Gold Nanoparticle-Based Systems for Targeting the Ara h2 Allergen: A Molecular Modeling Approach

Arachis hypogaea 2 (Ara h2), the major peanut allergen responsible for severe allergic reactions in a large proportion of the population, is a key target for the detection of peanut allergenicity. In this study, the ability of gold nanoparticles functionalized with a peptide group to bind Ara h2 was investigated using molecular dynamics (MD) simulations. According to the structure of the peanut allergen Ara h2, which binds to a high-affinity IgE receptor, 130 amino acids of IgE have considerable interaction with the Ara h2 allergen. Therefore, a new peptide comprising these amino acids was designed as a functionalization agent for gold nanoparticles. To investigate the role of nanoparticle shape in the dynamics and interactions between Ara h2 and the designed systems, 2 shapes of gold nanoparticles were selected: rod-shaped (NR-Pep) and spherical (NP-Pep). Moreover, given the widespread use of phosphate-buffered saline (PBS) in experimental studies to mimic physiological conditions, its influence on the stability and behavior of the complexes was investigated alongside commonly used standard physiological conditions in MD simulations. MD simulations show that buffer conditions enhance the structural stability and compactness of the Ara h2@IgE complex. Based on these results, Ara h2 was substantially affected when interacting with functionalized gold nanoparticles (NP-Pep and NR-Pep). Among the studied nanoparticles, the rod (NR-Pep) forms a more stable complex with Ara h2 than do NP-Pep and IgE, which is the human receptor for the peanut allergen. Multiple analyses confirm that the designed nanoparticles are promising candidates for adsorbing the peanut allergen Ara h2.