A dimerization model for the concentration dependent photophysical properties of diphenylhexatriene and its phospholipid derivatives. DPHpPC and DPHpPA.
A dimerization model for the concentration dependent photophysical properties of diphenylhexatriene and its phospholipid derivatives. DPHpPC and DPHpPA.
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DOI：
10.1016/s0006-3495(89)82720-1
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发表时间：
1989-10
影响因子：
3.4
通讯作者：
B. Lentz;S. W. Burgess
中科院分区：
文献类型：
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作者：
B. Lentz;S. W. Burgess
我们研究了1，6-二苯基-1，3，5-己三烯（DPH）及其磷脂衍生物1-棕榈酰-2-[2-[4-（2-甲基-2-苯基）-2-甲基-2-甲基-2-苯基]-1，3，5-己三烯（DPH）的荧光激发态寿命敏感的原因。（6-苯基-反式-1，3，5-己三烯基）苯基]乙基）羰基）-3-sn-磷脂酰胆碱（DPHpPC）和1-棕榈酰-2-[2-[4-（6-苯基-反式-1，3，5-己三烯基）苯基]乙基）羰基）-3-sn-磷脂酸（DPHpPA），这些探针在二棕榈酰磷脂酰胆碱（DPPC）多层膜中的浓度（巴罗，D.一、和B。R.伦茨，1985年。Biophys. J. 48：221-234; Parente，R.一、和B。R.伦茨1985.生物化学。24：6178-6185）。我们已经解释了自猝灭数据，激发和发射光谱，相位和调制寿命数据方面的一个模型，设想这些探针在膜双层二聚化。有人建议，二聚化改变的DPH激发态的对称性，以便允许更快的衰减通过通常的不允许的路线从1Ag* 状态。全球分析的荧光相移和调制比数据DPHpPC的二聚化模型提供了一个很好的拟合这些数据作为调制频率和探针浓度的函数。对带电磷脂DPHpPA的一组类似数据的全局分析预测，该探针比不带电的DPHpPC更不容易二聚化。这一物理上合理的结果为我们模型开发中的假设提供了支持。我们的结论是，二聚模型允许合理化的许多异常的物理性质的DPH及其衍生物在膜。
We have investigated the reason for the sensitivity of the fluorescence excited-state lifetime of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its phospholipid derivatives, 1-palmitoyl-2-[2-[4-(6-phenyl-trans-1,3,5- hexatrienyl)phenyl]ethyl)carbonyl)-3-sn-phosphatidylcholine (DPHpPC) and 1-palmitoyl-2-[2-[4-(6-phenyl-trans-1,3,5- hexatrienyl)phenyl]ethyl)carbonyl)-3-sn-phosphatidic acid (DPHpPA), to the concentration of these probes in dipalmitoylphosphatidylcholine (DPPC) multilamellar membranes (Barrow, D. A., and B. R. Lentz, 1985. Biophys. J. 48:221–234; Parente, R. A., and B. R. Lentz. 1985. Biochemistry. 24:6178–6185). We have interpreted self-quenching data, excitation and emission spectra, and phase and modulation lifetime data in terms of a model that envisions dimerization of these probes in a membrane bilayer. It is proposed that dimerization alters the symmetry of the DPH excited state so as to allow more rapid decay via the normally symmetry-disallowed route from the 1Ag* state. Global analysis of fluorescence phase shift and modulation ratio data for DPHpPC in terms of the dimerization model provided a good fit of these data as a function of both modulation frequency and probe concentration. Global analysis of a similar set of data for the charged phosphatide DPHpPA predicted that this probe was much less prone to dimerize than was the uncharged DPHpPC. This physically reasonable result provides support for the assumptions made in the development of our model. We conclude that the dimerization model allows rationalization of many of the anomalous photophysical properties of DPH and its derivatives in membranes.