Probably participates in a plant defense mechanism. Has antibiotic activity. Has a diuretic effect. Has a uterotonic effect in humans. Active against the Gram-positive S.aureus with a minimum inhibition concentration of approximately 0.2 microM. Relatively ineffective against Gram-negative bacteria such as E.coli and P.aeruginosa. Inhibitory effect on the growth and development of larvae from H.punctigera. The unmodified form has hemolytic activity, the oxidized form lacks hemolytic activity. If the protein is linearized, hemolytic activity is lost. Leaves and stems. Lower in roots. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Kalata-B1 is a cyclic peptide which occurs in three forms: with unmodified Trp-111, with Trp-111 oxidized to form oxindolylalanine and with Trp-111 oxidized to form N-formylkynurenine. Oxidation is enhanced by exposure to sunlight. With oxindolylalanine. With N-formylkynurenine. The uteroactive properties of Kalata have been discovered by African traditional medicine. It is used as an ingredient of a herbal tea to accelerate childbirth. Belongs to the cyclotide family. Moebius subfamily. The oxidation forms of Trp-111 are subject of controversy and could be the artifactual results of sample handling. The protein with a topological twist - Issue 20 of March 2002 Bio-Art - Issue 53 of December 2004