What MOTS-c is
MOTS-c is a 16-amino-acid peptide encoded by a short open reading frame within the mitochondrial 12S ribosomal RNA gene. That location is what makes it notable: mitochondrial DNA was long assumed to encode only components of the respiratory chain, and the identification of short ORFs producing peptides that act outside the mitochondrion opened a distinct area of cell biology.
Its sequence, MRWQEMGYIFYPRKLR, is short enough to synthesise reliably and contains a mixture of residues — two methionines, a tryptophan, two tyrosines — that has direct consequences for how it must be handled and analysed.
Molecular profile
| Property | Value |
|---|---|
| Sequence | MRWQEMGYIFYPRKLR |
| Length | 16 amino acids |
| Molecular weight | ~2,174 Da |
| Encoded by | Mitochondrial 12S rRNA gene (short ORF) |
| Appearance | White to off-white lyophilised powder |
Research context
MOTS-c is studied as a mitochondrial-derived signalling peptide, with published work covering:
- Metabolic regulation — reported effects on AMPK pathway activity and on the folate–methionine cycle in cultured cells.
- Cellular stress response — reported nuclear translocation under metabolic stress, which places it unusually among peptides as a candidate retrograde signal from mitochondrion to nucleus.
- Exercise and ageing physiology — reported changes in circulating levels with age and with exercise, which is much of what drives interest in it.
- Insulin sensitivity models — largely preclinical.
Supplied for in-vitro laboratory research only. No therapeutic claim is made and no dosing or administration guidance is provided.
Analytical notes
The composition of this sequence dictates its impurity profile.
Methionine oxidation is the dominant degradation route. Two of the sixteen residues are methionine, and methionine oxidises readily — during synthesis, during lyophilisation, and in storage. Each oxygen added shifts mass by 16 Da, which mass spectrometry resolves easily. The presence and abundance of oxidised species on a batch's mass spectrum is a direct readout of manufacturing and storage quality, and it is one of the more informative things a certificate for this compound can show.
Tryptophan is light-sensitive. The single tryptophan residue is photochemically labile, which is the specific reason light protection is not generic advice for this compound.
UV detection is favourable. Tryptophan and two tyrosines give this peptide strong absorbance at 280 nm as well as at the peptide-bond wavelength around 214 nm, so quantitation is more straightforward than for peptides with no aromatic residues.
Handling and storage
Store sealed at −20 °C, protected from light — genuinely, not nominally, given the tryptophan — and from moisture. Bring to room temperature before opening.
Reconstitute by running diluent down the vial wall and swirling. Store solution at 2–8 °C in the dark, prepare working solutions fresh where possible, and avoid repeated freeze-thaw: oxidation continues in solution, and each cycle is an opportunity for it.
What we supply
Released against a ≥99% purity specification, with HPLC purity and mass spectrometry identity confirmation on every batch and a batch-specific Certificate of Analysis. Select batches additionally receive independent third-party purity verification.