MOTS-c

MOTS-c is a synthetic 16-residue peptide of molecular formula C₁₀₁H₁₅₂N₂₈O₂₂S₂, with an average molecular mass of 2174.62 Da and a monoisotopic mass of 2173.1077 Da. Its sequence is Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg, assembled as an unmodified chain with a free N-terminal amine and a free C-terminal carboxylic acid. Reconstructing the formula from the sixteen residues and one water of hydrolysis reproduces the deposited composition exactly.

The peptide belongs to the mitochondrial-derived peptides, a small class of short sequences whose open reading frames lie within mitochondrial ribosomal RNA genes rather than in nuclear coding sequence; the reading frame in this case sits within the mitochondrial 12S ribosomal RNA gene. The N-terminal methionine is retained, consistent with a sequence defined from an initiation codon rather than excised during processing.

The two sulfur atoms in the formula correspond to methionine at positions 1 and 6, and they dominate the impurity profile. Each methionine can oxidise to the sulfoxide with a mass increment of 15.995 Da, so mono- and di-oxidised species appear at 2190.6 Da and 2206.6 Da average mass and are separated from the parent under reversed-phase gradients. Four aromatic residues, Trp3, Tyr8, Phe10 and Tyr11, give strong absorbance near 280 nm, allowing quantification at that wavelength in addition to 214 nm; the tryptophan residue is itself susceptible to photo-oxidation and contributes further oxidised species to the impurity profile. Three arginines and one lysine against one glutamate give a net basic charge and a high isoelectric point.

The compound has no target entry in either UniProt or ChEMBL, and the corresponding field is therefore blank. Its two-methionine, four-aromatic composition distinguishes it clearly from peptides of comparable length such as the aromatic-free BPC-157, whose ultraviolet and oxidation behaviour are the opposite in both respects.

This material is supplied strictly for in-vitro laboratory research. It is not a drug, food or supplement, and is not for human or veterinary use, diagnosis, or consumption.