Thermodynamics of adsorption of alcohol dehydrogenase on the gold nanoparticle surface: a model based analysis versus direct measurement

Abstract

Characterization of nanoparticle protein corona has gained tremendous importance lately. The parameters which quantitatively establish a specific nanoparticle-protein interaction need to be measured accurately since good quality data is necessary...

Exploring Enzymatic Conformational Dynamics at Surfaces through μ-FTIR Spectromicroscopy

“…This covalent interaction may also be responsible for the better homogeneity of ADH on the Au surface compared with the CaF 2 as the latter is stronger than the drag force hydrodynamic flow of the droplet . Additionally, spectroscopic analysis suggests a mechanism where the alteration of the Cys-Zn +2 cluster geometry in an α-helix structure (see Figure ) due to the interaction with Au or CaF 2 could be responsible for enzymatic activity variations, and complements recent studies regarding ADH adsorption monitored through second-harmonic light scattering …”

“…61 Additionally, spectroscopic analysis suggests a mechanism where the alteration of the Cys-Zn +2 cluster geometry in an αhelix structure (see Figure 5) due to the interaction with Au or CaF 2 could be responsible for enzymatic activity variations, and complements recent studies regarding ADH adsorption monitored through second-harmonic light scattering. 62 Figure 4c summarizes the deconvolution results for ADH immobilized on the Au-TGA surface. In this case, we observe around 25% of α-helical structure present at the center of the droplet, as well as 51% of β-sheets and 20% of β-turns.…”

Thermodynamics of multilayer protein adsorption on a gold nanoparticle surface

“…For ADH and insulin corona formation on GNPs, from second harmonic light scattering (SHLS) experiments we have earlier reported that monolayer binding of insulin and ADH is, indeed, happening at low protein concentrations. 11,52 To validate the adsorption parameters obtained from the three-parameter BET equation fit to the DLS data, we compared the equilibrium binding constant for the first layer (K s ) with the binding constant obtained from SHLS measurements done in our laboratory 11 under monolayer coverage conditions. We note that the values compare well and are of similar orders of magnitude.…”

“…have been derived from adsorption studies. 9,[11][12][13] A summary, Table 1, shows a brief survey of the adsorption studies of various proteins on spherical GNPs reported in the literature where an adsorption model was used to describe the binding quantitatively.…”

“…Earlier we have probed the NPC formation on the GNP surface and measured the thermo- dynamics of binding at ultralow concentrations using SHLS, fluorescence and DLS techniques. 9,11,16 At ultralow concentrations, ADH, insulin, and cytochrome c form a monolayer at nM protein concentrations and the data were fitted to a modified Langmuir adsorption isotherm. In this paper, we have followed the adsorption at much higher concentrations of proteins.…”