A recombinant insect-specific alpha-toxin of Buthus occitanus tunetanus scorpion confers protection against homologous mammal toxins.
We have constructed a cDNA library from venom glands of the scorpion Buthus occitanus tunetanus and cloned a DNA sequence that encodes an alpha-toxin. This clone was efficiently expressed in Escherichia coli as a fusion protein with two Ig-binding (Z) domains of protein A from Staphylococcus aureus. After CNBr treatment of the fusion protein and HPLC purification, we obtained approximately 1 mg recombinant apha-toxin/l bacterial culture. The toxin, called Bot XIV, displays no toxicity towards mammals but is active towards insects as shown by its paralytic activity against Blatella germanica cockroach and by electrophysiological studies on Periplaneta americana cockroaches. The Bot XIV protein fused to two Z domains is highly immunogenic in mice and induces production of antisera that specifically recognize and neutralize highly toxic components that had been injected into mice. This fusion protein could be very useful for development of potent protective antisera against scorpion venoms.
Bouhaouala-Zahar
B
B
Laboratoire Venins et Toxines, Institut Pasteur de Tunis, Tunisie.
Ducancel
F
F
Zenouaki
I
I
Ben Khalifa
R
R
Borchani
L
L
Pelhate
M
M
Boulain
J C
JC
El Ayeb
M
M
Ménez
A
A
Karoui
H
H
D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation; D001369:Axons / Q000187:drug effects / Q000648:ultrastructure; D001483:Base Sequence; D003001:Cloning, Molecular; D003058:Cockroaches / Q000187:drug effects*; D003429:Cross Reactions; D015342:DNA Probes; D018076:DNA, Complementary / Q000235:genetics; D007114:Immunization; D008322:Mammals; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D012604:Scorpion Venoms / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D010738:Type C Phospholipases / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology*
C100683:Bot XIV toxin; D015342:DNA Probes; D018076:DNA, Complementary; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D012604:Scorpion Venoms; D010738:Type C Phospholipases