Scil Proteins acquired a phage-display technology known as Tat Phage display from the German university patent exploitation agency, ipal, and Charité University Hospital. Scil will use the technology for the selection of Affilin® therapeutics against selected cancer, inflammation, and infectious disease targets.
In contrast to classical phage-display techniques that use the Sec-dependent transport system, the Tat Phage display method uses the twin-arginine-translocase (Tat) pathway for transport of proteins across the cytoplasmic membrane. Scil says this allows the transport of folded proteins in their native form.
The company has, to date, based its screening process on ribosome-display technology, which it accessed in 2006 through a cross-licensing deal with CAT/MedImmune. The company claims combining Tat Phage display with ribosome display will increase both speed and reliability of screening.
“Tat Phage display will significantly expand the range of applicable selection criteria available for an Affilin selection campaign,” comments Arnd Steuernagel Ph.D., Scil’s CSO. “In combination with our fully automated screening process, Affilin identification will become more flexible with regard to different target classes.”
Affilin molecules are small, nonimmunoglobulin proteins designed for selective binding of proteins and small molecules. Identified from diverse libraries, they are based on the human serum protein ubiquitin and can be produced efficiently in E. coli in soluble form, Scil maintains.
The specific binding activity of Affilin molecules occurs via the interactions of defined amino acids within a rather rigid surface-exposed beta sheet structure. This is in contrast with the flexible loop regions found in binding sites of immunoglobulins or alpha helical binding motifs of transcription factors.