Crystal structure of (uracil-1-ylethyl)(adenin-9-ylethyl)tryptophan dipeptide: An interaction model between nucleic acid base and aromatic amino acid.
作者:TOSHIMASA ISHIDA、YOSHIKO TOKURA、MARI SHIMAMOTO、MITSUNOBU DOI、MASATOSHI INOUE
DOI:10.1248/cpb.35.1691
日期:——
As a model compound for the interaction of tryptophan with nucleic acid bases, uracil and adenine, (uracil-1-ylethyl) (adenin-9-ylethyl) tryptophan dipeptide has been synthesized, and its molecular and crystal structure has been analyzed by the X-ray diffraction method. The crystal data are a=4.989 (2), b=30.056 (5), c=9.939 (1) Å, β=94.61 (3) °, Z=2, Dm=1.345 (1) g·cm-3, space group P21. The molecule takes a W-shaped extended conformation, and is linked with the neighboring molecule in a head-to-tail fashion through a reverse Watson-Crick base pairing. Consequently the molecules form an infinite chain along the b-axis. A weak stacking interaction is observed between the indole ring and the uracil base : the dihedral angle between them is 28.6 (3) °, and the average interplanar spacing is 3.95 Å. This stacking mode is formed by the dipole-dipole coupling between the respective aromatic rings.The result may indicate a possible access mode of a tryptophan residue to the uracil base of a single-stranded nucleic acid.
作为色氨酸与核酸碱基尿嘧啶和腺嘌呤相互作用的模型化合物,合成了(尿嘧啶-1-乙烯基)(腺嘌呤-9-乙烯基)色氨酸二肽,并用 X 射线衍射方法分析了其分子和晶体结构。晶体数据为 a=4.989 (2),b=30.056 (5),c=9.939 (1)埃,β=94.61 (3)°,Z=2,Dm=1.345 (1) g-cm-3,空间群 P21。分子呈 "W "形延伸构象,通过反向沃森-克里克碱基配对与邻近分子头尾相连。因此,分子沿 b 轴形成了一条无限链。吲哚环和尿嘧啶碱基之间存在微弱的堆叠作用:二者之间的二面角为 28.6 (3) °,平均平面间距为 3.95 Å。