LDN-57444是一种可逆的竞争性的蛋白酶体抑制剂，，抑制UCch-L1时，IC50为0.88 μM，比作用于亚型Uch-L3选择性高30倍。50 μM LDN-57444处理24小时，抑制70% 蛋白酶活性。25 μM 以上的LDN-57444显著降低细胞存活率，这种作用存在浓度依赖性，50 μM 时，细胞存活率降低至61.81％。LDN-57444通过细胞凋亡途径能够导致细胞死亡，通过降低泛素蛋白酶体系统的活性，并增加高度泛素化蛋白的水平，这两者都可以激活未折叠的蛋白反应。

>98%

Store at -20℃ for one year（Powder）；Store at 2-4℃ for two weeks；Store at -20℃ for six months after dissolution.

UCH-L1 Inhibitor；LDN57444

DMSO :19.9 mg/mL (50 mM)

UCH-L1,UCH-L1,UCH-L3

Treatment with 50 μM LDN-57444 for 24 h leads to 70% inhibition of the proteasome activity. LDN-57444 causes a significant and concentration-dependent decrease in cell viability at concentrations above 25 μM and the cell viability reduced to 61.81% at 50 μM. LDN-57444 is able to cause cell death through the apoptosis pathway by decreasing the activity of ubiquitin proteasome system and increasing the levels of highly ubiquitinated proteins, both of which can activate unfolded protein response. The apoptosis induced by LDN-57444 may be triggered by the activation of endoplasmic reticulum stress (ERS).

LDN-57444 causes dramatic alterations in synaptic protein distribution and spine morphology in vivo. Treatment with LDN also results in a rapid fall of Uch-L1 activity, but proteasome inhibition has no effect on cAMP levels over a period of several hours.