Adipotide (FTPP)

1 Identity

Synthetic chimeric peptidomimetic — disulfide-cyclized homing domain joined to an all-D amphipathic cationic repeat. and prohibitin-targeting peptidomimetic.

Sequence

CKGGRAKDC-GG-D(KLAKLAK)2-NH2. In full: a disulfide-cyclized nonapeptide homing domain, Cys-Lys-Gly-Gly-Arg-Ala-Lys-Asp-Cys, closed through a Cys1-Cys9 bridge; a Gly-Gly linker; and a fourteen-residue amphipathic cationic repeat, (Lys-Leu-Ala-Lys-Leu-Ala-Lys)2, in which every residue is the D-enantiomer; terminating in a C-terminal primary amide. Twenty-five residues, one intramolecular disulfide, one C-terminal amide, fourteen D-centers. The all-D second domain is the whole analytical problem: D- and L-peptides are isobaric and co-elute on achiral reversed-phase columns, so neither RP-HPLC nor mass spectrometry at any resolution or tolerance can detect a racemized or L-contaminated lot.

Molecular formula

C111H205N37O27S2 (free base, C-terminal amide, disulfide-closed)

Average mass

2554.213 Da for C111H205N37O27S2.

Monoisotopic mass

2552.52471 Da.

Salt / variant note

(1) the substitution with no mass difference at all, and it is the most likely one. A lot synthesized wholly or partly from L-amino acids in the KLAKLAK repeat carries the same formula and therefore the same mass — 2554.213 average, 2552.52471 monoisotopic — identical to the correct article at every decimal place, co-eluting on any achiral column, and undetectable by every test a research-channel certificate normally carries. Fourteen D-centers means fourteen opportunities, and the cheaper enantiomers are the ones in every peptide chemist's stockroom. (2) the form PubChem itself registers under this name: the linear reduced free acid, C111H206N36O28S2, 2557.21 / 2555.5244 — plus 3.00 Da, both termini and both thiols wrong, and it is what a public database returns to anyone who looks the name up. (3) The reduced ring-open amide with two free thiols, C111H207N37O27S2, 2556.23 / 2554.5404, exactly 2.02 Da heavier. (4) The des-amido free acid with the disulfide still closed, C111H204N36O28S2, 2555.20 / 2553.5087, 0.98 Da heavier — inside any tolerance stated in whole daltons. (5) A three-glycine linker construct, CKGGRAKDC-GGG-D(KLAKLAK)2-NH2, C113H208N38O28S2, 2611.27 / 2609.5462: this matters because two independent sellers both publish 2611.41 g/mol for their Adipotide — 57.20 Da above the correct article and within 0.15 Da of a one-glycine-longer construct. Those same listings print the molecular formula C152H252N44O42, whose own average mass is 3367.954 Da, contradicting the 2611.41 printed beside it by 756.54 Da. Whether their material is that construct or their numbers are simply wrong cannot be determined from the certificates they publish, and the ambiguity is the finding. (6) Fragment substitutions, both far cheaper to make: the amphipathic domain alone, D(KLAKLAK)2-NH2 with no homing domain and no linker, C72H139N21O14, 1523.04 / 1522.0810 — 1031.18 Da lighter, containing no cysteine, so a free-thiol assay on it returns zero and a disulfide map finds nothing to fail; and the cyclized homing nonapeptide alone, CKGGRAKDC free acid, C35H62N14O12S2, 935.09 / 934.4113. (7) An intermolecular disulfide-scrambled dimer appears near 5108 Da; disulfide-scrambled isomers of the monomer are exactly isobaric with the correct article. (8) Counterion arithmetic as a check on the certificate rather than on the molecule: this construct carries nine strongly basic sites, eight lysines and one arginine, so a fully loaded nona-trifluoroacetate salt is roughly 29 percent w/w counterion before any water is counted — a certificate reporting 99 percent purity and no counterion figure is describing at most 71 percent of the vial.

2 Class & testing panel

Form

Single article

Testing panel

P3 — panel definition

3 Primary sources & evidence

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

Mouse, rat and non-human primate pharmacology and toxicology from the originating academic group, including the primate work that recorded the dose-limiting renal finding, plus one registered first-in-human study. What does not exist: a completed controlled human efficacy trial reported to completion, a marketing authorization in any jurisdiction, and any independent replication of the primate work by a group outside the originating program. The citation index page states the discontinuation and the renal finding in the first line rather than in a footnote, because both are material to anyone deciding whether to buy it.

4 Storage & specification

Storage

Would be supplied as a lyophilized solid, acetate salt, in Type I amber glass under a nitrogen headspace with an elastomeric stopper and crimp seal, labeled for storage at -20 degrees C plus or minus 5 degrees C, protected from light and moisture. The nitrogen headspace is the control on thiol-disulfide scrambling at the Cys1-Cys9 bridge, which is the article's principal solid-state vulnerability. No vial is filled and no label is printed.

Shelf life

None assigned. A disulfide-cyclized construct of this type would not be given more than a provisional 12 months at -20 degrees C in any event, because tracking scrambling requires a non-reducing peptide map that this company would have to develop and validate before it could defend any interval at all.