摘要
采用完全计数法,研究了二维紧密蛋白质链在不同HP序列时的构象性质,特别是具有唯一基态能量的折叠序列的性质.对于具有N个单体的紧密蛋白质链,发现有一定比例的序列为折叠序列.在这些折叠序列中,疏水基团(H)的数目比亲水基团(P)多20%,并同200种真实蛋白质分子的疏水基团和亲水基团的结果进行了比较.对于不同的折叠序列,根据序列中其疏水基团的数目,把具有相同疏水基团数目的序列归在同一类,发现这样的序列在总的序列中的相对含量满足高斯分布.同时还对序列中H(或者P)团族大小及其分别进行了研究,发现折叠序列与无规随机序列不同.还研究了不同折叠序列在不同链长时的比热情况,发现其相转变温度TC主要与链长有关,与折叠序列无关.
Statistical properties of folding sequences of two-dimensional compact protein were investigated by using the enumeration calculation method. The number of folding sequences, SN, may be expressed as SN∝2N , Here 2^N means the total number of sequences for N-monomer compact chains. For folding sequences, HH/Np≈1. 197, here NH and Np represent the total number of hydrophobic（H） and hydrophilic（P） groups in all folding sequences. Comparisons with real proteins were also made. Distributions of folding sequences in all sequences according to thenumber of hydrophobic amino acid residues were investigated, and they had the form of the Gaussion distribution. The cluster size and its distributions were also studied, and there existed a difference between folding sequences and random sequences. The coil-to-globule transition temperature Tc , estimated from the location of the peak on the heat capacity, depended on the chain length and was almost sequence independent.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2005年第4期540-543,共4页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号20174036
20274040)
浙江省自然科学基金(基金号R404047)资助项目
