Recombinant Human Cystatin B Protein (His Tag)

Name: Recombinant Human Cystatin B Protein (His Tag)
Brand: Beta LifeScience
SKU: BLPSN-1528
Availability: InStock

Collections: Other recombinant proteins, Recombinant proteins

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Product Overview

Tag	His
Host Species	Human
Accession	P04080
Synonym	CST6, EPM1, EPM1A, PME, STFB, ULD
Background	Cystatin-B, also known as CPI-B, Liver thiol proteinase inhibitor, Stefin-B, CSTB and CST6, is a cytoplasm and nucleus protein which belongs to thecystatin family. Cystatin-B / CSTB is an intracellular thiol proteinase inhibitor. Tightly binding reversible inhibitor of cathepsins L, H and B. Cystatin-B / CSTB is able to form a dimer stabilized by noncovalent forces, inhibiting papain and cathepsins l, h and b. Cystatin-B / CSTB is also thought to play a role in protecting against the proteases leaking from lysosomes. Defects in Cystatin-B / CSTB are the cause of progressive myoclonic epilepsy type 1 (EPM1) which is an autosomal recessive disorder characterized by severe, stimulus-sensitive myoclonus and tonic-clonic seizures. The cystatins are a family of cysteine protease inhibitors with homology to chicken cystatin. Cystatins are physiological inhibitors of cysteine proteinases which are widely distributed in human tissues and fluids. Cystatins typically comprise about 115 amino acids, are largely acidic, contain four conserved cysteine residues known to form two disulfide bonds. Cystatins may be glycosylated and / or phosphorylated, with similarity to fetuins, kininogens, stefins, histidine-rich glycoproteins and cystatin-related proteins. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired inhibitory activity. Cystatins mainly inhibit peptidases belonging to peptidase families C1 (papain family) and C13 (legumain family).
Description	A DNA sequence encoding the human CSTB (P04080) (Met 2-Phe 98) was expressed, with a His tag at the N-terminus.
Source	E.coli
Predicted N Terminal	Met
AA Sequence	Met 2-Phe 98
Molecular Weight	The recombinant human CSTB consisting of 108 a.a. and has a calculated molecular mass of 12.5 kDa. It migrates as an approximately 15 kDa band in SDS-PAGE under reducing conditions.
Purity	>95% as determined by SDS-PAGE
Endotoxin	Please contact us for more information.
Bioactivity	Measured by its ability to inhibit papain cleavage of a fluorogenic peptide substrate Z-FR-AMC (R&D Systems, Catalog # ES009). The IC50 value is < 15 nM.
Formulation	Lyophilized from sterile 50mM Tris, 50mM NaCl, pH 8.0.
Stability	The recombinant proteins are stable for up to 1 year from date of receipt at -70°C.
Usage	For Research Use Only
Storage	Store the protein under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.

Target Details

Target Function	This is an intracellular thiol proteinase inhibitor. Tightly binding reversible inhibitor of cathepsins L, H and B.
Subcellular Location	Cytoplasm. Nucleus.
Protein Families	Cystatin family
Database References	HGNC: 2482 OMIM: 254800 KEGG: hsa:1476 STRING: 9606.ENSP00000291568 UniGene: Hs.695
Associated Diseases	Epilepsy, progressive myoclonic 1 (EPM1)

