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.
机构:
Univ Utah, Dept Biochem, Sch Med, Salt Lake City, UT 84132 USA
Univ Utah, Dept Chem, Salt Lake City, UT 84132 USAUniv Utah, Dept Biochem, Sch Med, Salt Lake City, UT 84132 USA
机构:
Univ Utah, Dept Biochem, Sch Med, Salt Lake City, UT 84132 USA
Univ Utah, Dept Chem, Salt Lake City, UT 84132 USAUniv Utah, Dept Biochem, Sch Med, Salt Lake City, UT 84132 USA