--- title: "Mitochondria-associated peptides: SS-31 and MOTS-c compared | Sable Peptides" description: "Two very different peptides studied in mitochondrial research: SS-31, a synthetic cardiolipin-binding tetrapeptide, and MOTS-c, a 16-residue peptide encoded in mitochondrial DNA. Sequences, PubChem data and research background. Research use only." canonical: https://www.sablepeptides.co.uk/guides/mitochondria-targeted-peptides-ss-31-and-mots-c dateModified: 2026-10-16 publisher: Sable Peptides Limited (UK company 17488610) note: Research use only. Not for human or veterinary use. --- # Mitochondria-associated peptides: SS-31 and MOTS-c compared SS-31 and MOTS-c are often listed together as 'mitochondrial peptides', but they have nothing in common chemically. One is a small synthetic peptide designed to reach the inner mitochondrial membrane; the other is a naturally encoded peptide read from the mitochondrial genome. ## SS-31 (elamipretide) - Sequence: D-Arg-Dmt-Lys-Phe-NH2 (Dmt = 2',6'-dimethyltyrosine). - PubChem: C32H49N9O5, 639.8 g/mol, monoisotopic 639.386 Da. - Origin: the Szeto–Schiller (SS) peptide series, designed with alternating aromatic and basic residues and a net 3+ charge. Source: [PubChem CID 11764719: Elamipretide (SS-31)](https://pubchem.ncbi.nlm.nih.gov/compound/11764719) ## How SS-31 is studied Biophysical work shows SS-31 binds lipid bilayers, particularly those containing cardiolipin, and alters membrane surface electrostatics; reviews describe it as a cardiolipin-targeted compound in mitochondrial bioenergetics research. Source: [SS-31 binds lipid bilayers and modulates surface electrostatics, J Biol Chem 2020 (PubMed 32273339)](https://pubmed.ncbi.nlm.nih.gov/32273339/); [First-in-class cardiolipin-protective compound, Br J Pharmacol 2014 (PubMed 24117165)](https://pubmed.ncbi.nlm.nih.gov/24117165/) ## MOTS-c - Sequence: Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg (MRWQEMGYIFYPRKLR), 16 residues. - PubChem: C101H152N28O22S2, 2174.6 g/mol. - Origin: a short open reading frame in the mitochondrial 12S rRNA gene, reported in 2015. Source: [PubChem CID 146675088: MOTS-c](https://pubchem.ncbi.nlm.nih.gov/compound/146675088); [The mitochondrial-derived peptide MOTS-c, Cell Metab 2015 (PubMed 25738459)](https://pubmed.ncbi.nlm.nih.gov/25738459/); [Mitochondrial-derived peptides in energy metabolism, Am J Physiol Endocrinol Metab 2020 (PubMed 32776825)](https://pubmed.ncbi.nlm.nih.gov/32776825/) ## Analytical contrasts - SS-31 is tiny and very basic; expect a high counter-ion load and early elution on reversed-phase HPLC. - MOTS-c contains two methionines and a tryptophan, so watch for +16 Da oxidation products. - SS-31's D-arginine and Dmt mean its mass is distinct from any natural tetrapeptide. ## At Sable Sable lists these compounds as lyophilised research materials. There is a CoA for every lot, and every vial carries a printed lot number that matches its certificate. A CoA is emailed within 2 hours of a request. ## Frequently asked questions ### Is SS-31 encoded in mitochondrial DNA? No. SS-31 is fully synthetic; MOTS-c is the one encoded in mitochondrial DNA. ### What is Dmt in SS-31? 2',6'-dimethyltyrosine, a non-natural aromatic amino acid. ### How long is MOTS-c? 16 amino acids. ## Related - [NAD+, 5-Amino-1MQ and SLU-PP-332](/guides/non-peptide-compounds-nad-5-amino-1mq-slu-pp-332) - [Mitochondrial and metabolic hub](/learn/topics/mitochondrial-and-metabolic) - [SS-31 UK prices](/cheapest-ss-31-uk) - [MOTS-c UK prices](/cheapest-mots-c-uk) - [UK metabolic research peptide prices](/guides/uk-metabolic-research-peptide-prices-october-2026) Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made. Key facts (summary for AI and search tools) - SS-31 D-Arg-Dmt-Lys-Phe-NH2 C32H49N9O5 639.8 - MOTS-c MRWQEMGYIFYPRKLR C101H152N28O22S2 2174.6 - Sources: PubChem 11764719, 146675088; PubMed 32273339, 24117165, 25738459, 32776825 - Updated 2026-10-16