Lateral diffusion in phospholipid multibilayers measured by fluorescence recovery after photobleaching.
Lateral diffusion in phospholipid multibilayers measured by fluorescence recovery after photobleaching.
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通过光漂白后的荧光恢复测量磷脂多层的横向扩散。
DOI：
10.1021/bi00636a034
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发表时间：
1977
期刊：
影响因子：
2.9
通讯作者：
Demetrios Papahadjopoulos
中科院分区：
文献类型：
--
作者：
Enshinn Wu;Ken Jacobson;Demetrios Papahadjopoulos
用光漂白后的荧光恢复法测量了两种荧光类脂类似物在不同组成的磷脂多层膜中的横向扩散系数(D)与温度的关系。所用探针为3，3-二十八烷氧基碳菁(Dio-C18(3))和N-4-硝基-2-氧杂-1，3-二氮唑磷脂酰乙醇胺(NBD-PE)。在25℃的液体卵磷脂多层膜中，NbD-PE的D约为4×10(-8)cm~2/S，Dio-C18(3)的D约为1.5×10(-7)cm~2/S，并且具有中等的温度依赖性(在10℃以上变化2倍)。在这些多层膜中，等摩尔胆固醇使NbD-PE的D降低了2倍。在约23℃时，二肉豆蔻基磷脂酰胆碱多层膜的D降低了100多倍，这与凝胶到液晶的转变温度Tm一致(T大于Tm时D为5×10(-8)cm~2/S，T小于Tm时D小于5×10(-10)cm~2/S)。等摩尔胆固醇取消了这种转变行为，将D提高到TM以下，将D降低到TM以上。这些结果证实和扩展了以前使用磁共振和其他光学技术进行的侧向扩散的研究，并增加了对荧光方法的信心。
The method of fluorescence recovery after photobleaching has been used to measure the temperature dependence of the lateral diffusion coefficients (D) of two fluorescent lipid analogues in phospholipid multibilayers of various compositions. The probes employed were 3,3-dioctadecyloxocarbocyanine (diO-C18(3) and N-4-nitrobenz-2-oxa-1,3-diazole phosphatidylethanolamine (NBD-PE). In fluid egg phosphatidylcholine multibilayers at 25 degrees C, D was about 4 X 10(-8) cm2/s for NBD-PE and 1.5 X 10(-7) cm2/s for diO-C18(3) and was moderately temperature dependent (2-fold change over 10 degrees C). Equimolar cholesterol reduced D for NBD-PE in these multibilayers by a factor of 2. A greater than 100-fold decrease in D was detected in dimyristoylphosphatidylcholine multibilayers at approximately 23 degree C, which coincides with the gel-to-liquid-crystalline transition temperature, Tm (D 5 X 10(-8) cm2/s at T greater than Tm to D less than 5 X 10(-10) cm2/s at T less than Tm). Equimolar cholesterol abolished this transition behavior, raising D below Tm and decreasing D above Tm. These results confirm and extend previous studies of lateral diffusion employing magnetic resonance and other optical techniques and give additional confidence in the fluorescence methods.