Function
While Epitalon is reported to increase lifespan and reduce tumor incidence in animals, and to influence differentiation of neural and mesenchymal stem cells; is studied as an epigenetic regulatory peptide36, PEG-MGF is used experimentally to enhance muscle repair and hypertrophy after mechanical overload or injury by stimulating satellite-cell activation and protein synthesis6373138.
Mechanism
While Epitalon works as a synthetic tetrapeptide, Ala-Glu-Asp-Gly (AEDG), that has been shown to bind histones and modulate gene expression and chromatin state, with reported effects on pineal function, neurogenesis, and longevity in animal models36, PEG-MGF is a poly(ethylene glycol)-conjugated form of Mechano Growth Factor (IGF-1Ec splice variant) comprising the 24-aa C-terminal E-peptide of IGF-1, designed to extend half-life while activating IGF-1 receptor–mediated anabolic signaling in muscle satellite cells637322138.
Length and Sequence
Epitalon is 4 amino acids long, whereas PEG-MGF is longer as it has a length of 24 amino acids. Epitalon is made up of a sequence of Alanine, Glutamic acid, Aspartic acid, Glycine. PEG-MGF is made up of a sequence of Tyrosine, Glutamine, Proline, Proline, Serine, Threonine, Asparagine, Lysine, Asparagine, Threonine, Lysine, Serine, Glutamine, Arginine, Arginine, Lysine, Glycine, Serine, Threonine, Phenylalanine, Glutamic acid, Glutamic acid, Arginine, Lysine.