Self-Assembled Peptide Binding to Gold Nanoparticles

Self-assembled peptides have been a research focus for the last 50 years. At the same time, metallic nanoparticles have become a subject of interest, especially in the areas of photonics and surface plasmon enhancement. The properties of these two systems, combined with fluorescence, yield a very sensitive bio-assay. To achieve the biosensor, a De Novo peptide has been designed. This novel α-helix design contains a recognition motif for a TEV-protease as a model sensor. The prediction of the peptide structure is based on AI-based methods. AlphaFold [1] and PEP-FOLD [2] implementations of the AI algorithms have been used for the analysis. Experimental verification of the peptide properties have been achieved by solid phase peptide synthesis (SPPS) and followed by biophysical methods such as circular dichroism (CD) to verify the secondary structure, atomic force microscopy (AFM) to investigate the self-assembling properties of the gold nanoparticles (AuNPs) and surface plasmon resonance spectroscopy (SPR) for real-time binding and release studies. The experimental data are supplemented with molecular dynamics (MD) simulations. The self-assembly behaviour seen in the MD simulation agrees well with the images obtained by AFM. Simulation of peptide denaturation yields a denaturation temperature above 57∘C.