Native and Unfolded States of Phosphoglycerate Kinase Studied by Single-Molecule FRET

✍ Scribed by Tobias Rosenkranz; Dr. Ramona Schlesinger; Matteo Gabba; Dr. Jörg Fitter

• Book ID: 102812521
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 758 KB
• Volume: 12
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.201000701

✦ Synopsis

Abstract

Single‐molecule Förster resonance energy transfer (FRET) measurements with phosphoglycerate kinase from yeast were performed at different concentrations of guanidine hydrochloride. From these steady‐state measurements we obtained FRET efficiency histograms characterizing structural properties of individual proteins at different stages between the native and the fully unfolded state. Native proteins exhibit a slightly more expanded structure under buffer conditions without denaturant as compared to conditions with denaturant. At 0.5 M GndHCl an unfolded state population that exhibits a significantly expanded structure as compared to the native state, emerges. The unfolded state is characterized by a pronounced broadening of the efficiency distribution, which indicates a large structural and/or dynamical heterogeneity within the population. At high denaturant concentrations, well above the unfolding transition at C~1/2~∼0.7 M, we observe a progressive expansion of the protein structure, namely globule–coil transition.