Posted: Jun 14, 2018
(Nanowerk News) Researchers of the Institute of Biotechnology and Biomedicine (IBB-UAB) have achieved to generate 4 peptides -molecules smaller than proteins - capable of self-assembling in a controlled manner to form nanomaterials. The research, published in the journal ACS Nano ("Minimalist Prion-Inspired Polar Self-Assembling Peptides"), was conducted by Salvador Ventura, Marta Díaz and Susanna Navarro (IBB-UAB), and included the collaboration of Isabel Fuentes and Francesc Teixidor (Institute of Materials Science of Barcelona (ICMAB-CSIC).
The new molecules are formed by a chain of 7 amino acids, each of which are made up of only two different amino acids; thus, significantly speeding up and reducing the price of the process of creation of functional synthetic amyloid structures with which to generate nanomaterials to be used in biomedicine and nanotechnology.
With the new heptapeptides, researchers from the IBB-UAB demonstrate that only four different types of amino acids, distributed in a specific manner and combined always with another fifth type, are enough to obtain the complete code needed to form synthetic prion fibres.
In biotechnology, generating functional synthetic amyloid structures to form nanostructures by imitating the natural generation process is not new. The assembly of proteins into stable fibres allows creating supramolecular shapes which no isolated protein can create, and which are used as nanoconductors, photovoltaic structures, biosensors and catalysts.
Quite recently, prion protein sequences – also amyloids – began to be imitated to form nanomaterials. The interest in these sequences lies in the fact that the proteins assemble in a slower and more controlled manner, forming highly ordered non-toxic nanostructures. However, the fact that the sequence is so long, with over 150 amino acids, makes it very difficult and expensive to synthesise.
“We have demonstrated that an adequate design can permit the size of synthetic prion sequences to be reduced down to only 7 amino acids, while conserving the same properties. The four peptides we have fabricated are the shortest structures of this type created until now and capable of forming stable fibril assemblies," explains Salvador Ventura, researcher at the IBB and the UAB Department of Biochemistry and Molecular Biology.
The peptides assemble to form miniature enzymes capable of acting as catalysts in the formation of nanomaterials such as the conductive polymer polypyrrole. (click on image to enlarge)
The new molecules have numerous applications, but researchers aim to focus on “the generation of electrical nanoconductors, and make use of the knowledge of the amyloid structure to generate synthetic fibres capable of being catalysts for new chemical reactions. The final objective will be to generate hybrid peptide-inorganic materials capable of making complex reactions, as those created by the photosystems of plants," the IBB researcher points out.
![heptapeptides](https://www.nanowerk.com/nanotechnology-news/id50433.jpg)
Examples Which Demonstrate Their Efficacy
In the study, researchers verified the stability and functionality of the four fabricated peptides. They built one of the most degradation-resistant biological nanomaterials described to date, nanocables covered in silver which can act as electrical nanoconductors and fibrillar mini enzymes capable of acting as catalysts in the formation of organic nanomaterials.![peptides assemble to form miniature enzymes](https://www.nanowerk.com/nanotechnology-news/id50433_1.jpg)