Grups de recerca
23
juny
Seminari: Thomas T. Perkins
Benvolguts/Benvolgudes, Thomas Perkins de la Universitat de Colorado Boulder estarà de visita al grup del Fèlix Ritort al juny i s'ha organitzat un seminari on tindrem l'oportunitat de sentir el Dr, Thomas T. Perkins parlar sobre la dinàmica de sistemes biomoleculars mitjançant l’ús de microscòpia de força atòmica. El seminari serà el dijous 23 de juny a les 12h a l'aula 320 de P3.
Dates:
23-06-2023
Horari:
12:00
Lloc:
Seminar room 320, 3rd floor of the Faculty of Physics, UB
Afegeix-ho a l'agenda (iCal)
Probing the hidden dynamics and energetics of diverse biomolecular systems by AFM
Thomas T. Perkins (tperkins@colorado.edu)
JILA, NIST & University of Colorado, Boulder, CO, USA.
Atomic force microscopy (AFM)-based single-molecule force spectroscopy enables a wide array of studies, from measuring the strength of a ligand-receptor bond to elucidating the complex unfolding pathway of individual membrane proteins. Such studies and, more generally, the diverse applications of AFM across biophysics and nanotechnology are improved by enhancing the force stability, force precision, and time resolution of bio AFM. For an advanced, small-format commercial AFM, we uncovered how these three metrics were limited by the cantilever itself rather than the larger microscope structure, and then describe three increasingly sophisticated cantilever modifications using a focused ion beam that yielded enhanced data quality. High-precision single-molecule studies of membrane proteins—the target for over 50% of current and future drugs—have lagged analogous studies of globular proteins due to instrumental limitations. We revisited the unfolding of the canonical membrane protein bacteriorhodopsin with a 100- fold improvement in time resolution and a 10-fold improvement in force precision. The resulting data revealed the unfolding pathway in unprecedented detail. Toward the broader goal of measuring quantitative energetics, we leveraged these rapid and reversible dynamics to reconstruct the 1D free-energy landscape of bacteriorhodopsin’s initial unfolding to determine the free-energy change (ΔΔG0) for select point mutants. Hence, we established a platform for precisely quantifying membrane-protein energetics under native-like conditions. I will conclude by discussing extensions of this capability to other diverse biomolecules, including nucleic-acid structures and globular proteins involved in pathogenesis.
