Crystal and molecular structure of isoleucinomycin, cyclo[‐(D‐Ile‐Lac‐Ile‐D‐Hyi)3‐](C60H102N6O18)
Crystal and molecular structure of isoleucinomycin, cyclo[‐(D‐Ile‐Lac‐Ile‐D‐Hyi)3‐](C60H102N6O18)
复制标题
异亮霉素环[-(D-Ile-Lac-Ile-D-Hyi)3-](C60H102N6O18)的晶体和分子结构
DOI：
10.1002/bip.1980.360190808
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发表时间：
1980
期刊：
影响因子：
2.9
通讯作者：
W. Duax
中科院分区：
文献类型：
--
作者：
V. Pletnev;N. M. Galitskii;G. D. Smith;C. Weeks;W. Duax
用X射线衍射法测定了合成的呋喃霉素类似物环[-(D-Ile-Lac-Ile-D-Hyi)3-](C60H102N6O18)的晶体结构。晶体属正交晶系，空间群为P212121，晶胞参数a=11.516，b=15.705，c=39.310，Z=4。在各向异性热运动近似下对C、N、O原子进行了原子坐标修正，在各向同性近似下对H原子进行了坐标修正。修正后的标准(R)和加权(RW)可靠度系数分别为0.073和0.056。这个结构是完全不对称的。环状分子骨架由六个分子内氢键NH…稳定︁OC，5个键为4→1类型，1个为5→1类型。侧链位于分子外围。异亮霉素在晶体中的构象介于呋喃霉素和中-呋喃霉素的相应晶态之间。观察到的构象表明，络合可以通过离子进入具有L-Lac残基的面上进行，即较不拥挤的面上。
The crystal structure of a synthetic analog of valinomycin, cyclo[‐(D‐Ile‐Lac‐Ile‐D‐Hyi)3‐] (C60H102N6O18), has been determined by x‐ray diffraction procedures. The crystals are orthorhombic, space group P212121, with cell parameters a = 11.516, b = 15.705, c = 39.310 Å, and Z = 4. The atomic coordinates for the C, N, O atoms were refined in the anisotropic thermal motion approximation and for the H atoms in the isotropic approximation. Values of standard (R) and weighted (Rw) reliability factors after refinement are 0.073 and 0.056, respectively. The structure is completely asymmetric. The cyclic molecular backbone is stabilized by six intramolecular hydrogen bonds NH…︁OC, five bonds being of the 4→1 type and one being of the 5→1 type. The side chains are located on the molecular periphery. The conformational state of isoleucinomycin in the crystal is intermediate between the corresponding crystalline states of valinomycin and meso‐valinomycin. The observed conformation suggests that complexation could proceed via entry of the ion at the face possessing the L‐Lac residues, the less crowded face.