Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Venom doc’ tracks down snake bioweapons

01.03.2005


Evolutionary analysis of snake venom reveals that toxin proteins arose from multiple body tissues



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.

Maria A. Smit | EurekAlert!
Further information:
http://www.cshl.edu

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>