a-Hemolysin from Staphylococcus aureus Catalog Number H9395 Storage Temperature 2-8 °C CAS RN ; 94716-94-6 Reagent Synonym : a-Toxin Lyophilized powder containing sodium citrate buffer Product Description Precautions and Disclaimer Molecular weight : 33 kDa1,2 This product is for R&D use only, not for drug, Extinction Coefficient : E1% = 11 (280 nm)3 household, or other uses. Please consult the Material pI : 8.51 Safety Data Sheet for information regarding hazards and safe handling practices. a-Hemolysin is an extracellular protein secreted by most strains of pathogenic Staphylococcus aureus. It is Preparation Instructions selectively hemolytic and has a marked preference for Soluble in deionized water (0.5 mg/ml), yielding a rabbit red blood cells. It induces dermonecrosis, colorless, faint hazy solution. spastic muscle paralysis, and is lethal to laboratory animals.1 The mature protein contains 293 residues Storage/Stability 0 and has a molecular weight of 33,000.1 It is composed Store at 2-8 C. Under these conditions the product is primarily of b-sheets (65%), while the a-helical stable for 3 years. structures are a much smaller percentage (10%).1 References a-Hemolysin is secreted as a water-soluble monomer 1. Dinges, M. M. et al., Exotoxins of Staphylococcus which initially binds and incorporates into the target cell aureus. Clin. Microbiol. Rev., 13, 16-34 (2000). membrane. At low concentrations, the binding is 2. Fink, D. et al., Staphylococcus aureus a-toxin 2+ through a specific receptor, while at high activates phospholipases and induces a Ca influx concentrations, a-hemolysin nonspecifically adheres to in PC12 cells. Cell Signal., 1, 387-393 (1989). the cell membrane.1 Upon contact with lipid bilayers or 3. Harshman, S., et al., Preparation and purification of the detergent deoxycholate, the monomers assemble to staphylococcal a-toxin. Methods Enzymol. 165, 3-7 form an heptameric pore with a vestibule of 3 nm and a (1988). pore-diameter of 1.5 nm.4,5 This pore allows rapid 4. Gouaux, E. J. et al., Subunit stoichiometry of efflux of K+ and small molecules, and influx of Na+, staphylococcal a-hemolysin in crystals and on Ca2+, and molecules with molecular weights less than membranes: A heptameric transmembrane pore. 1,000.1,2 Osmotic swelling of erythrocytes finally results Proc. Natl. Acad. Sci. USA, 91, 12828-12831 in rupture.1 The Ca2+ influx in endothelial cells can (1994). result in arachidonic acid metabolism which finally leads 5. Stefureac, R. et al., Transport of a-helical peptides to vasoconstriction. 1 a-Toxin effects on platelets can through a-Hemolysin and aerolysin pores. lead to procoagulation via Ca2+ influx. 1 Biochemistry, 45, 9172-9179 (2006). ES-S,PHC 02/07-1 Sigma brand products are sold through Sigma-Aldrich, Inc. Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product(s) for their particular use. Additional terms and conditions may apply. Please see reverse side of the invoice or packing slip..