Medchemexpress, HY-100223 50mg Calpeptin CAS:117591-20-5 Calpeptin is a potent, cell penetrating calpain inhibitor, with an ID 50 of 40 nM for Calpain I in human platelets [1] . Calpeptin is also an inhibitor of cathepsin K [2] . Purity:>98% Medchemexpress has over 10000 novel life-science reagents, reference compounds, APIs and natural compounds for laboratory and scientific use. Other quantity can also be offered.