New insight into multitalented protein sheds light on HIV mysteries

WASHINGTON - National Institute of Standards and Technology (NIST) has developed a research method by which new insights into the infection process of human immunodeficiency virus (HIV) that leads to acquired immunodeficiency syndrome (AIDS) can be observed.

NIST scientists have glimpsed an important protein molecule’s behavior with unprecedented clarity.

The HIV protein known as Gag plays several critical roles in the assembly of the human immunodeficiency virus in a host cell, but persistent difficulties with imaging Gag in a lab setting have stymied researchers’ efforts to study how it functions.

“A better understanding of Gag’s behavior might allow researchers to develop antiviral drugs that target the HIV assembly process, which remains unassailed by medical science,” said Hirsh Nanda, a postdoctoral researcher at the NIST Center for Neutron Research (NCNR) and a member of the multi-institutional research team.

“Our method might reveal how to inhibit new viruses as they grow.”

The Gag molecule is a microscopic gymnast. At different stages during HIV assembly, the protein twists itself into several different shapes inside a host cell. One shape, or conformation, helps it to drag a piece of HIV genetic material toward the cell membrane, where the viral particles grow.

Gag’s opposite end becomes anchored there, stretching the protein into a rod-like conformation that eventually helps form a barrier surrounding the infectious genes in the finished virus. But while scientists have been aware for years that Gag appears to play several roles in HIV assembly, the specifics have remained mysterious.

The research team potentially solved this problem by creating an artificial cell membrane where Gag can show off its gymnastic prowess for the neutron probes at the NCNR. The center includes a variety of instruments specifically designed to observe large organic molecules like proteins. (ANI)