[New weak toxins from the cobra venom]
Bioorganicheskaia Khimiia
|April 21, 2009
Summary
Researchers isolated and sequenced novel weak toxins from cobra venom, including the first from Naja oxiana. These toxins bind to nicotinic receptors, offering new insights into snake venom neurotoxins.
Area of Science:
- Biochemistry
- Toxicology
- Molecular Biology
Context:
- Cobra venom (Naja spp.) is a complex mixture of biologically active proteins.
- Weak toxins are a class of neurotoxins that interact with nicotinic acetylcholine receptors.
- Previous research has identified various toxins, but characterization of weak toxins from specific cobra species remains ongoing.
Purpose:
- To isolate and characterize novel weak toxins from the venom of Naja oxiana and Naja kaouthia.
- To determine the complete amino acid sequences and identify modifications in these toxins.
- To investigate the biological activity and receptor binding properties of the isolated toxins.
Summary:
- A weak toxin (7485 Da) with five disulfide bonds was isolated and sequenced from Naja oxiana venom, representing the first weak toxin identified from this species.
- Two additional weak toxins (7628 Da and 7559 Da) were isolated from Naja kaouthia venom. One is a novel weak toxin, and the other is a known weak toxin (WTX) with an oxidized methionine at position 9, a modification previously unobserved in weak toxins.
- The N. oxiana toxin binds to muscle nicotinic cholinoreceptors and alpha7 nicotinic cholinoreceptors, consistent with the known function of weak toxins.
Impact:
- This study expands the known repertoire of snake venom toxins, specifically weak toxins.
- The identification of a novel weak toxin and a modified known weak toxin provides new molecular targets for research.
- Understanding the interaction of these toxins with nicotinic receptors can contribute to the development of potential therapeutic agents or antidotes.
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