References of "Sluysmans, Damien"
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See detailSynthetic oligorotaxanes exert high forces when folding under mechanical load
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

in Nature Nanotechnology (in press)

Folding is a ubiquitous process that nature uses to control the conformations of its molecular machines, allowing them to perform chemical and mechanical tasks. Over the years, chemists have synthesized ... [more ▼]

Folding is a ubiquitous process that nature uses to control the conformations of its molecular machines, allowing them to perform chemical and mechanical tasks. Over the years, chemists have synthesized foldamers that adopt well-defined and stable folded architectures, mimicking the control expressed by natural systems. Mechanically interlocked molecules, such as rotaxanes and catenanes, are prototypical molecular machines that enable the controlled movement and positioning of their component parts. Recently, combining the exquisite complexity of these two classes of molecules, donor–acceptor oligorotaxane foldamers have been synthesized, in which interactions between the mechanically interlocked component parts dictate the single-molecule assembly into a folded secondary structure. Here we report on the mechanochemical properties of these molecules. We use atomic force microscopy-based single-molecule force spectroscopy to mechanically unfold oligorotaxanes, made of oligomeric dumbbells incorporating 1,5-dioxynaphthalene units encircled by cyclobis(paraquat-p-phenylene) rings. Real-time capture of fluctuations between unfolded and folded states reveals that the molecules exert forces of up to 50 pN against a mechanical load of up to 150 pN, and displays transition times of less than 10 μs. While the folding is at least as fast as that observed in proteins, it is remarkably more robust, thanks to the mechanically interlocked structure. Our results show that synthetic oligorotaxanes have the potential to exceed the performance of natural folding proteins. [less ▲]

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See detailDynamic force spectroscopy of synthetic oligorotaxane foldamers
Sluysmans, Damien ULiege; Devaux, Floriane ULiege; Bruns, Carson J. et al

in Proceedings of the National Academy of Sciences of the United States of America (in press)

Wholly synthetic molecules involving both mechanical bonds and a folded secondary structure are one of the most promising architec- tures for the design of functional molecular machines with un ... [more ▼]

Wholly synthetic molecules involving both mechanical bonds and a folded secondary structure are one of the most promising architec- tures for the design of functional molecular machines with un- precedented properties. Here, we report dynamic single-molecule force spectroscopy experiments that explore the energetic details of donor–acceptor oligorotaxane foldamers, a class of molecular switches. The mechanical breaking of the donor–acceptor interactions responsible for the folded structure shows a high constant rupture force over a broad range of loading rates, covering three orders of magnitude. In comparison with dynamic force spectroscopy performed during the past 20 y on various (bio)molecules, the near-equilibrium regime of oligorotaxanes persists at much higher loading rates, at which bio- molecules have reached their kinetic regime, illustrating the very fast dynamics and remarkable rebinding capabilities of the intramolecular donor–acceptor interactions. We focused on one single interaction at a time and probed the stochastic rupture and rebinding paths. Using the Crooks fluctuation theorem, we measured the mechanical work produced during the breaking and rebinding to determine a free- energy difference, ΔG, of 6 kcal·mol−1 between the two local confor- mations around a single bond. [less ▲]

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See detailWhere Ion Mobility and Molecular Dynamics Meet to Unravel the (Un)Folding Mechanisms of an Oligorotaxane Molecular Switch
Hanozin, Emeline ULiege; Mignolet, Benoît ULiege; Morsa, Denis ULiege et al

in ACS Nano (2017), 11(10), 10253-10263

At the interface between foldamers and mechanically interlocked molecules, oligorotaxanes exhibit a spring-like folded secondary structure with remarkable mechanical and physicochemical properties. Among ... [more ▼]

