Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl

摘要

src="http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2017/ancham.2017.89.issue-22/acs.analchem.7b03488/20171115/images/medium/ac-2017-03488v_0007.gif">Dark fluorescence quenchers are nonfluorescent dyes that can modulate the fluorescence signal of an appropriate fluorophore donor in a distance-dependent manner. Dark quenchers are extensively used in many biomolecular analytical applications, such as studies with fluorogenic protease substrates or nucleic acids probes. A very popular dark fluorescence quencher is dabcyl, which is a hydrophobic azobenzene derivative. However, its insolubility in water may constitute a major drawback, especially during the investigation of biochemical systems whose natural solvent is water. We designed and synthesized a new azobenzene-based dark quencher with excellent solubility in aqueous media, which represents a superior alternative to the much-used dabcyl. The advantage of hydrodabcyl over dabcyl is exemplarily demonstrated for the cleavage of the fluorogenic substrate hydrodabcyl-Ser-Phe-EDANS by the proteases thermolysin and papain.