Fluorescence depolarization measurements on oriented membranes.
Fluorescence depolarization measurements on oriented membranes.
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DOI：
10.1016/s0006-3495(88)83179-5
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发表时间：
1988-06
影响因子：
3.4
通讯作者：
Marc Adler;Thomas R. TRIrrON
中科院分区：
文献类型：
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作者：
Marc Adler;Thomas R. TRIrrON
我们描述了荧光去偏振测量的理论和实验应用的小分子结合取向磷脂双层。结果产生洞察的方向和旋转运动的荧光团在膜环境中。为了实现这一点，偏振荧光强度的角分布是在由在已知坐标系中取向的堆叠磷脂双层组成的膜制备物上测量的。相当多的信息是从这个数据比可比的溶液相测量。三个参数来自数据：旋转扩散率和第二和第四度阶参数。后两个参数提供了膜双层中荧光团取向的平均分布的评估。数据已被仔细检查系统的实验文物和新的协议，这有助于消除在过去没有得到充分处理的错误。我们目前的数据为两种类型的荧光分子：（a）传统的膜探针，如二苯基己三烯，二萘嵌苯和anthrooxy脂肪酸;和（B）抗癌剂阿霉素和几个同类蒽环类抗生素。结果表明，膜的烃核心比以前认为的更刚性，特别是在热相变温度以上。我们还表明，小分子的取向是敏感的磷脂组合物和特定的功能基团与脂质双层的相互作用。结果进行了讨论，在充满活力的模型描述的小分子生物膜的结合的一般模式。
We describe the theory and experimental application of fluorescence depolarization measurements on small molecules bound to oriented phospholipid bilayers. The results yield insight into both the orientation and the rotational motion of fluorophores in a membrane environment. To accomplish this the angular distribution of polarized fluorescence intensities is measured on a membrane preparation consisting of stacked phospholipid bilayers oriented in a known coordinate system. Considerably more information is available from this data than in comparable solution phase measurements. Three parameters are derived from the data: the rate of rotational diffusion and the second and fourth degree order parameters. These latter two parameters provide an assessment of the average distribution of fluorophore orientation in the membrane bilayer. The data have been carefully examined for systematic experimental artifacts and new protocols are presented which help to eliminate errors that have not been amply treated in the past. We present data for two types of fluorescent molecules: (a) conventional membrane probes like diphenylhexatriene, perylene and anthroyloxy fatty acids; and (b) the anticancer agent adriamycin and several congeneric anthracycline antibiotics. The results show that the hydrocarbon core of membranes is more rigid than previously thought, particularly above the thermal phase transition temperature. We also show that the orientation of small molecules is sensitive to both the phospholipid composition and to the interaction of specific functional groups with the lipid bilayer. The results are discussed in terms of energetic models describing the general patterns for the binding of small molecules to biological membranes.