In recent years, engineered biological pores responsive to external stimuli have been fruitfully used for various biotechnological applications. Moreover, the strategy of tethering photo-switchable moieties into biomolecules has provided an unprecedented temporal control of purposely designed nanodevices, as demonstrated, for example, by the light-mediated regulation of the activity of enzymes and biochannels. Inspired by these advancements, we propose here a de novo designed nanodevice featuring the α-hemolysin (αHL) membrane channel purposely functionalized by an artificial "on/off" molecular switch. The switch, which is based on the photo-isomerization of the azobenzene moiety, introduces a smart nano-valve into the natural non-gated pore to confer tunable transport properties. We validated through molecular dynamics simulations and free energy calculations the effective inter-conversion of the engineered αHL pore between two configurations corresponding to an "open" and a "closed" form. The reported switchable translocation of a single-stranded DNA fragment under applied voltage supports the promising capabilities of this nanopore prototype in view of molecular sensing, detection and delivery applications at single-molecule level.

Introducing an artificial photo-switch into a biological pore: A model study of an engineered α-hemolysin

CHANDRAMOULI, BALASUBRAMANIAN;MANCINI, GIORDANO;BRANCATO, Giuseppe
2016

Abstract

In recent years, engineered biological pores responsive to external stimuli have been fruitfully used for various biotechnological applications. Moreover, the strategy of tethering photo-switchable moieties into biomolecules has provided an unprecedented temporal control of purposely designed nanodevices, as demonstrated, for example, by the light-mediated regulation of the activity of enzymes and biochannels. Inspired by these advancements, we propose here a de novo designed nanodevice featuring the α-hemolysin (αHL) membrane channel purposely functionalized by an artificial "on/off" molecular switch. The switch, which is based on the photo-isomerization of the azobenzene moiety, introduces a smart nano-valve into the natural non-gated pore to confer tunable transport properties. We validated through molecular dynamics simulations and free energy calculations the effective inter-conversion of the engineered αHL pore between two configurations corresponding to an "open" and a "closed" form. The reported switchable translocation of a single-stranded DNA fragment under applied voltage supports the promising capabilities of this nanopore prototype in view of molecular sensing, detection and delivery applications at single-molecule level.
DNA detection; Engineered protein; Light-activated channel gating; Molecular dynamics simulations; Nanopore analytics; α-Hemolysin membrane channel; Biosensing Techniques; DNA, Single-Stranded; Hemolysin Proteins; Light; Molecular Dynamics Simulation; Nanopores; Porosity; Protein Engineering
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11384/64162
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