Researchers Get First Good Look at HIV Protein Envelope

Researchers have obtained the first atomic-level view of the protein that envelops HIV, a key discovery in the development of an effective vaccine.

"Most of the prior structural studies of this envelope complex focused on individual subunits; but we've needed the structure of the full complex to properly define the sites of vulnerability that could be targeted, for example with a vaccine," said senior author of the research Ian A. Wilson, the Hansen Professor of Structural Biology at The Scripps Research Institute (TSRI).

One of the great obstacles facing HIV vaccines is the the virus's envelope protein, known as Env. Complex and delicate, Env represents a formidable foe to researchers looking to obtain the protein in a suitable form for the atomic-resolution needed to study it.

"It tends to fall apart, for example, even when it's on the surface of the virus, so to study it we have to engineer it to be more stable," said Ward, who is an assistant professor in TSRI's Department of Integrative Structural and Computational Biology.

In the new study, the researchers engineered a version of the Env trimer (three-component structure) that was both stable and true to the structure of the native Env, allowing them to study it in greater detail than ever before. The results revealed how the Env trimer assembles and then changes shape during infection, as well as how it compares to other viruses' envelope proteins.

Thirty-four million people are infected with HIV every year, 10 percent of whom are children, the World Health Organization reports. Currently, antiviral drugs are used to manage infections; however, researchers hope to prevent infection altogether through the creation of a vaccine, perhaps one day eliminating the disease.

A recent report issued by the United Nations indicated that new HIV infections have dropped a stunning 50 percent among children and a third among adults since 2001.