Function
While MOTS-c improves insulin sensitivity, enhances glycolysis, reduces oxidative stress, and shows protective effects in models of metabolic syndrome, aging, and ischemia-reperfusion injury8135146, 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 MOTS-c works as a 16-amino-acid mitochondrial-derived peptide that translocates to the nucleus under metabolic stress and regulates glucose and lipid metabolism largely via activation of AMPK and modulation of mTOR and folate-cycle–linked pathways854140146, 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
MOTS-c is 16 amino acids long, whereas PEG-MGF is longer as it has a length of 24 amino acids. MOTS-c is made up of a sequence of Methionine, Arginine, Tryptophan, Glutamine, Glutamic acid, Methionine, Glycine, Tyrosine, Isoleucine, Phenylalanine, Tyrosine, Proline, Arginine, Lysine, Leucine, Arginine. 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.