Anti-Stefin B CSTB Antibody Picoband® (monoclonal, 2B6)

Cystatin B (CSTB), also called STFB, is a small protein that is a member of the superfamily of cysteine protease inhibitors. It has been isolated from human spleen and liver and its amino acid sequence has been fully determined. The cystatin B gene is located on 21q22.3. It is widely distributed and is localized mostly intracellularly, but has been found extracellularly. The protein is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. Its role is thought to be as a protector against the proteinases leaking from lysosomes. A cystatin B multiprotein complex might have a specific cerebellar function, and that the loss of this function might contribute to the etiopathogenesis of EPM1. Upon differentiation to myotubes, CSTB becomes excluded from the nucleus and lysosomes, suggesting that the subcellular distribution of CSTB is dependent on the differentiation status of the cell.

E. coli-derived human Stefin B recombinant protein (Position: M1-F98) . Human Stefin B shares 78.6 % amino acid (aa) sequence identity with both mouse and rat Stefin B.

1. Alakurtti, K., Weber, E., Rinne, R., Theil, G., de Haan, G.-J., Lindhout, D., Salmikangas, P., Saukko, P., Lahtinen, U., Lehesjoki, A.-E. Loss of lysosomal association of cystatin B proteins representing progressive myoclonus epilepsy, EPM1, mutations. Europ. J. Hum. Genet. 13: 208-215, 2005. Note: Erratum: Europ. J. Hum. Genet. 13: 264 only, 2005. 2. Antonarakis, S. Personal Communication. Geneva, Switzerland 4/8/1997. 3. Bespalova, I. N., Adkins, S., Pranzatelli, M., Burmeister, M. Novel cystatin B mutation and diagnostic PCR assay in an Unverricht-Lundborg progressive myoclonus epilepsy patient. Am. J. Med. Genet. 74: 467-471, 1997.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.