Alpha-hemolysin (Hla)

Alpha-hemolysin is a pore-forming toxin produced by the bacterium *Staphylococcus aureus*. It is synthesized as a 293-residue, water-soluble monomer that binds to susceptible cell membranes, where seven monomers assemble into a heptameric beta-barrel pore. This pore formation disrupts cellular membrane integrity, causing leakage of ions and metabolites, resulting in cell death via either apoptosis or necrosis depending on concentration. Alpha-hemolysin plays a central role in the pathogenesis of S. aureus infections by lysing host cells (including erythrocytes and immune cells), contributing to tissue destruction, immune evasion, and disease severity. It is also widely used as a biotechnological nanopore tool in single-molecule sequencing research[1][2][4][5][7][8].

Other names

Alpha-toxinStaphylococcal alpha-toxinStaphylococcus aureus alpha-toxinHly

Binding to host cell membranes (specific receptor not fully identified) Oligomerization (usually as a heptamer) to form a transmembrane beta-barrel pore Pore formation results in uncontrolled ion flux, cell lysis, apoptosis (at low concentrations), and necrosis (at high concentrations)[1][2][4][5][8].