His-FLAG Tag as a Fusion Partner of Glycosylated Human Interferon-Gamma and Its Mutant: Gain or Loss?

ABSTRACT: In order to obtain glycosylated human interferon-gamma (hIFNγ) and its highly prone to aggregation mutant K88Q, a secretory expression in insect cells was employed. To facilitate recombinant proteins purification, detection, and stability the baculovirus expression vectors were constructed to bear N-terminal His₆-FLAG tag. Although the obtained proteins were glycosylated, we found that their biological activity was 100 times lower than expected. Our attempts to recover the biological properties of both proteins by tag removal failed due to enterokinase resistance of the tag. Surprisingly, the tag was easily cleaved when the proteins were expressed in E. coli cells and the tag-free proteins showed fully restored activity. To shed light on this phenomenon we performe

SUBMITTER: Krachmarova E 

PROVIDER: S-EPMC5480026 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature