Single molecule unzipping of coiled coils: sequence resolved stability profiles.
We use a high resolution atomic force microscopy technique to mechanically unzip and rezip single coiled-coil proteins. This allows us to read off the complete stability profile of the protein turn by turn. We investigated three coiled coils with different length as well as a point mutation and find force fluctuations between 9 and 15 pN that can be directly related to the amino-acid sequences. An equilibrium model previously applied to DNA fully describes the mechanical unzipping process including free-energy contributions of the individual turns and seed formation energy.
Bornschlögl
Thomas
T
Physik Department E22, Technische Universität München, James-Franck-Strasse, D-85748 München, Germany.
Rief
Matthias
M