S100 Calcium Binding Protein B (S100B) is a member of the S100 protein family, which is characterized by the presence of two EF-hand calcium-binding motifs. These proteins are localized in the cytoplasm and/or nucleus of a wide range of cells and are involved in the regulation of various cellular processes such as cell cycle progression and differentiation .
The S100B gene is located on chromosome 21q22.3 in humans and has orthologs in various species, including mice. The protein encoded by this gene is known for its role in the central nervous system (CNS), particularly in astrocytes, which are a type of glial cell . The recombinant form of S100B, tagged with a His (histidine) tag, is often used in research to facilitate purification and detection.
S100B has several critical functions:
S100B is secreted by astrocytes and can spill from injured cells into the extracellular space or bloodstream. Elevated levels of S100B in the serum are indicative of acute brain damage and have been used as a biomarker for blood-brain barrier (BBB) permeability and CNS injury. Elevated S100B levels are associated with neuropathological conditions such as traumatic head injury and neurodegenerative diseases .
The recombinant form of S100B, tagged with a His tag, is produced in a laboratory setting to facilitate research. The His tag allows for easy purification and detection of the protein using affinity chromatography techniques. This recombinant protein is used in various studies to understand the functions and mechanisms of S100B in both normal and disease states.