PROTEIN ARCHITECTURE - ASSEMBLY OF ORDERE D FILMS BY MEANS ALTERNATEDADSORPTION OF OPPOSITE CHARGED MACROMOLECULES

Methods for creation of molecularly ordered protein films are reviewed with a special attention to the recently developed technique of prote in multilayer assembly by alternate adsorption of opposite charged pol yions. This method has been applied for linear and branced polyions, D NA, polynucleotides, proteins, viruses and clay nanoplates. That provi des good prospects for biomolecular architecture. Quartz crystal micro balance, X-ray and neutron reflectivity, scanning electron microscopy, AFM and UV-absorbance data are used for analysis of the film structur e. Multilayer buildup by alternation of polyions and 16 different char ged proteins is discussied. In most cases, enzymes in the films retain ed their activity. Protein/ceramic nanocomposites consisting of altern ating montmorillonite clay and glucose oxidase layers electrostaticall y connected through polycations were also assembled. Protein layers ma y be arranged according to specific biological activity. Sequential en zyme reactions were performed by preparation of anisotropic protein la yers 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 n onreacted starch were separated by filtration when the substrate solut ion passed these multienzyme films assembled on a filter. The formatio n of alternate outermost layers (the opposite charge or the opposite s pecificity) at every adsorption cycle is the key point of the layer-by -layer assembly. Thus, multiyaers were obtained by alternate adsorptio n of concanavalin A and glycogen (or streptavidin and biotinylated pol ylysine) were designed using their biospecific interaction. Protein fi lms are extremely interesting as novel biologically active materials.