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Research area

Mitochondrial Compounds

For research use only. Not for human or veterinary use. Sold strictly for in-vitro laboratory research; not for diagnosis or treatment.

The three compounds in this research area are catalogued together for their association with mitochondrial research, but they belong to different chemical classes. MOTS-c is a synthetic linear peptide of sixteen residues, Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg, whose sequence corresponds to a short open reading frame in mitochondrial DNA. SS-31 is an aromatic-cationic tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2, that alternates basic and aromatic residues; it contains a D-arginine, the non-proteinogenic residue 2′,6′-dimethyltyrosine and a C-terminal amide. NAD+ (β-nicotinamide adenine dinucleotide) is not a peptide: it is a dinucleotide coenzyme, C21H27N7O14P2, formed from nicotinamide mononucleotide and adenosine monophosphate joined through a pyrophosphate linkage. Each product page lists the compound's formula and molecular weight, and the sequence of each peptide.

Compounds in this research area

  • NAD+

    In stock500 mg

    British Peptide Labs vial — NAD+
    £70.00

  • SS-31

    In stock50 mg

    British Peptide Labs vial — SS-31
    £150.00

  • MOTS-c

    In stock40 mg

    British Peptide Labs vial — MOTS-c
    £90.00

Structural features

The three compounds here are grouped by research field rather than molecular class, so their structures have little in common. MOTS-c is a linear peptide of sixteen standard amino acids, H-Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg-OH, with free termini. Four of its residues are basic (three arginines and a lysine) and four are aromatic (a tryptophan, two tyrosines and a phenylalanine), and its two methionines account for the two sulfur atoms in its formula, C101H152N28O22S2. A single glutamic acid is its only acidic residue, so the chain is strongly basic overall.

SS-31 is a tetrapeptide, H-D-Arg-Dmt-Lys-Phe-NH2, of the aromatic-cationic class: basic and aromatic residues alternate along the chain. It contains two features uncommon in short synthetic peptides, a D-arginine at the N-terminus and 2′,6′-dimethyltyrosine (Dmt), a tyrosine carrying two methyl groups on its aromatic ring, and it ends in a C-terminal amide. Its basic groups are the arginine guanidine, the lysine side-chain amine and the free N-terminal amine.

NAD+ (β-nicotinamide adenine dinucleotide) is not a peptide and contains no amino acids. It is a dinucleotide, C21H27N7O14P2: nicotinamide mononucleotide and adenosine monophosphate joined through a pyrophosphate (diphosphate) linkage, with each half built on a D-ribose sugar. The positive charge in its name sits on the nitrogen of the nicotinamide ring, and NAD+ is the oxidised member of the NAD+/NADH redox pair.

Identifiers at a glance

CompoundCAS numberMolecular formulaMolecular weight
NAD+53-84-9C21H27N7O14P2663.43 g/mol
SS-31736992-21-5C32H49N9O5639.79 g/mol
MOTS-c1627580-64-6C101H152N28O22S22174.6 g/mol

Analytical considerations

Because the classes differ, so do the methods. Both peptides are analysed by reversed-phase HPLC with mass spectrometry for identity, but their aromatic content shapes the ultraviolet picture: MOTS-c, with a tryptophan and two tyrosines, absorbs well at 280 nm, and the Dmt and phenylalanine of SS-31 give it measurable absorbance there too. MOTS-c's two methionines are the likeliest sites of oxidation, each adding 16 Da. SS-31 is short and strongly cationic, so it can be weakly retained on reversed-phase columns unless an ion-pairing agent is present, and it gives an intense series of multiply charged ions in electrospray mass spectrometry. MOTS-c, at 2174.6 g/mol, also appears as a short series of multiply charged ions rather than a single peak.

NAD+ is a small, polar molecule and is usually analysed by HPLC with ultraviolet detection at 260 nm, where the adenine ring absorbs, often on ion-pair reversed-phase or hydrophilic-interaction columns. Relevant related substances are nicotinamide, ADP-ribose and NADH, which shows an additional absorbance band at 340 nm and so can be distinguished spectroscopically. Because NAD+ has no peptide bond, the low-wavelength region that suits the two peptides is of little value for it. Like lyophilised peptides, NAD+ is hygroscopic, so water content belongs in a full specification.

Further reading