Featured Research

from universities, journals, and other organizations

New Natural Products Act Against Antibiotic-resistant Bacteria

Date:
October 20, 2008
Source:
Helmholtz Centre for Infection Research
Summary:
A group of antibiotic natural products points to a new mode of action against pathogenic bacteria. Isolated from myxobacteria, the substances prevent an enzyme of the pathogens from being able to translate their genetic material.

HZI biologist Dr. Herbert Irschik (left) and HZI chemist Dr. Rolf Jansen (right).
Credit: Image courtesy of Helmholtz Centre for Infection Research

A group of antibiotic natural products discovered at the Helmholtz Centre for Infection Research (HZI) in Braunschweig points to a new mode of action against pathogenic bacteria. Isolated from myxobacteria, the substances prevent an enzyme of the pathogens from being able to translate their genetic material. In this way, the propagation of bacteria – such as tuberculosis pathogens – is inhibited.

Related Articles


A working group at Rutgers University in New Jersey has now joined up with HZI researchers and discovered in detail how these compounds interact with the target in pathogenic bacteria. The novel target is different from the target of known antibiotics such as rifamycin, a standard medication to counteract tuberculosis.

This discovery makes the Braunschweig natural products extremely interesting candidates for a development as antibiotics – especially in view of the fact that the substances also kill bacterial strains that are resistant to antibiotics. Today, the scientists publish their results in the distinguished journal "Cell".

Antibiotics are an essential tool of medicine. We owe the antibiotics that diseases such as plague, cholera or tuberculosis are a thing of the past, at least in the industrialised world.

However, more and more bacteria are becoming resistant to medication. Consequently, doctors are in urgent need of new antibiotics. Their development is a demanding challenge: the drugs should attack the bacteria only but not interact with human cells. Subsequently, the number of effective antibiotic targets in bacteria is severely limited; every new active compound is warmly welcomed by the antibiotics researchers, especially if it highlights a new mode of action.

In the search for candidates which might be developed into such novel medicines the HZI enjoys a strong advantage: the institute has a unique collection of natural substances which has proved to be a highly effective source of drug candidates in the past. For example, the collection provided epothilone, which was approved as cancer medication last year. These substances are produced by myxobacteria, a group of microorganisms living in the soil.

The origin of the current success story is outlined by HZI biologist Dr. Herbert Irschik: "In our fundus we have three substances – myxopyronin, corallopyronin and ripostatin – which were isolated and characterised chemically and biologically. Already many years ago we recognized their unusual antibiotic effect. It was directed in an unknown manner against the bacterial RNA polymerase, i.e. the enzyme that reads the DNA of the pathogen. In eukaryontic cells, which human cells are also belonging to, the substances do not attack the RNA polymerase." However, before the initial evidence turned the substances into true antibiotic candidates, scientists had to reveal precisely how the growth of the bacteria was inhibited. "We began to develop a biotechnological processes which enabled us to produce and isolate the myxobacterial natural substances in large quantities," explains HZI chemist Dr. Rolf Jansen, who was also involved in the study.

Afterwards, the collaboration with the US research group at Rutgers University came off. The structural biologists studied the interaction of the HZI substances with the RNA polymerase. The results supported the indication that the natural substances block the bacterial RNA polymerase in a new manner: the natural substances append to another location within the RNA polymerase than the antibiotics previously investigated.

They attach to the enzyme – which looks like an open crab claw – directly at its joint position. Subsequently the enzyme is no longer able to open the claw. By this mechanism of action the active substances prevent the RNA polymerase from adhering to the DNA – reading of the genetic materials is suppressed completely. This new mechanism also operates in bacteria that are resistant to conventional antibiotics.

For Jansen and Irschik the results of the US researchers signalize that their substances now are facing a long process of development: " In their present form myxopyronin, corallopyronin and ripostatin are not yet applicable as antibiotics," explains Irschik. Further chemical development is now required, as Jansen adds: "Our natural agents are so-called chemical leads, which the chemists will modify in detail in order to increase their antibiotic action and minimize side-effects. This development will include extensive testing, which may take several years, before the new medicine will reach the hands of doctors finally."


Story Source:

The above story is based on materials provided by Helmholtz Centre for Infection Research. Note: Materials may be edited for content and length.


Cite This Page:

Helmholtz Centre for Infection Research. "New Natural Products Act Against Antibiotic-resistant Bacteria." ScienceDaily. ScienceDaily, 20 October 2008. <www.sciencedaily.com/releases/2008/10/081017082013.htm>.
Helmholtz Centre for Infection Research. (2008, October 20). New Natural Products Act Against Antibiotic-resistant Bacteria. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2008/10/081017082013.htm
Helmholtz Centre for Infection Research. "New Natural Products Act Against Antibiotic-resistant Bacteria." ScienceDaily. www.sciencedaily.com/releases/2008/10/081017082013.htm (accessed October 26, 2014).

Share This



More Plants & Animals News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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