LJEC2520 + PF-00835231
Crystals of PF-00835231 bound to SARS1/CoV-1 DC2 protease via cocrystallization: Freshly prepared SARS1/CoV-1 DC2 protease at 10.00 mg/mL was incubated with a 3-fold molar excess of PF-00835231 for 18 h at 4 °C. The complex was then passed through a 0.45 μM cellulose acetate spin filter and set up for crystallization using an NT-8 crystallization robot (Formulatrix). Using MRC-2 crystallization plates, wells containing 40 μL of 10% w/v PEG 6000, 0.1 M MES pH 6.0, and 10% glycerol were dispensed, and then sitting drops consisting of 0.15 μL protein were set up against a 0.15 μL well buffer. Crystallization plates were incubated at 21 °C, and rectangular crystals measuring 0.2 × 0.25 × 0.15 mm3 grew overnight. Crystals were flash-frozen in liquid nitrogen after being passed through a cryo consisting of a well buffer containing 20% glycerol.