Chlorotoxin

Chlorotoxin (Cltx) is a neurotoxin that was originally isolated from the venom of Leiurus quinquestriatus. Chlorotoxin is a specific ligand of glioma cells. Chlorotoxin binds to Cl– channels (small conductance epithelial chloride channels) in the brain and spinal cord and inhibits Cl– influx. Chlorotoxin most probably acts as a specific blocker, although residues both inside and outside of the pore region of the Cl– channels participate in chlorotoxin binding. It was demonstrated that chlorotoxin inhibits specifically the activity of matrix metalloproteinase-2 (MMP-2) without affecting MMP-1, MMP-3 and MMP-9. MMP-2 are upregulated in glioma cells and related cells making chlorotoxin a promising antitumoral drug and diagnosis tool.