Rattlesnake serum could reinvent fight against deadly venoms, Pg11

Key Highlights:

• Researchers have discovered that specific FETUA proteins found in rattlesnakes can effectively neutralize rattlesnake venom lethality in mice.
• The study, led by Dr. Sean B. Carroll at the University of Maryland, was published in the Proceedings of the National Academy of Sciences.
• These naturally occurring proteins demonstrated a potency roughly 10 times greater than commercial antivenom in neutralizing venom.
• The FETUA proteins primarily target metalloproteinases, a major class of venom toxins, surprisingly blocking overall venom lethality.

Detailed Insights:

• Vipers, including rattlesnakes, possess "toxin sponges" like Fetuin-A in their bloodstream that inhibit venom activity.
• Metalloproteinases are highly abundant toxins in rattlesnake venoms, responsible for causing hemorrhage, tissue damage, and disrupting blood coagulation.
• The research team specifically identified four FETUA proteins from the western diamondback rattlesnake (Crotalus atrox) for their investigation.
• The FETUA proteins exhibited cross-reactivity, neutralizing venoms from other species such as the eastern diamondback rattlesnake (Crotalus adamanteus), Malayan pit viper (Calloselasma rhodostoma), and Chinese moccasin (Deinagkistrodon acutus).
• A significant advantage of these proteins is their potential for recombinant production in unlimited quantities, unlike traditional antivenoms derived from immunized animals.
• A key limitation is that FETUA proteins do not neutralize neurotoxins, which are critical components of venoms from elapids like cobras.
• For countries like India, which host both vipers and elapids, a comprehensive strategy would involve identifying FETUAs from native vipers and combining them with agents targeting neurotoxic elapids.
• Partial protection was observed against the venom of Sochurek’s saw-scaled viper (Echis carinatus sochureki), which is one of India's Big Four venomous snakes.

Scientific/Technical Concepts Involved:

• FETUA proteins: A family of serum proteins found in vipers that act as "toxin sponges" to neutralize specific venom components.
• Metalloproteinases: A class of venom toxins that cause hemorrhage, tissue damage, and disrupt blood coagulation.
• Antivenom: A biological product containing antibodies used to treat venomous bites or stings.
• Neurotoxins: Toxins that specifically target and disrupt the function of nerve cells or nerve tissue.