Scientists at The Scripps Research Institute have discovered a class of compounds that block the SARS virus from replicating, a finding that may open the door to new drug targets against the deadly disease. The study was conducted by researchers from Scripps Research; the
Chi-Huey Wong is currently the Ernest W. Hahn Chair in Chemistry at the Skaggs Institute of Chemical Biology and directs the Scripps Research lab heading the study. He said the new finding is an important step in developing a possible drug treatment against SARS.
"We have been working on the problem of SARS since the epidemic started in 2003," Wong said. "This new class of inhibitors represents the most potent SARS virus protease inhibitors known today."
The path to todays research finding has taken several years. In 2002, Severe Acute Respiratory Syndrome (SARS) emerged in rural
Researchers have known since 2003 that a site on the virus is responsible for mediating proteases that allow the virus to replicate. Since then researchers have been testing protease inhibitors to lock up this site, known as SARS 3CLpro, and effectively stop the virus from infecting additional cells in the body.
In 2004, Wongs lab discovered that Lopinavir, a protease inhibitor of HIV also known as TL3, also served as weak inhibitor of the SARS 3CLpro site (PNAS, 101, 10012-10017). Since then, members of Wongs group further studied Lopinavir and are preparing it for clinical trials against SARS.
Researchers in Wongs lab at Scripps Research and in
These organic compounds are called benzotriazole esters. The esters entered the SARS protease site, formed an intermediary compound, then inactivated the SARS enzyme. The findings were confirmed using mass spectrometry analysis of the enzyme intermediary.
"These benzotriazole esters are relatively stable and act as suicide inhibitors," Wong said. "They block the enzyme, are transformed through a co-valent bond, and are unable to get out."
Wong said the findings published today provide better insight into the mode of action of the enzyme, which may lead to development of a drug against SARS. The findings were made by using rapid drug discovery techniques developed in the Wong lab to screen large numbers of weak enzyme inhibitors, and then attaching additional compounds to look for stronger reactions.
Research associate Chung-Yi Wu, a member of the Wong lab, is the papers lead author. He said the finding was unexpected. "We wanted to improve Liponavir activity," Wu said. "But we found this very surprising and serendipitous result."
Other authors of the study include Ke-Yung King, Chih-Jun Kuo, Jim-Min Fang, Ying-Ta Wu, Ming-Yi Ho, Chung-Lin Liao, Jiun-Jie Shie and Po-Huang Liang of the
Source: Scripps Research Institute