Biological and biochemical characterization of Fusobacterium necrophorum leukotoxin.
Biological and biochemical characteristics of the leukotoxin of Fusobacterium necrophorum were determined. Culture supernatant of F necrophorum was toxic to polymorphonuclear neutrophilic leukocytes from cattle and sheep, but not to those from pigs and rabbits. Culture supernatant and sonicated bacterial cell fractions had low hemolytic activity and did not cause dermonecrosis in a guinea pig. Supernatant-derived leukotoxin was inactivated at 56 C for 5 minutes and became unstable at pH > 7.8 or < 6.6. Chemical treatment with 0.1% sodium dodecyl sulfate, 0.25% sodium deoxycholate, 5.2% sodium sulfide, or 0.25 mM titanium (III) citrate markedly decreased leukotoxicity. Enzymatic treatment with protease, trypsin, and chymotrypsin inactivated the toxin completely, whereas amylase had no effect. Use of protease inhibitors failed to prevent loss of leukotoxin activity. Using membrane partition chromatography and gel filtration, the estimated molecular weight of the toxin was > 300,000. On reduction and denaturation, the toxin dissociated into several components by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Department of Animal Sciences and Industry, College of Veterinary Medicine, Kansas State University, Manhattan 66506.
Z L
ZL
Tan
T G
TG
Nagaraja
M M
MM
Chengappa
J S
JS
Smith
D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005098:Exotoxins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D005675:Fusobacterium necrophorum / Q000737:chemistry*; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects; D011480:Protease Inhibitors / Q000494:pharmacology; D011817:Rabbits; D012756:Sheep; D013552:Swine; D013696:Temperature
D001427:Bacterial Toxins; D005098:Exotoxins; D011480:Protease Inhibitors; C018579:leukotoxin