The detailed structures will reveal the precise locations and chemical properties of pockets where the enzymes bind the SARS virus's long protein chain.
This information will help Arun Ghosh, professor of chemistry at UIC, build protease inhibitors, like the prototype he assembled earlier, through what is called structure-based drug design. He will create computer images of each enzyme coupled with compounds anticipated to obstruct the pockets, revealing whether and how tightly the molecules fit in the space. If the fit is poor, he can explore a library of alternative molecules that might meet the chemical and configurational requirements.
Ghosh will then assemble the molecules that appear to work, as if the chemicals were the sticks and spools of a Tinkertoy, to create a potential drug.
Crucial to the endeavor is Ghosh's strategy of targeting not the sidechains of the proteases, but their backbones. When viruses mutate, as they frequently do, thwarting the action of drugs, the mutations typically occur in these sidechains.
"By targeting the backbone, we create a drug that the virus probably will not be able to evade," Johnson said.
Susan Baker, a microbiologist at Loyola University Stritch School of Medicine collaborating in the research, will test the newly developed protease inhibitors to determine whether and how quickly they slow the enzymes' activity inside living cells.
The prototype drug developed earlier by Ghosh, an inhibitor of 3CLpro, was an improvement on a design published
Source:University of Illinois at Chicago