Biophysical Society Thematic Meeting - October 25-30, 2015

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

20-POS Board 20 Highly Oriented, Epitaxially Generated Beta-amyloid-based Nanoarray for Nanobiotechnological Applications Róbert Nagy 1 , Gábor Olajos 2 , Vivien Hársfalvi 1 , Ünige Murvai 1 , Lívia Fülöp 3 , Botond Penke 3 , Tamás Martinek 2 , Miklós S. Kellermayer 1 . 1 Semmelweis University, Budapest, Hungary, 3 University of Szeged, Szeged, Hungary. 2 University of Szeged, Szeged, Hungary, The self-assembly of biomolecular systems are of fundamental appeal for nanobiotechnological applications. However, the lack of easy chemical access and nano- to micro-scale structural order often hinders the nanotechnological use of conventional biomolecules. We have previously shown that the amyloid beta 25-35 peptide (Aß25-35) forms a trigonally oriented network on mica by epitaxial mechanisms. To enhance the chemical reactivity and the structural complexity of this nano-network, here we synthesized and utilized a chemically accessible mutant and various Aß-foldamer chimeras. Oriented network of amyloid fibrils was generated by incubating mutant, Aß25-34_N27C peptides or its wild-type mixtures on mica at varying KCl concentrations. To functionalize the fibrils we used maleimido-nanogold (1.4 nm). As evidenced by high-resolution atomic-force microscopy, we were able to tune the average length of the amyloid fibrils by adjusting the peptide and KCl concentrations. In the nanogold-labeled amyloid network spherical particles of 1.4-nm diameter lined up along the oriented fibrils, demonstrating that the fibrils can indeed be chemically addressed and functionalized. The Aß-foldamer chimeras were conjugates of an Aß25-29 peptide and a 2-aminocyclopentane-carbonic acid hexamer located at the N- and C-terminals, respectively. We found that the Aß-foldamer chimeras formed, on a time-scale of minutes, trigonally oriented network on mica in which the individual fibrils reached lengths up to several microns. Apparently the Aß component is responsible for the oriented surface binding and epitaxis, while the foldamer enhances the assembly of extended fibrils. In sum, the oriented amyloid-based network may be used towards the construction of functional biomolecular nanoarrays with complex, tunable geometries and properties.

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