Featured Research

from universities, journals, and other organizations

Plastic Protein Protects Bacteria From Stomach Acid's Unfolding Power

Date:
March 30, 2009
Source:
University of Michigan
Summary:
A tiny protein helps protect disease-causing bacteria from the ravaging effects of stomach acid, researchers at the University of Michigan and Howard Hughes Medical Institute have discovered.

Disease-causing bacteria such as the notorious E. coli are protected from stomach acid by a tiny protein called HdeA.

A tiny protein helps protect disease-causing bacteria from the ravaging effects of stomach acid, researchers at the University of Michigan and Howard Hughes Medical Institute have discovered.

Stomach acid aids in food digestion and helps kill disease-causing bacteria. One way that acid kills bacteria is by causing the proteins in them to unfold and stick together in much the same way that heating an egg causes its proteins to form a solid mass. Just as it is virtually impossible for a cook to unboil an egg, it is also very difficult for bacteria to dissolve these protein clumps, so bacteria and most living things can die when exposed to acid or heat.

However, disease-causing bacteria such as the notorious E. coli are protected from stomach acid by a tiny protein called HdeA. In the PNAS paper, James Bardwell and coworkers describe how this protein works to protect bacteria. Like other proteins, HdeA unfolds and becomes more flexible when exposed to acid. But in a clever twist, the unfolding process that inactivates most other proteins activates HdeA. Once unfolded, this plastic protein molds itself to fit other bacterial proteins that have been made sticky by acid- induced unfolding.

"Just as plastic wrappers prevent candies from sticking together, HdeA prevents the unfolded proteins from sticking together and forming clumps," said Bardwell, a professor of molecular, cellular and developmental biology and of biological chemistry, as well as a Howard Hughes Medical Institute Investigator.

Postdoctoral fellow Tim Tapley, who spearheaded the research, said: "HdeA directly senses acid and changes from its inactive to active form within a fraction of a second." Instead of becoming completely unfolded in response to acid and sticking to itself, HdeA is only partially unfolded. It then uses the flexibility it gains through partial unfolding to rapidly become plastic enough to adapt to and bind various damaged proteins. This helps E. coli evade the otherwise deadly effects of stomach acid.

In addition to Bardwell and Tapley, the paper's authors are undergraduate students Jan Kφrner and Julia Hupfeld, graduate student Madhuri Barge, research investigator Joseph Schauerte, professor of biological chemistry Ari Gafni and associate professor of molecular, cellular and developmental biology Ursula Jakob. The research was funded in part by the National Institutes of Health.

These findings were published online in the Proceedings of the National Academy of Sciences the week of March 23.


Story Source:

The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.


Journal Reference:

  1. Timothy L. Tapley, Jan L. Kφrner, Madhuri T. Barge, Julia Hupfeld, Joseph A. Schauerte, Ari Gafni, Ursula Jakob, and James C. A. Bardwell. Structural plasticity of an acid-activated chaperone allows promiscuous substrate binding. Proceedings of the National Academy of Sciences, 2009; DOI: 10.1073/pnas.0811811106

Cite This Page:

University of Michigan. "Plastic Protein Protects Bacteria From Stomach Acid's Unfolding Power." ScienceDaily. ScienceDaily, 30 March 2009. <www.sciencedaily.com/releases/2009/03/090323212033.htm>.
University of Michigan. (2009, March 30). Plastic Protein Protects Bacteria From Stomach Acid's Unfolding Power. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2009/03/090323212033.htm
University of Michigan. "Plastic Protein Protects Bacteria From Stomach Acid's Unfolding Power." ScienceDaily. www.sciencedaily.com/releases/2009/03/090323212033.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) — The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) — Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) — America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) — China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 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