体外研究
HQNO is a potent inhibitor of mitochondrial type II NADH:quinone oxidoreductase (NDH-2) in many species, including Yarrowia lipolytica , S. cerevisiae , Gluconobacter oxydans , T. gondii , P. falciparum , and S. aureus . HQNO targets the Q-site of NDH-2. HQNO concentrations are varied from 0 to 100 μM and 0 to 300 μM for wild-type (WT) and I379E C. thermarum NDH-2 variant, respectively to determine IC 50 values. WT NDH-2 has an IC 50 value of 10.5±1.3 μM HQNO in the presence of 400 μM Menadione (MD). In the presence of 50 μM MD, the IC 50 value for HQNO decreases slightly to 7.3±1.2 μM and near complete inhibition (~15% residual activity) is observed with >50 μM HQNO. At 50 μM MD, HQNO inhibition is observed with an IC 50 value of 54.3±1.2 μM.