Molecular film assembly via layer-by-layer adsorption of oppositely charged macromolecules (linear polymer, protein and clay) and concanavalin A and glycogen

Protein multilayer assemblies were prepared by two different methods: (1) alternate adsorption of oppositely charged polyions; (2) alternate adsorption with specific enzyme/substrate interaction. The formation of alternate outermost layers (opposite charge or opposite specificity) at each adsorption cycle is the key point of the procedure. Three modes of polyion film assembly were demonstrated: (a) alternation of linear polyanions and polycations; (b) insertion of charged particles in the multilayer at every other step (twelve different globular proteins were assembled alternating with Na (poly (styrenesulfonate), poly(ethyleneimine)) or Cl (poly(diallyldimethylammonium))); (c) alternation of polyions and preformed charged plates: delaminated montmorillonite clay. Specific interaction was obtained between consecutive layers of glycogen and concanavalin A. Concanavalin A possesses four binding sites for its ligand D-glucose and allows the binding of glycogen (branched poly (glucose)) layers on both sides of the protein.