Regensburg 2016 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 3: Protein Structure and Dynamics

BP 3.6: Vortrag

Montag, 7. März 2016, 11:30–11:45, H44

Molecular dynamics study of the mechanical stability of dimeric coiled-coils under strain — •Chuanfu Luo, Ana Vila Verde, and Reinhard Lipowsky — Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany

Coiled-coils are ubiquitous folding motifs found in proteins. They consist of two alpha-helices wrapped around each other in a super helix configuration. In biological systems, coiled coils are highly versatile: they play an important role in various intracellular regulation processes as well as in membrane fusion. Their unusual structure suggests that it may also be possible to use them as biological force sensors to detect forces involved in biochemical processes in vivo. We investigated this possibility by carrying out Steered Molecular Dynamics to simulate the shear pulling of de novo designed coiled-coils with different lengths. We find that the pulling force at slow constant pulling speed is independent of either the total length or the contact length of the coiled-coils, and is the same as the force for unfolding a single alpha-helix. The results suggest that short coiled-coils under slow shear strain move via a dislocation mechanism: a defect is created at the pulled end of the helix and travels to the other end of the helix in tens of nanoseconds.