Hexarelin

Follistatin-344 Peptide

Follistatin-344 is a naturally occurring glycoprotein that is considered to be present in almost all tissues. It is considered an autocrine chemical, meaning that the cell produces a chemical messenger through a cell signal, which binds to its autocrine receptors, resulting in cell modification.(1) Follistatin naturally occurs in two isoforms, FST 317 and FST 344, each containing 288 and 315 amino acids, respectively. These two isoforms may be produced through an alternative splicing process of the mRNA.(2) Their names are based on the parent molecules from which they are derived and contain 317 and 344 amino acids, respectively. Follistatin-344 is considered to be the predominantly expressed molecule in most tissues, while the Follistatin-317 isoform may account for less than 5% of the encoded mRNA.

Follistatin-344 is a synthetic version of the endogenous Follistatin-344 protein isoform. Although the number of amino acids differs in Follistatin isoforms, at its core, the protein comprises 63 amino acid residues and three domains: FSD1, FSD2, and FSD3, with an identical structure in the synthetic peptide.(3) These domains comprise 73-77 amino acid residues and are characterized by 10 conserved cysteine residues.

Overview

Researchers posit that Follistatin's primary potential may exist in activin-binding action.(4) Follistatin has been suggested to have a collaborative role in reproductive functioning alongside other chemicals like activin and inhibins. Scientists posit that the ovarian follicle mainly releases activin to enhance the secretion of follicle-stimulating hormone. Follistatin may bind with activin and attenuate its action by inhibiting the secretion of the FSH hormone.

While the origin and mechanism of the peptide hormone are not entirely understood, it has been suggested that Follistatin-344 is locally produced in the pituitary gland, gonads, testes, and ovaries. Additionally, Follistatin may be vastly distributed in various organs and potentially may be present in blood circulation due to its secretion from the blood vessels.

Further, Follistatin-344 is hypothesized to interact with various proteins within the Transforming Growth Factor-beta (TGFβ) superfamily.(16) This superfamily includes several key regulatory proteins in cellular growth and differentiation. One potential interaction is with the Bone Morphogenetic Proteins (BMPs), which are believed to play roles in bone formation, embryonic development, and cellular growth. It is conjectured that Follistatin-344 might modulate the activity of certain BMPs, though the specific proteins and mechanisms remain uncertain and require further exploration. Another possible interaction involves Growth Differentiation Factor 9 (GDF9), crucial for ovarian follicle development in female organisms. The binding of Follistatin-344 to GDF9 may suggest a regulatory role in reproductive processes, but this interaction is not fully understood and is subject to ongoing research.

However, the most notable of these interactions is with Growth Differentiation Factor 8 (GDF8), commonly known as myostatin. Myostatin is deemed integral to controlling muscle cell growth and differentiation, acting as a natural inhibitor to prevent excessive muscle development. It is proposed that Follistatin-344 binds to myostatin, potentially inhibiting its function. This inhibition may theoretically facilitate an increase in muscle mass by allowing muscle cells greater freedom to grow and differentiate. The potential for Follistatin-344 to enhance muscle growth through myostatin inhibition presents a significant area of interest, although the actual outcomes may vary and are highly dependent on singular biological conditions.

Chemical Makeup

Molecular Formula: N/A
Molecular Weight: 3780 g/mol
Other Known Titles: Activin-Binding Protein, FSH-Suppressing Protein, FST