(α/β)_8桶状蛋白质中紧密接触对的统计性质研究  

CONFIGURATION-DEPENDENT PROPERTIES OF CONTACTS IN(α/β)_8 BARREL PROTEINS

作　　者：陈进[1] 成军[1] 姜舟婷[1] 章林溪[1] 赵得禄[2] 

机构地区：[1]浙江大学物理系,杭州310027 [2]中国科学院化学研究所高分子物理及化学国家重点实验室,北京100080

出　　处：《高分子学报》2004年第5期688-692,共5页Acta Polymerica Sinica

基　　金：国家自然科学基金 (基金号 2 98740 2 1;2 0 1740 3 6;2 0 2 740 40 );浙江省自然科学然金 (基金号 10 10 0 2 )资助项目

摘　　要：在计算蛋白质分子中的氨基酸紧密接触对时采用以氨基酸的重心代替Cα 原子的新方法 ,通过计算(α/β) 8桶状蛋白质中的中程和远程紧密接触对的数目 ,研究了不同氨基酸在形成紧密接触对时所具有的不同能力以及在蛋白质结构稳定性中所起的不同作用 .发现在 (α β) 8桶状蛋白质中氨基酸形成的远程紧密接触对数目与它的Fauchere Pliska疏水性实验数值 (FPH)存在着非常好的线性关系 ,而对于氨基酸所形成的中程紧密接触对数目不存在这种关系 .同时还研究了 (α β) 8桶状蛋白质分子大小 ,发现其回转半径大小与表示远程接触对数目的远程次序值LRO存在着关系 .表明这一类 (α β) 8桶状蛋白质具有相似的结构 ,分子的远程接触对数目越多 ,分子越紧密 ,分子尺寸就越小 .同时还研究了不同氨基酸之间形成紧密接触对的能力 .The residue-residue contacts contribute more function to the protein folding and play an active role in the stability of proteins.We calculate the number of medium- and long-range contacts for 90 (α/β) 8 barrel proteins with considering the distance between the centers of two residues in defining residue-residue contacts.The ability to forming contacts in each(α/β) 8 barrel protein was discussed through calculating the number of long- and medium-ranges contacts for different residues in proteins.The relationship between the average numbers of medium-and long-range contacts with Fauchere-Pliska hydrophobicity value (FPH) for 20 amino acid residues was studied,and it was found that the average number of long-range contacts had a linear relation with the Fauchere-Pliska hydrophobicity value (FPH),however,it had not valid for medium-range contacts.The dimension of (α/β) 8 barrel proteins has a good relation to the long-range contact of proteins,and the characteristic ratio of mean-square radius of gyration <S2>an be expressed as〈S2〉/N=a′+b′×LRO;where LRO is the long-range order,N is the number of residues,and a′=2.32,b′=-0.131.When a protein has a large LRO value,the structure is compact and it has a small dimension value.These investigations can provide some insights into structure of (α/β) 8 the barrel proteins.

关 键 词：(α/β)8桶状蛋白质 氨基酸 紧密接触对 远程次序值 Fauchere—Pliska疏水性值 

分 类 号：O629[理学—有机化学]