EXPRESSION OF AN INSECT ANTIFUNGAL PROTEIN OF TENEBRIO-MOLITOR IN ESCHERICHIA-COLI

We previously isolated an antifungal protein, termed tenecin 3, from T enebrio molitor larvae, which inhibits growth of the fungus Candia alb icans. By using a cDNA sequence for tenecin 3, in this study, we have constructed plasmids expressing recombinant tenecin 3 proteins in Esch erichia coli. The recombinant tenecin 3 was expressed as fusions to ma ltose-binding protein (MBP) which were able to produce tenecin 3 and M BP moieties by cleavage with factor Xa protease. The MBP-tenecin 3 fus ion protein showed good repression of the growth of C. albicans and Cr yptococus neoformans, although the cleavage with factor Xa showed more inhibition on the fungal growth. The fusion protein, however, did not inhibit the growth of Aspergillus nidulans and Saccharomyces cerevisi ae regardless of the treatment with factor Xa, The results indicate th at the MBP fusion protein expression system provides a rapid and simpl e method for obtaining large quantities of active recombinant tenecin 3 in E. coli.