Human monoclonal ScFv neutralize lethal Thai cobra, Naja kaouthia, neurotoxin.
Animal derived anti-Naja. kaouthia (Thai cobra) venom is used for specific treatment of the snake bitten victims. Many recipients develop allergic reaction or anti-isotype response which causes serum sickness. A better therapeutic antibody is needed. In this study, long alpha-neurotoxin was purified from the N. kaouthia holovenom and verified by 2D-LC/MS-MS. The toxin was used as antigen in a phage bio-panning to select phage clones displaying human single chain variable antibody fragments (HuScFv) from a phage display antibody library constructed from immunoglobulin genes of non-immunized Thai blood donors. HuScFv that specifically bound to the neurotoxin were produced from huscfv-phagemid transformed E. coli clones and affinity purified. The HuScFv could neutralize toxicity of the N. kaouthia neurotoxin and rescued the envenomized mice from the neurotoxin mediated lethality. Peptide mimotope of the neutralizing HuScFv matched with an amino acid sequence (epitope) located in the loop-3 of the N. kaouthia long alpha-neurotoxin which functions in acetylcholine receptor binding. The mimotope is also similar to peptide sequences found on other snake venom neurotoxins implying a possibility of the HuScFv to exert pan-neutralizing activity against multiple snake neurotoxins.
Kulkeaw
Kasem
K
Faculty of Allied Health Sciences, Thammasat University, Rangsit Center, Pathum-thani 12120, Thailand.
Sakolvaree
Yuwaporn
Y
Srimanote
Potjanee
P
Tongtawe
Pongsri
P
Maneewatch
Santi
S
Sookrung
Nitat
N
Tungtrongchitr
Anchalee
A
Tapchaisri
Pramuan
P
Kurazono
Hisao
H
Chaicumpa
Wanpen
W
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D001483:Base Sequence; D002853:Chromatography, Liquid / Q000379:methods; D004546:Elapid Venoms / Q000032:analysis* / Q000737:chemistry; D017815:Elapidae; D007128:Immunoglobulin Fragments / Q000032:analysis* / Q000737:chemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000032:analysis* / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000911:Antibodies, Monoclonal; D004546:Elapid Venoms; D007128:Immunoglobulin Fragments; C521753:Naja kaouthia venom; D009498:Neurotoxins