Search results for "plasmon"
showing 10 items of 614 documents
Energy Transfer between Surface-Immobilized Light-Harvesting Chlorophyll a/b Complex (LHCII) Studied by Surface Plasmon Field-Enhanced Fluorescence S…
2010
The major light-harvesting chlorophyll a/b complex (LHCII) of the photosynthetic apparatus in green plants can be viewed as a protein scaffold binding and positioning a large number of pigment molecules that combines rapid and efficient excitation energy transfer with effective protection of its pigments from photobleaching. These properties make LHCII potentially interesting as a light harvester (or a model thereof) in photoelectronic applications. Most of such applications would require the LHCII to be immobilized on a solid surface. In a previous study we showed the immobilization of recombinant LHCII on functionalized gold surfaces via a 6-histidine tag (His tag) in the protein moiety. …
Template-Assembled Synthetic G-Quadruplex (TASQ): A Useful System for Investigating the Interactions of Ligands with Constrained Quadruplex Topologies
2010
A new biomolecular device for investigating the interactions of ligands with constrained DNA quadruplex topologies, using surface plasmon resonance (SPR), is reported. Biomolecular systems containing an intermolecular-like G-quadruplex motif 1 (parallel G-quadruplex conformation), an intramolecular G-quadruplex 2, and a duplex DNA 3 have been designed and developed. The method is based on the concept of template-assembled synthetic G-quadruplex (TASQ), whereby quadruplex DNA structures are assembled on a template that allows precise control of the parallel G-quadruplex conformation. Various known G-quadruplex ligands have been used to investigate the affinities of ligands for intermolecular…
Surface plasmons and vibrations of self-assembled silver nanocolumns
2006
6 pags. ; 5 figs. 1 tab.
Plasmonic Nanosensors for Simultaneous Quantification of Multiple Protein–Protein Binding Affinities
2014
Most of current techniques used for the quantification of protein-protein interactions require the analysis of one pair of binding partners at a time. Herein we present a label-free, simple, fast, and cost-effective route to characterize binding affinities between multiple macromolecular partners simultaneously, using optical dark-field spectroscopy and individual protein-functionalized gold nanorods as sensing elements. Our NanoSPR method could easily become a simple and standard tool in biological, biochemical, and medical laboratories.
2NH and 3OH are crucial structural requirements in sphingomyelin for sticholysin II binding and pore formation in bilayer membranes.
2013
AbstractSticholysin II (StnII) is a pore-forming toxin from the sea anemone Stichodactyla heliantus which belongs to the large actinoporin family. The toxin binds to sphingomyelin (SM) containing membranes, and shows high binding specificity for this lipid. In this study, we have examined the role of the hydrogen bonding groups of the SM long-chain base (i.e., the 2NH and the 3OH) for StnII recognition. We prepared methylated SM-analogs which had reduced hydrogen bonding capability from 2NH and 3OH. Both surface plasmon resonance experiments, and isothermal titration calorimetry measurements indicated that StnII failed to bind to bilayers containing methylated SM-analogs, whereas clear bind…
Sizzled Is Unique among Secreted Frizzled-related Proteins for Its Ability to Specifically Inhibit Bone Morphogenetic Protein-1 (BMP-1)/Tolloid-like …
2012
BMP-1/tolloid-like proteinases (BTPs) are major enzymes involved in extracellular matrix assembly and activation of bioactive molecules, both growth factors and anti-angiogenic molecules. Although the control of BTP activity by several enhancing molecules is well established, the possibility that regulation also occurs through endogenous inhibitors is still debated. Secreted frizzled-related proteins (sFRPs) have been studied as possible candidates, with highly contradictory results, after the demonstration that sizzled, a sFRP found in Xenopus and zebrafish, was a potent inhibitor of Xenopus and zebrafish tolloid-like proteases. In this study, we demonstrate that mammalian sFRP-1, -2, and …
Formation of irreversibly bound annexin A1 protein domains on POPC/POPS solid supported membranes
2008
AbstractThe specific interaction of annexin A1 with phospholipid bilayers is scrutinized by means of scanning force and fluorescence microscopy, quartz crystal microbalance, ellipsometry, and modeled by dynamic Monte Carlo simulations. It was found that POPC/POPS bilayers exhibit phase separation in POPC- and POPS-enriched domains as a function of Ca2+ concentration. Annexin A1 interacts with POPC/POPS bilayers by forming irreversibly bound protein domains with monolayer thickness on POPS-enriched nanodomains, while the attachment of proteins to the POPC-enriched regions is fully reversible. A thorough kinetic analysis of the process reveals that both, the binding constant of annexin A1 at …
Monitoring the formation of biosilica catalysed by histidine-tagged silicatein.
2004
Surface bound silicatein retains its biocatalytic activity, which was demonstrated by monitoring the immobilisation of silicatein using a histidine-tag chelating anchor and the subsequent biosilicification of SiO(2) on surfaces by surface plasmon resonance spectroscopy, atomic force microscopy and scanning electron microscopy.
A mid-IR Plasmonic Graphene Nanorectenna-based Energy Harvester to Power IoT Sensors
2022
In this paper, the design of a graphene arrow- bowtie nanoantenna mid-IR energy-harvester to power IOT wireless sensor is presented. For the first time, a sensitivity analysis of the mid-IR nanoantenna resonant frequencies in terms of different graphene number of sheets and chemical potential (μCP) without substrate and on a two-layer substrate composed of SiO2 and Si, is carried out. The obtained simulation results by 3D CST 2020 are useful to design an efficient infrared nanorectenna, composed of the nanoantenna and a rectifying MIM diode inside the gap. The analysis of the complete energy-harvester (EH), composed of an NxM nanorectenna array, a low-pass filter, and a DC-DC converter, is …
A Novel Plasmonic Nanoantenna for High Efficiency Energy Harvesting Applications
2020
In this paper, the results of a geometric investigation of plasmonic nanoantennas for energy harvesting applications in terms of field enhancement and available power are presented. Optimum performances are obtained by a particular arrow-shaped bowtie nanoantennas geometry. The novel nanoantenna geometry is here presented. The simulations of the novel nanoantennas made of aluminium, on a three-layers substrate, composed by silicon, silicon oxide, and aluminium, carried out with CST 2018 tool, are reported and compared with the classical bowtie nanoantennas ones. This study can guide both the engineering and the fabrication of plasmonic nanoantennas.