MOTS-c + Humanin

1 Identity

Fixed-ratio two-component article: two all-L mitochondrial-derived peptide free acids, co-lyophilized - a 16-residue chain encoded in a short open reading frame within the mitochondrial 12S rRNA gene, and a 24-residue chain encoded within the 16S rRNA gene. No metal center, no acyl chain, no conjugate, no non-proteinogenic residue. One free cysteine thiol, on the 24-residue component. Also indexed by its two component names; no trade title for this article has been identified, and the catalog names it by its components. Neither component name is stable in the market: "MOTS-c" covers free acid, acetate, trifluoroacetate and analog forms, and "Humanin" denotes both the native 24-residue chain and the S14G analog, which is a different molecule and carries a large share of the published work.

Sequence

Per component, cross-referenced. MOTS-c H-Met-Arg-Trp-Gln-Glu-Met-Gly-Tyr-Ile-Phe-Tyr-Pro-Arg-Lys-Leu-Arg-OH (MRWQEMGYIFYPRKLR), 16 residues, free acid. Humanin H-Met-Ala-Pro-Arg-Gly-Phe-Ser-Cys-Leu-Leu-Leu-Leu-Thr-Ser-Glu-Ile-Asp-Leu-Pro-Val-Lys-Arg-Arg-Ala-OH (MAPRGFSCLLLLTSEIDLPVKRRA), 24 residues, free acid, with a free thiol at Cys8 and no disulfide.

Molecular formula

Per component; a mixture has no combined formula and none is written. MOTS-c C101H152N28O22S2 free acid; Humanin C119H204N34O32S2 free base. Both chains carry two sulfurs, but for different reasons - two methionines in one, one methionine plus one cysteine in the other - so a total sulfur figure is uninformative, and the certificate distinguishes thioether from thiol. Counterion is measured per component; both are supplied as acetate or trifluoroacetate salts at stoichiometries that are not fixed.

Average mass

Per component, on IUPAC 2021 abridged conventional atomic weights: MOTS-c 2,174.62 Da; Humanin 2,687.27 Da. AT A nominal 10 mg + 10 mg fill, 20 mg total, the 1.00 : 1.00 mass ratio is a molar ratio of 1.236 : 1.000 - 4.59850 and 3.72125 micromol. The two components are close enough in mass that an equal-mass fill lands nearer equimolar than in any other blend in this catalog except the two heptapeptide articles, which is a convenience and not a reason to conflate the two figures.

Monoisotopic mass

Per component. MOTS-c 2,173.10774 neutral, worked from the multiply charged envelope. Humanin 2,685.4822 neutral, [M+H]+ 2,686.4895, [M+2H]2+ 1,343.7484, [M+3H]3+ 896.1680. The species A method must not miss is the Humanin disulfide-linked homodimer at twice the neutral less 2.016 Da, 5,368.949 monoisotopic, which forms in air from the free Cys8 thiol; MOTS-c carries no cysteine, so no mixed dimer is chemically available, and any dimer seen is Humanin's alone.

Salt / variant note

(1) MOTS-c: at least five articles circulate under the name - free acid 2,174.62, mono-acetate, mono-trifluoroacetate, and analog forms carried on the MOTS-c variants record in this catalog - and one reagent catalog prints a formula weight of 2288.6 for its trifluoroacetate salt, which is a salt weight and not the peptide's. (2) humanin: the analog is the substitution risk. HNG, the S14G analog, is a different molecule, is separately cataloged by institutional suppliers, and carries a large share of the published work; a vial sold as "Humanin" may contain either. (3) cysteine state: free thiol against homodimer against S-acetamidomethyl-protected material. (4) ratio: no standard has been identified.

2 Class & testing panel

Form

Fixed-ratio blend

Testing panel

P1 — panel definitionfor both components, run per component and never once for the vial; the union adds nothing beyond P1. The article's analytical character is set by oxidation rather than by panel breadth: three methionines, one tryptophan and one free cysteine thiol across two chains in one headspace, which makes the inert blanket a release-relevant control rather than packaging. The MOTS-c marker is chosen for hydrolysis robustness rather than for uniqueness on paper: tryptophan is unique but is destroyed by standard hydrolysis, while tyrosine, which Humanin entirely lacks, does the same job and survives

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

Published literature exists for each component, is graded on that component's record and is cross-referenced rather than restated; both files sit within the mitochondrial-derived-peptide literature originating in large part from the University of Southern California program, and a material share of the Humanin corpus was generated with the S14G analog rather than the native chain, which is graded on that record. None of it is literature about this mixture. No published study of this fixed two-component combination has been identified.

4 Storage & specification

Storage

Lyophilized solid at -20 degrees C plus or minus 5 degrees C, desiccated over silica, protected from light, sealed under argon or nitrogen, in an amber borosilicate vial with a fluoropolymer-faced closure; non-sterile, carrying no sterility claim. The inert headspace is not decoration on this article: two methionines and a tryptophan on one chain and a free thiol plus a methionine on the other make atmospheric oxygen the principal degradation route for both components at once, and a vial held open-headspace will breach its oxidation and dimer limits before it breaches its purity limit. A failed seal is an out-of-trend event in its own right.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C under inert headspace, desiccated, from QA release - the shorter of the two component intervals and provisional pending this company's own data. The oxidation and dimer impurities are the stability-indicating attributes rather than gross purity: pulls at 0, 3, 6, 9, 12, 18 and 24 months, with methionine sulfoxide reported per site, each tryptophan oxidation product individually, free thiol content and Humanin homodimer at every pull, plus a headspace-integrity check accompanying each pull.