FRAX486 is a potent p21-activated kinase (PAK) inhibitor with IC50 values of 14, 33, 39 and 575 nM for PAK1, PAK2, PAK3 and PAK4 respectively.

PAK2:33 nM, PAK3:39 nM, PAK1:14 nM, PAK4:575 nM

在WPMY-1细胞中，FRAX486以浓度依赖的方式（1-10 μM）引起肌动蛋白纤维的退化。这与增殖率的减弱相伴随，从1到10 μM FRAX486开始观察到。FRAX486在WPMY-1细胞中的细胞毒性是时间和浓度依赖的。在1-5 μM的浓度下，FRAX486对WPMY-1细胞的肌动蛋白组织、存活和增殖已经有影响。在这些浓度下，可以预期完全抑制PAK1-3，而PAK4可能只部分被抑制[2]。

FRAX486能穿透血脑屏障，治疗所需浓度的FRAX486能在1小时内到达大脑，并且在服药后24小时内仍然保持，其在靶组织中的最大浓度出现于8小时。每日给药可在大脑中维持FRAX486的稳态水平。FRAX486特异性地挽救了Fmr1 KO异常，在顶端神经元存在脊柱表型而不仅仅是降低脊柱密度，这一点与基因型或表型的存在无关。此外，FRAX486能减少过度活跃和刻板动作，这两种表型是Fragile X综合症小鼠模型的特征。

Cells are grown in 96-well plates (20,000 cells/well) for 24 h, before FRAX486, IPA3, or DMSO are added in indicated concentrations (1, 5, 10 μM). Subsequently, cells are grown for different periods (24, 48, 72 h). Separate controls are performed for each period. At the end of this period, 10 μl of [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-8) from CCK-8 is added, and absorbance in each well is measured at 450 nm after incubation for 2 h at 37°C.(Only for Reference)