PURIFICATION OF A TOXIC FACTOR FROM ARABIAN GULF CATFISH EPIDERMAL SECRETIONS

The Arabian Gulf catfish, Arius bilineatus (Valenciennes) secretes a p roteinaceous epidermal secretion when threatened or injured. A toxic f actor has been isolated and purified from the crude extract (crude ski n toxin) of these secretions by a combination of gel filtration on Sep hacryl S-300 and preparative discontinuous polyacrylamide gel electrop horesis. The purified skin toxin has a molecular weight of 39 000 Da a nd an isoelectric point (pI) of 5.45. Injection of the purified skin t oxin into rabbits i.v. and determination of the LD50 indicated that th e protein had been purified approximately 30 fold by these procedures. Injection of the purified skin toxin into rabbits caused agitation, c onvulsions and death within 5 min. Analysis of plasma levels of lactat e dehydrogenase, glutamate-oxaloacetate transaminase and glutamate-pyr uvate transaminase in injected rabbits indicated that the skin toxin c aused cardiac and liver damage to the animals. (C) 1998 Elsevier Scien ce Ltd. All rights reserved