S-100b Protein, Bovine Brain

Research area: NEUROSCIENCE

Native homodimeric S-100b isoform composed of ββ-subunits, purified from bovine brain. The S100 calcium-binding protein B (S100B) exists in the form of homo- or hetero-dimers comprised of two subunits, A and B. Specifically, the S-100AB and S-100BB types are referred to as S100B protein and are known for their strong association with nervous tissue. This protein can be found in the cytosol of glial and Schwann cells. The gene responsible for encoding the S100B protein is situated in the chromosomal region 21q22. Under nonreducing conditions both the dimeric and monomeric forms may be visible.

S100 calcium-binding protein B (S100B) has been used:

• to study the interaction between the serotonin 5-HT7 receptor and the calcium-binding protein S100B using surface plasmon resonance-based method.
• as a probe to detect and study the binding interactions with proteins during the far-western blotting technique.
• to investigate the role of S100B in relation to blood-brain barrier (BBB) integrity and its potential involvement in the production of autoantibodies against S100B.
• to study the mechanism of communication between thermogenic adipocytes and sympathetic neurons mediated by Calsyntenin-3β and S100b, providing insights into the regulation of sympathetic innervation in adipose tissue.

The S100 calcium-binding protein B (S100B) is known to interact with the cytoskeleton and plays crucial roles in cell proliferation, survival, regulation of calcium homeostasis, and enzyme activities. S100B has been observed to have several effects, including up-regulating the expression of inducible NOS, inducing the release of nitric oxide (NO) in astrocytes and microglia, up-regulating cyclooxygenase-2 expression in microglia and monocytes, triggering NO-dependent death of astrocytes and neurons, increasing the production of reactive oxygen species in neurons, and causing disruption of lipid homeostasis and cell cycle arrest. Elevated levels of S100B have also been observed in the CSF of patients with brain tumors, as well as in the blood of patients with Alzheimer′s disease and Parkinson′s disease. Elevated serum level of S-100b is used as a marker of stroke and cerebral edema. The S-100 proteins are acidic Ca2+ binding proteins found predominately in glial cells. Evidence indicates that upon binding to Ca2+, S-100 proteins expose a hydrophobic domain to the solvent in a manner similar to calmodulin. Within the cell, S-100 proteins have been reported to regulate adenylate cyclase, aldolase activities, ATPase, microtubules, and protein phosphorylation.

Toxicity: Standard Handling (A)

Lyophilized from 50 mM Tris-HCl, pH 7.5, 50 mM NaCl, 100 µM DTT.

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

Momotani, E., et al. 1993. J. Comp. Pathol. 108, 291.
Baudier, J., et al. 1992. Proc. Natl. Acad. Sci. USA 89, 11627.
Donato, R. 1991. Cell Calcium12, 713.
Isobe, T., et al. 1977. Biochim. Biophys. Acta494, 222.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany