Part:BBa_K3003005

PelB-PenetraMax-SCI57-Linker

Single Chain Insulin 57 (SCI57) is used for insulin expression in the E. coli with a linker peptide. SCI57 is insulin analog that demonstrates high activity and ultrastability. We took SCI-57 design from the study “Design of an active ultrastable single-chain insulin analog: synthesis, structure, and therapeutic implications” done by Hua QX et al. SCI-57 differs from other single chain insulin analogs by modification in isoelectric points of determined amino acids and it was aimed for isoelectric points to be near as insulin. Binding affinity of SCI57 is considerably higher than the wild-type insulin. Linker peptide provides SCI57 to be expressed in E. coli as a single chain form. The linker peptide chosen for this part is taken from a 1996 patent design having the patent code EP0741188A2 of European Patent Office. Progression of wild-type insulin is processed in a 3 stage. Production of Pre-Proinsulin, Proinsulin and Insulin. Proinsulin contains c peptide between alpha and beta chain as a linker. C peptide is cleaved by secretory vesicles found in Golgi apparatus and final form of insulin is secreted by Beta Cells in pancreas. Due to the inefficiency of E. coli to cleave this peptide, insulin analogs which are expressed in a single chain insulin form with peptide linker that provides this formation. PenetraMax is a cell penetrating peptide which included in this part. Cell penetrating peptide is used in this part for SCI57 to penetrate the intestinal epithelium for getting through the bloodstream. Tobacco Etch Virus (TEV) Linker part’s function is providing recognition sequence for TEV enzyme to cut the protein of interest (SCI57) for releasing and bridge between Ag43 Alpha Subunit to be displayed in the surface.