ELECTRON ELECTRON DOUBLE-RESONANCE AND SATURATION-RECOVERY STUDIES OF NITROXIDE ELECTRON AND NUCLEAR-SPIN-LATTICE RELAXATION-TIMES AND HEISENBERG EXCHANGE-RATES - LATERAL DIFFUSION IN DIMYRISTOYL PHOSPHATIDYLCHOLINE
ELECTRON ELECTRON DOUBLE-RESONANCE AND SATURATION-RECOVERY STUDIES OF NITROXIDE ELECTRON AND NUCLEAR-SPIN-LATTICE RELAXATION-TIMES AND HEISENBERG EXCHANGE-RATES - LATERAL DIFFUSION IN DIMYRISTOYL PHOSPHATIDYLCHOLINE
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DOI：
10.1073/pnas.79.8.2559
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
HYDE, JS
中科院分区：
文献类型：
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作者：
POPP, CA;HYDE, JS
本文测定了硬脂酸氮氧自由基自旋标记物2-（14-羧基十四烷基）-2-乙基-4，4-二甲基-3-恶唑啉在二肉豆蔻酰磷脂酰胆碱分散液中的横向扩散常数。电子-电子双共振方法被用来确定双分子碰撞频率和Tle的产品，电子自旋晶格弛豫时间。Tle又通过饱和恢复技术测量。Trauble和Sackmann的理论模型，然后被用来与双分子碰撞频率的扩散常数。结果与其他方法一致。需要比先前EPR研究中使用的自旋标记浓度更低的自旋标记浓度（标记-脂质比< 0.5摩尔%）。数据的分析还产生氮氧部分的氮核自旋-晶格弛豫时间的值。这些值指示膜流动性。
Lateral diffusion constants of the stearic acid nitroxide radical spin label 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolindinyl oxide in dispersions of dimyristoyl phosphatidylcholine were measured. Electron-electron double resonance methods were used to determine the product of the bimolecular collision frequency and Tle, the electron spin-lattice relaxation time. Tle in turn was measured by the technique of saturation recovery. The theoretical model of Trauble and Sackmann was then used to relate the bimolecular collision frequencies to the diffusion constants. Results are in agreement with other methods. Lower spin-label concentrations than were used in previous EPR studies are needed (label-to-lipid ratio < 0.5 mol%). Analysis of the data also yields values of the nitrogen nuclear spin-lattice relaxation time of the nitroxide moiety. These values are indicative of membrane fluidity.