Karle I, Wieland T
Int J Pept Protein Res. 1987 May;29(5):596-603.
The cyclic decapeptide antamanide and the synthetic, biologically active analog [Phe4 Val6]antamanide (cyclic[ValProProPhePhe]2) crystallize in various crystal forms as a function of the solvent. The present crystalline polymorph obtained from acetone/water (also from ethanol/water and DMSO/water) crystallizes in space group P2(1)2(1)2(1) with a = 20.194 (30) A, b = 21.118 (31) A, c = 16,132 (25) A and four molecules of peptide in the unit cell. There are five cocrystallized water molecules per peptide molecule, of which four water molecules are intrinsic to the peptide molecule. Although the molecular packing is entirely different in each of the polymorphs, the conformation of the peptide molecule, including the intrinsic water molecules, is very similar in all the polymorphs.
环状十肽蚂蚁毒素和合成的生物活性类似物[Phe4 Val6]蚂蚁毒素（环[ValProProPhePhe]2）根据溶剂的不同会以多种晶体形式结晶。从丙酮/水（也可从乙醇/水和二甲基亚砜/水）中获得的当前晶体多晶型物在空间群P2(1)2(1)2(1)中结晶，a = 20.194 (30) Å，b = 21.118 (31) Å，c = 16,132 (25) Å，晶胞中有四个肽分子。每个肽分子有五个共结晶水分子，其中四个水分子是肽分子固有的。尽管每种多晶型物中的分子堆积完全不同，但在所有多晶型物中，肽分子的构象，包括固有的水分子，非常相似。
