Cytolysin-2 Radianthus Magnifica Recombinant Protein

Function: Pore-forming protein that forms cations-selective hydrophilic pores of around 1 nm and causes cytolysis. Pore formation is a multi-step process that involves specific recognition of membrane sphingomyelin (but neither cholesterol nor phosphatidylcholine) using aromatic rich region and adjacent phosphocholine (POC) binding site, firm binding to the membrane (mainly driven by hydrophobic interactions) accompanied by the transfer of the N-terminal region to the lipid-water interface and finally pore formation after oligomerisation of several monomers. Ref.1

Subunit structure: Tetramer in the presence of a lipidic interface. Monomer, in soluble state

By similarity.

Subcellular location: Secreted. Nematocyst. Target cell membrane. Note: Forms an alpha-helical membrane channel in the prey.

Domain: The N-terminal region, before the pore is formed, is bound to the lipid membrane. It partitions into the lipid-water interface and stabilizes the monomeric molecule on the membrane. Finally, it traverses the bilayer, thus forming the transmembrane pore

By similarity.The Trp-rich region is important for the binding to lipid membrane

By similarity.

Toxic dose: LD50 is 320 µg/kg by intravenous injection into mice. Ref.1

Miscellaneous: Hemolytic activity is 3.3 x 104 HU/mg.The discrimination between sphingomyelin and phosphatidylcholine occurs in the region directly below the phosphorylcholine headgroup

By similarity.

Sequence similarities: Belongs to the sea anemone actinoporin family.