Engel A K, Cowburn D
Rockefeller University, New York, New York 10021.
J Biomol Struct Dyn. 1983 Oct;1(1):319-35. doi: 10.1080/07391102.1983.10507442.
Deuterium NMR has been widely used to investigate flexibility in phospholipids. Usually, the measured deuterium quadrupolar couplings are directly related to segmental motion via a single Saupe order parameter. A more complete description avoiding assumptions concerning orientation and modes of motion can be obtained from five order parameters for a particular segment. Employing this approach, we present experimental NMR measurements using isotopic isomers of dipalmitoyl phosphatidyl choline in bilayer dispersions for the two stereospecific deuterium quadrupole couplings, the carbon-proton dipole couplings, and, preliminarily, the proton-proton dipole couplings, for the C-2 methylene segment of the sn-2 chain of dipalmitoyl phosphatidyl choline. In addition, we discuss the relation of these couplings to the significant order parameters, and calculate tentative orientations of the sn-2 alpha methylene segment.
氘核磁共振已被广泛用于研究磷脂的灵活性。通常，测得的氘四极耦合通过单个索普序参数与片段运动直接相关。对于特定片段，可以从五个序参数获得更完整的描述，而无需对取向和运动模式做假设。采用这种方法，我们展示了在双层分散体中使用二棕榈酰磷脂酰胆碱的同位素异构体进行的实验核磁共振测量，测量对象包括二棕榈酰磷脂酰胆碱sn-2链C-2亚甲基片段的两个立体专一性氘四极耦合、碳-质子偶极耦合以及初步的质子-质子偶极耦合。此外，我们讨论了这些耦合与重要序参数的关系，并计算了sn-2α亚甲基片段的暂定取向。
