Lakowicz J R, Prendergast F G
Science. 1978 Jun 23;200(4348):1399-401. doi: 10.1126/science.663620.
Diffusional motions of 1,6-diphenyl-1, 3, 5-hexatriene (DPH) were observed by differential polarized phase fluorometry. The measurements indicated that the depolarizing rotations of DPH in propylene glycol are isotropic. The results in vesicles of dimyristoyl-l-alpha-phosphatidylcholine indicated that diffusional rotations of DPH are dominated by hindered torsional motions. Combined use of both differential phase and steady-state anisotropy measurements showed that the average rotational angle of DPH, at times long compared to the fluorescence lifetime, is limited to about 23 degrees at temperatures below the transition temperature of the lipid and that these rotations become less hindered above the transition temperature. The evidence that the depolarizing rotations of DPH in a lipid bilayer are different from those in an isotropic solvent calls into question the meaning of membrane microviscosity as determined by fluorescence anisotropy.
通过差示偏振相荧光法观察了1,6 - 二苯基 - 1,3,5 - 己三烯(DPH)的扩散运动。测量结果表明,DPH在丙二醇中的去偏振旋转是各向同性的。在二肉豆蔻酰 - l - α - 磷脂酰胆碱囊泡中的结果表明,DPH的扩散旋转受受阻扭转运动支配。差示相测量和稳态各向异性测量的联合使用表明,与荧光寿命相比时间较长时,DPH的平均旋转角度在低于脂质转变温度的温度下限制在约23度,并且在转变温度以上这些旋转的受阻程度变小。DPH在脂质双层中的去偏振旋转与在各向同性溶剂中的不同,这一证据对通过荧光各向异性测定的膜微粘度的意义提出了质疑。