Listeriolysin O, PEST-free, Recombinant (LLO)

The secreted pore-forming protein listeriolysin O (LLO) is an essential virulence determinant of the facultative intracellular bacterium Listeria monocytogenes that allows the pathogen to escape from the phagocytic vacuole and reach the host cytosol. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST-like sequence that may target this toxin for degradation. This motif seems to be essential for bacterial virulence too, since its deletion causes a defect in bacterium phagosomal escaping.\n\nDescription: \nRecombinant Listeriolysin O lacking both the signal secretion sequence and the PEST- like sequence. LLO-PEST minus is composed of 471 amino acids, starting from amino acid 60 to amino acid 529, with the addition of a methionine in its NH2-terminus.\n\nActivity:\n~1.25x106 HU/mg. 2 mM DTT could be use to reactivate the toxin.\n\nEndotoxin: \n<0.1ng/ug (IEU/ug) of LLO.\n\nApplications: \na. Cytosolic delivery of molecules, peptides, oligonucleodides and plasmid DNA (4). b. Production of specific monoclonal antibodies (5). c. Detection of anti-listeriolysin O antibodies (6).\n\nStability: \nrLLO although stable at 140C for 1 week, should be stored desiccated below -180C. Please prevent freeze-thaw cycles. Please avoid freeze-thaw cycles.

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SPECIFICATIONS

Catalog Number

L2650-53

Size

10ug

Form

Supplied as a liquid in 50mM NaH2PO4, 1mM EDTA, 2.7mM potassium chloride, 1mM DTT, 5% glycerol and 0.5M sodium chloride

Purity

(same/more than) 90% as determined by: \n(a) Analysis by RP-HPLC. \n(b) Analysis by reducing and non-reducing SDS-PAGE Silver Stained gel.

References

1. Listeriolysin O: a key protein of Listeria monocytogenes with multiple functions. FEMS Microbiol Rev 2006 Jul;30(4):514-29 2. Listeriolysin O derived from Listeria monocytogenes inhibits the effector phase of an experimental allergic rhinitis induced by ovalbumin in mice. Clin Exp Immunol 2006 Jun;144(3):475-84 3. Exploring the role of the CTL epitope region of listeriolysin O in the pathogenesis of Listeria monocytogenes. Microbiology 2006 May;152(Pt 5):1287-96 4. Liposome-doped nanocomposites as artificial-cell-based biosensors: detection of listeriolysin O. Biotechnol Prog 2006 Jan-Feb;22(1):32-7 5. Phosphorylation, ubiquitination and degradation of listeriolysin O in mammalian cells: role of the PEST-like sequence. Cell Microbiol 2006 Feb;8(2):353-64 6. Listeria monocytogenes listeriolysin O and phosphatidylinositol-specific phospholipase C affect adherence to epithelial cells. Can J Microbiol 2005 Sep;51(9):745-51