Featured Research

from universities, journals, and other organizations

'Venom Doc' Tracks Down Snake Bioweapons

Date:
March 10, 2005
Source:
Cold Spring Harbor Laboratory
Summary:
Bryan Grieg Fry, Ph.D., a scientist from the University of Melbourne, Australia, has conducted the first comprehensive analysis of the origin and evolution of one of nature's most sophisticated bioweapons: snake venom.

MELBOURNE, Australia, Tues., March 1, 2005 – Bryan Grieg Fry, Ph.D., a scientist from the University of Melbourne, Australia, has conducted the first comprehensive analysis of the origin and evolution of one of nature's most sophisticated bioweapons: snake venom. His results are reported in the March issue of the journal Genome Research.

Venomous snakes, all of which belong to the superfamily Colubroidea, evolved glands for the storage and dispersal of their saliva approximately 60-80 million years ago. Since that time, various prey-immobilizing toxins have evolved from innocuous proteins that were normally produced in other body tissues.

Scientists believe that snakes, rather than simply tweaking proteins already expressed in their saliva, recruited and altered proteins for their chemical arsenal from other body tissues. This enabled snakes to develop more specific, highly potent toxins, ones that would cause their victims' bodies to turn against themselves upon injection. Over time, these newly derived toxins became a normal part of the saliva protein repertoire. To date, 24 different snake venom toxins have been characterized by scientists, but the evolutionary history – or tissue origin – of these proteins has not been documented.

In his March 2005 Genome Research article, Fry, the Deputy Director of the Australian Venom Research Unit, identified the origin of the 24 known snake toxin types. Surprisingly, rather than being saliva-modified proteins, 21 of the toxins were shown to have been originally derived from proteins normally expressed in other body tissues, including brain, eye, lung, heart, liver, muscle, mammary gland, ovary, and testis.

Only two of the toxins were derived from proteins presumably expressed in ancient reptile saliva. Both of these toxin types, CRISP and kallikrein, are closely related to toxins called helothermine and gilatoxin, which are produced by the Beaded Lizard and the Gila Monster, respectively.

One of the toxins in this study (called the waglerin peptide) did not exhibit any similarity to known proteins. Fry believes that it may be a reptile-specific protein.

"The wide-ranging origins of snake venom toxin - body counterparts explain the amazing diversity of ways that venomous snakes can kill their prey and why they have so much potential use in medical research," Fry explains.

Fry hopes that his findings will further research efforts focused on the use of snake toxins for therapy and treatment of diseases, including cancer, arthritis, and heart disease. "There is something peculiarly fascinating in the use of a deadly toxin as a life-saving medicine," Fry says. "The natural pharmacology that exists within animal venoms is a tremendous resource waiting to be tapped."

By comparing the amino acid sequence of each toxin to the amino acid sequences of multiple proteins from non-venomous tissues, Fry was able to reconstruct the phylogenetic history of each snake venom constituent. He determined which protein family each toxin type belonged to, and based the normal expression pattern of that protein family, he predicted from which tissue type each toxin protein had been derived.

Despite the differences in tissue origin, Fry observed that all toxins were derived from protein families with secretory function. This means that the proteins were produced in a specific tissue type and later transported out of that tissue, a necessary biochemical characteristic for saliva production in the snake venom glands.

Fry also observed that the proteins most frequently recruited and modified into toxins where those with a very stable molecular structure – those that are rich in the amino acid cysteine, which enables proteins to form intramolecular disulfide linkages. "These structures provided an excellent framework for the 60-80 million years of 'evolutionary tinkering' that have turned these proteins into potent, highly specific snake venom toxins," Fry concluded.


Story Source:

The above story is based on materials provided by Cold Spring Harbor Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Cold Spring Harbor Laboratory. "'Venom Doc' Tracks Down Snake Bioweapons." ScienceDaily. ScienceDaily, 10 March 2005. <www.sciencedaily.com/releases/2005/03/050308093140.htm>.
Cold Spring Harbor Laboratory. (2005, March 10). 'Venom Doc' Tracks Down Snake Bioweapons. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2005/03/050308093140.htm
Cold Spring Harbor Laboratory. "'Venom Doc' Tracks Down Snake Bioweapons." ScienceDaily. www.sciencedaily.com/releases/2005/03/050308093140.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins