov 24;489(2):191-206. doi: 10.1016/0005-2760(77)90138-2.
Vibrational Raman spectra of polycrystalline 1,2-dipalmitoyl phosphatidylcholine-d9 (fully deuterated choline methyl groups) and 1,2-dipalmitoyl phosphatidylcholine-d62 (fully deuterated acyl chains) were recorded in the 3050- 2800, 2250-2050 and 1800-700 cm-1 regions. The fundamental vibrational modes were assigned primarily on the basis of isotopic frequency shift ratios, group frequency correlations and comparisons with specific model compounds. Since deuterium-substituted lipids provide well-isolated spectral probes, particularly in the carbon-deuterium stretching region, the dependence of the 2250-2050 cm-1 region on lipid phase was examined for the dipalmitoyl phosphatidylcholine-d62 species. The methylene CD2 deformation and twisting modes at 984 and 919 cm-1, respectively, also exhibit intense, isolated vibrational transitions which should prove useful for monitoring molecular order in mixed dueterated and undeuterated lipid systems. Except for the relatively weak choline methyl C-D and C-H stretching modes, the spectrum of 1,2-dipalmitoyl phosphatidylcholine-d9 is not distinguishable from that of the undeuterated system. For both the d9 and undeuterated species, the vibrational modes associated with the lipid head group region are sensitive to slight hydration.
记录了多晶态1,2 - 二棕榈酰磷脂酰胆碱 - d9（胆碱甲基完全氘代）和1,2 - 二棕榈酰磷脂酰胆碱 - d62（酰基链完全氘代）在3050 - 2800、2250 - 2050和1800 - 700 cm-1区域的振动拉曼光谱。基本振动模式主要基于同位素频移比、基团频率相关性以及与特定模型化合物的比较来进行归属。由于氘取代的脂质提供了隔离良好的光谱探针，特别是在碳 - 氘伸缩区域，因此针对1,2 - 二棕榈酰磷脂酰胆碱 - d62物种研究了2250 - 2050 cm-1区域对脂质相的依赖性。分别位于984和919 cm-1处的亚甲基CD2变形和扭曲模式也表现出强烈、孤立的振动跃迁，这对于监测混合氘代和未氘代脂质体系中的分子有序性应是有用的。除了相对较弱的胆碱甲基C - D和C - H伸缩模式外，1,2 - 二棕榈酰磷脂酰胆碱 - d9的光谱与未氘代体系的光谱无法区分。对于d9和未氘代的物种，与脂质头部基团区域相关的振动模式对轻微水合作用敏感。
