ИСТИНА

The development of medical adhesives is an important issue for healing tissue. Proteinbased glues are biocompatible and biodegradable [1]. Supercharged unfold peptides (SUP, Pic.1 (A)) are comparable to cyanoacrylates superglue in adhesion strength but in the case of SUP, an adhesion process runs without the formation of covalent bonds. This work is dedicated to the simulation of stoichiometric supercharged unfold peptides – sodium dodecyl benzyl sulfonate(Pic.1(B))/sodium dodecyl sulfonate (SUP-SDBS/SDS) complexes. SUP formed domains separated by surfactant with a thickness 0.8-1.7 nm. We measured a toughness of SUP-SDBS/SDS complex by splitting unit applied external forces (Pic.1 (C)). SDBS case was 1.5 times stronger than SDS case. It means complex toughness is provided by cation-π and π-π interactions and not by electrostatic interaction. The surfactant domain was the weakest part of complex because the hydrophobic interaction of dodecyl tails is weaker than cation-π interaction between charged moiety of peptide and aromatic part of SDBS. Only T-shaped type of the π-π interaction was observed. The presence of charged sulfonate group in surfactant could prevent the formation of other types of stacking. References:[1] Liu, Kai, D. Pesce, C. Ma, M. Tuchband, M. Shuai, D. Chen, J. Su, Q. Liu, J.Y. Gerasimov, A. Kolbe, W. Zajaczkowski, W. Pisula, K. Mьllen, N. Clark, A. Herrmann, Advanced Materials 27(15) (2015). Acknowledgements: The financial support of the Russian Science Foundation, project no. 15-13-00124 is gratefully acknowledged.