Effect of tryptophan residues on gold mineralization by a gold reducing peptide. Issue 66 (6th November 2020)

• Record Type: Journal Article
• Authors: Ozaki, Makoto; Yoshida, Shuhei; Oura, Maho; Tsuruoka, Takaaki; Usui, Kenji
• Is Part Of: RSC advances. Volume 10:Issue 66(2020)
• Page Start: 40461
• Page End: 40466
• Publication Date: 2020-11-06
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra07098j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Increasing the number of tryptophan (Trp) in peptides led to higher gold reducing ability and the peptides could disperse the generated gold-nanoparticles. Abstract : AuBP1, obtained by phage display selection, was previously shown to produce gold nanoparticles without reducing agents. The tryptophan (Trp) residue located at the N-terminus of this peptide contributes to the reduction of Au 3+ to Au 0 and is involved in the nucleation and crystal growth of gold nanoparticles. However, clear guidelines for relationships between the number of Trp residues in the peptide and its gold reducing ability have not been established. We focused on gold mineralization and attempted to elucidate aspects of the underlying mechanism. We performed a detailed evaluation of the effects of modifying the N-terminus of the core sequence on gold mineralization without reducing agents. Besides, advantages of utilizing peptides in manufacturing gold nanoparticles are shown. UV-Vis measurements, TEM observations, and kinetic analyses were used to show that increasing the number of Trp residues in the peptide increases the reducing ability, causing predominance of the nucleation reaction and the production of small gold nanoparticles. In addition, these peptides also had the ability as a dispersant to protect the surface of gold nanoparticles. Furthermore, the catalytic activity of mineralized gold nanoparticles with peptides was higher than that of a commercial gold nanoparticle. This study should help to elucidate the relationship between peptide sequence and mineralization ability for use in materials chemistry.