(97) Assay Card

General Information
Summary Tb3+/DPA Liposome Assay on cycloviolacin O2 showed an effect within minutes
Condition 100 mM POPC suspension in 50 mM TbCl3, 85 mM Na3 citrate, 10 mM TES, pH 7, extruded 25 times through a 100 nm polycarbonate filter. Flourescence was measured at room temperature using excitation/emission of 260/545 nm.
Result Cycloviolacin O2 showed a concentration-dependent effect on POPC liposomes. The EC50 value of 1 was 14.3 uM, which corresponds to a peptide-to-lipid molar ratio (P/L) of 6.5. Full effect was acheived within minutes. For the reference peptide alamethicin, the EC50 value was calculated to be 0.4 uM; that is, P/L = 0.2. The slope of the curve for alamethicin was different, and the height was found to be almost 3 times as high as that of cycloviolacin O2.
AssayType Membrane Binding Assay

Svangard E, Burman R, Gunasekera S, Lovborg H, Gullbo J, Goransson U (2007) Mechanism of action of cytotoxic cyclotides: cycloviolacin O2 disrupts lipid membranes. J Nat Prod 70:643-647

Proteins Assayed cycloviolacin O2