Background
Follistatin is a secreted protein that binds to ligands of the TGF-β family and regulates their activity by inhibiting their access to signaling receptors. It was originally discovered as activin antagonists whose activity suppresses expression and secretion of the pituitary hormone FSH (follicle stimulating hormone). In addition to being a natural antagonist, follistatin can inhibit the activity of other TGF-β ligands including BMP-2,-4,-6,-7, Myostatin, GDF-11, and TGF-β1. Follistatin is expressed in the pituitary, ovaries, decidual cells of the endometrium, and in some other tissues. Recombinant human Follistatin is a 31.5 kDa protein containing 288 amino acids. Its primary structure contains three cysteine-rich domains (called FS domains), each followed by a protease-inhibitory kazal domain.
Specifications
Additional Names
FS, activins-binding protein
Preparation
Biological activity was determined by its ability to neutralize Activin A inhibitory effect of murine MPC - 11 cells. The expected ED50 is 0.1 - 0.4 μg/ml in the presence of 7.5 ng/ml Activin A.
Location
GNCWLRQAKN GRCQVLYKTE LSKEECCSTG RLSTSWTEED VNDNTLFKWM IFNGGAPNCI PCKETCENVD CGPGKKCRMN KKNKPRCVCA PDCSNITWKG PVCGLDGKTY RNECALLKAR CKEQPELEVQ YQGRCKKTCR DVFCPGSSTC VVDQTNNAYC VTCNRICPEP ASSEQYLCGN DGVTYSSACH LRKATCLLGR SIGLAYEGKC IKAKSCEDIQ CTGGKKCLWD FKVGRGRCSL CDELCPDSKS DEPVCASDNA TYASECAMKE AACSSGVLLE VKHSGSCN
Source
E. coli
Reactivity
n/a
Tested Application
n/a
Storage
The lyophilized Follistatin recombinant protein is stable for at least 2 years from date of receipt at -20ËšC. Reconstituted Follistatin is stable for at least 3 months when stored in working aliquots with a carrier protein at -20ËšC. As with any protein, exposing Follistatin recombinant protein to repeated freeze / thaw cycles is not recommended. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.
Species Reactivity
n/a
Purity
Greater than 95% by SDS-PAGE gel and HPLC analyses.
Endotoxin level is less than 0.1 ng per μg (1EU/μg).
