PURIFICATION AND PARTIAL CHARACTERIZATION OF STONUSTOXIN (LETHAL FACTOR) FROM SYNANCEJA-HORRIDA VENOM

1. The lethal factor of the stonefish (Synanceja horrida) venom, designated as the stonustoxin, was purified to homogeneity by a two-step procedure on Sephacryl S-200 High Resolution (HR) gel permeation and DEAE Bio-Gel A anion exchange chromatography. 2. Stonustoxin has a native mol. wt of 148,000 and an isoelectric point of 6.9. 3. SDS-polyacrylamide gel electrophoresis revealed two subunits (designated alpha and beta) with mol. wts of 71,000 and 79,000, respectively. 4. The amino acid composition of both subunits and the N-terminal amino acid sequence of the beta subunit were also determined. 5. Purified stonustoxin had an LD50 of 0.017-mu-g/g which is 22-fold more potent than that of the crude venom. 6. The toxin exhibited potent haemolytic activity in vitro and endema-inducing activity with a minimum edema dose (MED) of 0.15-mu-g in mouse paw. The edema effect was not antagonized by diphenhydramine.