Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Exploring Peptide Adducts on a Montmorillonite Clay Surface

Interactions between peptides and clay mineral surfaces are central to understanding biomolecule anchoring and surface recognition processes. In this work, density functional theory (DFT) calculations were employed to study arginylglycylaspartic acid (RGD) peptide adsorption on montmorillonite clay. As a key recognition motif in fibronectin protein that binds integrins and mediates cell adhesion, understanding RGD–clay interactions is vital for tissue regeneration and biomaterial engineering. Multiple protonation states and conformations (compact, flat, and unfolded) were modeled to identify the most stable adsorption geometries and binding energies. Charge density difference and magnetization density analyses were performed to assess the role of surface charge in stabilizing peptide–clay interactions. Simulated thermal desorption provided estimates for the temperature at which peptide detachment occurs. Results show distinct conformational preferences tied to protonation site and reveal how charge localization governs adsorption strength. These findings contribute to a molecular-level understanding of peptide–surface interactions relevant to biomineralization, adhesion, and early biochemical evolution.