Detection of the conformational changes of Discosoma red fluorescent proteins adhered on silver nanoparticles-based nanocomposites via surface-enhanced Raman scattering. (14th February 2019)

• Record Type: Journal Article
• Authors: Scarangella, Adriana; Soumbo, Marvine; Mlayah, Adnen; Bonafos, Caroline; Monje, Marie-Carmen; Roques, Christine; Marcelot, Cecile; Large, Nicolas; Dammak, Thameur; Makasheva, Kremena
• Is Part Of: Nanotechnology. Volume 30:Number 16(2019)
• Publication Date: 2019-02-14
• Subjects: silver nanoparticles -- plasma deposition process -- plasmonic substrate -- surface-enhanced Raman scattering -- Discosoma red-fluorescent protein DsRed -- protein conformation; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/aaff79
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Description of the relationship between protein structure and function remains a primary focus in molecular biology, biochemistry, protein engineering and bioelectronics. Moreover, the investigation of the protein conformational changes after adhesion and dehydration is of importance to tackle problems related to the interaction of proteins with solid surfaces. In this paper the conformational changes of wild-type Discosoma recombinant red fluorescent proteins (DsRed) adhered on silver nanoparticles (AgNPs)-based nanocomposites are explored via surface-enhanced Raman scattering (SERS). Originality in the present approach is to work on dehydrated DsRed thin protein layers in link with natural conditions during drying. To enable the SERS effect, plasmonic substrates consisting of a single layer of AgNPs encapsulated by an ultra-thin silica cover layer were elaborated by plasma process. The achieved enhancement of the electromagnetic field in the vicinity of the AgNPs is as high as 10 5 . This very strong enhancement factor allowed detecting Raman signals from discontinuous layers of DsRed issued from solution with protein concentration of only 80 nM. Three different conformations of the DsRed proteins after adhesion and dehydration on the plasmonic substrates were identified. It was found that the DsRed chromophore structure of the adsorbed proteins undergoes optically assisted chemical transformations when interacting with the optical beam, which leads to reversible transitions between the three different conformations. The proposed time-evolution scenario endorses the dynamical character of the relationship between protein structure and function. It also confirms that the conformational changes of proteins with strong internal coherence, like DsRed proteins, are reversible.