Exploring enzymatic systems that use adenosine triphosphate (ATP) can improve our understanding of various biological pathways. The production of ATP cleavage products can be monitored in vitro using radioactive ATP analogues or by the colorimetric detection of released phosphate or pyrophosphate. These methods do not allow the continuous detection of ATP turnover. Enzyme-coupled assays offer an alternative means to explore these systems, but require consideration of the effects of additional enzymes. Thus, there is a need for probes that enable the continuous study of enzymatic ATP consumption.
This HOT article describes the synthesis of ATP analogues labelled with a fluorescence donor and a fluorescence acceptor, suitable for Förster Resonance Energy Transfer. Excitation promotes energy transfer from the fluorescence donor to the fluorescence acceptor on the same molecule. Cleavage of the ATP analogue prevents energy transfer via an intramolecular pathway, resulting in a large change in fluorescence. Synthetic routes to seven new doubly labelled ATP analogues are reported and the fluorescence properties of these molecules are described using snake venom phosphodiesterase as a model enzyme.
Synthesis and fluorescence characteristics of ATP-based FRET probes
Norman Hardt, Stephan M. Hacker and Andreas Marx
Org. Biomol. Chem., 2013, DOI: 10.1039/C3OB41751D