The disulfide bridges of toxin 2 from the scorpion Centruroides noxius Hoffmann and its three-dimensional structure calculated using the coordinates of variant 3 from Centruroides sculpturatus.
The disulfide bridges of toxin 2 from the venom of the scorpion Centruroides noxius Hoffmann were found by amino acid sequence determination of fragments of native toxin, produced by enzymatic cleavage and separated by high-performance liquid chromatography (HPLC). They are: Cys12-Cys65, Cys16-Cys41, Cys25-Cys46 and Cys29-Cys48. The coordinates of the X-ray diffraction structure of toxin variant 3 of C. sculpturatus [(1980) Proc. Natl. Acad. Sci. USA 77, 6496-6500] were used to construct a three-dimensional model of toxin 2. All the amino acid replacements were easily accommodated, and the modeled structure reveals a clustered pattern of sequence variation, which may help to identify residues responsible for functional differences among toxins of mammals and insects.
Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca.
G B
GB
Gurrola
G
G
Moreno-Hagelsieb
F Z
FZ
Zamudio
M
M
García
X
X
Soberon
L D
LD
Possani
D000595:Amino Acid Sequence; D000818:Animals; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry*; D011487:Protein Conformation; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
C085813:Centruroides neurotoxin, variant 3; D004220:Disulfides; D009498:Neurotoxins; D012604:Scorpion Venoms; C072990:toxin 2, Centruroides noxius; D003545:Cysteine