Carbon-13 nuclear magnetic resonance spectroscopy of phospholipids in solution. Spectral and stereochemical assignments based on carbon-13-phosphorus-31 and carbon-13-nitrogen-14 couplings
Carbon-13 nuclear magnetic resonance spectroscopy of phospholipids in solution. Spectral and stereochemical assignments based on carbon-13-phosphorus-31 and carbon-13-nitrogen-14 couplings
复制标题
溶液中磷脂的碳 13 核磁共振波谱。
DOI：
10.1021/jo00132a034
复制
发表时间：
1982
影响因子：
3.6
通讯作者：
W. Baumann
中科院分区：
文献类型：
--
作者：
R. Murari;M. M. El;Y. Wedmid;S. Parthasarathy;W. Baumann
在氯仿-甲醇-水（50：50：15，体积比）中测定了生物化学感兴趣的各种合成和天然磷脂的天然丰度碳-13 NMR光谱。在这种溶剂中，nonaggregation表示由窄共振，由可重复的化学位移，并通过两个键和三个键的碳-磷耦合的一致性，观察到的磷脂含有胆碱，乙醇胺，或溴乙醇头基。胆碱磷脂也显示出明确的13 C-14 N偶联。进一步取代烷基的酰基侧链或二醇的甘油骨架允许明确的分配头基和骨架碳共振。VCp耦合的幅度（平均7.6 Hz）清楚地表明，在溶液中，各种胆碱和乙醇胺磷脂的头基和骨架（C6）的碳（Cb）相对于磷更倾向于反式取向;只有在1，3-二酰基甘油-2-磷酸胆碱中，甘油骨架基本上保持着扭曲构象。观察到的碳-磷和碳-氮耦合和2 JCP和3 t/CP值被证明是分配磷脂的13 C NMR谱中的化学位移的有用标准。碳-13核磁共振（NMR）光谱2通常是确定溶液中复杂生物分子的结构参数、构象和相互作用的选择方法。然而，大多数磷脂，由于其两亲性，通过形成脂质体而抵抗在极性和非极性溶剂中的增溶
Natural-abundance carbon-13 NMR spectra of various synthetic and natural phospholipids of biochemical interest were measured in chloroform-methanol-water (50: 50: 15, by volume). In this solvent, nonaggregation is indicated by narrow resonances, by reproducible chemical shifts, and by the consistency of two-bond and three-bond carbon-phosphorus couplings which were observed for phospholipids containing a choline, ethanolamine, or bromoethanol headgroup. The choline phospholipids also showed well-defined 13C-14N couplings. Further substitution of alkyl for acyl side chains or of diols for the glycerol backbone permitted unequivocal assignment of headgroupand backbone carbon resonances. The magnitude of VCp couplings (averaging 7.6 Hz) clearly demonstrates that the respective carbons (Cb) of theheadgroup and backbone (C6) of a wide range of choline and ethanolamine phospholipids in solution prefer trans orientation relative to the phosphorus; only in 1, 3-diacylglycero-2-phosphocholine, the glycerol backbone remains essentially in gauche conformation. Observation of carbon-phosphorusand carbon-nitrogen couplings and 2JCP and 3t/CP values are shown to be useful criteria in assigning chemical shifts in 13C NMR spectra of phospholipids.Carbon-13 nuclear magnetic resonance(NMR) spec-troscopy2 is often the method of choice for defining structural parameters, conformations, and interactions of complex biomolecules in solution. Yet, most phospho-lipids, due to their amphiphilic nature, resist solubilization in polar as well as nonpolar solvents by forming liposomes