1. A biologically active hydrophobic T-1-conotoxin from the venom of Conus spurius
- Author
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Leticia Lezama-Monfil, Edgar P. Heimer de la Cotera, María Maillo, Heriberto Pedraza-Lara, Manuel B. Aguilar, and Estuardo López-Vera
- Subjects
Physiology ,Mollusk Venoms ,Peptide ,Motor Activity ,Mass spectrometry ,Biochemistry ,Peptides, Cyclic ,Conus spurius ,Cellular and Molecular Neuroscience ,Mice ,Endocrinology ,Animals ,Conotoxin ,Amino Acid Sequence ,Peptide sequence ,chemistry.chemical_classification ,Chromatography ,Edman degradation ,biology ,Behavior, Animal ,Protein primary structure ,Conus Snail ,biology.organism_classification ,Molecular Weight ,chemistry ,Monoisotopic mass ,Conotoxins ,Hydrophobic and Hydrophilic Interactions - Abstract
A major, very hydrophobic peptide, sr5a, was purified from the venom duct of Conus spurius specimens collected in the Yucatan Channel, Mexico. Its amino acid sequence (IINWCCLIFYQCC; calculated monoisotopic mass assuming two disulfide bridges 1616.68 Da) was determined by automatic Edman degradation after reduction and alkylation, and confirmed by mass spectrometry (ESI monoisotopic mass, 1616.60; MALDI monoisotopic mass 1616.42 Da). The primary structure of sr5a showed the pattern that characterizes the family of the T-1-conotoxins, which belong to the T-superfamily of conotoxins. The disulfide bonds were determined by partial reduction and alkylation with N-ethylmaleimide, followed by total reduction and alkylation with 4-vinylpyridine, and automatic Edman sequencing. The connectivity of the Cys residues (I-III, II-IV) is the same as that found in the T-1-conotoxin family. When injected intracranially (2.0 nmol) into mice, peptide sr5a caused depressed behavioral activity.
- Published
- 2005