Accepted name: kallikrein 8
Reaction: Cleavage of amide substrates following the basic amino acids Arg or Lys at the P1 position, with a preference for Arg over Lys
Other name(s): KLK8; PRSS19; human kallikrein 8; hK8; mK8; ovasin; tumor-associated differentially expressed gene 14; TADG-14; NP; neuropsin
Comments: The enzyme is activated by removal of an N-terminal prepropeptide [2,4]. The highest amidolytic activity is observed using Boc-Val-Pro-Arg┼7-amido-4-methylcoumarin, which is a substrate of α-thrombin [2,4]. Substrates lacking basic amino acids in the P1 position are not cleaved [4]. The enzyme degrades casein, fibronectin, gelatin, collagen type IV, fibrinogen, and high-molecular-mass kininogen [3] and is associated with diseases such as ovarian cancer and Alzheimer’s disease [4]. Belongs in peptidase family S1A.
1.  Chen, Z.L., Yoshida, S., Kato, K., Momota, Y., Suzuki, J., Tanaka, T., Ito, J., Nishino, H., Aimoto, S., Kiyama, H. and Shiosaka, S. Expression and activity-dependent changes of a novel limbic-serine protease gene in the hippocampus. J. Neurosci. 15 (1995) 5088–5097. [PMID: 7623137]
2.  Shimizu, C., Yoshida, S., Shibata, M., Kato, K., Momota, Y., Matsumoto, K., Shiosaka, T., Midorikawa, R., Kamachi, T., Kawabe, A. and Shiosaka, S. Characterization of recombinant and brain neuropsin, a plasticity-related serine protease. J. Biol. Chem. 273 (1998) 11189–11196. [PMID: 9556608]
3.  Rajapakse, S., Ogiwara, K., Takano, N., Moriyama, A. and Takahashi, T. Biochemical characterization of human kallikrein 8 and its possible involvement in the degradation of extracellular matrix proteins. FEBS Lett. 579 (2005) 6879–6884. [PMID: 16337200]
4.  Kishi, T., Cloutier, S.M., Kündig, C., Deperthes, D. and Diamandis, E.P. Activation and enzymatic characterization of recombinant human kallikrein 8. Biol. Chem. 387 (2006) 723–731. [PMID: 16800733]
[EC created 2006]