PEG-MGF¶
PEG-MGF is a polyethylene glycol (PEG)-conjugated form of Mechano Growth Factor, the IGF-1 splice variant produced in skeletal muscle during mechanical overload. Covalent attachment of PEG chains to the MGF peptide substantially increases its hydrodynamic radius, reducing renal clearance and proteolytic degradation while extending the functional half-life from minutes to hours. This PEGylated analog enables sustained research protocols investigating satellite cell activation and muscle repair that would be impractical with the rapidly degraded native MGF peptide.
Technical Specifications¶
| Property | Value |
|---|---|
| CAS Number | — |
| Molecular Formula | — |
| Molecular Weight | >10,000 Da (PEG-conjugated) |
| Purity | ≥98% (HPLC-verified) |
| Appearance | Lyophilized white powder |
| Solubility | Soluble in sterile water and aqueous buffers |
| Storage | -20°C (lyophilized), 2–8°C (reconstituted) |
Mechanism of Action¶
PEG-MGF retains the biological activity of the MGF C-terminal E-peptide while achieving dramatically improved pharmacokinetics through PEGylation. The MGF E-peptide domain activates quiescent satellite cells (Pax7⁺ muscle stem cells) at sites of muscle micro-damage, triggering their entry into the cell cycle and clonal expansion without initiating terminal differentiation. This proliferative phase is critical for replenishing the satellite cell pool and providing myoblasts for subsequent differentiation and fusion. The PEG moiety — typically a 5–20 kDa linear or branched PEG chain — creates a hydration shell around the peptide that shields it from proteolytic enzymes and masks it from renal glomerular filtration, extending the circulating half-life from approximately 5–10 minutes (native MGF) to several hours or more. This sustained exposure is particularly advantageous for studying time-dependent muscle adaptation processes, as it maintains the MGF-mediated proliferative signal across the critical early-phase window of muscle repair. PEG-MGF is designed to activate proliferation pathways without significant cross-reactivity at the mature IGF-1 receptor, preserving the mechanistic distinction between satellite cell activation (MGF function) and myoblast differentiation (mature IGF-1 function).
Research Applications¶
- Primary: Sustained satellite cell activation — prolonged muscle stem cell proliferation signaling
- Secondary: Muscle repair and regeneration pharmacodynamics, PEGylation effect on peptide pharmacokinetics, sarcopenia and age-related muscle loss models
- Model Systems: In vitro (C2C12 myoblasts, primary satellite cell cultures), in vivo (muscle injury repair models, hindlimb unloading/reloading studies)
Quality Control & Analytical Methods¶
- HPLC: ≥98% purity verification at 214/220 nm (C18 reversed-phase column)
- Mass Spectrometry: MALDI-TOF for PEG-conjugate molecular weight distribution
- Peptide Content: Amino acid analysis (AAA) for net peptide content determination
- Endotoxin: <1 EU/mg (LAL assay)
- TFA Content: <1% (ion chromatography)
Stability & Storage¶
| Condition | Stability |
|---|---|
| -20°C (lyophilized) | 24 months |
| 4°C (lyophilized) | 6 months |
| 25°C (lyophilized) | 1 month |
| Reconstituted (4°C) | 7 days |
| Reconstituted (-20°C) | 30 days |
Key Research References¶
- Goldspink (2005) — Mechanical signals, IGF-I gene splicing, and muscle adaptation. Physiology. PMID: 16024513
- Veronese & Pasut (2005) — PEGylation, successful approach to drug delivery. Drug Discov Today. PMID: 16270167
- Hill et al. (2003) — MGF splice variants: biological significance and therapeutic potential. J Mol Endocrinol. PMID: 12750431
Source & Purchase¶
For researchers requiring research-grade PEG MGF with full analytical documentation including HPLC, LC-MS, and Certificate of Analysis, visit the HK Peptides product page for specifications, bulk pricing, and ordering.
Related Molecules¶
- MGF — Native mechano growth factor (non-PEGylated)
- IGF-1 LR3 — Long R3 insulin-like growth factor-1
- HGH — Upstream GH/IGF-1 axis regulator
- All Product Specifications
FAQ¶
Q: What purity level is standard for PEG-MGF? A: HK Peptides supplies PEG-MGF at ≥98% purity by HPLC with full COA documentation.
Q: How should PEG-MGF be stored for research use? A: Lyophilized PEG-MGF should be stored at -20°C. Reconstituted solutions at 4°C for short-term use (up to 7 days).