Q-VD-OPH (Quinoline-Val-Asp-Difluorophenoxymethylketone) is a pan-caspase inhibitor with potent antiapoptotic properties.

Caspase-8:25 nM-400 nM, Caspase-1:25 nM-400 nM, Caspase-3:25 nM-400 nM, Caspase-9:25 nM-400 nM

Q-VD-OPh（5-100 μM）在WEHI 231细胞中抑制放线菌素D诱导的DNA阶梯化及其后续的凋亡，并且毒性极低。Q-VD-OPh阻止了caspase介导的PARP切割和效应者caspases的激活。[2] 在体外实验中，Q-VD-OPh能够保护心肌细胞免受病毒诱导的凋亡。[4]

Q-VD-Oph 在小鼠缺血性ARF中抑制caspase-1、IL-18蛋白表达和中性粒细胞浸润。[3] 在体内，Q-VD-Oph 通过抑制caspase来防护病毒引起的心肌损伤，降低 caspase-3 活性。[4] 在TgCRND8小鼠中，Q-VD-OPh抑制 caspase-7活化，抑制包括caspase裂解在内的与tau蛋白相关的病理变化。[5]

Enzyme assay is conducted in buffer containing 25 mM Tris, pH 8.0, 1 mM DTT, 1 mM spermine, 50 mM KCl, 0.01% Nonidet P-40, and 1 mM MgCl2. PARP reaction contains 0.1 μCi [3H]NAD+ (200?000 DPM), 1.5 μM NAD+, 150 nM biotinylated NAD+, 1 μg/mL activated calf thymus, and 1?5 nM PARP-1. Autoreactions utilizing SPA bead-based detection are carried out in 50 μL volumes in white 96-well plates. Compounds (e.g., MK-4827) are prepared in 11-point serial dilution in 96-well plate, 5 μL/well in 5% DMSO/Water (10× concentrated). Reactions are initiated by adding first 35 μL of PARP-1 enzyme in buffer and incubating for 5 min at room temperature and then 10 μL of NAD+ and DNA substrate mixture. After 3 h at room temperature, these reactions are terminated by the addition of 50 μL of streptavidin-SPA beads (2.5 mg/mL in 200 mM EDTA, pH 8). After 5 min, they are counted using a TopCount microplate scintillation counter. IC50 data is determined from inhibition curves at various substrate concentrations[1].

Caspase inhibitors are added at the indicated concentrations 30 minutes prior to the addition of apoptotic stimuli. Viability and cell number are determined by trypan blue exclusion from three random fields of greater than 200 cells/field. All experiments are performed a minimum of three times.(Only for Reference)