Featured Research

from universities, journals, and other organizations

Ricin's Deadly Action Revealed By Glowing Probes

Date:
August 11, 2008
Source:
University of California - San Diego
Summary:
A new chemical probe can rapidly detect ricin, a deadly poison with no known antidote that is feared to be a potential weapon for terrorists and cannot quickly be identified with currently available tests. Chemists at UC San Diego developed the probe, which glows when bound to a ricin-damaged part of the body's protein-making machinery. Because the test pinpoints the specific injury underlying the poison's toxicity, it could also help to develop drugs to counteract the effect of ricin.

Fluorescent probes glow in the presence of damage characteristic of deadly toxins like ricin.
Credit: Seergazhi Srivatsan/UCSD

A new chemical probe can rapidly detect ricin, a deadly poison with no known antidote that is feared to be a potential weapon for terrorists and cannot quickly be identified with currently available tests.

The probe, developed by chemists at UC San Diego, glows when bound to a ricin-damaged part of the body’s protein-making machinery, they report in the international edition of the journal Angewandte Chemie. Because the test pinpoints the specific injury underlying the poison’s toxicity, it could also help to develop drugs to counteract the effect of ricin.

Ricin toxin is among the most deadly. Just 400 micrograms, about the size of a grain of salt, is enough to kill an adult, according to a report by the Congressional Research Service. Several other toxins including saporin and sarcin all cause harm in similar ways.

These poisons nick a crucial loop of RNA that is part of the cellular structure that synthesizes proteins called the ribosome. That small alteration, the loss of a single piece at the apex the loop, is enough to shut down the manufacture of proteins. Damage of this type is unusual in the absence of these specific toxins.

“We found a chemical reporter that detects a relatively rare event, one that is related to the action of the toxin,” said Yitzhak Tor, a professor of chemistry and biochemistry at UCSD.

Tor, along with postdoctoral researcher Seergazhi Srivatsan and graduate student Nicholas Greco, created a short string of RNA building blocks, or nucleotides, that will attach to the loop. At one position, matching the site ricin damages, they substituted a synthetic nucleoside that glows when the piece that belongs there is missing. If the toxin has damaged the loop, ultraviolet light shone on the sample will fluoresce bright blue.

“Our reporter probe shows that the reaction is taking place,” Tor said. “When there’s no toxin, there will be no light emission.”

Ricin worries security experts because the toxin, an extract of castor beans, is relatively easy to make and difficult to detect. Right now, tests rely on antibodies that recognize the ricin toxin protein itself, which take at least 48 hours to complete, according to the Centers for Disease Control and Prevention. The new test works quickly; it can reveal the presence of damaged ribosome loops in less than 30 minutes.

Tor’s team has developed their probe using isolated RNA loops. These will be the basis for the future design of a sensitive chip that could be used in the field to detect quickly the presence of dangerous toxins.

And because their probe detects the action, rather than merely the presence of the toxin, it could be used to develop ways to help people who have been exposed, Tor said. “Now that we have an assay that senses the toxin’s activity, we can try to discover inhibitors of the toxin or antidotes.”

The National Institute for General Medical Sciences funded this research.


Story Source:

The above story is based on materials provided by University of California - San Diego. The original article was written by Susan Brown. Note: Materials may be edited for content and length.


Journal Reference:

  1. Seergazhi G. Srivatsan, Nicholas J. Greco, Yitzhak Tor. A Highly Emissive Fluorescent Nucleoside that Signals the Activity of Toxic Ribosome-Inactivating Proteins. Angewandte Chemie, Published Online: Aug 6 2008 DOI: 10.1002/anie.200802199

Cite This Page:

University of California - San Diego. "Ricin's Deadly Action Revealed By Glowing Probes." ScienceDaily. ScienceDaily, 11 August 2008. <www.sciencedaily.com/releases/2008/08/080807112641.htm>.
University of California - San Diego. (2008, August 11). Ricin's Deadly Action Revealed By Glowing Probes. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2008/08/080807112641.htm
University of California - San Diego. "Ricin's Deadly Action Revealed By Glowing Probes." ScienceDaily. www.sciencedaily.com/releases/2008/08/080807112641.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
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