Görbitz Carl Henrik
Department of Chemistry, University of Oslo, Norway.
Acta Crystallogr B. 2010 Feb;66(Pt 1):84-93. doi: 10.1107/S0108768109053257. Epub 2010 Jan 22.
The hydrogen-bonding patterns in crystal structures of unprotected, zwitterionic dipeptides are dominated by head-to-tail chains involving the N-terminal amino groups and the C-terminal carboxylate groups. Patterns that include two concomitant chains, thus generating a hydrogen-bonded layer, are of special interest. A comprehensive survey shows that dipeptide structures can conveniently be divided into only four distinct patterns, differing by definition in the symmetry of the head-to-tail chains and amide hydrogen-bonding type, but also in other properties such as peptide conformation and the propensity to include solvent water or various organic guest molecules. Upon crystallization, the choice of pattern for a specific dipeptide is not random, but follows from the amino acid sequence.
未受保护的两性离子二肽晶体结构中的氢键模式主要由涉及N端氨基和C端羧基的头对尾链主导。包含两条相伴链从而形成氢键层的模式尤其令人感兴趣。一项全面的调查表明，二肽结构可以方便地分为仅四种不同的模式，根据定义，它们在头对尾链的对称性和酰胺氢键类型上有所不同，而且在其他性质上也有所不同，如肽构象以及包含溶剂水或各种有机客体分子的倾向。在结晶时，特定二肽的模式选择并非随机，而是由氨基酸序列决定的。
