MOTS-c + GHK-Cu + KPV

1 Identity

Fixed-ratio three-component article: one 16-residue synthetic peptide free acid, one copper(II) coordination complex of a tripeptide ligand, and one tripeptide free acid. The metal is the fact that reorganizes the specification. Each component's full identity lives on its own record and is cross-referenced from here rather than restated. The descriptive market listings that name the three components with the 40 mg / 25 mg / 20 mg split. The component names are the weak point, not the title: "MOTS-c" is sold as human, rat and mouse sequences and as (1-12) and (1-13) fragments, "GHK-Cu" is sold as the free ligand and as the complex, and "KPV" is sold as the free acid and as the C-terminal amide. This record specifies human MOTS-c free acid, the 1:1 copper complex and the KPV free acid.

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, all-L, with the oxidation inventory that governs its handling - methionines at positions 1 and 6, not 1 and 5, one tryptophan at 3, two tyrosines at 8 and 11. GHK-Cu ligand H-Gly-L-His-L-Lys-OH as the 1:1 copper(II) complex. KPV H-Lys-Pro-Val-OH, free acid.

Molecular formula

Per component; a mixture has no combined formula and none is written. MOTS-c C101H152N28O22S2 (free acid, salt-free), mono-acetate C103H156N28O24S2, mono-trifluoroacetate C103H153F3N28O24S2, mono-sulfoxide C101H152N28O23S2. GHK-Cu C14H22CuN6O4, free ligand C14H24N6O4. KPV C16H30N4O4 free acid, the C-terminal amide C16H31N5O3 being a different article. MOTS-c is the only sulfur-containing component and GHK-Cu the only metal-containing one, so each has an isotope signature the other two lack.

Average mass

Per component, on IUPAC 2021 abridged conventional atomic weights: MOTS-c 2174.621 Da; GHK-Cu 401.914 Da, copper 15.81 percent w/w; KPV 342.440 Da. At the observed 40 mg / 25 mg / 20 mg fill, 85 mg total - a mass ratio of 2.00 : 1.25 : 1.00 - the molar figures are 18.3940, 62.2024 and 58.4044 micromol, a molar ratio of 1.0000 : 3.3817 : 3.1752, and the 25 mg of complex carries 3.95 mg of elemental copper into the vial. The component present in the largest mass is present in the smallest molar amount by more than threefold. No single blend "molecular weight" is printed.

Monoisotopic mass

Per component. MOTS-c 2173.10774 neutral, [M+2H]2+ 1087.56115, [M+3H]3+ 725.37652. GHK-Cu 401.0999 neutral for the 63Cu isotopologue, [M+H]+ 402.1072, 65Cu isotopologue 403.0980. KPV 342.22671 neutral, [M+H]+ 343.23399, with the C-terminal amide 0.98 Da lighter at 341.24269. Two internal collisions carry this panel: the MOTS-c K14Q polymorph sits 0.03639 Da from the parent neutral, 0.01213 Da apart at 3+, demanding resolving power near 1 in 60,000 and excluded only by LC-MS/MS coverage across residue 14 or an amino acid analysis Lys:Gln ratio; and MOTS-c mono-sulfoxide sits at +15.99491.

Salt / variant note

(1) ratio: 40/25/20 mg is the commonly observed fill and is not a standard; other splits circulate, and the split on any given vial is an observed presentation rather than a specification. (2) MOTS-c FORK: human 2174.62 against rat 2516.03 and mouse 1446.75, plus (1-12) 1620.91 and (1-13) 1777.10, and the K14Q polymorph 0.036 Da from the parent. (3) GHK-Cu FORK: free ligand 340.38 against the 1:1 complex 401.91 against the mono-acetate 461.97. (4) KPV fork: free acid 342.440 against the C-terminal amide 341.46, with two institutional suppliers selling the two under one shared product name. (5) salt per component, KPV bis-trifluoroacetate being 40.0 percent counterion by gross weight.

2 Class & testing panel

Form

Fixed-ratio blend

Testing panel

P1 — panel definitionfor MOTS-c and KPV, P5 for GHK-Cu, run per component and never once for the vial. The P5 element governs the other two by contamination rather than by chemistry: free Cu(II) interferes with AQC and OPA derivatization, so a desalting or EDTA step is written into the amino acid analysis method for the whole article rather than left to the laboratory. The deconvolution of the three components is the best-conditioned of the copper blends in this catalog: three robust unique markers, no labile marker, and total lysine available as a fourth equation

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. None of it is literature about this three-component mixture. No published study of this fixed combination has been identified, and no consensus specification for it has been identified either.

4 Storage & specification

Storage

Co-lyophilized solid, blue to blue-violet from the copper complex, in Type I amber glass with a PTFE-lined closure, nitrogen headspace and in-pack desiccant. Store at -20 degrees C plus or minus 5 degrees C, desiccated and protected from light - a non-sterile laboratory chemical carrying no sterility claim and no injection format. The inert headspace is set by the MOTS-c oxidation inventory, and the label states that reason so a receiving technician cannot treat it as optional. Vials are equilibrated to ambient before opening.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C from QA release, the shortest of the three component intervals and provisional pending this company's own data; the blend runs its own protocol and inherits no component study. The compatibility question here is the sharpest of the copper blends and is answered by data: the most oxidation-labile peptide in the catalog is co-lyophilized with a redox-active copper complex, so methionine sulfoxide and tryptophan oxidation are tracked from time zero on every lot rather than assumed to behave as they do in the single-article study. Other stability-indicating attributes: per-component content, the measured ratio, copper-to-ligand stoichiometry, free ligand, cyclo(Lys-Pro), water, counterion and any new peak above 0.10 percent. Pulls at 0, 3, 6, 12, 18, 24 and 36 months.