The enzyme-mediated autodeposition of casein: effect of enzyme immobilization on deposition of protein structures

The enzyme-mediated autodeposition on the example of casein is reviewed, and deposition of casein structures is investigated in relation to applied immobilization methods of enzyme. First, casein is described in detail with respect to its structure in aqueous environments, followed by presentation of historical and current nonfood applications of casein. The presented process uses enzymes to trigger deposition of bio-based particles in close proximity to a support surface and allows for a high control over film formation and site-specificity. This is ensured by immobilization of enzyme on the support material. The herein described system is based on casein as protein and chymosin as enzyme. Different immobilization methods are investigated with respect to obtainable casein coatings, layers, and structures. Physical adsorption of enzyme enables the formation of casein coatings with controllable film thickness and is suitable for in situ buildup of adhesive layers due to diffusion of enzyme. The highest control over film formation is provided by covalent attachment of enzyme. Based on the attained results, the enzyme-mediated autodeposition gives new insights into biological material design. [GRAPHICS]