Biophysical Society Thematic Meeting - October 25-30, 2015

Polymers and Self Assembly: From Biology to Nanomaterials Poster Session I

44-POS Board 44 Material Characterization of Ultra-Short Peptides at Low and High Concentrations in Water Christophe Tarabout 1 , Carmen Valverde Tercedor 1 , Stephan Jokisch 2 , Luca Bertinetti 1 , Damien Faivre 1 . 1 Max planck institut for colloids and interfaces, Potsdam, Germany, 2 Universität Bayreuth, Bayreuth, Germany. Ultra-short peptides can be used for systematic mutation studies because of their simplicity and low cost. Understanding their self-assembly is important for controlling the growth of the structures and creating new biomaterials. Recently, a few teams have used bioinformatic methods to predict their potential for aggregation. We have taken the opposite approach and characterized a family of related short peptides from a material science point of view. For peptides at low concentrations in water, we observe in rheometry experiments that small changes in the sequence can modify the behavior from shear thinning to shear thickening. For peptides at high concentration, amorphous solids and fibers were studied using DSC, mechanical testing, X-ray diffraction and SEM. For some sequences, with the right amount of water, the materials could exhibit self-healing capacity. We will also report how replacement of counterions, modification of charge, size, aromaticity/aliphaticity, hydrophilicity/hydrophobicity and order of the aminoacid sequence affect the macroscopic material properties. The most noticeable effects are the material resistance to heating and propensity to absorb humidity. This study is a necessary step to understand and tune the properties of small peptides as new materials.

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