2 Research Teams Discover Shape of Molecule Critical to AIDS Virus

Two groups of scientists report that they have discovered the exact shape of a molecule that is essential for the AIDS virus to spread and infect cells, an achievement that could help researchers design a drug to block it.

The human immunodeficiency virus has several key components. Understanding their three-dimensional structure has become important to researchers trying to develop effective therapies. By seeing how the molecules are shaped, scientists can attempt to design specific drugs that fit directly into them like a key in a lock.

“If you can make this molecule fail to do its job, that virus stops knowing how to infect cells,” said Manuel A. Navia, leader of the group from Merck, Sharp and Dohme Research Laboratories who reported the shape of the molecule Thursday in the British journal Nature. “By understanding the structure we can now attempt to see what works.”

The Merck report establishes the chemical equivalent of a blueprint for the enzyme protease. It is the first to solve the three-dimensional structure of any part of the virus. A study by another group of researchers at the National Cancer Institute reported similar results today in Science magazine.

Essentially, the researchers have assembled a molecular map of the virus’ protease enzyme, which plays a vital role in the way the virus reproduces. Enzymes are proteins that carry out specific chemical reactions. Protease molecules break down proteins.

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