Structural characterization of the saxitoxin-targeting APTSTX1 aptamer using optical tweezers and molecular dynamics simulations

Autoři: Nathalie Casanova-Morales aff001;  Nataniel L. Figueroa aff001;  Karol Alfaro aff002;  Felipe Montenegro aff003;  Nelson P. Barrera aff003;  J. R. Maze aff001;  Christian A. M. Wilson aff004;  Pablo Conejeros aff002
Působiště autorů: Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile aff001;  CIGREN. Instituto de Biología. Facultad de Ciencias. Universidad de Valparaíso, Valparaíso, Chile aff002;  Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile aff003;  Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile aff004;  Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile aff005
Vyšlo v časopise: PLoS ONE 14(11)
Kategorie: Research Article
doi: 10.1371/journal.pone.0222468


Optical tweezers have enabled the exploration of picoNewton forces and dynamics in single–molecule systems such as DNA and molecular motors. In this work, we used optical tweezers to study the folding/unfolding dynamics of the APTSTX1–aptamer, a single-stranded DNA molecule with high affinity for saxitoxin (STX), a lethal neurotoxin. By measuring the transition force during (un)folding processes, we were able to characterize and distinguish the conformational changes of this aptamer in the presence of magnesium ions and toxin. This work was supported by molecular dynamics (MD) simulations to propose an unfolding mechanism of the aptamer–Mg+2 complex. Our results are a step towards the development of new aptamer-based STX sensors that are potentially cheaper and more sensitive than current alternatives.

Klíčová slova:

Biochemical simulations – Lasers – Magnesium – Microfluidics – Microspheres – Molecular dynamics – Simulation and modeling – Toxins


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2019 Číslo 11