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. Recombinant 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. , Activity:, ~1.25x10e6 HU/mg. 2 mM DTT could be use to reactivate the toxin. Applications: Suitable for use in Cytosolic delivery of molecules, peptides, oligonucleodides and plasmid DNA, Production of specific monoclonal antibodies and detection of anti-listeriolysin O antibodies. Other applications not tested. Recommended Dilutions: Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.