Studies on the Molecular Interactions between Plant-Derived Protein Zein and Small Molecules

Zein, a kind of plant-derived natural polymer, has a unique self-assembly behavior due to its unique structure and is an ideal material for the preparation of nanocarriers. The present study aims at detecting molecular interactions and affinity between zein and small molecules with different polarities by employing UV spectroscopy, dynamic laser light scattering, and fluorescence spectroscopy to provide some reference for the development and utilization of zein-based nanocarriers. The ethanol concentration dependent solubility and UV spectra were confirmed and compared. The hydrodynamic diameter, ζ potential, and productivity of resultant nanoparticles were comprehensively collected to evaluate the self-assembly behaviors of zein. The fluorescence correlation spectroscopy and thermodynamic principle were used to analyze the noncovalent interaction between zein and small molecules. The main driving force between hydrophobic 8-anilinonaphthalene-1-sulfonic acid (ANS) and zein is hydrophobic force, while those with hydrophilic rhodamine B are hydrogen bonds and van der Waals forces.