(Invited) Peptide Screening for the Regulation of Gold Nano-Biomineralization Using Peptide Array Technology

Abstract

Some peptides have been utilized in the functionalization of nanomaterials, the control of nanoparticle (NP) synthesis, as biotemplating for morphological control, and biocatalysts for the NP crystallization. The catalytic peptides used for NP synthesis, named biomineralisation peptides, generally demonstrate high specific binding to a target material, and are screened from a peptide library (e.g. phage display library). However, the properties of NPs synthesized, using such biomineralization peptides, cannot be predicted from screening process; thus the development of a rational peptide screening method which can be used to synthesize NPs with specific morphological and optical properties would greatly expand the potential of biomineralization peptides.Herein, we focused on gold, which is also used as an electrode material for sensors, and developed an efficient method for identifying peptides that bind to gold nanoparticles (AuNPs). Using the spot synthesis-based peptide array technique, AuNP binding activities of approximately 1,800 peptides were firstly evaluated and revealed various activities ranging from positive (high-affinity binding peptides) to negative (weak- or null-affinity binding peptides). Among 50 peptides showing the highest AuNP binding activity, 46 sequences showed the presence of tryptophan-based motifs including W[Xn]W, H[Xn]W, and W[Xn]H (W: tryptophan, X: any amino acid, n: 1 to 8 amino acid residues), whereas none of these motifs was found in the WORST50 peptides. Notably, by using peptide array comprising high-binding peptides, more than 100 sequences were discovered at once to have AuNP synthetic ability on the peptide array. In addition, the image analysis of peptide array disclosed the optical property information from synthesized AuNPs at each peptide spot. Subsequently, screened peptides were demonstrated as suitable agents for the one-pot aqueous-phase synthesis of AuNPs and optical properties shown in the solution were consistent with that of array. Furthermore, obtained AuNPs were characterized to three types regarding to their optical properties, which are red, green and blue. The particle sizes were around 8.9, 2.6 and 34.7 nm respectively. These techniques are show potential not only in improved AuNP biomineralizations, but also could be used in the synthesis of other inorganic nanomaterials, such as semiconductor and magnetic particles in ambient condition. In this talk, I will also present some research examples using peptide array technology for biosensor development. References Tanaka, M., et al., (2017) Acta Biomaterialia, 49, 495-506.Tanaka, M., et al., (2019) Nanoscale Adv., 1, 71-75.Tanaka, M., et al., (2020) Int. J. Mol. Sci., 21(7), 2377Komikawa, T., et al., (2020) Biosens. Bioelectron., 153, p112030 Figure 1