Application

α-Hemolysin was used in a study to test the efflux pump and haemolysin activity of Escherichia coli of dairy origin. It was also used to test its adaptation to benzalkonium chloride and the effect of ciprofloxacin on biofilm formation.

α-Hemolysin from Staphylococcus aureus has been used: as a component of electrolyte solution for testing pore formation in lipid bilayer using electrophysiological measurementsto test its osteogenesis suppressive effects in bone marrow stromal cells (BMSCs)in the preparation of α-hemolysin molecular imprinted polymer (MIP) for Biacore and surface plasmon resonance

Biochem/physiol Actions

α-Hemolysin is selectively hemolytic and the monomeric form binds to a membrane and specific receptors are not required for binding. Upon binding to biological membranes and/or artificial membranes, self-oligomerization occurs, resulting in ring structures (hexameric aggregates) believed to represent transmembrane pores, which are permeable to ions and small metabolites. It has a marked preference for rabbit red blood cells. α-hemolysin stimulates cellular phospholipases and induces a Ca²⁺influx. It leads to membrane disruption of the endothelial barrier and leakage of cytoplasmic components and osmotic lysis of the cells. α-hemolysin is implicated in the pathogenesis of sepsis.

General description

α-Hemolysin, a pore-forming cytotoxin is an extracellular protein secreted by most strains of pathogenicStaphylococcus aureus. It is secreted as a water-soluble monomer and is a small β-barrel protein.

Packaging

Package size based on protein content

Unit Definition

One hemolytic unit will cause 50% lysis of a 1% suspension of rabbit red blood cells in phosphate buffered saline, pH 7.0, containing 1% bovine serum albumin after 30 min at 37 °C followed by refrigeration for 30 min at 4 °C.