Significance of Knotted Structures for Function of Proteins and Nucleic Acids - September 17-21, 2014

Significance of Knotted Structures for Function of Proteins and Nucleic Acids

Poster Session I

12 – POS Board 12 Chirality Transfer between the Helical Flow and Chiral Particles Magdalena Gruziel 1,2 , Piotr Szymczak 1 . 1 University of Warsaw, Faculty of Physics, Warsaw, Poland, 2 University of Warsaw, ICM, Warsaw, Poland. Helical structures are abundant in nature: from alpha-helical motifs in proteins, or DNA strands, through coiled-coil protein structures to protein fibrils or microtubules. The latter examples are particularily interesting as these macromolecular aggregates, although built from identical achiral ''bricks'' (either beta-strands of peptides for protein fibrils or tubulin dimers for microtubules) are nevertheless chiral. What is even more interesting, especially with regard to protein fibrils, is the observation of structures with opposite handedness that aggregated from identical monomers, however at different conditions (such as temperature, or intensity of vortexing) [1]. Other experiments, at micrometer scale, demonstrated that enantiomers of simple epoxy-based particles can be separated by helical flow [2]. Thus, a question arises, whether a flow can influence the handedness of a growing structure? Or, in particular, whether the flow of non-zero helicity could determine the handedness of bistable, chiral particles? We explore the latter question with numerical simulations of simple particles that can assume two different conformarions of equal energy but opposite chiralities. [1] A.Loksztejn and W.Dzwolak, Chiral bifurcation in aggregating insulin: an induced circular dichroism study, J. Mol. Biol., 2008, 379 [2] M.Aristov, R.Eichhorn, and C.Bechinger, Separation of chiral colloidal particles in a helical flow field, Soft Matter, 2013, 9

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