Featured Research

from universities, journals, and other organizations

Engineered Protein-like Molecule Protects Cells Against HIV Infection

Date:
August 18, 2009
Source:
University of Wisconsin-Madison
Summary:
With the help of the human immunodeficiency virus (HIV) and molecular engineering, researchers have designed synthetic protein-like mimics convincing enough to interrupt unwanted biological conversations between cells.

With the help of the human immunodeficiency virus (HIV) and molecular engineering, researchers have designed synthetic protein-like mimics convincing enough to interrupt unwanted biological conversations between cells.

Interactions between proteins are fundamental to many biological processes, including some less-than-desirable ones like infections and tumor growth. For example, HIV and several other human viruses — including influenza, Ebola and the severe acute respiratory syndrome (SARS) virus — rely on interactions both among their own proteins and with host cell proteins to infect the cells.

"There's a lot of information transfer that occurs when proteins come together, and one would often like to block that information flow," says Samuel Gellman, a chemistry professor at the University of Wisconsin-Madison.

In a fundamental study of how to control protein shape, Gellman's UW-Madison research team, including former postdoctoral fellow W. Seth Horne, now at the University of Pittsburgh, and graduate student Lisa Johnson, created a set of peptide-like molecules that successfully blocked HIV infection of human cells in laboratory experiments.

By interacting with a piece of a crucial HIV protein called gp41, the synthetic molecules physically prevent the virus from infecting host cells.

The idea shows promise as a new avenue for targeting other unwanted protein interactions as well, Gellman says. The work, performed with a group led by John Moore and Min Lu at the Weill Medical College of Cornell University, is described in a paper appearing online the week of Aug. 17 in the Proceedings of the National Academy of Sciences.

Past attempts to prevent infection by selectively interfering with these interactions have had limited success, he says. Most drugs are small molecules and are not very effective at blocking most protein-protein interactions, which involve large molecular surfaces. Short snippets of proteins, or peptides, can be more effective than small molecules but are easily broken down by enzymes in the body and so require large and frequent doses that are difficult for patients to manage.

The new synthetic approach avoids these pitfalls by creating peptide-like molecules with a modified structure that degrading enzymes have trouble recognizing.

"We want to find an alternate language, an alternate way to express the information that the proteins express so that we can interfere with a conversation that one protein is having with another," Gellman explains.

Like engineers adjusting molecular blueprints, Gellman and his colleagues made structural tweaks to the backbones of their synthetic molecules to improve stability while retaining the three-dimensional shape necessary to recognize and interact with the HIV gp41 protein. The resulting molecules — dubbed "foldamers" — are hybrids of natural and unnatural amino acid building blocks, a combination that allows the scientists to control shape, structure and stability with much greater precision than is currently possible with natural amino acids alone.

In addition to adopting a shape that can interrupt the protein-protein dialogue, the novel foldamer has the additional advantage of being highly resistant to degradation by naturally occurring enzymes, which are stymied by the foldamer's unusual structure. This means the molecule can remain effective for a longer time and at lower doses.

Several of the synthetic foldamers showed potent antiviral activity against HIV when applied to cultured human cell lines in a dish. Although it is not clear that the foldamers themselves could ever be used as anti-HIV drugs, Gellman emphasizes, the results show that this type of approach has great potential to lead to new ways to think about designing molecules for antiviral therapies and other biomedical applications.

"You don't have to limit yourself to the building blocks that nature uses," Gellman says. "There's a huge potential here because the strategy we use is different from what the pharmaceutical and biotech industries now employ."

The study was supported by grants from the National Institutes of Health.


Story Source:

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


Cite This Page:

University of Wisconsin-Madison. "Engineered Protein-like Molecule Protects Cells Against HIV Infection." ScienceDaily. ScienceDaily, 18 August 2009. <www.sciencedaily.com/releases/2009/08/090817184441.htm>.
University of Wisconsin-Madison. (2009, August 18). Engineered Protein-like Molecule Protects Cells Against HIV Infection. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2009/08/090817184441.htm
University of Wisconsin-Madison. "Engineered Protein-like Molecule Protects Cells Against HIV Infection." ScienceDaily. www.sciencedaily.com/releases/2009/08/090817184441.htm (accessed April 25, 2014).

Share This



More Health & Medicine News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Companies Ramp Up Wellness to Lower Health Costs

Companies Ramp Up Wellness to Lower Health Costs

AP (Apr. 24, 2014) That little voice telling you to exercise, get in shape and get healthy is probably coming from your boss. More companies are beefing up wellness programs to try and cut down their health care costs. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
FDA Wants To Ban Sales Of E-Cigarettes To Minors

FDA Wants To Ban Sales Of E-Cigarettes To Minors

Newsy (Apr. 24, 2014) The Food and Drug Administration wants to crack down on the use of e-cigarettes, banning the sale of the product to minors. 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