Follistatin is a secreted protein that binds to ligands of the TGF-beta 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-beta ligands including BMP-2,-4,-6,-7, Myostatin, GDF-11, and TGF-beta1. Follistatin is expressed in the pituitary, ovaries, decidual cells of the endometrium, and in some other tissues. Recombinant human Follistatin is a 31.5kD protein containing 288aa. Its primary structure contains three cysteine-rich domains (called FS domains), each followed by a protease-inhibitory kazal domain.
Source:
Recombinant protein corresponding to human Follistatin, expressed in E.coli.
Biological Activity:
Determined by its ability to neutralize Activin A inhibitory effect of murine MPC-11 cells. The expected ED50 is 0.1-0.4ug/mlin the presence of 7.5ng/ml Activin A.
Endotoxin:
<0.1ng/ug (1EU/ug)
AA Sequence:
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
Storage and Stability:
May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.