NEUTRON-DIFFRACTION STUDIES ON SELECTIVELY DEUTERATED PHOSPHOLIPID BILAYERS
NEUTRON-DIFFRACTION STUDIES ON SELECTIVELY DEUTERATED PHOSPHOLIPID BILAYERS
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DOI：
10.1038/271182a0
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发表时间：
1978-01-01
期刊：
影响因子：
64.8
通讯作者：
SEELIG, J
中科院分区：
文献类型：
--
作者：
BULDT, G;GALLY, HU;SEELIG, J
中子衍射与选择性氘化脂质的使用相结合可以提供有关膜分子结构的详细信息。由于氢（-3.74费米）和氘（6.67费米）的相干散射长度之间存在巨大差异，氘化膜片段在中子密度分布中显示为强烈的峰值，因此可以很容易地在膜中定位1-3。我们已将此方法应用于 1,2-二棕榈酰-sn-甘油-3-磷酸胆碱 (DPPC) 双层膜，在极性头基和烃链的 12 个不同位置选择性氘化。我们在此报告，在大多数情况下，可以以优于±1 Å的精度确定膜内氘化片段的平均位置。凝胶态和液晶态的磷酸胆碱基团的平均取向几乎平行于膜表面。在凝胶状态下，两条烃链的步调不一致，约为 1.8 Å，水会渗透至脂质分子的甘油主链。
NEUTRON diffraction combined with the use of selectively deuterated lipids can provide detailed information on the molecular structure of membranes. Because of the large difference between the coherent scattering length of hydrogen ( −3.74 fermis) and deuterium (6.67 fermis) the deuterated membrane segments show up as intense peaks in the neutron density profile and can thus easily be located in the membrane1–3. We have applied this method to bilayer membranes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), selectively deuterated at 12 different positions in the polar head group and the hydrocarbon chains. We report here that the mean position of the deuterated segments within the membrane can be determined in most cases to a precision of better than ±1 Å. The average orientation of the phosphocholine group in the gel state as well as in the liquid crystalline state is almost parallel to the membrane surface. In the gel state the two hydrocarbon chains are out of step by about 1.8 Å, and water penetrates up to the glycerol backbone of the lipid molecules.