Abcam, ab211315, Recombinant human Cystatin-B protein

Size: 10µg
Recombinant human Cystatin-B protein is a Human Full Length protein, in the 1 to 98 aa range, expressed in Escherichia coli, with >95%, < 1 EU/µg endotoxin level, suitable for SDS-PAGE, FuncS, Mass Spec.
Key facts
Purity:>95% SDS-PAGE,
Endotoxin level:< 1 EU/µg,
Expression system:Escherichia coli,
Tags:His tag N-Terminus,
Applications:FuncS, Mass Spec, SDS-PAGESee reactivity dataSee the reactivity data table below for information on validated species and application combinations.,
Biologically active:Yes,
Biological activity:The IC50 value is < 3.0nM. The inhibitory function of Stefin B on protease activity of papain was measured by a fluorometric assay using Z-FR-AMC at pH 7.5 at 25°C.,
Accession:P04080,
Animal free:No,
Carrier free:Yes,
Species:Human,
Storage buffer:pH: 8Constituents: 0.32% Tris HCl, 0.29% Sodium chloride

Product details:
This product was previously labelled as Stefin B

Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage duration-1-2 weeks, Appropriate short-term storage conditions-+4°C, Appropriate long-term storage conditions--20°C, Aliquoting information-Upon delivery aliquot, Storage information-Avoid freeze / thaw cycle

Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
Cystatin-B also known as STEFIN-B is a protease inhibitor with a molecular mass of approximately 11 kilodaltons. It belongs to the family of cystatins which are expressed widely in human tissues with notable presence in the brain liver and kidneys. Cystatin-B acts by inhibiting cysteine proteases preventing them from degrading proteins indiscriminately. The inhibition is important for maintaining cellular protein balance and integrity.
Biological function summary
Cysteine protease inhibition by Cystatin-B protects cells from uncontrolled proteolysis which can lead to tissue damage. This protein plays an important role in the regulation of various cellular processes including apoptosis phagocytosis and the response to oxidative stress. It does not form part of a larger complex but interacts directly with its target proteases to exert its inhibitory effects.
Pathways
Cystatin-B influences proteolytic pathways by modulating the activity of cysteine proteases such as cathepsins. By inhibiting these enzymes Cystatin-B participates in the regulation of the lysosomal degradation pathway and apoptotic pathways which are important for cellular turnover and programmed cell death. Cathepsins particularly cathepsin B and L are related proteins that are significantly modulated through their interaction with Cystatin-B.
Mutations or dysregulation of Cystatin-B are associated with progressive myoclonus epilepsy and certain neurodegenerative diseases. The lack of functional Cystatin-B leads to excessive activity of proteases like cathepsin B resulting in increased proteolysis and neuronal damage. In some cases this can also connect to disorders involving oxidative stress exacerbating the detrimental cycle of cellular injury.