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S5265 Sigma

Streptolysin O from Streptococcus pyogenes

lyophilized powder, Protein ~3 % by Lowry, 25,000-50,000 U/vial



Related Categories Antibiotics, Antibiotics A to Z, Antibiotics N-S, Application Index, Biochemicals and Reagents,
form   lyophilized powder
mol wt   native mol wt 69 kDa
composition   Protein, ~3% Lowry
color   white
solubility   H2O: soluble 1 mg/mL
Mode of action   cell membrane | interferes
storage temp.   2-8°C
Gene Information   Streptococcus pyogenes MGAS8232 ... slo(993428)



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

Streptolysin O is a toxin secreted by Streptococcus pyogenes and is a prototype member of poreforming bacterial cytolysins. It is used permeabilize cell membranes to permit cellular uptake of large or charged molecules. It is used to study macromolecule delivery. It is a potential anticancer agent and is used to study suicide cancer gene therapy.



Unit Definition

One unit will cause 50% lysis of 2% red blood cell suspensions in phosphate buffered saline, pH 7.4, after incubation at 37 °C for 30 min.

Physical form

Lyophilized powder containing Tris buffer salts, sodium azide, PMSF, and EDTA.

Biochem/physiol Actions

Streptolysin O possesses a single polypeptide chain with a molecular weight of f62 kDa. Streptolysin O binds to membrane cholesterol and oligomerizes to create a ring structure that consists of 45 to 50 units. The ring structure inserts into the membrane to make a large pore (25 to 30 nm), which DNA, RNA, peptides and proteins may pass. It is thiol-activated. It is inhibited by allicin, an active component of garlic.

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.

Other Notes

Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place

Price and Availability

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Biomedical Applications

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Safety & Documentation

Safety Information

GHS06  GHS06
Signal word 
Hazard statements 
UN 2811PIH 6.1 / PGI
WGK Germany 
Protocols & Articles

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