we have developed our own permeable yeast strain!

As the yeast two-hybrid experts we have adapted our technologies to identify small molecules that inhibit protein-protein interactions. For this purpose, Hybrigenics has developed a variety of specific tools and know-how:
  > Y2H strains (Gal4 and LexA system) were genetically
     engineered to increase
     their permeability to small molecules by more than two
     orders of magnitude compared to the parental strains.
  > a variety of Y2H vectors that allow to fine-tune the interaction
     signal and facilitate its inhibition.

In-yeast interaction assay principle. Interaction between Protein1 and Protein2 is detected by reporter gene transcription in yeast. To increase compound efficacy, Hybrigenics permeable Yeast Two-Hybrid strains are deleted in ATP binding cassette transporters and transcriptional regulators. Screening can be performed in plates or in liquid cultures using quantitative b-Galactosidase assays. Compound toxicity to yeast cells is evaluated and used to normalize the results.