Brocchieri L, Karlin S
Department of Mathematics, Stanford University, CA 94305-2125.
Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9297-301. doi: 10.1073/pnas.91.20.9297.
The relative spatial disposition of interacting side-chain planar groups (aromatic, guanidinium, amide, carboxyl, imidazole) is analyzed for 186 non-homologous well-resolved protein structures. The dihedral angle of amide or carboxyl planar groups with other planar groups accords with a random distribution of planes. By contrast, the dihedral angle of the planes between close aromatic rings or of the histidine ring interacting with aromatic residues is significantly nonrandom, showing an approximately uniform distribution. Our results indicate that edge-to-edge and edge-to-center spatial dispositions of residue planar sections are prevalent, while complete stacking configurations are uncommon. The hypothesis that electrostatic forces are a major determinant of the geometry of interactions between side-chain planar groups is discussed.
对186个非同源且分辨率良好的蛋白质结构，分析了相互作用的侧链平面基团（芳香族、胍基、酰胺基、羧基、咪唑基）的相对空间布局。酰胺基或羧基平面基团与其他平面基团的二面角符合平面的随机分布。相比之下，紧密芳香环之间或与芳香族残基相互作用的组氨酸环平面之间的二面角明显非随机，呈现近似均匀分布。我们的结果表明，残基平面部分的边对边和边对中心空间布局很普遍，而完全堆叠构型并不常见。讨论了静电力是侧链平面基团间相互作用几何结构主要决定因素的假设。
