Scientists in South Korea have isolated the part of a protein found in primates that blocks the progression of human immunodeficiency virus in apes.

The discovery could lead to the accelerated development of an AIDS cure, according to Prof. Oh Byung-ha at Pohang University of Science and Technology.

Previous studies had identified a protein called TRIM5 as being able to fend off retrovirus infections — like HIV —in monkeys.

Oh and his team of researchers now say they have further isolated a part of the proteinthat may be key to unravelling the monkey's defence mechanism.

"Scientists learned that TRIM5 helps fight HIV in 2004, but they failed to discover how the protein works against the virus," Oh told the Korea Times.

"But we found a domain in TRIM5, called B30.2/SPRY, that blocks the progression of HIV," Oh said.

The TRIM5 protein is also present in humans, and scientists have been investigating whetherthe human version of theprotein can be altered to fight HIV.

Oh told the Times that further study of the domain will lead to drugs capable of handling the disease.

"It will not happen overnight," he said. "I bet it will take a long time to develop such drugs. But this is a breakthrough in fighting AIDS."

The research will be published in the next issue of Molecular Cell, a biology journal.

Acquired Immune Deficiency Syndrome, or AIDS,is the name given to the collection of symptoms and infections resulting from depletion of the immune system caused by HIV.

Drugs exist to slow the progress of AIDS, but there are no cures for the disease. UNAIDS estimates 39.5 million people have HIV and 2.9 million would die from it in 2006.