title: Nucleation of Amyloid Oligomers by RepA-WH1-Prionoid-Functionalized Gold Nanorods.
abstract: Understanding protein amyloidogenesis is an important topic in protein science, fueled by the role of amyloid aggregates, especially oligomers, in the etiology of a number of devastating human degenerative diseases. However, the mechanisms that determine the formation of amyloid oligomers remain elusive due to the high complexity of the amyloidogenesis process. For instance, gold nanoparticles promote or inhibit amyloid fibrillation. We have functionalized gold nanorods with a metal-chelating group to selectively immobilize soluble RepA-WH1, a model synthetic bacterial prionoid, using a hexa-histidine tag (H6). H6-RepA-WH1 undergoes stable amyloid oligomerization in the presence of catalytic concentrations of anisotropic nanoparticles. Then, in a physically separated event, such oligomers promote the growth of amyloid fibers of untagged RepA-WH1. SERS spectral changes of H6-RepA-WH1 on spherical citrate-AuNP substrates provide evidence for structural modifications in the protein, which are compatible with a gradual increase in β-sheet structure, as expected in amyloid oligomerization.
authors.affiliation: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas-CSIC, 28040, Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Fernández
authors.affiliation: Departamento de Química Física I, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain.|BioNanoPlasmonics Laboratory, CIC biomaGUNE, Donostia-, 20009, San Sebastián, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: González-Rubio
authors.affiliation: BioNanoPlasmonics Laboratory, CIC biomaGUNE, Donostia-, 20009, San Sebastián, Spain.
authors.forename: Judith
authors.initials: J
authors.lastname: Langer
authors.affiliation: Departamento de Química Física I, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Tardajos
authors.affiliation: BioNanoPlasmonics Laboratory, CIC biomaGUNE, Donostia-, 20009, San Sebastián, Spain.|Ikerbasque, Basque Foundation for Science, 48013, Bilbao, Spain.|Biomedical Research Networking Center in Bioengineering, Biomaterials, and Nanomedicine, CIBER-BBN, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán
authors.affiliation: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas-CSIC, 28040, Madrid, Spain. rgiraldo@cib.csic.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Giraldo
authors.affiliation: Departamento de Química Física I, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain. aguerrero@quim.ucm.es.
authors.forename: Andrés
authors.initials: A
authors.lastname: Guerrero-Martínez
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D004265:DNA Helicases / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D015534:Trans-Activators / Q000737:chemistry*
chemical_list: D000682:Amyloid; D015534:Trans-Activators; C045264:replication initiator protein; D006046:Gold; D004265:DNA Helicases
keywords: SERS; amyloidosis; gold nanorods; oligomers; prions