Snake venoms share similar ingredients

Dec 20, 2007

Venoms from different snake families may have many deadly ingredients in common, more than was previously thought. A study published in the online open access journal BMC Molecular Biology has unexpectedly discovered three-finger toxins in a subspecies of the Massasauga Rattlesnake, as well as evidence for a novel toxin genes resulting from gene fusion.

Susanta Pahari from National University of Singapore, Singapore (currently working at Sri Bhagawan Mahaveer Jain College, Bangalore, India) used venom glands from a rare rattlesnake that lives in arid and desert grasslands. Known as Desert Massasauga (Sistrurus catenatus edwardsii), this pitviper is a subspecies of the North American Massasauga Rattlesnake (Sistrurus catenatus).

Together with Stephen Mackessy from the University of Northern Colorado, USA and R. Manjunatha Kini from National University of Singapore, Singapore, Pahari constructed a cDNA library of the snake's venom gland and created 576 tagged sequences. A cocktail of recognized venom toxin sequences was detected in the library, but the venom also contained three-finger toxin-like transcripts, a family of poisons thought only to occur in another family of snakes (Elapidae).

The team also spotted a novel toxin-like transcript generated by the fusion of two individual toxin genes, a mechanism not previously observed in toxin evolution. Toxin diversity is usually the result of gene duplication and subsequently neofunctionalization is achieved through several point mutations (called accelerated evolution) on the surface of the protein. Pahari says "In addition to gene duplication, exon shuffling or transcriptional splicing may also contribute to generating the diversity of toxins and toxin isoforms observed among snake venoms."

Previously, researchers identified venom compounds using protein chemistry or individual gene cloning methods. However, less abundant toxins were often missed. The library method has now revealed new toxin genes and even new families of toxins. Taking low abundance toxins into consideration shows advanced snakes' venoms actually have a greater similarity than previously recognized.

Snake venoms are complex mixtures of pharmacologically active proteins and peptides. Treating snake venom victims can be complicated because of the variation between venoms even within snake families. Kini says "Such a diversity of toxins provides a gold mine of bioactive polypeptides, which could aid the development of novel therapeutic agents."

Source: BioMed Central

Explore further: Lemurs match scent of a friend to sound of her voice

add to favorites email to friend print save as pdf

Related Stories

Romania keeps ancient tradition of bee medicine alive

Apr 10, 2014

Bee venom to combat multiple sclerosis, pollen for indigestion, honey to heal wounds—the humble bee has been a key source of alternative medicines since ancient times, and Romania is working to keep the ...

Cone snails have multiple venoms

Mar 27, 2014

(Phys.org) —Cone snails change "weapons" depending on whether they are hunting or defending themselves, University of Queensland researchers have discovered.

How a scorpion gets its sting

Jan 14, 2014

Defensins, as their name implies, are small proteins found in plants and animals that help ward off viral, bacterial or fungal pests. One fascinating question of invertebrate evolution is how these proteins evolved into venoms ...

Recommended for you

Lemurs match scent of a friend to sound of her voice

11 hours ago

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

Chrono, the last piece of the circadian clock puzzle?

13 hours ago

All organisms, from mammals to fungi, have daily cycles controlled by a tightly regulated internal clock, called the circadian clock. The whole-body circadian clock, influenced by the exposure to light, dictates the wake-sleep ...

User comments : 0

More news stories

ESO image: A study in scarlet

This new image from ESO's La Silla Observatory in Chile reveals a cloud of hydrogen called Gum 41. In the middle of this little-known nebula, brilliant hot young stars are giving off energetic radiation that ...

First direct observations of excitons in motion achieved

A quasiparticle called an exciton—responsible for the transfer of energy within devices such as solar cells, LEDs, and semiconductor circuits—has been understood theoretically for decades. But exciton movement within ...

Warm US West, cold East: A 4,000-year pattern

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...