Cystatin-B is a protein that in humans is encoded by the CSTBgene.[1][2]
The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and kininogens. This gene encodes a stefin that functions as an intracellular thiol protease inhibitor. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. The protein is thought to play a role in protecting against the proteases leaking from lysosomes. Evidence indicates that mutations in this gene are responsible for the primary defects in patients with progressive myoclonic epilepsy (EPM1).[2]
↑Pennacchio LA, Lehesjoki AE, Stone NE, Willour VL, Virtaneva K, Miao J, D'Amato E, Ramirez L, Faham M, Koskiniemi M, Warrington JA, Norio R, de la Chapelle A, Cox DR, Myers RM (Apr 1996). "Mutations in the gene encoding cystatin B in progressive myoclonus epilepsy (EPM1)". Science. 271 (5256): 1731–4. Bibcode:1996Sci...271.1731P. doi:10.1126/science.271.5256.1731. PMID8596935.
↑Pavlova, Alona; Björk Ingemar (Sep 2003). "Grafting of features of cystatins C or B into the N-terminal region or second binding loop of cystatin A (stefin A) substantially enhances inhibition of cysteine proteinases". Biochemistry. United States. 42 (38): 11326–33. doi:10.1021/bi030119v. ISSN0006-2960. PMID14503883.
Järvinen M, Rinne A, Hopsu-Havu VK (1988). "Human cystatins in normal and diseased tissues--a review". Acta Histochem. 82 (1): 5–18. doi:10.1016/s0065-1281(87)80043-0. PMID3122506.
Kos J, Lah TT (1998). "Cysteine proteinases and their endogenous inhibitors: target proteins for prognosis, diagnosis and therapy in cancer (review)". Oncol. Rep. 5 (6): 1349–61. doi:10.3892/or.5.6.1349. PMID9769367.
Jerala R, Trstenjak M, Lenarcic B, Turk V (1988). "Cloning a synthetic gene for human stefin B and its expression in E. coli". FEBS Lett. 239 (1): 41–4. doi:10.1016/0014-5793(88)80541-6. PMID3053245.
Lenarcic B, Kos J, Dolenc I, et al. (1988). "Cathepsin D inactivates cysteine proteinase inhibitors, cystatins". Biochem. Biophys. Res. Commun. 154 (2): 765–72. doi:10.1016/0006-291X(88)90206-9. PMID3261170.
Ritonja A, Machleidt W, Barrett AJ (1985). "Amino acid sequence of the intracellular cysteine proteinase inhibitor cystatin B from human liver". Biochem. Biophys. Res. Commun. 131 (3): 1187–92. doi:10.1016/0006-291X(85)90216-5. PMID3902020.
Spiess E, Brüning A, Gack S, et al. (1994). "Cathepsin B activity in human lung tumor cell lines: ultrastructural localization, pH sensitivity, and inhibitor status at the cellular level". J. Histochem. Cytochem. 42 (7): 917–29. doi:10.1177/42.7.8014475. PMID8014475.
Lehesjoki AE, Koskiniemi M, Norio R, et al. (1993). "Localization of the EPM1 gene for progressive myoclonus epilepsy on chromosome 21: linkage disequilibrium allows high resolution mapping". Hum. Mol. Genet. 2 (8): 1229–34. doi:10.1093/hmg/2.8.1229. PMID8104628.
Lafrenière RG, Rochefort DL, Chrétien N, et al. (1997). "Unstable insertion in the 5' flanking region of the cystatin B gene is the most common mutation in progressive myoclonus epilepsy type 1, EPM1". Nat. Genet. 15 (3): 298–302. doi:10.1038/ng0397-298. PMID9054946.
1stf: THE REFINED 2.4 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF RECOMBINANT HUMAN STEFIN B IN COMPLEX WITH THE CYSTEINE PROTEINASE PAPAIN: A NOVEL TYPE OF PROTEINASE INHIBITOR INTERACTION