PNNL

Abstract

Understanding the binding interactions of complexes of multiple proteins is an important area of medical research since many biological signaling pathways involve multiple protein complexes. A number of sensor technologies have been adapted to monitoring biomolecular interactions. Acoustic wave devices such as flexural plate wave devices, surface transverse waves, and quartz crystal microbalances detect the mass increase observed upon binding of a solution biomolecule to a surface bound biomolecule. However, these devices will also respond to changes in viscosity, temperature, liquid density, and viscoelastic effects, which may confound the interpretation of observed signals. Nonspecific binding is indistinguishable from specific binding. Several techniques for refractive index sensing, such as planar wave guides and surface plasmon resonance (SPR), can also be used to observe biomolecular interactions localized at a surface. Again, nonspecific binding is indistinguishable from specific binding. In addition, the derivatized surface must be very thin and uniform to obtain adequate sensitivity and reproducibility, and the technique is not suited for monitoring large mulitple protein complexes since the measurement sensitivity decreases rapidly with distance from the sensor surface. All of these techniques use planar surfaces that are difficult to prepare and characterize, and must be prepared fresh for each assay.