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Curtatoxins. Neurotoxic insecticidal polypeptides isolated from the funnel-web spider Hololena curta.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1990 Feb 05; Vol. 265 (4), pp. 2054-9. - Publication Year :
- 1990
-
Abstract
- Three polypeptide neurotoxins (curtatoxins) were isolated from the venom of the spider Hololena curta by reverse-phase high performance liquid chromatography, gel permeation, and ion-exchange chromatography. The purified toxins induced an immediate paralysis in the cricket Acheta domestica that resulted in desiccation and death of the insect within 24-48 h (LD50 congruent to 4-20 micrograms/g); this toxic effect is consistent with irreversible presynaptic neuromuscular blockade. Curtatoxins are a class of sequence-related, cysteine-rich, carboxyl-terminal amidated polypeptides of 36 to 38 amino acid residues. The cysteine residues are conserved at identical sequence positions among these polypeptides and form 4 intramolecular disulfide bonds. Hydropathy calculations show that the toxins have an internal hydrophobic region flanked by hydrophilic and oppositely charged amino- and carboxyl-terminal ends. By analogy to other cysteine-rich arthropod venom proteins, the folded structure of the curtatoxins is likely important for their target specificity and mode of action at the neuromuscular junction.
- Subjects :
- Agatoxins
Amino Acid Sequence
Animals
Chromatography, Gel
Chromatography, High Pressure Liquid
Chromatography, Ion Exchange
Gryllidae
Lethal Dose 50
Molecular Sequence Data
Neuropeptides toxicity
Protein Conformation
Spiders
Structure-Activity Relationship
Neuropeptides isolation & purification
Neurotoxins isolation & purification
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 265
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 2298738