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 an activin antagonist 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.
FS, Activin-binding protein
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
≥ 95% by SDS-PAGE gel and HPLC analyses.
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.
Calculated Molecular Weight:
Not for human use.