SS-31
Four residues, and two of the four are not standard amino acids at all. This is a designed molecule in the strict sense — the alternating aromatic and basic pattern was drawn on purpose, not copied from anything.
- Class
- Synthetic tetrapeptide (4 residues), C-terminally amidated
- Also written
- Elamipretide; MTP-131; Bendavia
- Molecular formula
- C32H49N9O5
- Molecular weight
- 639.8 g/mol
- CAS number
- 736992-21-5
- Appearance
- White lyophilised powder
- Purity specification
- 99%+ by HPLC
- Vial size stocked
- 25 mg
Sequence
D-Arg – Dmt – Lys – Phe – NH2
D-arginine, 2′,6′-dimethyltyrosine (Dmt), L-lysine, L-phenylalanine, with an amidated C-terminus. Two non-standard features carry the molecule: the first residue is the D-enantiomer of arginine rather than the L-form, and the second is a tyrosine bearing two extra methyl groups on the ring. Neither is a substitution a ribosome could make.
Origin
SS-31 belongs to the Szeto-Schiller family of small peptides, developed at Cornell and named for Hazel Szeto and Peter Schiller. The alternating aromatic-cationic pattern is the family's defining feature. It is made entirely by solid-phase synthesis; nothing in this sequence occurs naturally in this arrangement.
Solubility
Freely soluble in water. Strongly basic: the arginine and the lysine both carry a positive charge across the ordinary working pH range, and the C-terminal amide removes the one acidic group a free acid terminus would have provided.
Storage and handling
- Lyophilised powder: store at −20 °C, protected from light and moisture.
- Bring the vial to room temperature before opening, so condensation does not form on the powder.
- In solution: refrigerate, protect from light, and treat the working life as far shorter than that of the powder.
- Avoid repeated freeze-thaw cycles; aliquot first if the solution will be drawn on more than once.
- Label every reconstituted vial with compound, lot, concentration and date.
How your lot is verified
An independent third-party laboratory tests the material first, then we test it again in-house when it arrives — purity by HPLC, identity by mass spectrometry — and only then does it ship. On a peptide with a D-residue and a modified aromatic, HPLC does double duty: the retention time is what separates the intended molecule from its all-L or unmethylated cousins, which weigh differently but not by much. How we verify.
Supplied for laboratory research use only. Not for human or veterinary use. No statement on this page has been evaluated by the Food and Drug Administration, and nothing here is intended to diagnose, treat, cure, or prevent any disease. Alpha Aminos is a chemical supplier and does not provide guidance on the use of any compound.