Computational Protein-Ligand Docking and Experimental Study of Bioplastic Films from Soybean Protein, Zein, and Natural Modifiers

Plant-based proteins are emerging at the forefront of functional food trends, as well as sustainable components for various environmentally friendly and sustainable polymeric materials. This study focuses on the application of a combined computational and experimental approach in the design of plant protein-based films from soy protein and zein (corn protein). This work, for the first time, shows the application of a computational protein-ligand docking approach in the design of protein-based films by modeling the intermolecular (non-covalent) interactions of selected renewable modifiers with plant proteins, which demonstrated the effect of the incorporated modifiers on the properties of protein-based films. Based on predictive modeling, we successfully prepared films experimentally based on both modified soy protein and zein protein which exhibit promising physical and mechanical behaviors. Adding natural additives to plant proteins of varying chemical structure yields a broad range of protein-based film properties. By the incorporation of natural plasticizers (glycerol and sorbitol) and a reinforcement agent (microfibrillated cellulose) into protein systems, more flexible films (elongation 2-120%) with Young's modulus of 99-400 MPa and higher surface hydrophobicity can be prepared, which confirmed the initial computational estimations. As a result, we found that the computational protein-ligand docking approach can be used as an effective and accurate method in guiding the experiment and predicting the physical properties of a film upon incorporation of modifiers into plant protein-based systems.