Kolaric Branko, Sliwa Michel, Brucale Marco, Vallée Renaud A L, Zuccheri Giampaolo, Samori Bruno, Hofkens Johan, De Schryver Frans C
Katholieke Universiteit Leuven, Department Chemistry and Institute for Nanoscale Physics and Chemistry (INPAC), Celestijnenlaan 200F, Heverlee, B-3001, Belgium.
Photochem Photobiol Sci. 2007 Jun;6(6):614-8. doi: 10.1039/b618689k. Epub 2007 Feb 21.
Several authors demonstrated that an oligonucleotide based pH-sensitive construct can act as a switch between an open and a closed state by changing the pH. To validate this process, specially designed fluorescence dye-quencher substituted oligonucleotide constructs were developed to probe the switching between these two states. This paper reports on bulk and single molecule fluorescence investigations of a duplex-triplex pH sensitive oligonucleotide switch. On the bulk level, only a partial quenching of the fluorescence is observed, similarly to what is observed for other published switches and is supposed to be due to intermolecular interactions between oligonucleotide strands. On the single molecule level, each DNA-based nanometric construct shows a complete switching. These observations suggest the tendency of the DNA construct to associate at high concentration.
几位作者证明，基于寡核苷酸的pH敏感构建体可以通过改变pH值在开放状态和封闭状态之间起到开关的作用。为了验证这一过程，人们开发了经过特殊设计的荧光染料-猝灭剂取代的寡核苷酸构建体，以探测这两种状态之间的转换。本文报道了双链-三链pH敏感寡核苷酸开关的整体和单分子荧光研究。在整体水平上，只观察到荧光的部分猝灭，这与其他已发表的开关所观察到的情况类似，据推测这是由于寡核苷酸链之间的分子间相互作用所致。在单分子水平上，每个基于DNA的纳米构建体都显示出完全的转换。这些观察结果表明DNA构建体在高浓度下有聚集的趋势。
