Interaction of 7-Nitrobenz-2-oxa-1,3-diazol-4-yl-Labeled Fatty Amines with 1-Palmitoyl, 2-Oleoyl-sn-glycero-3-phosphocholine Bilayers: A Molecular Dynamics Study
Interaction of 7-Nitrobenz-2-oxa-1,3-diazol-4-yl-Labeled Fatty Amines with 1-Palmitoyl, 2-Oleoyl-sn-glycero-3-phosphocholine Bilayers: A Molecular Dynamics Study
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DOI：
10.1021/jp203532c
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发表时间：
2011-08-25
影响因子：
3.3
通讯作者：
Loura, Luis M. S.
中科院分区：
文献类型：
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作者：
Filipe, Hugo A. L.;Moreno, Maria Joao;Loura, Luis M. S.
采用原子分子动力学（MD）模拟，研究了插入1-棕榈酰，2-油基-sn-甘油-3-磷脂胆碱（POPC）双分子层的具有不同烷基链长的7-硝基苯-2-氧-1,3-二唑-4-基（NBD）标记的脂肪胺的完整同源序列。对于所有两亲体，NBD荧光团位于POPC的甘油主链/羰基区附近，并与POPC酯氧原子建立稳定的氢键。观察到的荧光团横向位置的微小差异与其他计算参数以及最近在分子的光物理性质中测量到的微小差异相关。长链NBD-C-n两亲体在靠近双分子层中间层的地方表现出明显的质量密度，并且这些衍生物的链在相对的双分子层小叶上有一定程度的交叉。这种现象导致长链衍生物的横向扩散速度较慢（n bbb12）。与酰基链标记的NBD探针相比，这些两亲分子对宿主脂质结构和动力学的影响相对温和。通过这项工作获得的分子细节允许对最近通过实验获得的两亲体的非单调行为进行合理化，包括光物理参数以及它们与POPC膜相互作用的动力学和热力学参数。
A complete homologous series of fluorescent 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)-labeled fatty amines of varying alkyl chain length, NBD-C-n, inserted in 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers, was studied using atomistic molecular dynamics (MD) simulations. For all amphiphiles, the NBD fluorophore locates near the glycerol backbone/carbonyl region of POPC and establishes stable hydrogen bonding with POPC ester oxygen atoms. Small differences observed in the transverse location of the fluorophore correlate with other calculated parameters and with small discrepancies recently measured in the photophysical properties of the molecules. The longer-chained NBD-C-n amphiphiles show significant mass density near the bilayer midplane, and the chains of these derivatives interdigitate to some extent the opposite bilayer leaflet. This phenomenon leads to a slower lateral diffusion for the longer-chained derivatives (n > 12). Effects of these amphiphiles on the structure and dynamics of the host lipid were found to be relatively mild, in comparison with acyl-chain-labeled NBD probes. The molecular details obtained by this work allow the rationalization of the nonmonotonic behavior, recently obtained experimentally, for the photophysical parameters of the amphiphiles and the kinetic and thermodynamic parameters for their interaction with the POPC membranes.