Purification and partial characterization of stonustoxin (lethal factor) from Synanceja horrida venom

Abstract

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 α and β) 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 β subunit were also determined. 5. Purified stonustoxin had an LD50 of 0.017 μg/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 μg in mouse paw. The edema effect was not antagonized by diphenhydramine.