FST Human, His

Follistatin is known for its ability to bind and neutralize members of the transforming growth factor-beta (TGF-β) superfamily, particularly activin . By binding to activin, follistatin functions as an activin antagonist, thereby inhibiting the biosynthesis and secretion of pituitary FSH . This interaction is crucial for regulating various physiological processes, including reproductive functions, cell growth, and differentiation .

Follistatin is expressed in numerous tissues beyond the gonads, including the brain, adrenal glands, bone marrow, and placenta . It plays a significant role in early embryogenesis and is involved in local regulatory functions in these tissues . The activin-follistatin system is particularly important in the anterior pituitary, the classical target tissue for inhibin .

Recombinant human follistatin, tagged with a histidine (His) tag, is produced using expression systems such as HEK293 cells . The His tag facilitates purification and detection of the protein. The recombinant protein is typically lyophilized and can be reconstituted for use in various research applications . It is measured for its ability to neutralize activin-mediated inhibition on cell proliferation, with an effective dose (ED50) typically ranging from 5-40 ng/mL .

Recombinant human follistatin is widely used in research to study its role in various biological processes and diseases. It has been linked to conditions such as polycystic ovary syndrome (PCOS) and hyperandrogenemia . Additionally, follistatin’s regulatory roles in extragonadal tissues make it a valuable tool for investigating its functions in different physiological contexts .

Lyophilized recombinant follistatin is stable for up to 12 months when stored at -20 to -80°C . Once reconstituted, the protein solution can be stored at 4-8°C for 2-7 days, and aliquots can be kept at -20°C for up to 3 months . It is typically formulated in sterile PBS with added protectants such as trehalose, mannitol, and Tween80 .