| Date | 31st, Oct 2018 |
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Scientists from IMDEA Nanociencia follow and operate one molecular shuttle-at-a-time, in real time, for several hundreds of cycles.
In a molecular shuttle, a ring molecule is trapped onto a linear thread and can move between two portions of the thread, called stations. Although the thermodynamics of synthetic molecular shuttles are to date well understood, information on single-molecule mechanics is lacking.
The molecular shuttle is attached to two polystyrene beads through two DNA molecules. Picture credit: Scixel.
Scientists from IMDEA Nanociencia and the University of Barcelona -led by Emilio Pérez and Borja Ibarra- have engineered a novel system to measure the dynamics of a single artificial molecular switch under near-physiological conditions. The system comprises a tetraamide macrocycle locked onto a oligoethyleneglycol thread by two diphenylethyl groups (stoppers) at the end of the axle, and fumaramide and succinic amide-ester stations.
Each station can stablish up to four hydrogen bonds with the macrocycle. This single shuttle was interfaced with two functionalized beads using DNA molecules. The beads are trapped with optical tweezers and serve as probes to control the stochastic motion of the macrocycle between two stations.
The exquisite sensitivity of optical tweezers and the robustness of their method allowed the authors to quantify the piconewton forces (
