Protein adsorption on nanostructured silica surfaces
type: CreativeWork
description: This Ph.D. thesis presents a study of the interaction of globular proteins with nanostructured silica surfaces. It aims to gain a better understanding of the consequences of a high surface curvature and confinement on the adsorption behavior and morphology of the adsorbed protein. The adsorption behavior of lysozyme and 𝛽-lactoglobulin on silica nanoparticles was studied from pH 2 to 11 and ionic strength until 100 mM. Within this pH range the surface charge distribution on proteins and silica changes drastically. Specifically it was possible to study the interactions between particles and 𝛽-lactoglobulin on both sides of the isoelectric point of the protein. Resulting data were evaluated with the Guggenheim – Anderson – de Boer adsorption isotherm equation which accounts for multilayer adsorption from liquid phases. The orientation of the globular protein cytochrome c adsorbed on silica nanoparticles was determined as a function of solution pH using small angle neutron scattering. The scattering data was evaluated with a form factor model accounting specifically for 'raspberry-shaped' structures. A pronounced shift in the adsorption orientation relative to the particle surface was detected between pH 3 and 4. This behavior was correlated with the dipole moment of the protein. Simulations of the dipole moment for different protonation states of cytochrome c show a distinctive change in the dipole moment orientation for the same pH region. In preceding studies it was found that protein adsorption can cause hetero-aggregation of the silica nanoparticles. Here, the large-scale structure of these aggregates was studied by confocal laser scanning microscopy with fluorescently labeled lysozyme. Stacks of 2D images were used to reconstruct the 3D aggregate structure and estimate the global structural properties in terms of their surface-area-to-volume ratio. Protein uptake in nanometer-sized pores depends on the accessible pore space and the interaction of the protein with…
abstract: This Ph.D. thesis presents a study of the interaction of globular proteins with nanostructured silica surfaces. It aims to gain a better understanding of the consequences of a high surface curvature and confinement on the adsorption behavior and morphology of the adsorbed protein. The adsorption behavior of lysozyme and 𝛽-lactoglobulin on silica nanoparticles was studied from pH 2 to 11 and ionic strength until 100 mM. Within this pH range the surface charge distribution on proteins and silica changes drastically. Specifically it was possible to study the interactions between particles and 𝛽-lactoglobulin on both sides of the isoelectric point of the protein. Resulting data were evaluated with the Guggenheim – Anderson – de Boer adsorption isotherm equation which accounts for multilayer adsorption from liquid phases. The orientation of the globular protein cytochrome c adsorbed on silica nanoparticles was determined as a function of solution pH using small angle neutron scattering. The scattering data was evaluated with a form factor model accounting specifically for 'raspberry-shaped' structures. A pronounced shift in the adsorption orientation relative to the particle surface was detected between pH 3 and 4. This behavior was correlated with the dipole moment of the protein. Simulations of the dipole moment for different protonation states of cytochrome c show a distinctive change in the dipole moment orientation for the same pH region. In preceding studies it was found that protein adsorption can cause hetero-aggregation of the silica nanoparticles. Here, the large-scale structure of these aggregates was studied by confocal laser scanning microscopy with fluorescently labeled lysozyme. Stacks of 2D images were used to reconstruct the 3D aggregate structure and estimate the global structural properties in terms of their surface-area-to-volume ratio. Protein uptake in nanometer-sized pores depends on the accessible pore space and the interaction of the protein with…
author: Meißner, Jens
language: en
license: http://rightsstatements.org/vocab/InC/1.0/
date published: 2018
date modified: 2026-07-27T21:28:26Z
provider: Technische Universität Berlin
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Technische Universität Berlin

PropertyValue
property ID: DOI
value: 10.14279/depositonce-6751