Follistatin 344 (Myostatin Inhibitor) (95%) (1mg)

Follistatin 344 (FS344) Peptide

Isoform: Follistatin-315 (FS315) - Systemic Isoform Format: Sterile Lyophilized Powder (Vial) Mechanism: High-Affinity Ligand Trap (TGF-β Superfamily) Purity: >95% (HPLC) Content: 1mg per vial

Product Overview

Follistatin 344 is a recombinant glycoprotein designed to inhibit members of the TGF-β superfamily, most notably Myostatin (GDF-8) and Activin A. It corresponds to the alternatively spliced transcript that encodes the FS315 isoform.

Unlike the tissue-bound FS288 isoform, Follistatin 344 contains an acidic C-terminal tail that masks its heparin-binding site. This modification allows it to circulate freely in the bloodstream, making it the preferred reagent for research requiring systemic muscle hypertrophy and metabolic modulation.

Mechanism of Action: The Ligand Trap

Follistatin 344 acts as a "molecular clamp," physically sequestering ligands to prevent them from binding to their receptors (ActRIIB).

• Myostatin Inhibition: By neutralizing Myostatin, the primary negative regulator of muscle mass, Follistatin releases the "brake" on muscle growth, driving hypertrophy via the activation of mTOR and satellite cell fusion.

• Activin A Blockade: Follistatin binds Activin A with even higher affinity than Myostatin. This is crucial for its anti-inflammatory effects and its ability to suppress fibrosis in models of muscular dystrophy.

• Wnt Signaling: In hair follicle research, it antagonizes BMPs to permit Wnt-mediated transition from the resting (telogen) to growth (anagen) phase.

Key Research Applications

1. Musculoskeletal Hypertrophy Follistatin 344 is the gold standard for inducing rapid muscle growth.

• Hypertrophy: Studies report gains of 20% to >100% in muscle mass depending on the model (e.g., AAV gene therapy vs. peptide).

• Fiber Type: Drives a shift toward glycolytic (Type II) fibers, increasing force generation capacity.

2. Disease Models (Dystrophy & SMA)

• Spinal Muscular Atrophy (SMA): In murine models, daily administration extended lifespan by ~30% and increased motor neuron survival.

• Duchenne Muscular Dystrophy: Unlike myostatin-specific antibodies, Follistatin also blocks Activin A, significantly reducing fibrosis (scar tissue) in dystrophic muscle.

3. Inflammation & Metabolism

• Cytokine Storm: Acts as a potent anti-inflammatory by neutralizing the Activin A surge seen in sepsis and endotoxemia.

• Metabolic Health: Hypertrophied muscle acts as a glucose sink, improving insulin sensitivity and reducing visceral fat mass in obesity models.

Storage & Handling

• Physical State: Lyophilized (Freeze-Dried) Powder.

• Storage (Powder): Store at -20°C (Freezer). Stable for up to 12 months.

• Reconstitution:

  • Solvent: Bacteriostatic Water or Sterile PBS (pH 7.4).

  • Carrier Protein: Recommended to add 0.1% BSA or HSA to prevent adsorption to the vial wall.

• Storage (Liquid): Store at 4°C. Do not freeze-thaw repeatedly. Use aliquots.

Disclaimer

FOR RESEARCH USE ONLY. This product is a chemical compound intended strictly for laboratory research and development. It is not approved by the FDA for clinical use, diagnostics, or therapeutic procedures in humans or animals. The physiological and toxicological properties of this chemical have not been fully investigated.