Label-Free, Real-Time Interaction and Adsorption Analysis 1: Surface Plasmon Resonance

Abstract

A key requirement for the development of proteins for use in nanotechnology is an understanding of how individual proteins bind to other molecules as they assemble into larger structures. The introduction of labels to enable the detection of biomolecules brings the inherent risk that the labels themselves will influence the nature of biomolecular interactions. Thus, there is a need for label-free interaction and adsorption analysis. In this and the following chapter, two biosensor techniques are reviewed: surface plasmon resonance (SPR) and the quartz crystal microbalance (QCM). Both allow real-time analysis of biomolecular interactions and both are label-free. The first of these, SPR, is an optical technique that is highly sensitive to the changes in refractive index that occur with protein (or other molecule) accumulation near an illuminated gold surface. Unlike QCM ( Chapter 18 ) SPR is not affected by the water that may be associated with the adsorbed layer nor by conformational changes in the adsorbed species. SPR thus provides unique information about the interaction of a protein with its binding partners.

Conserved S/T Residues of the Human Chaperone DNAJB6 Are Required for Effective Inhibition of Aβ42 Amyloid Fibril Formation

“…The nonbinding (NBS) surface is a Corning proprietary treatment technology used on polystyrene microplates to create a nonionic hydrophilic surface [poly­(ethylene oxide)-based] that minimizes molecular interactions. These PEGylated plates were chosen on the basis of the finding that no Aβ42 binding to PEGylated surfaces could be detected by QCMD . The ThT fluorescence was measured every 120, 150, or 300 s under quiescent conditions at 37 °C using a Fluostar Optima plate reader (BMG Labtech, Offenburg, Germany) with excitation at 440 nm and emission at 480 nm.…”

Development of a surface plasmon resonance assay to measure the binding affinity of wild‐type influenza neuraminidase and its H274Y mutant to the antiviral drug zanamivir

“…Immobilizing (tethering) a ligand via a primary amine group to an activated SPR chip surface is convenient, rapid and simple. However, the steric proximity of the chip may have a significant effect on ligand binding by an analyte (Fee, ). To avoid the chip surface interfering with NA‐zanamivir binding, zanamivir was first conjugated to a spacer molecule that could present a single primary amine suitable for amine coupling.…”

Diagnosing dengue virus infection: rapid tests and the role of micro/nanotechnologies

“…Unlike QCM, SPR is not affected by water associated with the adsorbed layer nor by conformational changes in the adsorbed species. 87 Associated with the surface plasmon is an evanescent field that probes local changes induced in the refractive index of the ambient medium upon analyte binding, resulting in a measurable shift in the angle of incidence at which SPR excitation occurs. Monitoring this shift as a function of time yields a sensogram containing binding event information.…”