A molecular dynamics study on heat conduction characteristics in DPPC lipid bilayer
A molecular dynamics study on heat conduction characteristics in DPPC lipid bilayer
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DOI：
10.1063/1.3481650
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发表时间：
2010-10-21
影响因子：
4.4
通讯作者：
Ohara, Taku
中科院分区：
文献类型：
--
作者：
Nakano, Takeo;Kikugawa, Gota;Ohara, Taku
本文对单组分1,2-二棕榈酰- n-甘油-3-磷脂酰胆碱脂双分子层进行了非平衡分子动力学模拟，研究了其导热性及其各向异性。为了评估导热性，我们将恒定的热通量应用于脂质双分子层，沿着和穿过带有环境水的膜。并对分子相互作用对热传导的贡献进行了评价。与水分子之间的相互作用相比，在双层平面上脂分子之间的相互作用传递的热能较少。在整个双层平面上，局部热导率取决于占据结构域的成分（即水、脂质分子的头基和尾基）。尽管脂质分子尾部基团的分子内热能传递有效地促进了该区域的高局部导热性，但由于共价键的损失和低数字密度，脂质分子的酰基链相互面对的脂质双分子层中心出现了最高的热阻。对脂质双分子层在平行和垂直于脂质膜方向上的总体导热系数进行了比较，发现向膜方向的导热系数高于沿膜方向的导热系数，但仍小于散装水的导热系数。(C) 2010年美国物理研究所。(doi: 10.1063/1.3481650)
In this paper, nonequilibrium molecular dynamics simulations were performed on a single component 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine lipid bilayer in order to investigate the thermal conductivity and its anisotropy. To evaluate the thermal conductivity, we applied a constant heat flux to the lipid bilayer along and across the membrane with ambient water. The contribution of molecular interaction to the heat conduction was also evaluated. Along the bilayer plane, there is little transfer of thermal energy by the interaction between lipid molecules as compared with the interaction between water molecules. Across the bilayer plane, the local thermal conductivity depends on the constituents (i.e., water, head group, and tail group of lipid molecule) that occupy the domain. Although the intramolecular transfer of thermal energy in the tail groups of lipid molecules works efficiently to promote high local thermal conductivity in this region, the highest thermal resistance appears at the center of lipid bilayer where acyl chains of lipid molecules face each other due to a loss of covalent-bond and low number density. The overall thermal conductivities of the lipid bilayer in the directions parallel and perpendicular to the lipid membrane have been compared, and it was found that the thermal conductivity normal to the membrane is higher than that along the membrane, but it is still smaller than that of bulk water. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3481650]