CRYSTAL-STRUCTURE AND MOLECULAR-CONFORMATION OF HYDRATED CYCLIC HEXAPEPTIDE CYCLO(L-ALA-L-PRO-D-PHE)2
CRYSTAL-STRUCTURE AND MOLECULAR-CONFORMATION OF HYDRATED CYCLIC HEXAPEPTIDE CYCLO(L-ALA-L-PRO-D-PHE)2
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DOI：
10.1021/ja00440a020
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发表时间：
1976-01-01
影响因子：
15
通讯作者：
TELLER, RG
中科院分区：
文献类型：
--
作者：
BROWN, JN;TELLER, RG
通过单晶X射线衍射分析确定了环肽环(L-Ala-L-Pro-D-Phe)2水合物的晶体和分子结构。该晶体为斜方晶系，空间群 P21212，a = 15.908 (1)、b = 13.350 (1) 和 c = 9.643 (1) ANG.。在具有铜辐射的 Picker 衍射仪上收集完整的 3 维 X 射线衍射数据，并精炼得到残差 R = 0.13 和 Rw = 0.08。该六肽表现出 C2 对称性，其构象与 NMR 数据预测的相似。两个脯氨酸残基均位于β的2位。转，其中没有发现预期的强 4-1 H 键。该肽与结晶水参与广泛的分子间氢键网络，并且不存在肽-肽分子间氢键。
The crystal and molecular structure of the cyclic peptide cyclo(L-Ala-L-Pro-D-Phe)2 hydrate was determined by single-crystal X-ray diffraction analysis. The crystals are orthorhombic, space group P21212 with a = 15.908 (1), b = 13.350 (1) and c = 9.643 (1) .ANG.. Complete 3-dimensional X-ray diffraction data were collected on a Picker diffractometer with copper radiation and refined to give residuals R = 0.13 and Rw = 0.08. The hexapeptide exhibits C2 symmetry and has a conformation resembling that predicted by NMR data. Both proline residues are in the 2-positions of .beta. turns, in which the expected strong 4-1 H-bond is not found. The peptide is involved in an extensive network of intermolecular H-bonding with water of crystallization and there are no peptide-peptide intermolecular H-bonds.