A team of researchers has determined the structure of a key part of the HIV envelope protein, the gp41 membrane proximal external region (MPER), which previously eluded detailed structural description.
The research by scientists at Duke University will help focus HIV vaccine development efforts, which have tried for decades to slow the spread of the virus.
"One reason vaccine development is such a difficult problem is that HIV is exceptionally good at evading the immune system. The virus has all these devious strategies to hide from the immune system," author Bruce Donald said.
One of those strategies is a dramatic structural transformation that the virus undergoes when it fuses to a host cell. The envelope protein complex is a structure that protrudes from HIV's membrane and carries out the infection of healthy host cells.
Scientists have long targeted this complex for vaccine development, specifically its three copies of a protein called gp41 and closely associated partner protein gp120.
The authors said they think about a particular region of gp41, called MPER, as an Achilles' heel of vulnerability.
Leonard Spicer, senior author of the study said that the attractiveness of this region is that, it is relatively conserved and has two particular sequences of amino acids that code for the binding of important broadly neutralizing antibodies.
The HIV envelope region near the virus membrane is the spot where some of the most effective antibodies found in HIV patients bind and disable the virus.
The study is published in Proceedings of the National Academy of Sciences.
