Evaluation Study for Selection of an Appropriate Yeast Host

In contrast to the Hansenula and Arxula Feasibility Study, the Xplor Vector Study aims at comparative evaluation of qualitative differences in the recombinant protein expressed from different yeast species (e.g. Hansenula, Arxula, Pichia, Saccharomyces, Debaryomyces, Yarrowia). Differences in processing of protein precursor, in protein stability or in post-translational modification can be examined in such a study making use of the Xplor Vector. rDNA elements allow for stable integration of the expression cassette in all yeast species applied up-to-date for recombinant protein production. Auxotrophic marker or dominant resistance marker are chosen in the Xplor Vector System to select recombinant strains with single or multi-copy expression cassettes. A single promoter, the Arxula TEF1-promoter, enables constitutive expression of a heterologous gene in all species included in the study.

With this tool ARTES offers the possibility to generate information relevant for the best choice of a yeast expression system. The expression cassette used in this type of study may be excised from the Xplor Vector and applied newly in a Feasibility Study aiming at optimized generation of production cell lines in one selected yeast.

The Xplor Vector Study includes cloning of suitable expression cassettes, transformation and integration into selected yeast hosts, evaluation of expression level and preliminary qualitative comparison of recombinant proteins expressed.