Na^+在环八肽纳米管中的传输  

Na^+ Transport in Cyclic Octa-Peptide Nanotube

作　　者：李敬[1] 程杰[1] 

机构地区：[1]华侨大学化工学院,福建厦门361021

出　　处：《华侨大学学报（自然科学版）》2014年第4期419-423,共5页Journal of Huaqiao University(Natural Science)

摘　　要：为了探究环肽纳米管介导离子和小分子物质的跨膜转运机制,以环八肽纳米管中Na+为模型,采用拉伸分子动力学方法,研究了Na+在自组装环八肽纳米管{cyclo[-(D-Ala-L-Ala-)4-]}10中的传输.Na+沿纳米管轴向拉力作用方向运动,在每个环平面波动较长时间,占据环中心位置,然后迅速通过环间,跃迁到下一环平面.研究结果表明:Na+以跳跃方式在环肽纳米管中传输的平均速度为0.837m·s-1,其中在环平面的传输速度几乎为0,而在环间的瞬时传输速度可达350.8m·s-1,平均传输速度为111.8m·s-1.Na+在环肽纳米管内的环平面内受到阻力作用,在环间受到拉力作用.In order to explore the mechanisms of cyclic peptide nanotube-mediated transmembrane transport of ions and small molecules, Na＋ constrained in cyclic octa-peptide nanotube was selected as the model to investigate Na＋ transport in the self-organized {cyclo[-（D-Ala-L-Ala-）4-]}10 peptide nanotube using steered molecular dynamics （SMD）. Na＋ moves along the pulling force direction which is parallel to the channel axis, and vibrates up and down at the center of every ring plane for a long time, then quickly jumps through the inter-ring to the next ring plane. The results show that in the jumping way Na＋ transport through cyclic octa-peptide nanotube, the average transport rate is 0. 837 m· s-1 ; the speed is almost zero at ring plane; while the instantaneous speed is up to 350. 8 m· s-1 and the average rate is 111.8 m· s-1 be- tween the middle planes. The force exerted on Na＋ appears to be the resistance force at the ring plane and the pulling force between neighboring rings.

关 键 词：环肽纳米管 跨膜离子通道 拉伸动力学 分子模拟 传输 

分 类 号：TQ460.1[化学工程—制药化工]