Developments in the use of baculoviruses for the surface display of complex eukaryotic proteins

The ability to couple genotype to phenotype has proven to be of immense val ue in systems such as phage display and has allowed genes encoding novel fu nctions to be selected directly from complex libraries. However, the comple xity of many eukaryotic proteins places a severe constraint on successful d isplay in Escherichia coli. This restriction could be resolved if a eukaryo tic virus could be similarly engineered for display purposes. Preliminary d ata have suggested that the baculovirus Autographa californica, a multiple nuclear polyhedrosis virus (AcMNPV) is a candidate for eukaryotic virus dis play because the insertion of peptides into the native virus coat protein, or the expression of foreign proteins as coat protein fusions, results in i ncorporation of the sequence of interest onto the surface of virus particle s. A variety of strategies are currently under investigation to develop fur ther the display capabilities of AcMNPV and to im prove the complexity of l ibrary that might be accommodated. Several expression vectors for different forms of surface display have been developed and, coupled with improved re combination strategies, represent progress towards a refined tool for use i n functional genomics and in vitro protein evolution.