Kokkinidis M, Tsernoglou D, Brückner H
Biochem Biophys Res Commun. 1986 May 14;136(3):870-5. doi: 10.1016/0006-291x(86)90413-4.
The crystal structure of Z-Aib-Aib-Aib-Ala-Ala-Aib-OtBu, an end-protected hexapeptide with a sequence corresponding to residues 7-12 of several trichotoxin A-50 sequence analogues has been determined by X-ray crystallography. The hexapeptide adopts a right-handed 3(10)-helical conformation consisting of four consecutive beta-turns of type III. The helix is stabilized by four intramolecular hydrogen bonds. In the crystal the molecules are connected head to tail with intermolecular hydrogen bonding interactions among translationally related molecules thus forming infinitely long helical columns. The column-column interactions in the crystal are hydrophobic and occur predominantly between antiparallel directed columns.
Z-Aib-Aib-Aib-Ala-Ala-Aib-OtBu是一种末端保护的六肽，其序列对应于几种曲毒素A-50序列类似物的第7至12位残基。通过X射线晶体学确定了其晶体结构。该六肽采用右手3(10)螺旋构象，由四个连续的III型β-转角组成。螺旋通过四个分子内氢键得以稳定。在晶体中，分子通过平移相关分子间的分子间氢键相互作用首尾相连，从而形成无限长的螺旋柱。晶体中的柱-柱相互作用是疏水的，主要发生在反平行排列的柱之间。
