Theses and Dissertations

ORCID

0000-0002-9702-3756

Advisor

Fitzkee, Nicholas

Committee Member

Johnson, Christopher

Committee Member

Mlsna, Todd

Committee Member

Tanner, Eden

Committee Member

Emerson, Joseph

Date of Degree

8-12-2026

Original embargo terms

Visible MSU Only 1 year

Document Type

Dissertation - Campus Access Only

Major

Chemistry

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Arts and Sciences

Department

Department of Chemistry

Abstract

When nanoparticles enter biological or environmental systems, they are quickly coated by proteins, forming a protein corona that defines their biological identity, interactions, and fate. Despite many studies, a clear quantitative understanding of the molecular factors that control protein–nanoparticle interactions remains limited. In particular, an open question is how protein structure and stability influence binding energetics. In this dissertation, we aim to address this gap by combining thermodynamic analysis with biophysical characterization to develop a mechanistic understanding of how protein stability relates to nanoparticle binding behavior. Using polystyrene nanoparticles (PSNPs) as a model system and the GB3 protein, we analyzed a series of lysine-to-alanine variants using isothermal titration calorimetry and fluorescence denaturation experiments. The results reveal a strong correlation between binding affinity and protein structural stability in the presence of nanoparticles. Strongly binding proteins are more destabilized and tend to form monolayers, while weakly binding proteins are more likely to form multilayers. These findings provide direct thermodynamic evidence linking protein stability and nanoparticle binding behavior. To further explore this relationship, a host–guest framework was developed by substituting all 20 amino acids at a single position in the protein. A similar correlation between protein stability and binding affinity was observed, which was further developed into a predictive model to estimate binding affinity from high-throughput stability measurements. This approach provides a practical strategy for studying protein–nanoparticle interactions on a larger scale. Finally, structural changes during nanoparticle binding were quantified by analyzing the heat capacity changes obtained from temperature-dependent ITC experiments using the thermodynamic framework developed by Spolar and Record. This analysis estimates the number of residues undergoing folding or unfolding, providing a quantitative measure of conformational changes. Overall, this work establishes a direct connection between protein stability, conformational changes, and nanoparticle binding energetics, and provides a useful framework for predicting protein corona formation and designing nanomaterials with controlled biological interactions.

Sponsorship (Optional)

This work was supported by the National Science Foundation under awards OIA 2414443, and CBET 2405018. Support for the MSU NMR Facility was provided by the National Science Foundation under awards CHE/MCB 2304919 and DBI 2215258.

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