Jasplakinolide is a natural macrocyclic peptide first isolated from a marine sponge. It potently inhibits the proliferation of PC3 prostate carcinoma cells (IC50 = 35 nM) by binding F-actin (KD = 15 nM). This binding of jasplakinolide to actin, which is competitive with phalloidin, stabilizes actin filaments in vitro but disrupts actin filaments and induces irregular polymerization of monomeric actin in vivo. This compound is used to investigate the role of actin in diverse cellular roles, such as motility, transport, and development.
