Spectroscopic recognition of guanine dimeric hairpin quadruplexes by a carbocyanine dye.

AUTOR(ES)

Chen, Q

RESUMO

Isolated guanine quadruplex structures have been described at high resolution both in solution and in the solid state. The existence of this unusual DNA structure in vivo and its biological significance remain to be determined. We describe the binding of 3,3'-diethyloxadicarbocyanine to dimeric hairpin guanine quadruplexes. This interaction results in a set of unique spectrophotometric signatures, none of which arises from binding to single strands or Watson-Crick duplexes. These unique signatures include a new absorbance peak (lambda max = 534 nm), an induced circular dichroism (lambda = 534-626 nm), a quenching of the dye fluorescence upon excitation with visible light, and strong energy transfer from DNA. This last effect provides the basis for detecting hairpin quadruplex structures in the presence of excess amounts of nonquadruplex DNA structures, such as single strands and Watson-Crick duplexes. The mechanism of quadruplex recognition by this dye is discussed, along with the possibility of using this dye as a probe for hairpin quadruplex structures in vitro and in vivo.

Documentos Relacionados

• Suppression of tuberculoimmunity in mice by Evans blue dye.
• Cable properties of a straight neurite of a leech neuron probed by a voltage-sensitive dye.
• Differential spore and lipid staining at room temperature by use of fluorescent dye.
• Measurement and modification of free calcium transients in frog skeletal muscle fibres by a metallochromic indicator dye.
• Cable properties of arborized Retzius cells of the leech in culture as probed by a voltage-sensitive dye.