Cell-permeable. LDN-57444 is a potent, reversible, competitive and active site-directed inhibitor of UCHL1 (Ki = 0.4 µM). Decreases proteasome activity and increases levels of ubiquitinated proteins. Induces apoptosis. Causes dramatic alterations in synaptic protein distribution and spine morphology in vivo.http://www.creative-enzymes.com/product/LDN57444_2648.html