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BP: Fachverband Biologische Physik

BP 26: From Single-Molecule to Tissue Dynamics

BP 26.1: Hauptvortrag

Donnerstag, 25. März 2010, 14:00–14:30, H43

Molecular misfolding investigated by mechanically unzipping nucleic acids — •Felix Ritort — Departament de Fisica Fonamental, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain) — CIBER-BBN of Bioengeneering, Biomaterials and Nanomedicine, ISCIII, Madrid (Spain)

Recent developments in micro and nano technologies allow for the controlled manipulation of individual molecules by exerting and detecting forces in the piconewton range. The possibility to detect such tiny forces together with the ability of measuring extensions with nanometer resolution allows scientists to monitor molecular reactions in real time (e.g. molecular folding) and characterize thermodynamics and kinetics of individual molecules (e.g. nucleic acids and proteins) with unprecedented energy accuracy within tenths of a kcal/mol.

Single molecule manipulation make possible to disrupt molecular bonds that hold native structures in nucleic acids and proteins. In this talk I will show experimental results on irreversibility and dissipation in nucleic acid hairpins that are mechanically unzipped using optical tweezers. Our aim is to explore complex molecular free energy landscapes and nonequilibrium behavior in small systems . For this we have designed DNA hairpins of specific sequences that exhibit molecular misfolding to investigate the role of irreversibility and dissipation during the folding process. Our results suggest the existence of a universal mechanism used by chaperones to assist molecular folding of RNAs and proteins.