Production of heterologous proteins using S. cerevisiae expression system

Abstract

In the present work, yeast expression vectors bearing either thioredoxin-encoding gene fused with Abeta peptide (trx-ab) or its mutant sequence or glucose dehydrogenase gene fused with Abeta (GDH-ab) under the control of galactose-inducible CYC1-GAL promoter were constructed. After a successful transformation of yeast Saccharomyces cerevisiae strains, 3PMR-1, 21PMR and α’1 the eukaryotic producents of the hybrid proteins were isolated. Analysis of stability of heterologous expression plasmids indicated a 90–95% maintenance of auxotrophic markers and only 50% of that of trx-ab or GDH-ab genes. Optimization of cultivation allowed a synthesis of ~20 μg of thioredoxin-Abeta and GDH-Abeta proteins from 1 g of wet yeast biomass. Keywords: Saccharomyces cerevisiae, heterologous expression system, hybrid proteins, Abeta peptide, thioredoxin, glucose dehydrogenase