DNA-Templated Synthesis of Trimethine Gyanine Dyes: A Versatile Fluorogenic Reaction for Sensing G-Quadruplex Formation

摘要

It has been known for several decades that guanine-rich nucleic acid sequences have a propensity to fold into highly stable four-stranded structures in vitro in the presence of physiological cations, notably potassium and sodium. Such structures, termed quadruplexes, have had their biological significance demonstrated for a number of processes. For example, the single-stranded 3'-end of telomeric DNA could adopt a quadruplex conformation under near physiological conditions, which has implications on telomere maintenance mechanisms. More recently, a number of DNA G-quad-ruplex sequences have been identified in the promoter region of genes that have been proposed to act as regulatory elements for gene expression at the transcriptional level.