title: Modulation of Plasmon-Enhanced Resonance Energy Transfer to Gold Nanoparticles by Protein Survivin Channeled-Shell Gating.
abstract: The resonance energy transfer (RET) from excited fluorescent probe molecules to plasmonic gold nanoparticles (AuNPs) can be gated by modulating the width of channels (gates) in submonolayer protein shells surrounding AuNPs. We have explored the gated-RET (gRET) processes using an antiapoptotic protein survivin (Sur) as the gating material, citrate-capped gold nanoparticles (AuNP@Cit), and fluorescein isothiocyanate as the fluorescent probe. Despite the electrostatic repulsive forces between these components, a strong modulation of RET efficiency by Sur down to 240 pM (S/N = 3) is possible. Using piezometric measurements, we have confirmed the Sur adsorbability on Cit-coated Au surfaces with monolayer coverage: γSur = 5.4 pmol/cm(2) and Langmuirian adsorption constant KL,Sur = 1.09 × 10(9) M(-1). The AuNP@Cit/Sur stability has been corroborated using resonance elastic light scattering. The quantum mechanical calculations indicate that multiple hydrogen bonding between Cit ligands and -NH3(+), =NH2(+), and -NH2 groups of lysines and arginines of Sur have likely facilitated Sur bonding to nanoparticles. A theoretical model of gated-RET has been developed, enabling predictions of the system behavior. In contrast to the positive slope of the Stern-Volmer quenching dependence (F0/F) = f(QA), a negative slope has been obtained for gRET relationship (F0/F) = f(cP), attributed to the dequenching.
authors.affiliation: Department of Biophysics, Warsaw University of Life Sciences (SGGW) , 02776 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Stobiecka
authors.affiliation: Institute of Nanoparticle Nanocarriers , 11010 Barczewo, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Chalupa
mesh_terms: D000327:Adsorption; D004735:Energy Transfer; D006046:Gold / Q000737:chemistry*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D000077022:Survivin
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D000077022:Survivin; D006046:Gold