Arrangement of water molecules in cavities and channels of the lattice of [Phe4Val6]antamanide dodecahydrate.
Arrangement of water molecules in cavities and channels of the lattice of [Phe4Val6]antamanide dodecahydrate.
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[Phe4Val6]antamanide 十二水合物晶格的空腔和通道中水分子的排列。
DOI：
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发表时间：
1977
影响因子：
11.1
通讯作者：
E. Duesler
中科院分区：
文献类型：
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作者：
I. Karle;E. Duesler
天然金刚胺的合成的、具有生物活性的 [Phe4Val6] 类似物已从含有硝酸钙、丙酮和乙腈的溶液中结晶出来。该晶体不含任何 Ca2+ 离子，但每个肽分子含有 12 个水分子。该十二水合物的构象与从正己烷/乙酸甲酯中结晶的三水合物相同。两种晶体中的堆积非常相似，由苯基和吡咯烷环堆积的平行带以及溶剂分子（本例中为水，以及先前研究中的正己烷/乙酸甲酯）的连续通道控制。这两种结构并不是理想的同构，因为这两个晶胞的 c 晶胞参数相差超过 1.0 A。 H2O 分子具有三种功能：肽环内部的三个内在 H2O 分子、与暴露的 C=O 基团结合的 H2O 以及填充溶剂通道中空间的 H2O 分子。相邻肽分子之间没有直接的氢键，并且只有两个分子内 NH-O=C 键（5 个导致 1 种）。
The synthetic, biologically active, [Phe4Val6] analog of natural antamanide has been crystallized from a solution containing calcium nitrate, acetone, and acetonitrile. The crystal does not contain any Ca2+ ions but does contain 12 water molecules per peptide molecule. The conformation of this dodecahydrate is identical to the trihydrate crystallized from n-hexane/methyl acetate. The packing in both crystals is very similar, governed by parallel bands of phenyl and pyrrolidine ring stacking and by continuous channels for the solvement molecules, water in this case and n-hexane/methyl acetate in the previous study. The two structures are not ideally isomorphous, since the c cell parameter differs by more than 1.0 A in the two cells. There are three functions for H2O molecules: the three intrinsic H2O molecules in the interior of the peptide ring, the H2O bound to the exposed C=O groups, and the H2O molecules that fill space in the solvent channels. There are no direct hydrogen bonds between neighboring peptide molecules and there are only two intramolecular NH-O=C bonds (of the 5 leads to 1 type).