Formation of Porphyrin-metal Complex Catalyzed by Single Strand DNA

单链 DNA 催化卟啉金属配合物的形成

基本信息

批准号：
09640664
负责人：
TAJIMA Kunihiko
金额：
$ 2.05万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

In this study, the structural study on porphyrin-DNA interactions was performed in order to clarify whether it is possible for single-stranded DNAs to fold to create specific binding pockets for anionic porphyrins, which do not naturally bind to nucleic acids.The kinetics of the metallation of Cu^<2+> into MPIX was first examined in the presence and absence of PS5.ST1 (dTCGTGGGTCATTGTGGGTGGGTGTGGCTGGTCC) and other G-rich oligomers by HPLC.The results were almost identical to that as previously reported (3).CD spectroscopy has been used to distinguish between parallel and antiparallel G-quadruplexes (4,5) The former quadruplexes exhibit a positive CD band around 260 nm and a negative CD band at 240 nm. The latter quadruplexes exhibit a positive CD band around 290 nm and a weaker negative band at 265 nm. CD spectroscopy was carried out for PS5.ST 1 (25 muM) at various temperatures in the absence and presence of K^+ ion. In the absence of K^+, this sample showed two positive peaks at 265 and 285 nm at 0ﾟC, while at increasing temperatures, one at 265 nm disappeared, and the other at 285 nm decreased. Temperature-dependent CD spectroscopy was also performed for PS5.ST1 in the presence of K^+ ion in the temperature range of 0-80ﾟC.Both the positive peaks appeared below 25ﾟC, and the intensity of the peak at 265 nm was much stronger than that in the absence of K^+ ion. These results indicate that even in the absence of K^+ ion, PS5.ST1 takes an ordered structure, and that the addition of K^+ ion induces components of parallel G-quadruplexes.^1HNMR measurements were carried out for PS5.ST1 in the absence and presence of K^+ ion. The imino proton signals are an indicator of symmetry and stoichiometry. The NMR spectra show some change in the chemical shifts of the peaks, which may correspond with the change in the CD spectra.

在这项研究中，进行了有关卟啉-DNA相互作用的结构研究，以阐明单链DNA是否有可能折叠以创建特定的阴离子卟啉的特定结合口袋，而卟啉并不自然地与核酸结合。 (dTCGTGGTCATTGTGGGTGGTGTGGTGGTGGTGGTGGTCC) and other G-rich oligomers by HPLC.The results were almost identical to that as previously reported (3).CD spectroscopy has been used to distinguish between parallel and antiparallel G-quadruplexes (4,5) The former quadruplexes exposed a positive CD band around 260 nm and a negative CD band at 240 nm。后者四链体在290 nm附近暴露了一个正cd带，在265 nm处暴露了较弱的负带。在不存在和存在K^+离子的情况下，在各种温度下对PS5进行CD光谱。在不存在K^+的情况下，该样品在265和285 nm处显示了两个正峰，而温度升高，一个在265 nm处消失，另一个在285 nm处下降。在0-80°C的温度范围内，在存在K^+离子的情况下，还为PS5.ST1进行了温度依赖性的CD光谱。C。均出现的正峰出现在25°C以下，而在265 nm处的峰强度远比K^+离子不存在的峰强得多。这些结果表明，即使在没有K^+离子的情况下，PS5.ST1采用有序结构，并且添加K^+离子会诱导平行G Qu-Quadruplexes的成分。 Imino质子信号是对称和化学计量学的指标。 NMR光谱显示峰的化学位移发生了一些变化，这可能与CD光谱的变化相对应。