Recombinant Escherichia coli Microcin J25 (mcjA)

Peptide antibiotic that functions through inhibition of the bacterial DNA-dependent RNA polymerase (RNAP) . Inhibits transcription by binding deep within RNAP secondary channel, where it sterically blocks the folding of the trigger loop, which is essential for efficient catalysis. In addition, it also seems to restrict access of nucleotide substrates to the catalytic center, and shows a partially competitive mode of inhibition with them. Exhibits potent bacteriocidal activity against a range of Enterobacteriaceae, including several pathogenic E.coli, Salmonella and Shigella strains. Also acts on the cytoplasmic membrane of Salmonella newport, producing alteration of membrane permeability and disruption of the subsequent gradient dissipation, which inhibits several processes essential for cell viability, such as oxygen consumption. Induces bacterial filamentation in susceptible cells in a non-SOS-dependent way, but this phenotype may result from impaired transcription of genes coding for cell division proteins.

If the delivery form is liquid, the default storage buffer is Tris/PBS-based buffer, 5%-50% glycerol. If the delivery form is lyophilized powder, the buffer before lyophilization is Tris/PBS-based buffer, 6% Trehalose, pH 8.0.

We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Please reconstitute protein in deionized sterile water to a concentration of 0.1-1.0 mg/mL.We recommend to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20°C/-80°C. Our default final concentration of glycerol is 50%. Customers could use it as reference.

"The antibacterial action of microcin J25: evidence for disruption of cytoplasmic membrane energization in Salmonella newport." Rintoul M.R., de Arcuri B.F., Salomon R.A., Farias R.N., Morero R.D. FEMS Microbiol. Lett. 204:265-270 (2001)

The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.