Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 28: Single Molecule Biophysics

BP 28.2: Vortrag

Donnerstag, 15. März 2018, 09:45–10:00, H 1058

Coiled Coils as structural building blocks: A sequence-based approach towards tuning Coiled Coil mechanics — •Patricia López-García, Melis Göktas, and Kerstin G. Blank — Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany

The natural abundance of coiled coil (CC) motifs in cytoskeleton and extracellular matrix proteins suggests that CCs play an important role as passive (structural) and active (regulatory) mechanical building blocks. It is well established that modifications in CC sequence, e.g. in hydrophobic core or solvent-exposed residues, are responsible for the thermodynamic stability of CCs; however, nothing is known about how these factors affect CC mechanics.

With the goal of shedding light on the sequence-structure-mechanics relationship of CCs we have chosen thermodynamically well-characterized sequences and analyzed their mechanical stability using single molecule force spectroscopy, applying force parallel to the helical axis in the shear geometry. Modifications in the hydrophobic core or the helix propensity alter the binding potential with different outcomes: a less tightly packed hydrophobic core increases the potential width without significantly affecting the barrier height (koff). In contrast, a reduced helix propensity decreases both potential width and barrier height. Our goal is to use this information for developing a library of mechanically characterized CCs that can be applied as calibrated building blocks for a wide range of applications: from molecular force sensors to mechanosensitive material crosslinks in protein nanostructures and synthetic ECM mimics.