IMBB/FORTH, 70013 Iraklion, Crete, Greece.
Department of Food Sciences, Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392 Giessen, Germany.
Acta Crystallogr C Struct Chem. 2020 Dec 1;76(Pt 12):1057-1061. doi: 10.1107/S2053229620014254. Epub 2020 Nov 9.
The achiral tetrapeptide monohydrate N-(benzyloxycarbonyl)glycyl-α-aminoisobutyrylglycyl-α-aminoisobutyric acid monohydrate, Z-Gly-Aib-Gly-Aib-OH·HO (Z is benzyloxycarbonyl, Aib is α-aminoisobutyric acid and Gly is glycine) or CHNO·HO, exhibits two conformations related by the symmetry operation of an inversion centre. It adopts only one of two possible intramolecular hydrogen bonds in a type I (and I') β-turn and forms a maximum of intermolecular hydrogen bonds partly mediated by water. The space group, the molecular structure and the crystal packing differ from two already described (Gly-Aib) peptides which vary only in the protecting groups. This structure confirms the high structural flexibility of Gly-Aib peptides and points to a strong relationship between intermolecular hydrogen bonding and crystal quality and size.
无手性的四肽单水合物 N-(苄氧羰基)甘氨酰-α-氨基异丁酸甘氨酰-α-氨基异丁酸单水合物，Z-Gly-Aib-Gly-Aib-OH·H2O（Z 是苄氧羰基，Aib 是 α-氨基异丁酸，Gly 是甘氨酸）或 CHNO·H2O，通过对称操作的反演中心相关有两种构象。它只采用一种可能的 I 型（和 I'）β-转角的分子内氢键，形成最多的通过部分水介导的分子间氢键。空间群、分子结构和晶体堆积与已经描述的两种（Gly-Aib）肽不同，它们仅在保护基团上有所不同。该结构证实了 Gly-Aib 肽的高结构灵活性，并指出了分子间氢键与晶体质量和尺寸之间的强关系。
