不同螺旋结构类蛋白质分子管道传输动力学研究  

DYNAMICS OF DIFFERENT HELICAL PROTEIN-LIKE CHAINS TRANSLOCATING THROUGH A CYLINDRICAL CHANNEL

作　　者：孙婷婷[1] 姜舟婷[2] 

机构地区：[1]浙江工商大学信息与电子工程学院,杭州310018 [2]中国计量学院理学院,杭州310018

出　　处：《高分子学报》2013年第8期1058-1063,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20904047;21204078);浙江省自然科学基金(基金号LY12B04003;Y6110304);浙江省科技厅钱江人才项目(项目号2010R10022)

摘　　要：采用动态蒙特卡洛模拟(Dynamical Monte Carlo,DMC)对不同螺旋结构的类蛋白质分子穿越管道的动力学过程进行了研究.计算了不同螺旋能参数下类蛋白质链的传输时间,传输成功率,管道内单体数目<nin>,形状因子<δ>,均方位移g等.结果发现螺旋能较小的链传输时间较短,变化不明显,而螺旋能较大的链随着螺旋能的增强传输时间迅速增大.计算表明相同类型的分子链其传输成功率随着电场的增大而减小.而对于不同螺旋结构的链,螺旋能参数εh=0的链传输成功率最大,达到80%左右,略小于自避链;而εh=-0.5的类蛋白质链传输成功率突然减小.随着螺旋能的增强,传输成功率又开始增大.另外<nin>的计算表明自避链的传输过程比类蛋白质链平稳.<δ>在传输过程中的变化都存在了最大值,说明链在传输时有一个最松散的构象.对于均方位移的计算得到εh=0的链均方位移变化最快,说明传输过程中扩散最快.同时发现εh=-3.0的链比εh=-1.5的链均方位移扩散快.形状因子和均方位移的趋势均能很好的解释不同螺旋参数下的类蛋白质链不同的传输性质.这些研究对生物大分子的输运行为有一定的指导意义.The dynamics of different helical protein-like chains translocating through a channel has been studied by Dynamical Monte Carlo(DMC) simulation.Translocation time,translocation probability,the number of monomers inside channel <nin>,shape factor <δ> and mean-square displacement of center of mass g are discussed.It is shown translocation time of protein-like chain with small helical energy is short,and changes little.However,for chains of large helical energy,the translocation time quickly increases when εh becomes stronger.The results show that the translocation probability is smaller as the electric field becomes stronger.For different helical chains the translocation probability of εh=0 is the largest,about 80%,smaller than that of SAW chain.But it suddently drops for εh=-0.5.Then the translocation probability increases again as the helical energy becomes stronger.Furthermore,the curve of <nin> shows the translocation process of SAW chains is more steady than that of protein-like chains.The maximum value in the curves of <δ> suggests there exists the loosest conformation during translocation.Another discussion about the mean-square displacement of center of mass g shows that g of εh=0 changes faster than others.It shows diffusion of εh=0 is the fastest.It is also observed that the value g of εh=-3.0 changes faster than that of εh=-1.5.The discussion of shape factor and mean-sqare displacement can explain the different properties of different helical protein-like chains.All these studies will be useful for the complex translocation behaviors of macromolecules.

关 键 词：动态蒙特卡洛(DMC) 类蛋白质分子 螺旋结构 

分 类 号：O643.1[理学—物理化学]