Full distance-resolved folding energy landscape of one single protein molecule.
Kinetic bulk and single molecule folding experiments characterize barrier properties but the shape of folding landscapes between barrier top and native state is difficult to access. Here, we directly extract the full free energy landscape of a single molecule of the GCN4 leucine zipper using dual beam optical tweezers. To this end, we use deconvolution force spectroscopy to follow an individual molecule's trajectory with high temporal and spatial resolution. We find a heterogeneous energy landscape of the GCN4 leucine zipper domain. The energy profile is divided into two stable C-terminal heptad repeats and two less stable repeats at the N-terminus. Energies and transition barrier positions were confirmed by single molecule kinetic analysis. We anticipate that deconvolution sampling is a powerful tool for the model-free investigation of protein energy landscapes.
Physik Department E22, Technische Universität München, James Franck Strasse, 85748 Garching, Germany.
J Christof M
JC
Gebhardt
Thomas
T
Bornschlögl
Matthias
M
Rief
D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics; D055592:Biophysical Phenomena; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008969:Molecular Sequence Data; D052898:Optical Tweezers; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics; D013816:Thermodynamics
D050976:Basic-Leucine Zipper Transcription Factors; C501391:GCN4 protein, S cerevisiae; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins