Anderson W, Burt S, Loew G
Int J Pept Protein Res. 1979;14(5):402-8. doi: 10.1111/j.1399-3011.1979.tb01951.x.
The optimized energies of seven beta-bends, repeating C5 and C7, and right- and left-handed alpha-helical conformations for each of eight tetrapeptides have been computed using empirical methods. Eight tetramers were selected: four helix-forming sequences with hydrophobic residues such as Val, Leu, Ile and Trp, and four helix-breaking sequences with hydrophilic residues such as Asp, Asn and Ser, as determined by their frequency of occurrence in beta turns in proteins. Analysis of the optimized conformations with energies less than or equal to 2.1 kcal/mol from the absolute minimum energy conformer for each tetramer reveals a correlation between low-energy conformations and those predicted from observed protein structures. These results show that energy calculations on small peptide fragments may be usefulin predicting protein structure.
使用经验方法计算了八个四肽中七种β-转角、重复的C5和C7以及右手和左手α-螺旋构象的优化能量。选择了八个四聚体：四个具有疏水残基（如Val、Leu、Ile和Trp）的螺旋形成序列，以及四个具有亲水残基（如Asp、Asn和Ser）的螺旋破坏序列，这是根据它们在蛋白质β-转角中的出现频率确定的。对每个四聚体中能量低于或等于2.1千卡/摩尔（相对于绝对最低能量构象）的优化构象进行分析，结果表明低能量构象与从观察到的蛋白质结构预测的构象之间存在相关性。这些结果表明，对小肽片段进行能量计算可能有助于预测蛋白质结构。
