Streptolysin O from Streptococcus pyogenes

Streptolysin O (SLO) is an immunogenic, oxygen-labile toxin, hemolytic exotoxin which is reversibly activated by dithiothreitol. ^[1] It is released into the extracellular medium along with other toxins, including streptolysin S, during the growth of most strains of group A and many strains of groups C and G Streptococci. ^[1,2] SLO and Streptolysin S differ from each other in that SLO is immunogenic and oxygen-labile while Streptolysin S is oxygen-stable, nonimmunogenic and only active when associated with a carrier protein.^[3] The hemolytic activity of SLO is mediated by formation of multimeric nanopores in cholesterol containing lipid membranes.

SLO may be used for cell permeabilization or hemolysis. The susceptibility of hemolysis by SLO varies significantly for erythrocytes from different animal species.^[1] Permeabilization of cells using SLO has been performed on multiple cell types and for various applications. For instance it has been used to introduce antisense oligonucleotides into cultured eukaryotic cells;^[3] to investigate the effect of guanine nucleotide analogues on phosphatidylinositol metabolism and protein kinase C (PKC) activation in live human T lymphocytes;^[4] to monitor cholesterol oxidation within a membrane lipid bilayer; ^[5] and to label proteins inside living cells using external fluorophores.^[6]

Permeabilizes membranes to permit cellular uptake of large or charged molecules.

Thiol-activated toxin that permeabilizes animal cell membranes. The protein binds as a monomer to membrane cholesterol and subsequently polymerizes into large arc- and ring-shaped structures surrounding pores of >12 nm.

Thiol-activated toxin that permeabilizes animal cell membranes..

This product is produced by recombinant expression in Escherichia coli and contains the complete native protein sequence of SLO (Uniport ID: P0DF96 aa 34-571) without any added purification tags and has calculated molecular weight of 60,144 Dalton. The material is lyophilized from a solution containing 20 mM Sodium Hepes pH 7.5, 150 mM Sodium Chloride and 2 mM EDTA.

Lyophilized powder containing Hepes buffer salts and EDTA.

One unit will cause 50% lysis of 50 ul of a 2% human red blood cell suspension in phosphate buffered saline, pH 7.4, at 37 °C for 30 minutes.