Stidham M A, Siedow J N, McIntosh T J, Porter N A, Moreland D E
Biochim Biophys Acta. 1985 Feb 14;812(3):721-30. doi: 10.1016/0005-2736(85)90266-4.
A number of phenylamide herbicides are observed to uncouple electron transport in isolated chloroplasts and mitochondria and alter the H+ permeability of artificial liposomes. Several of these phenylamides were incorporated into phosphatidylcholine multilamellar and small unilamellar vesicles to measure their effects on the physical properties of membranes. X-ray diffraction analysis of the multilamellar vesicles revealed that the herbicides partitioned into the hydrocarbon chain region of the bilayer, but caused only minimal perturbations on hydrocarbon chain packing. 31P-NMR spectroscopy of these multilamellar vesicles showed both a broadening and lowering of the phase transition temperature of the bilayer lipids upon addition of the herbicides. 13C-NMR spectroscopy of small, unilamellar phosphatidylcholine vesicles was performed to measure the effects of the phenylamides on the chemical shifts and the spin-lattice relaxation times of the individual phosphatidylcholine carbon atoms. None of the added compounds had any measurable effect on the 13C-NMR chemical shifts of the phosphatidylcholine. However, the herbicides significantly modified spin-lattice relaxation times of certain of the lipid carbon atoms. These results generally indicate that the herbicides orient in the lipid bilayers such that the hydrocarbon chains of the phenylamides associate with the hydrocarbon chains of the lipid, whereas the phenyl moiety resides in the polar region of the bilayer.
已观察到多种苯基酰胺类除草剂会使分离的叶绿体和线粒体中的电子传递解偶联，并改变人工脂质体的氢离子通透性。将其中几种苯基酰胺掺入磷脂酰胆碱多层囊泡和小单层囊泡中，以测量它们对膜物理性质的影响。对多层囊泡的X射线衍射分析表明，除草剂分配到双层的烃链区域，但对烃链堆积仅产生最小程度的扰动。对这些多层囊泡进行的31P核磁共振光谱显示，加入除草剂后双层脂质的相变温度变宽且降低。对小单层磷脂酰胆碱囊泡进行13C核磁共振光谱分析，以测量苯基酰胺对各个磷脂酰胆碱碳原子的化学位移和自旋晶格弛豫时间的影响。添加的化合物均未对磷脂酰胆碱的13C核磁共振化学位移产生任何可测量的影响。然而，除草剂显著改变了某些脂质碳原子的自旋晶格弛豫时间。这些结果总体表明，除草剂在脂质双层中取向，使得苯基酰胺的烃链与脂质的烃链缔合，而苯基部分位于双层的极性区域。
