Transient signal generation in a self-assembled nanosystem fueled by ATP.

Cristian Pezzato,Leonard J Prins

doi:10.1038/ncomms8790

Abstract

A fundamental difference exists in the way signal generation is dealt with in natural and synthetic systems. While nature uses the transient activation of signalling pathways to regulate all cellular functions, chemists rely on sensory devices that convert the presence of an analyte into a steady output signal. The development of chemical systems that bear a closer analogy to living ones (that is, require energy for functioning, are transient in nature and operate out-of-equilibrium) requires a paradigm shift in the design of such systems. Here we report a straightforward strategy that enables transient signal generation in a self-assembled system and show that it can be used to mimic key features of natural signalling pathways, which are control over the output signal intensity and decay rate, the concentration-dependent activation of different signalling pathways and the transient downregulation of catalytic activity. Overall, the reported methodology provides temporal control over supramolecular processes.

Highlights

A fundamental difference exists in the way signal generation is dealt with in natural and synthetic systems
The initial concentration of ATP regulates the intensity of the output signal and its duration and determines whether one or two signals are generated in the case where two reporter molecules are used
The same mechanism is evoked when applied to the transient downregulation of the catalytic activity of the nanoparticles

Summary

Introduction

A fundamental difference exists in the way signal generation is dealt with in natural and synthetic systems. Nature has evolved elaborate signalling pathways relying on circular enzymatic networks to regulate all intra and extracellular functions[2,3] In such networks, a trigger can up or downregulate an enzymatic cascade reaction leading to the transient generation of an output signal, after which the system returns to the original state. A common feature of these systems is that signal generation is thermodynamically driven, that is, the system adapts to a trigger-induced change in the energetic landscape developing into a new, energetically more favourable, resting state This change is accompanied with a change in a property (fluorescence, current, catalysis, solubility and so on) that can be measured and correlated to the intensity of the trigger. An entirely different approach towards (irreversible) transient signal generation has been reported[23]

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Results

Conclusion