Follistatin 288

Follistatin 288 (FS-288) is the shortest isoform of natural follistatin, encoded by the human FST gene. It is a single-chain protein of 288 amino acids (approx. 31.5 kDa) belonging to the group of regulators that bind TGF-β superfamily signalling proteins. In in vitro research models, it is studied for its ability to bind activin A and myostatin with high affinity and to sterically block these ligands before they interact with cell-surface receptors. A characteristic feature is its basic sequence, through which FS-288 attaches strongly to cell-surface heparan sulfate proteoglycans, so in research it is regarded as a localised ligand binder.

FS-288 is used as a tool in cellular and tissue culture models of the TGF-β signalling pathway and the regulation of myogenesis. It is used to analyse how neutralising activin A and myostatin affects signal transduction in vitro, and the attachment of the protein itself to the cell surface is also studied. Structural studies describe the architecture of the myostatin–follistatin 288 complex and its significance for receptor blocking and heparin binding (EMBO Journal, 2009). All these studies are limited to cell and tissue cultures and do not examine effects on the human or animal body.

The product is supplied as a lyophilised (dry) powder of ≥99% purity (HPLC). Each vial contains 1 mg of the active substance (follistatin 288). For laboratory preparation, the powder is dissolved in bacteriostatic water, which is sold separately; the vial is swirled carefully until a clear solution forms – do not shake.

Keep the unopened vial of dry powder in a refrigerator at +2–8 °C, or in a freezer (−20 °C) for longer storage, protected from light. Once reconstituted in bacteriostatic water, keep the solution refrigerated and use it within the time set out in your research protocol. Avoid repeated thaw–freeze cycles.

In the research context, FS-288 is most often studied together with its targets – activin A and myostatin (GDF-8) – in binding and neutralisation experiments, using methods such as surface plasmon resonance (SPR) analysis and cell-based signalling assays. In cellular models of myogenesis, it is combined with muscle cell cultures (e.g. myoblast lines) to analyse regulation of the TGF-β pathway. These are exclusively in vitro research combinations; no doses for humans or animals are given.

Absolutely not. This product is sold exclusively for laboratory research and scientific experiments. It is not intended for human or animal consumption and is not a medicine, dietary supplement or cosmetic product.