Hybrid Conjugates Formed between Gold Nanoparticles and an Amyloidogenic Diphenylalanine-Cysteine Peptide

Author(s)

Pelin, Juliane N. B. D. ^[1] ; Gatto, Emanuela ^[2] ; Venanzi, Mariano ^[2] ; Cavalieri, Francesca ^{[2, 3]} ; Oliveira, Cristiano L. P. ^[4] ; Martinho, Herculano ^[1] ; Silva, Emerson R. ^[5] ; Aguilar, Andrea M. ^[6] ; Souza, Juliana S. ^[1] ; Alves, Wendel A. ^[1]

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre - Brazil

^[2] Univ Roma Tor Vergata, Dept Chem Sci & Technol, Rome - Italy

^[3] Univ Melbourne, Dept Chem & Biomol Engn, Melbourne, Vic - Australia

^[4] Univ Sao Paulo, Inst Fis, BR-05314970 Sao Paulo - Brazil

^[5] Univ Fed Sao Paulo, Dept Biofis, BR-04023062 Sao Paulo - Brazil

^[6] Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema - Brazil

• Document type: Journal article
• Source: CHEMISTRYSELECT; v. 3, n. 24, p. 6756-6765, JUN 29 2018.
• Web of Science Citations: 2

Abstract

We investigated the effect of gold nanoparticles (AuNPs) on the aggregation of a CFF (C=cysteine; F=phenylalanine) tripeptide (derived from A beta peptide) in aqueous medium. Special attention was dedicated to the role of AuNPs as inducers and inhibitors during nucleation kinetics and the structure of the resulting scaffolds was carefully investigated. At millimolar concentrations, the tripeptide was found to form beta-sheet structures organized into long filaments. Spectral signatures and topography of the filaments were studied by Raman spectroscopy and atomic force microscopy (AFM), revealing that conjugation to AuNPs not only stabilizes the system, but also inhibit or enhance amyloid-like features depending on the synthesis route used in the preparation of AuNPs. Sodium borohydride (NaBH4) mediated synthesis of AuNPs gave rise to a strong absorption peak close to 520nm, indicating that AuNPs were dispersed, independently of the peptide concentration added in the reaction. However, when the peptide/gold salt mixture was heated at 60 degrees C, AuNPs and AuNP-decorated filaments were both formed in solution and the fractions of which population were found to be dependent on the {[}HAuCl4]/{[}CFF] ratio, as illustrated by TEM images. In addition, the insertion of AuNPs at the surface of CFF nanostructures can promote electron transfer from the metallic nanoparticles to the CFF surface, creating an n-type semiconductor, and causing a peak shift of the phenylalanine absorption band. (AU)

• FAPESP's process: 15/24018-1 - Polymer-Peptide Conjugates for hydrogel formulation and its usage in detection
• Grantee: Wendel Andrade Alves
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/20446-9 - Study of auto-organization in solution of hierarchical structures of peptide in presence of metallic nanoparticles
• Grantee: Juliane Nogueira Batista Dias Pelin
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/24409-3 - Cell-Penetrating Peptides for Transport of Plasmid DNA and microRNA: from Nanoscopic Structure to Gene Delivery.
• Grantee: Emerson Rodrigo da Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
• Grantee: Marco Aurelio Zezzi Arruda
• Support Opportunities: Research Projects - Thematic Grants