Featured Research

from universities, journals, and other organizations

New way to attack TB

Date:
March 25, 2010
Source:
Johns Hopkins Medical Institutions
Summary:
Suspecting that a particular protein in tuberculosis was likely to be vital to the bacteria's survival, scientists screened 175,000 small chemical compounds and identified a potent class of compounds that selectively slows down this protein's activity and, in a test tube, blocks TB growth, demonstrating that the protein is indeed a vulnerable target.

Suspecting that a particular protein in tuberculosis was likely to be vital to the bacteria's survival, Johns Hopkins scientists screened 175,000 small chemical compounds and identified a potent class of compounds that selectively slows down this protein's activity and, in a test tube, blocks TB growth, demonstrating that the protein is indeed a vulnerable target.

This class of chemical compounds attacks TB by inhibiting methionine aminopeptidase (MetAP), an essential enzyme found in organisms ranging from bacteria to humans, and that clearly has been conserved throughout evolution because of its important task of ensuring the proper manufacture of proteins.

"The MetAP inhibitors we discovered are hits, or leads in the sense that they provide a framework -- a starting point -- for the future development of an anti-TB drug," says Jun O. Liu, Ph.D., professor of pharmacology and molecular sciences, Johns Hopkins University School of Medicine.

The research appears in the January 29 edition of Chemistry & Biology.

The scientists cautioned that although the MetAP inhibitors prevent TB growth in test tubes, they have a long way to go before being declared safe and effective to treat TB patients. To understand how the MetAP inhibitors work, Liu suggests thinking of proteins as a strand of pearls folded in unique 3-D shapes, with each bead representing a protein building block, or amino acid. Invariably, the first bead, or amino acid, in every string, whether human or bacterial protein, is a methionine. The methionine ultimately needs to be removed in order for the protein to mature and fold correctly. Its removal is the job of enzymes called methionine aminopeptidases, or MetAPs.

"If you knock out this enzyme in TB bacteria, the bacteria will not survive," Liu says. "We expected that would happen, and confirmed it by manipulating how much enzyme is expressed to see what happens to the sensitivity of the bacteria when inhibitors are present."

What caught the team by surprise, however, was finding a potent class of compounds (called 2,3-dichloro-1, 4-naphthoquinone) that inhibits this enzyme. That discovery involved the use of large-scale, high-throughput screening of 175,000 compounds and measuring the potencies of a dozen related hits against the enzyme.

The final experiment by the team was to test the MetAP inhibitors on TB bacteria in culture to see if it had any effect on bacteria growth.

"Judging from potency, a MetAP inhibibitor alone probably won't wipe out TB," Liu says. "TB is so hard to treat that the standard therapy involves a cocktail of multiple drugs; no single compound is powerful enough. Our hope is that someday an inhibitor of MetAP will become a new component to enhance the existing therapy."

This study was funded by the National Institutes of Health.

In addition to Liu, authors of this paper are Omonike Olaleye, Tirumalai R. Raghunand, Shridhar Bhat, Sandeep Tyagi, Gyanu Lamichhane, Peihua Gu, Jiangbing Zhou, Ying Zhang, Jacques Grosset, and William R. Bishai, all of Johns Hopkins.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "New way to attack TB." ScienceDaily. ScienceDaily, 25 March 2010. <www.sciencedaily.com/releases/2010/03/100324183431.htm>.
Johns Hopkins Medical Institutions. (2010, March 25). New way to attack TB. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2010/03/100324183431.htm
Johns Hopkins Medical Institutions. "New way to attack TB." ScienceDaily. www.sciencedaily.com/releases/2010/03/100324183431.htm (accessed April 16, 2014).

Share This



More Health & Medicine News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. Video provided by Newsy
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com
Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Newsy (Apr. 14, 2014) Richard van As lost all fingers on his right hand in a woodworking accident. Now, he's used the incident to create a prosthetic to help hundreds. 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:
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