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采用蒙特卡罗方法和基于三维格点的ODI模型,研究了类蛋白质分子二级结构变化与表面吸附能的关系.分别计算了链长为29,39,49时、不同吸附能下类蛋白质分子二级结构的个数.包括α螺旋、β折叠、紧密接触对.吸附能参数aε<2εh时,这三类二级结构个数均没有明显的变化,而在2εh<εa<4εh,二级结构的个数迅速减小,εa>4hε时,二级结构的个数基本维持不变.同时发现吸附能增强对螺旋结构变化的影响最大,对折叠结构的影响其次,对紧密接触对影响最小.这体现在螺旋结构的减小幅度为90%,折叠结构减小的幅度为45%,而紧密接触对减小的幅度为35%.通过统计吸附单体个数,得到当吸附单体占总单体数的40%时,二级结构开始变化,直至吸附单体为总单体数的90%时,二级结构基本不变.另外还计算了二级结构个数的涨落δNh、δNc以及吸附单体个数的涨落δNa.在εa>2εh时,涨落突然增大,在aε=2εh时,δNh和δNb具有涨落极大值,这是二级结构相变的临界点.在εa=3.75εh处,δNc和δNa具有极大值.
The relationship between the secondary structure of protein-like molecules and the surface adsorption energy was studied by using the Monte Carlo method and ODI model based on three-dimensional lattice points. The number of secondary structures, including α-helix, β-sheet and close-contact pairs, showed no significant change in the number of secondary structure at aε <2εh, while at 2εh <εa <4εh, The number of structure decreases rapidly, the number of secondary structure remains unchanged when εa> 4hε, and the effect of enhanced adsorption energy on the change of spiral structure is found to be the greatest, and the effect on the folded structure is secondly, .This is reflected in the reduction of the helical structure is 90%, the folded structure is reduced by 45%, while the close contact pair is reduced by 35% .According to the number of adsorption monomer, When the total monomer number is 40%, the secondary structure begins to change, and the secondary structure does not change until the monomer is 90% of the total monomer number.In addition, the δNh of the number of secondary structure, δNc, and the number of adsorbed monomers δNa. At εa> 2εh, the fluctuations suddenly increase, When aε = 2εh, δNh and δNb have the maximum of fluctuation, which is the critical point of the secondary structure transformation, and δNc and δNa have the maximum at εa = 3.75εh.