Crystal structure of cathepsin X: a flip-flop of the ring of His23 allows carboxy-monopeptidase and carboxy-dipeptidase activity of the protease.
Guncar, G., Klemencic, I., Turk, B., Turk, V., Karaoglanovic-Carmona, A., Juliano, L., Turk, D.(2000) Structure 8: 305-313
- PubMed: 10745011 
- DOI: https://doi.org/10.1016/s0969-2126(00)00108-8
- Primary Citation of Related Structures:  
1EF7 - PubMed Abstract: 
Cathepsin X is a widespread, abundantly expressed papain-like mammalian lysosomal cysteine protease. It exhibits carboxy-monopeptidase as well as carboxy-dipeptidase activity and shares a similar activity profile with cathepsin B. The latter has been implicated in normal physiological events as well as in various pathological states such as rheumatoid arthritis, Alzheimer's disease and cancer progression. Thus the question is raised as to which of the two enzyme activities has actually been monitored.
Organizational Affiliation: 
Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Ljubljana, 1000, Slovenia.