Recombinant Opisthacanthus cayaporum Venom peptide Ocy4
Description
Definition and Source
Recombinant Ocy4 is a 21-amino acid peptide (sequence: NRTFKTNTKC HVKNQCNFLC Q) produced through recombinant DNA technology in yeast (Pichia pastoris) or E. coli systems . It corresponds to the cytoplasmic domain of the native venom peptide Ocy4, which is secreted by the scorpion’s venom gland . The peptide is cataloged under UniProt ID P86109 and is characterized by a molecular weight of approximately 2.5 kDa (calculated from its sequence) .
Expression Systems
| System | Yield & Purity | Notes |
|---|---|---|
| Yeast | >85% purity | Preferred for eukaryotic PTMs |
| E. coli | >85% purity | Cost-effective, scalable |
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Reconstitution: Soluble in sterile deionized water (0.1–1.0 mg/mL). Glycerol (5–50%) is recommended for long-term storage .
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Stability:
Pharmacological Profile
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Antimicrobial Activity: Scorpine-like peptides from O. cayaporum inhibit Staphylococcus aureus growth (72% inhibition at 1.8 μM) .
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Ion Channel Modulation: Peptides like OcyKTx2 block Kv1.3 potassium channels (Kd = 18 nM), suggesting potential immunosuppressive applications .
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Neurotoxicity: Crude venom shows insect-specific neurotoxicity (ED50 = 1.1 mg/mL in cockroach nerves) .
Comparative Analysis with Native Venom Components
| Component | Molecular Weight | Function |
|---|---|---|
| rOcy4 | ~2.5 kDa | Cytoplasmic fragment |
| Scorpine-like peptide | 8.3 kDa | Antimicrobial |
| Phospholipase A2 | ~14 kDa | Enzymatic, membrane disruption |
| OcyKTx2 | 3.8 kDa | K⁺-channel blocker |
Applications and Research Potential
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Drug Development: Structural simplicity and lack of disulfide bonds make rOcy4 a candidate for engineering analogs targeting ion channels or microbial membranes.
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Venom Proteomics: Used as a reference peptide in mass spectrometry studies to map venom composition .
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Toxicity Studies: Insect-specific activity suggests utility in bioinsecticide research .
Limitations and Future Directions
Current data gaps include:
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Direct evidence of rOcy4’s mechanism of action.
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In vivo toxicological profiles.
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Optimization of expression systems for higher yields.
Ongoing research should focus on functional assays (e.g., patch-clamp electrophysiology) and structural studies (NMR or crystallography) to elucidate its bioactive conformation .
