The Baculovirus expression system as a tool for generating diversity by viral surface display

It has become a major goal of molecular biologists, biochemists, and immuno logists to be able to modulate the structure of proteins, in order to incre ase their antigenicity, alter their biological properties and/or explore th eir function. Based on the concept of bacterial phage display, by which pro teins are being selected and analyzed in conjunction with their genetic inf ormation, eukaryotic systems have been investigated for their use in genera ting biomolecular diversity. The advantage of posttranslational modificatio n and the possible harbouring of structural complex proteins has lead scien tists to include eukaryotic systems in the wide field of molecular design. The ideal expression vectors for surface display are eukaryotic viruses, th at allow large gene insertions, efficiently present foreign proteins on the particle surface, are easy to propagate and, if possible, not pathogenic t o humans. By inserting peptides into a native virus coat protein or by expr essing foreign proteins as coat protein fusion proteins or linked to specif ic anchor domains it becomes possible to display polypeptides of interest o n the surface of replicating particles. A variety of different strategies a re currently under investigation in order to utilize the baculovirus insect cell expression system for efficient display on the surface of virus parti cles as well as on the surface of virally infected insect cells. Increasing the transfection efficiency, optimizing cloning procedures, and establishi ng applicable selection methods have lead to the development of a powerful tool for drug screening and ligand screening.