Heterologous expression of the plant proteins strictosidine synthase and berberine bridge enzyme in insect cell culture

The heterologous expression of cDNAs encoding the alkaloid biosynthetic enzymes, strictosidine synthase [EC 4.3.3.2] from Rauvoifia serpentina and the berberine bridge enzyme [(S)-reticuline: oxygen oxidoreductase (methylene-bridge-forming), EC 1.5.3.9] from Eschscholtzia californica, has been achieved in a cell culture (Sf9) of the fall army worm, Spodoptera frugiperda, using a baculovirus-based expression system. The expression resulted in the overproduction of each plant enzyme in a catalytically active form. The maximal production attained was 4 mg purified, active enzyme per litre cell culture for both the strictosidine synthase and berberine bridge enzymes.