Viscosity Heterogeneity inside Lipid Bilayers of Single-Component Phosphatidylcholine Liposomes Observed with Picosecond Time-Resolved Fluorescence Spectroscopy
Viscosity Heterogeneity inside Lipid Bilayers of Single-Component Phosphatidylcholine Liposomes Observed with Picosecond Time-Resolved Fluorescence Spectroscopy
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DOI：
10.1021/jp503921e
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发表时间：
2014-07-24
影响因子：
3.3
通讯作者：
Iwata, Koichi
中科院分区：
文献类型：
--
作者：
Nojima, Yuki;Iwata, Koichi
许多生化反应在生物膜内进行。由于化学反应的速率受反应场的化学性质影响，因此检查生物膜或脂质双层膜内的化学性质对于理解生化反应非常重要。在这项研究中，我们估计内的粘度脂质体的脂质双层皮秒时间分辨荧光光谱。反式-芪溶解在由磷脂酰胆碱、DSPC、DOPC、DPPC、DMPC和DLPC（其烷基链中分别具有18、18、16、14和12个碳原子）和卵-PC形成的脂质双层中。脂双层内的粘度估计从光异构化速率常数和从旋转弛豫时间的第一激发单重态的反式-芪。考察了烃链长度和温度对粘度的影响。两个溶剂化环境内的脂质双层的存在下表示从两个独立的估计。一种环境的粘性是另一种环境的30到290倍。甚至单组分脂质双层也可能具有异质结构。
A number of biochemical reactions proceed inside biomembranes. Because the rate of a chemical reaction is influenced by chemical properties of the reaction field, it is important to examine the chemical properties inside the biomembranes, or lipid bilayer membranes, for understanding biochemical reactions. In this study, we estimate viscosity inside the lipid bilayers of liposomes with picosecond time-resolved fluorescence spectroscopy. trans-Stilbene is solubilized in the lipid bilayers formed by phosphatidylcholines, DSPC, DOPC, DPPC, DMPC, and DLPC, with 18, 18, 16, 14, and 12 carbon atoms in their alkyl chains, respectively, and egg-PC. Viscosity inside the lipid bilayer is estimated from the photoisomerization rate constant and from the rotational relaxation time of the first excited singlet state of trans-stilbene. The effect of the hydrocarbon chain length and temperature on viscosity is examined. The presence of two solvation environments within the lipid bilayer is indicated from the two independent estimations. One environment is 30 to 290 times more viscous than the other. Even single-component lipid bilayers are likely to have heterogeneous structures.