Produced in insect cells. Full length glycosylated human procathepsin K.

Recombinant glycosylated procathepsin K (also known as cathepsin O or cathepsin O2) cloned from human cDNA, expressed in insect cells, and purified as full-length proenzyme. Cathepsin K, a member of the papain family of cysteine proteases, acts upon proteins such as collagen, AL amyloid, kinin, and elastin.

It is a lysosomal protease expressed primarily in osteoclasts, but also in other cell types such as macrophages. It functions in bone remodeling and is implicated in disease states such as atherosclerosis, arthritis, and pycnodysostosis.