Scientists watch as HIV matures

COLUMBIA, Mo., Oct. 8 (UPI) -- U.S. scientists say they have, for the first time, witnessed the human immunodeficiency virus mature from an inactive form into an active infection.

"We actually saw the process occur," said University of Missouri Assistant Professor Chun Tang, "We now understand more about the maturation process. We hope this will be a stepping stone to intervening before the infection progresses."

The researchers said the HIV-1 protease is responsible for releasing the essential building blocks of an infective HIV-1 viral particle that causes AIDS. But the HIV-1 protease -- one of the primary targets of therapeutic treatment -- is constantly mutating in an effort to gain drug resistance.

"HIV-1 protease is not an active enzyme when it is first expressed in cells. It has to be activated to do its job," Tang said. "What we were able to see is how it self-activates from an immature form when the virus is not infective into a mature form when the virus gains infectivity."

Tang and his colleagues saw the temporary joining of two halves of HIV-1 protease precursor -- something that has not been possible using conventional techniques.

The research is reported in the journal Nature.