球状蛋白质分子中氨基酸紧密接触对性质的研究

采用CSU软件 (Contactsofstructuralunits) ,对 61种球状蛋白质分子中氨基酸紧密接触对 (Residue residuecontact)进行了研究 .重点研究了不同氨基酸在形成远程紧密接触对 (Long rangecontact)和近程紧密接触对 (Short rangecontact)时的不同能力 .发现氨基酸Leu,Val,Ile,Met,Phe,Tyr,Cys,Trp(疏性氨基酸 ,H)比较容易形成远程紧密接触对 ,氨基酸Glu,Gln ,Asp ,Asn,Lys,Ser,Arg,Pro(亲水氨基酸 ,P)比较难形成远程紧密接触对 ,而氨基酸Ala,Gly,Thr,His(中性氨基酸 ,N)在形成远程紧密接触对时能力一般 .它们平均每个氨基酸可形成 6 0 3 ,3 64和 4 43个远程紧密接触对 .同时它们在形成近程紧密接触对时能力非常接近 ,平均每个氨基酸可形成的近程紧密接触对数目在 2 3 4～ 2 85变化 ,差别非常小 .亲水氨基酸 (P) ,中性氨基酸 (N)和疏水性氨基酸 (H)在蛋白质分子结构稳定性上起着不同的作用

A STUDY OF RESIDUE-RESIDUE CONTACTS IN GLOBULAR PROTEIN MOLECULES

The residue\|residue contacts in 61 globular protein molecules were studied by using CSU software. The aim is to find the ability of forming the short\|range and long\|range residue\|residue contacts for several residues. It is found that it is easy to form the long\|range residue\|residue contacts for Leu, Val, Ile, Met, Phe, Tyr, Cys, Trp residues, and it is difficult to form the long\|range residue\|residue contacts for Glu, Gln, Asp, Asn, Lys, Ser, Arg, Pro residues.The residuce are called residues hydrophobic (H) and hydrophilic (P) residues, respectively, and the other residues is called neutral residue (N). The average number of long\|range contacts per residue is 6\^03, 4\^43 and 3\^64 for H, N and P residues respectively. However, the average number of short\|range contacts per residue ranges from 2\^34 to 2\^85, and it is almost no difference among those residues in forming the short\|range contacts. Our research may provide some insights into the stability and folding of protein molecules.