At the interface between foldamers and mechanically interlocked molecules, oligorotaxanes exhibit a spring-like folded secondary structure with remarkable mechanical and physicochemical properties. Among these properties, the ability of oligorotaxanes to act as molecular switches through controlled modulations of their spatial extension over (un)folding dynamics is of particular interest. The present study aims to assess and further characterize this remarkable feature in the gas phase using mass spectrometry tools. In this context, we focused on the [4]5NPR+12 oligorotaxane molecule complexed with PF6 - counterion and probed its co-conformational states as a function of the in-source-generated charge states. Data were interpreted in light of electronic secondary structure computations at the PM6 and DFT levels. Our results highlight two major co-conformational groups associated either with folded compact structures, notably stabilized by intramolecular π-π interactions and predominant for low charge states or with fully stretched structures resulting from significant Coulombic repulsions at high charge states. Between, the oligorotaxane adopts intermediate folded co-conformations, suggesting a stepwise unfolding pathway under increasing repulsive Coulombic constraints. The reversibility of this superstructural transition was next interrogated under electron-driven (nondissociative electron transfer) and heat-driven (collision-induced unfolding) activation stimuli. The outcomes support the feasibility to either unfold or (partially) refold the oligorotaxane foldamer on purpose in the gas phase. Our results show that the balance between the stabilizing π-π interactions and the versatile Coulomb interactions dictates the elongation state of the foldamer in the gas phase and emphasizes the adequacy of mass spectrometry tools for the superstructural characterization of desolvated prototypical artificial molecular machines. © 2017 American Chemical Society. [less ▲]

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See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2017, June)

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See detailCoulombic driven multi-conformational aspects of oligorotaxane switches studied by ion mobility mass spectrometry and molecular dynamics
Hanozin, Emeline ULiege; Mignolet, Benoît ULiege; Morsa, Denis ULiege et al

Conference (2017, June)

Introduction Artificial Molecular Machines (AMMs), such as Mechanically Interlocked Molecules (MIMs) and foldamers, have recently raised tremendous interest due to their unique properties. Under the ... [more ▼]

Introduction Artificial Molecular Machines (AMMs), such as Mechanically Interlocked Molecules (MIMs) and foldamers, have recently raised tremendous interest due to their unique properties. Under the influence of an appropriate stimuli (pH, redox potential, light…), such molecules are able to reversibly switch between distinct conformational states. Scientists may capitalize on such exclusive properties to get a better understanding of the biomacromolecular level or to design innovative “smart” materials. At the interface between foldamers and MIMs, oligorotaxanes exhibit a spring-like folded secondary structure with remarkable mechanical and physicochemical properties. In the present study, we use ion mobility coupled with mass spectrometry (IM-MS) to probe the conformational states of differentially charged oligorotaxanes in the gas phase. Method Oligorotaxanes are donor-acceptor polymers composed of a π electron-donating dumbbell over which a discrete number of π electron-accepting tetracationic cyclophanes are threaded. The numerous intra-molecular interactions provide them a highly-stabilized rigid rod-like structure in solution. We use IM-MS as implemented in the Synapt G2 HDMS (Waters, Manchester, UK) to investigate the structure of the ionized oligorotaxanes. Our purposes are to probe (i) the different populations of stable conformers generated according to the charge state z and (ii) the reversibility of an electron-driven or thermal-driven conformational change in the gas phase implemented via an electron transfer or collisional activation process prior to the mobility separation. Our experimental observations are supported by electronic structure optimizations at the PM6 and DFT levels coupled with Born-Oppenheimer Molecular Dynamics simulations. Preliminary data Our results highlight a progressive elongation of the oligorotaxane structure with increasing charge numbers until it reaches a maximum extension state. Matching the experimental data with theoretical simulations, we find that the oligorotaxanes adopt an entropically-favored globular shape at low z. As z increases, coulombic repulsions occurring between the cyclophanes gradually outweigh the stabilizing π-stacking interactions and force the structure to elongate. This process occurs in a multistep fashion, each corresponding to a distinct group of helical-shaped conformers, before it eventually results in a fully stretched structure. On the other hand, our results also highlight that a charge reduction driven by a non-dissociative electron transfer process leads to a refolding of the structure so that it adopts a size similar to its electrospray-generated counterpart when the appropriate number of electrons is added. This observation may be imparted to the gradual decrease of the Coulomb repulsions between the cyclophanes mediated through increasing numbers of transferred electrons. These results suggests that the transition from one conformer to another is reversible so that the electrostatic balance between the cyclophanes may be used to further tune the structural state adopted by this artificial molecular switch. The second stimulus relied on collisional activation whose inelastic component provides a way to build up energy into the accessible vibrational degrees of freedom. The conformational landscapes of such-activated oligorotaxanes ions were found unchanged in term of collision cross section position but the repartition of population was altered with a promotion of the most elongated conformer, provided the absence of selective fragmentation. Altogether, these results highlight the feasibility of handling the elongation state of oligorotaxanes in the gas phase through appropriate inputs and underline its conformational reversibility properties. Novel aspect Stimuli-induced reversible conformational rearrangements of innovative AMMs studied by IM-MS and molecular dynamics in the gas phase. [less ▲]

