The SPP (Single Protein Production) System utilizes a modified version of Takara's cold shock expression vectors along with expression of the endoribonuclease mazF to achieve remarkable protein purity and stable isotopic labeling (up to 90% of the newly-synthesized protein) of target proteins.
Principle of the SPP System
The mazF (mRNA Interferase) protein is a sequence-specific endoribonuclease that specifically cleaves single-stranded RNAs at their ACA sequences. As a result, the expression of mazF virtually eliminates expression of most cellular mRNAs while allowing synthesis of the target protein for up to 72 hours post-induction. The SPP System for cold shock expression consists of two co-expressed plasmids: An ACA-less pCold expression vector for expression of an ACA-less version of the target gene, and a vector carrying the mazF gene for inducible expression of the mazF protein. This system suppresses host protein expression more effectively than the pCold system alone, resulting in higher purity and labeling efficiency for a wider variety of desired proteins. This also enables soluble protein expression applications such as structural analysis by NMR (nuclear magnetic resonance) or other technologies.
The SPP System was developed by Takara Bio in collaboration with Dr. Masayori Inouye at the University of Medicine and Dentistry of New Jersey, USA.