Follistatin 315 1 mg

Follistatin 315 (FST-315, also written FS-315) is the 315-amino-acid mature isoform of the secreted glycoprotein follistatin, an autocrine/paracrine regulator encoded by the FST gene (UniProt P19883). It is generated from the 344-residue follistatin precursor (FST-344) by removal of a 29-amino-acid N-terminal signal peptide (residues 1-29), yielding the mature chain (residues 30-344) that is the predominant circulating form of the protein. Structurally it comprises an N-terminal domain followed by three cysteine-rich follistatin domains, and it is distinguished from the cell-surface-associated FST-288 isoform by an acidic C-terminal tail that reduces its affinity for cell-surface heparan sulfate, making FST-315 the principal systemically circulating variant.

Follistatin belongs to the family of TGF-beta superfamily antagonists. In preclinical and in-vitro research, FST-315 has been studied as a high-affinity binding partner that sequesters activins and myostatin (GDF-8), limiting their interaction with type II receptors. Because of this activity, laboratory investigations using cellular and rodent models have examined follistatin in the context of skeletal-muscle signaling and myostatin neutralization, as well as roles in tissue regeneration, inflammatory and fibrotic pathways, and reproductive-axis signaling. All such findings are observations from preclinical and animal studies and have not been established in humans.

Specifications: Sequence/length 315 amino acids (mature FST-315 isoform, derived from the 344-residue precursor minus a 29-aa signal peptide) · Approximate molecular weight ~35 kDa (calculated for the unglycosylated 315-residue chain; native follistatin migrates ~31-49 kDa depending on glycosylation) · UniProt P19883 (FST gene) · Purity typically >=95% (HPLC) · Form lyophilized powder · Available sizes Default

Storage and handling: Store the lyophilized powder at -20C and protect it from light. Reconstitute with bacteriostatic (BAC) water for laboratory use. Keep the reconstituted solution refrigerated and use it within a few weeks; avoid repeated freeze-thaw cycles.

For research use only. Not for human consumption. This product is not a drug, food, or dietary supplement and is not intended to diagnose, treat, cure, or prevent any disease.