BRP Plasmids
Bacteriocin Release Protein (BRP) Plasmids

APPLICATIONS

• Release of periplasmic or cytoplasmic proteins into the culture medium does not require a signal sequence
• Release of toxic proteins allows expression of "lethal" sequences.
• Prevent protein degradation by cytoplasmic proteinases
• Avoid inclusion body formation
• Large scale production of proteins in continuous culture
• Purify proteins from the culture medium

The plasmids pJL3 and pSW1 express the Bacteriocin Release Protein (BRP), which initiates release of periplasmic and cytoplasmic E. coli proteins into the culture medium. Being compatible with most of the commonly used expression vector systems (such as, ColE1-vectors like pAX, PheBo, pBR322-derivatives), BRP vectors can be co-transformed with a vector producing a recombinant protein of interest. Controlled induction of the BR-Protein with IPTG (pJL3) or mitomycin C (pSW1) will activate phospholipase A in the outer E. coli membrane resulting in the permeable zones in the cell envelope through which proteins are released into the medium. A moderate induction prevents lysis of producer cells making the system suitable for large-scale protein production in a continuous culture. Since cloned proteins are no longer accumulated in the cytoplasm, problems associated with lethality of recombinant proteins, their preferential degradation or inclusion body formation are avoided. Examples of proteins released by activity of BRP from the E. coli periplasm include: Bacillus penicillinase, a-amylase and cellulase; Human growth hormone and tumor necrosis factor-a; b-lactamase, to name a few.

Figure a. pSW1, mitomycin-C inducible (recA-dependent SOS-response) host: recA-; ori: p151A; Pclo, pCloDF13 promoter; BRP, Bacteriocin Release Protein. b. pJL3, IPTG inducible, host: recA-.; ori : p(5A); CmR, chloramphenical resis- tance; (ppp, E.coli lipoprotein promoter, lacp, lac promoter operator system; lac l, lac repressor.

Cat. No.	Description	Size/Vol.
5300-400	pJL3 vector DNA	5 µg, lyophilized
5300-410	pSW1 vector DNA	5 µg, lyophilized
Shipped at RT; store at 4°C