Gene Functions References

cystatin B expression was significantly and inversely correlated with lung tumor stage and tumor grade PMID: 29037838
The results demonstrate that cystatin B interferes with the STAT-1 signaling and IFN-beta-antiviral responses perpetuating HIV in macrophage reservoirs. PMID: 27137788
apoptosis is accompanied by degradation of the cysteine cathepsin inhibitor stefin B (StfB). CatD did not exhibit a crucial role in this step. However, this degradation was partially prevented through pre-incubation with the antioxidant N-acetyl cysteine PMID: 28543404
Homozygous for a c.218dupT (p.His75Serfs*2) mutation in exon 3 of CSTB causes neurodegeneration, progressive cerebral volume loss and diffuse hypomyelination. PMID: 28378817
CSTB downregulation may promote the development of gastric cancer. PMID: 28281969
It was shown that decreased expression of cystatin B enhances cathepsin activity in Niemann-Pick C cerebellar degeneration patient fibroblasts. PMID: 26908626
High expression of stefin B may be an important factor contributing to the development and metastasis of Hepatocellular Carcinoma. PMID: 26753874
CSTB null mutation associated with microcephaly, early developmental delay, and severe dyskinesia. PMID: 26843564
Data shows that CYTB and ANXA4 overexpression may be involved in carcinogenesis and histopathological differentiation of ovarian clear cell carcinoma and suggest they may serve as a potential diagnostic biomarkers. PMID: 25633807
A role for disease-causing mutations in cystatin B gene in patients with juvenile myoclonic epilepsy was not supported. PMID: 25752200
Even though the majority of EPM1 patients have a uniform genetic mutation, the actual size of the longer CSTB expansion mutation allele is likely to have a modulating effect on the age at disease onset, myoclonus severity, and cortical neurophysiology. PMID: 25770194
The study shows detection of stefin B dimers in HEK293 cells and the importance of their residual activity. PMID: 25047918
glutamate dehydrogenase is a euchromatin-associated enzyme, and its H3 clipping activity is regulated by chromatin structure, histone modifications and an in vivo inhibitor. PMID: 25263734
detected a homozygous expansion of dodecamer repeats in the CSTB gene in four patients with clinical diagnosis of ULD. PMID: 23883076
The increased CSTB expression in ovarian tissue represents tumor progression and is dysregulated by the TGF-beta signaling pathway. PMID: 24452274
A reciprocal influence of CSTB and SOD1 at the gene expression level and for a direct interaction of the two proteins, is reported. PMID: 24234043
The present study was performed on two more missense mutants of human stefin B, G50E and Q71P, and they similarly showed numerous aggregates upon overexpression. PMID: 24909779
The co-localization of stefin B wild type and EPM1 mutants with cathepsins showed that cathepsins accumulate around the aggregates formed by the EPM1 mutants. PMID: 23362198
Skull thickening and an increased prevalence of abnormal findings in skeletal radiographs of patients with EPM1 suggest that this condition is connected to defective cystatin B function. PMID: 23010349
This study suggested that CSTB mutations other than the common dodecamer expansion predict particular phenotypes, including marked seizure severity and polymorphous seizure types. PMID: 23205931
Elevated StefA mRNA level is associated with invasive glioblastoma. PMID: 22287159
S-glutathionylation and S-cysteinylation were described as extensive PTM of a salivary protein and the first time that these PTMs were detected in naturally occurring cystatin B. PMID: 22057043
patients compound heterozygous for the dodecamer repeat expansion and the c.202C>T mutations seem to have a severer form of Unverricht-Lundborg disease (EPM1) than patients homozygous for the expansion mutation PMID: 21757863
At pH 7.0 the mutant H75W folded in three kinetic phases to a native-like intermediate, analogous to folding of stefin B at pH 4.8. PMID: 22033403
Intracellular stefin b aggregation shows a negative correlation with cell survival PMID: 20078424
Stefin B interacts with histones and cathepsin L in the nucleus PMID: 20075068
oligomers of stefin B and amyloid-beta interact in vitro and in cells PMID: 19955183
Oligonucleotides containing EPM1 repeat adopt secondary structures that may facilitate strand slippage thereby causing the expansion. PMID: 11697734
Intramolecular i-motif structure at acidic pH for progressive myoclonus epilepsy (EPM1) repeat d(CCCCGCCCCGCG)n. PMID: 11697735
analysed eight markers flanking CSTB(GT10-D21S1890-D21S1885-D21S2040-D21S1259- CSTB-D21S1912-PFKL-D21S171) and one intragenic variant in the CSTB 3' UTR (A2575G) PMID: 12215838
first demonstration of cysteine protease activity being regulated by CSTB activity in a biological context; effects of decreased CSTB activity in EPM1 pathogenesis may be mediated by cathepsins through increased activity of cathepsins S and L PMID: 12452481
Prefibrillar oligomers/aggregates of stefin B also increase the surface pressure at an air-water interface, i.e. they have amphipathic character and are surface seeking. PMID: 15955063
These data show that cystatin B inhibits bone resorption by down-regulating intracellular cathepsin K activity despite increased osteoclast survival. PMID: 16321512
Study shows that copper binding by stefin B inhibits the amyloid fibril formation and, to a lesser degree, the initial aggregation. PMID: 16939620
Several alternatively spliced CSTB isoforms were identified in patients with progressive myoclonus epilepsy of Unverricht-Lundborg type . PMID: 17003839
Results describe the influence of pH and trifluoroethanol on amyloid fibril growth and morphology from human stefin B. PMID: 17701471
cystatin B in vivo has a polymeric structure sensitive to the redox environment and that overexpression of the protein generates aggregates. PMID: 17920138
CSTB is specifically overexpressed in most HCCs and is also elevated in the serum of a large proportion of HCC patients PMID: 18281540
Data show that wild-type stefin B and its Y31 isoform are able to form pores in planar lipid bilayers, whereas the G4R isoform destroys the bilayer by a non pore-forming process. PMID: 18397316
The mechanism of amyloid-fibril formation by stefin B: temperature and protein concentration dependence of the rates;the observed kinetics follow the nucleation and growth behavior observed for many other amyloidogenic proteins. PMID: 18636508
potential role for CSTB in HIV replication in placental macrophages PMID: 18951626
cystatin B interacts with STAT-1 and the levels of STAT-1 tyrosine phosphorylation (but not serine phosphorylation) between uninfected and HIV-infected PM and MDM are differentially regulated. PMID: 19342095

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