Methods for creation of molecularly ordered protein films are reviewed with a special attention to the recently developed technique of protein multilayer assembly by alternate adsorption of opposite charged polyions. This method has been applied for linear and branced polyions, DNA, polynucleotides, proteins, viruses and clay nanoplates. That provides good prospects for biomolecular architecture. Quartz crystal microbalance, X-ray and neutron reflectivity, scanning electron microscopy, AFM and UV-absorbance data are used for analysis of the film structure. Multilayer buildup by alternation of polyions and 16 different charged proteins is discussied. In most cases, enzymes in the films retained their activity. Protein/ceramic nanocomposites consisting of alternating montmorillonite clay and glucose oxidase layers electrostatically connected through polycations were also assembled. Protein layers may be arranged according to specific biological activity. Sequential enzyme reactions were performed by preparation of anisotropic protein layers and precise control of distances between active layers (1-50 nm). Film superlattices containing ordered layers of more than one protein were constructed with myoglobin, lysozyme, peroxidase, glucoamylase, glucose oxidane and catalase. Glucoamylase glucose oxidase/peroxidase catalyse the reaction starch-glucose-H2O2. The reaction products and nonreacted starch were separated by filtration when the substrate solution passed these multienzyme films assembled on a filter. The formation of alternate outermost layers (the opposite charge or the opposite specificity) at every adsorption cycle is the key point of the layer-by-layer assembly. Thus, multiyaers were obtained by alternate adsorption of concanavalin A and glycogen (or streptavidin and biotinylated polylysine) were designed using their biospecific interaction. Protein films are extremely interesting as novel biologically active materials.
|Number of pages||3|
|Publication status||Published - 1997|