Kostansek E C, Lipscomb W N, Yocum R R, Thiessen W E
Biochemistry. 1978 Sep 5;17(18):3790-5. doi: 10.1021/bi00611a019.
A single crystal X-ray diffraction analysis of beta-amanitin, a bicyclic octapeptide toxin isolated from the poisonous mushroom Amanita phalloides, shows that the molecule has distinct regions of hydrophilic and hydrophobic residues and two 18-membered rings. The study confirms the proposed chemical sequence and the configuration of the residues. All eight peptide groups are in the trans conformation. Four intramolecular hydrogen bonds, two strong and two weak, occur in the structure. The toxin cocrystallizes with seven water and three ethanol molecules and participates in an extensive hydrogen-bonding network. The crystal structure was solved by direct methods. The space group is P2(1)2(1)2(1), and unit cell dimensions are a = 14.004(3), b = 14.943(3), and c = 30.794(7) A.
从毒蘑菇毒蝇伞中分离出的双环八肽毒素β-鹅膏毒肽的单晶X射线衍射分析表明，该分子具有亲水性和疏水性残基的不同区域以及两个18元环。该研究证实了所提出的化学序列和残基的构型。所有八个肽基团均处于反式构象。结构中存在四个分子内氢键，两个强氢键和两个弱氢键。该毒素与七个水分子和三个乙醇分子共结晶，并参与广泛的氢键网络。晶体结构通过直接法解析。空间群为P2(1)2(1)2(1)，晶胞尺寸为a = 14.004(3)，b = 14.943(3)，c = 30.794(7) Å。
