A spectroscopic study of the conformation of poly d(G-C).poly d(G-C) modified with the carcinogenic 2-aminofluorene.
A spectroscopic study of the conformation of poly d(G-C).poly d(G-C) modified with the carcinogenic 2-aminofluorene.
复制标题
致癌性 2-氨基芴修饰的聚 d(G-C).聚 d(G-C) 构象的光谱研究。
DOI：
10.1093/carcin/9.6.1017
复制
发表时间：
1988
期刊：
影响因子：
4.7
通讯作者：
R. Grondelle
中科院分区：
文献类型：
--
作者：
L. V. Houte;J. Westra;J. Retèl;R. Grondelle
2-氨基芴（AF）修饰的合成多核苷酸聚d（G-C）的B型和z型螺旋的构象性质。用各种光学技术（紫外吸收、线性二色、圆二色和荧光光谱）对聚d（G-C）进行了广泛的研究。光谱结果表明：(1)聚d（G-C）中存在AF加合物。聚d（G-C）促进右手性b型多核苷酸转化为左手性z型聚d（G-C）。聚d（G-C）双相；（ii） B型和z型聚d（G-C）。聚d(G-C)-AF致癌残基与DNA位于一个特定的有序复合体中，其中AF发色团明显固定，芴环系统的长轴与DNA碱基平面平行；（iii） b型聚d（G-C）。poly d(G-C)-AF致癌残留物与邻近的DNA碱基表现出强烈的堆叠相互作用，这与含有af的b -双工的重要不稳定性相耦合；（iv）与b型复合物相比，含af -的z型DNA高度稳定，af -碱基相互作用显著减少；(v)为z形多边形d（G-C）。poly d(G-C)-AF AF发色团位于中等曝光位置。综合数据支持一个构象模型，其中平面AF插入b型多核苷酸螺旋，而致癌残留物插入z型多核苷酸螺旋（G-C）。poly d(G-C)-AF结构置于外侧位置。
The conformational properties of both the B- and Z-form helix of the 2-aminofluorene (AF) modified synthetic polynucleotide poly d(G-C).poly d(G-C) were extensively studied with a variety of optical techniques (UV absorbance, linear dichroism, circular dichroism and fluorescence spectroscopy). The spectroscopic results show, that: (i) the presence of the AF adduct in poly d(G-C).poly d(G-C) facilitates the conversion of the right-handed B-form polynucleotide to the left-handed Z-type poly d(G-C).poly d(G-C) duplex; (ii) in B- as well as in Z-form poly d(G-C).poly d(G-C)-AF the carcinogenic residue is situated in a specific and ordered complex with the DNA, in which the AF chromophore is significantly immobilized and the long axis of the fluorene ring system is positioned in a parallel mode to the DNA base planes; (iii) in B-type poly d(G-C).poly d(G-C)-AF the carcinogenic residue exhibits strong stacking interactions with the adjacent DNA bases, which are coupled to an important destabilization of the AF-containing B-duplex; (iv) in contrast to the B-form complex, the AF-containing Z-type DNA is highly stabilized and a remarkable reduction of the AF-base interactions is observed; (v) in Z-form poly d(G-C).poly d(G-C)-AF the AF chromophore resides at a medium-exposed position. The combined data support a conformational model, in which the planar AF is inserted in the B-type polynucleotide helix, while the carcinogenic residue in the Z-form poly d(G-C).poly d(G-C)-AF structure is placed in an outside position.