Mangel worked with fellow Brookhaven scientists William McGrath and Vito Graziano, along with Kathy Zabrocka, a student from Stanford University who was conducting an undergraduate internship in his lab. The research built on work Mangel's lab initiated years earlier to decipher the atomic-level structure of the adenovirus proteinase, an enzyme conserved throughout all strains of the virus that cleaves proteins during the assembly of new virus particles.
"Once those proteins are cleaved, the newly synthesized virus particle is infectious," Mangel explained. "If those proteins are not cleaved, then the infection is aborted. Thus, inhibitors of the adenovirus proteinase should be effective antiviral agents against all strains of adenovirus," he said.
Over several years, Mangel's group found that the activity of the enzyme was highly regulated by two cofactors, a small piece of another adenovirus protein and the viral DNA. Structures of the enzyme alone and in the presence of its cofactors, determined by x-ray crystallography at the NSLS, revealed key regions that could serve as potential targets for blocking the enzyme's activation or protein-cleaving ability.
"All that remained was to find compounds that bind to these targets to prevent the enzyme from functioning," Mangel said.
To find these compounds, the scientists used a technique called DOCKing, which entails computationally probing a region of the protein structure against databases of small molecules to determine which might bind most strongly. Out of a database of 140,000 potential compounds, the scientists identified 30 molecules predicted to fit best and ordered samples to test for inhibitor activity.
Two of the molecules that DOCKing identified turned out to be excellent inhibitors of the adenovirus proteinase. At the con
|Contact: Karen McNulty Walsh|
DOE/Brookhaven National Laboratory