Synthetic Protein-Like Molecule may Protect Against HIV Infection

by VR Sreeraman on Aug 22 2009 11:25 AM

Researchers have used the human immunodeficiency virus (HIV) and molecular engineering to design synthetic protein-like molecule, which may be able to put a stop to unwanted biological interactions between the cells.

The pioneering study may protect cells against HIV infection.

In a bid to control protein shape, Samuel Gellman, a chemistry professor and his University of Wisconsin-Madison research team, created a set of peptide-like molecules that were successful in blocking HIV infection of human cells in the laboratory.

Adjusting molecular blueprints, Gellman and his colleagues made small structural changes 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, named "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.

The team found that the interaction of synthetic molecules with a piece of HIV protein gp41 physically obstructs the virus from infecting host cells.

The findings have appeared online in the August 17 issue of the Proceedings of the National Academy of Sciences.

Interactions between proteins are not only fundamental to many biological processes, but also to infections like HIV and tumours.

"There's a lot of information transfer that occurs when proteins come together, and one would often like to block that information flow," said Gellman.

These synthetic molecules not only interrupt protein-protein interaction, but are also highly resistant to degradation by naturally occurring enzymes, which do not recognize their unusual structure. This means even a low dose of these molecules can remain effective for a longer time.

"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.

Gellman said the results of their study show that this type of approach could be very useful in designing molecules for antiviral therapies and other biomedical applications.

He said: "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."