Isolation and primary structure of a potent toxin from the venom of the scorpion Centruroides sculpturatus Ewing.
A potent toxin has been purified from the venom of the scorpion Centruroides sculpturatus Ewing using the ion-exchange resin CM-Sepharose CL-6B at basic pH. The toxin, designated CsE M1, comprised 65 amino acid residues and its primary structure was established as: Lys-Glu-Gly-Tyr-Leu-Val-Asn-Ser-Tyr-Thr10-Gly-Cys-Lys-Tyr-Glu-Cys- Leu-Lys-Leu- Gly20-Asp-Asn-Asp-Tyr-Cys-Leu-Arg-Glu-Cys-Arg30-Gln-Gln-Tyr- Gly-Lys-Ser-Gly-Gly - Tyr-Cys40-Tyr-Ala-Phe-Ala-Cys-Trp-Cys-Thr-His-Leu50-Tyr-Glu- Gln-Ala-Val-Val-Trp - Pro-Leu-Pro60-Asn-Lys-Thr-Cys-Asn. CsE M1 is the most lethal protein to be identified in C. sculpturatus venom and the LD50 of the toxin, determined by subcutaneous injection into Swiss mice, is 87 micrograms/kg. CsE M1 shows strong structural similarity (92% positional identity) to the most potent beta-toxin, Css II, from the Mexican scorpion, Centruroides suffusus suffusus but is quite dissimilar to the previously characterized toxins with low potency isolated from C. sculpturatus Ewing.
Pete
M J
MJ
Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, Nebraska.
Conlon
J M
JM
Murphy
R F
RF
D000595:Amino Acid Sequence; D000818:Animals; D002852:Chromatography, Ion Exchange; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification; D012604:Scorpion Venoms / Q000737:chemistry / Q000302:isolation & purification*; D014118:Toxins, Biological / Q000737:chemistry / Q000302:isolation & purification*
C079677:CSE M(1); D011506:Proteins; D012604:Scorpion Venoms; D014118:Toxins, Biological