Hydration and Energy Dissipation Measurements of Biomolecules on a Piezoelectric Quartz Oscillator by Admittance Analyses

Abstract

By using a 27-MHz piezoelectric quartz oscillator connected with a vector network analyzer, we obtained resonance frequency decreases (-DeltaFwater) and energy dissipation increases (DeltaDwater) during binding of biotinylated bovine serum albumin, biotinylated ssDNA, biotinylated dsDNA, and biotinylated pullulan to a NeutrAvidin-immobilized 27-MHz quartz crystal microbalance (QCM) plate in aqueous solution, as well as in the wet air phase (98% humidity, -DeltaFwet and DeltaDwet) and in the dry air phase (-DeltaFair and DeltaDair). -DeltaFwater indicates the total mass of the molecule, bound water, and vibrated water in aqueous solutions. -DeltaFwet indicates the total mass of the molecule and bound water. -DeltaFair simply shows the real mass of the molecule on the QCM. In terms of results, (-DeltaFwet)/(-DeltaFair) values indicated the bound water ratios per unit biomolecular mass were on the order of pullulan (2.1-2.2) > DNAs = proteins (1.4-1.6) > polystyrene (1.0). The (-DeltaFwater)/(-DeltaFair) values indicated the hydrodynamic water (bound and vibrated water) ratios per unit biomolecular mass were on the order of dsDNA (6.5) > ssDNA = pullulan (3.5-4.4) > proteins (2.4-2.5) > polystyrene (1.0). Energy dissipation parameters per unit mass in water (DeltaDwater/(-DeltaFair)) were on the order of pullulan > dsDNA > ssDNA > proteins > polystyrene. Energy dissipation in the wet and dry air phases (DeltaDwet and DeltaDair) were negligibly small, which indicates even these biomolecules act as elastic membranes in the air phase (without aqueous solution). We obtained a good linear relationship between [(-DeltaFwater)/(-DeltaFair) - 1], which is indicative of hydration and DeltaDwater/(-DeltaFair) of proteins. The aforementioned values suggest that the energy dissipation of proteins was mainly caused by hydration and that proteins themselves are elastic molecules without energy dissipation in aqueous solutions. On the contrary, plots in cases of denatured proteins, DNAs, and pullulans were relatively deviant toward the large hydration and energy dissipation from the theoretical line as perfect elastic materials, meaning that the large energy dissipation occurs because of viscoelastic properties of denatured proteins, linear DNAs, and pullulans in the water phase, in addition to energy dissipation due to the hydration of molecules. These two parameters could characterize various biomolecules with structural properties in aqueous solutions.

Influence of the molecular architecture on the adsorption onto solid surfaces: comb-like polymers

“…Olanya et al 43 have pointed out that an increase in the dissipation factor is associated with a lower entropic contribution. This assumption was also used by Ozeki et al 44 in the analysis of the binding processes of different biopolymers to the quartz crystal sensor. Fig.…”

Application of Quartz Crystal Microbalance as a Tool for Detergency Evaluation of Fatty Acid Contamination in Aqueous Systems

“…In a liquid medium, the mass change calculated from the QCM frequencies before and after the SA-LB film deposition by the Sauerbrey equation 15 is lesser than the actual deposited mass because of the missing mass effect 16,17 .…”

Development of a combined surface plasmon resonance/surface acoustic wave device for the characterization of biomolecules

“…• Water will be coupled to most biomolecules in the form of a rigidly attached hydration shell and / or in the form of viscous drag [2], [10], [21].…”

“…• As a result of the latter, acoustic sensors are sensitive to size and shape of the target molecule [10], [11], [22]. This is important since the conformation and shape of a biomolecule can change as a result of a biochemical reaction or a change in environmental conditions [6], [10], [11].…”

“…This is important since the conformation and shape of a biomolecule can change as a result of a biochemical reaction or a change in environmental conditions [6], [10], [11].…”