Production and characterization of monoclonal antibodies against Naja naja atra cobrotoxin.
Twelve monoclonal antibodies against cobrotoxin from Naja naja atra venom were tested for cross-reactivity with eight different snake toxins, binding to linear epitopes, prevention of cobrotoxin binding to acetylcholine receptor (AchR) in vitro, and protection in mice concomitantly given a lethal dose of cobrotoxin. The antibodies were highly specific, as evidenced by little reactivity with other snake toxins. None of the monoclonal antibodies bound to reduced cobrotoxin or synthesized 8-mer regions spanning the whole molecule, thus suggesting the recognition of conformational epitopes. The in vitro binding of toxin to AchR was competitively inhibited (23-79%) with a 1.66:1 mole ratio of antibody:AchR. Preincubation of monoclonal antibody with toxin before adding AchR (3:1 mole ratio of AchR:antibody) inhibited the in vitro binding of toxin to AchR by 20-80%. Monoclonal antibodies added after the preincubation of toxin with AchR did not dissociate the toxin-AchR complex. An antibody:toxin mole ratio of 2.5:1, with 6 micrograms of cobrotoxin, delayed the time to death of mice 3.7-23.8-fold over control mice. The monoclonal antibodies that most effectively prevented in vitro binding of toxin to AchR also provided the longest delay in time to death in mice.
Stiles
B G
BG
Department of Toxicology, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702-5011.
Lidgerding
B C
BC
Sexton
F W
FW
Guest
S B
SB
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology; D000918:Antibody Specificity; D000997:Antivenins / Q000096:biosynthesis* / Q000276:immunology; D002460:Cell Line; D003429:Cross Reactions / Q000276:immunology; D004546:Elapid Venoms / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000032:analysis; D011950:Receptors, Cholinergic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000997:Antivenins; D004546:Elapid Venoms; D000939:Epitopes; D010455:Peptides; D011950:Receptors, Cholinergic