Completely geometrically optimized DFT/ONIOM triple-helical collagen-like structures containing the ProProGly, ProProAla, ProProDAla, and ProProDSer triads
Completely geometrically optimized DFT/ONIOM triple-helical collagen-like structures containing the ProProGly, ProProAla, ProProDAla, and ProProDSer triads
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DOI：
10.1021/ja053768y
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发表时间：
2005-10-19
影响因子：
15
通讯作者：
Dannenberg, JJ
中科院分区：
文献类型：
--
作者：
Tsai, M;Xu, YJ;Dannenberg, JJ
我们报告完全优化ONIOM DFT/AM 1分子轨道计算几个胶原样三重螺旋的基础上重复的三重，ProProGly。胶原蛋白中每隔三个氨基酸需要Gly，这可归因于其对映体性质，因为其在胶原蛋白中表现为α D氨基酸。因此，我们探索了相关的胶原样三重螺旋，其中一个中心Gly突变为LorDAla; L-Ala明显不稳定，而D-Ala稍微稳定三重螺旋结构。相同的Gly突变为DSer，即简单的DAla，其中一个甲基H被OH取代，由于在该OH和相邻肽链上的CO之间形成了额外的H-键，因此诱导了更大的稳定性。能量的三重螺旋和它们的组件链（优化和扭曲的三重螺旋几何形状）相对于组件氨基酸。相对能量的变化与选定的参考划定。
We report completely optimized ONIOM DFT/AM1 molecular orbital calculations on several collagen-like triple helices based upon the repeating triad, ProProGly. The requirement of Gly as every third amino acid in collagen can be attributed to its enantiomorphic nature, as it behaves as aDamino acid in collagen. We, therefore, explored related collagen-like triple helices with one of the central Gly's mutated to eitherLorDAla; l-Ala appreciably destabilizes, while d-Ala slightly stabilizes the triple helical structure. Mutation of the same Gly toDSer, which is simplyDAla with an OH in place of one of the methyl H's, induces a much greater stabilization due to an additional H-bond formed between this OH and a CO on an adjacent peptide strand. Energies are presented for the triple helices and their component strands (both optimized and distorted to their triple helical geometries) relative to the component amino acids. The variation of relative energies with the chosen reference is delineated.