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See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2016, October)

Detailed reference viewed: 13 (0 ULiège)
See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2016, July)

Detailed reference viewed: 25 (4 ULiège)
See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Scientific conference (2016, July)

Detailed reference viewed: 9 (4 ULiège)
See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Stoddart, J. Fraser; Duwez, Anne-Sophie ULiege

Conference (2016, May)

Detailed reference viewed: 8 (3 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Stoddart, J. Fraser; Duwez, Anne-Sophie ULiege

Conference (2016, April)

Detailed reference viewed: 5 (2 ULiège)
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See detailForce measurements reveal how small binders perturb the dissociation mechanisms of DNA duplex sequences
Burmistrova, Anastasia ULiege; Fresch, Barbara ULiege; Sluysmans, Damien ULiege et al

in Nanoscale (2016), 8

The force-driven separation of double-stranded DNA is crucial to the accomplishment of cellular pro- cesses like genome transactions. Ligands binding to short DNA sequences can have a local stabilizing or ... [more ▼]

The force-driven separation of double-stranded DNA is crucial to the accomplishment of cellular pro- cesses like genome transactions. Ligands binding to short DNA sequences can have a local stabilizing or destabilizing effect and thus severely affect these processes. Although the design of ligands that bind to specific sequences is a field of intense research with promising biomedical applications, so far, their effect on the force-induced strand separation has remained elusive. Here, by means of AFM-based single mole- cule force spectroscopy, we show the co-existence of two different mechanisms for the separation of a short DNA duplex and demonstrate how they are perturbed by small binders. With the support of Mole- cular Dynamics simulations, we evidence that above a critical pulling rate one of the dissociation pathways becomes dominant, with a dramatic effect on the rupture forces. Around the critical threshold, we observe a drop of the most probable rupture forces for ligand-stabilized duplexes. Our results offer a deep understanding of how a stable DNA–ligand complex behaves under force-driven strand separation [less ▲]

Detailed reference viewed: 108 (29 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2015, June)

Detailed reference viewed: 14 (4 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2015, April)

Detailed reference viewed: 7 (2 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Stoddart, J. Fraser; Duwez, Anne-Sophie ULiege

Conference (2015, January)

Detailed reference viewed: 3 (2 ULiège)
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See detailUnraveling the complexity of the interactions of DNA nucleotides with gold by single molecule force spectroscopy
Bano, Fouzia; Sluysmans, Damien ULiege; Wislez, Arnaud ULiege et al

in Nanoscale (2015), 7

Addressing the effect of different environmental factors on the adsorption of DNA to solid supports is critical for the development of robust miniaturized devices for applications ranging from biosensors ... [more ▼]

Addressing the effect of different environmental factors on the adsorption of DNA to solid supports is critical for the development of robust miniaturized devices for applications ranging from biosensors to next generation molecular technology. Most of the time, thiol-based chemistry is used to anchor DNA on gold – a substrate commonly used in nanotechnology – and little is known about the direct interaction between DNA and gold. So far there have been no systematic studies on the direct adsorption behavior of the deoxyribonucleotides (i.e., a nitrogenous base, a deoxyribose sugar, and a phosphate group) and on the factors that govern the DNA–gold bond strength. Here, using single molecule force spectroscopy, we investigated the interaction of the four individual nucleotides, adenine, guanine, cytosine, and thymine, with gold. Experiments were performed in three salinity conditions and two surface dwell times to reveal the factors that influence nucleotide–Au bond strength. Force data show that, at physiological ionic strength, adenine–Au interactions are stronger, asymmetrical and independent of surface dwell time as compared to cytosine–Au and guanine–Au interactions. We suggest that in these conditions only adenine is able to chemisorb on gold. A decrease of the ionic strength significantly increases the bond strength for all nucleotides. We show that moderate ionic strength along with longer surface dwell period suggest weak chemisorption also for cytosine and guanine. [less ▲]

Detailed reference viewed: 15 (8 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Duwez, Anne-Sophie ULiege

Scientific conference (2014, December)

Detailed reference viewed: 3 (2 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Bruns, Carson; Zhu, Zhixue et al

Conference (2014, December)

Detailed reference viewed: 4 (2 ULiège)
See detailSingle molecule force spectroscopy on oligorotaxane foldamers
Sluysmans, Damien ULiege; Bruns, Carson; Zhu, Zhixue et al

Poster (2014, October)

Detailed reference viewed: 13 (3 ULiège)