Thymosin Alpha-1 + TB-4 + BPC-157 + KPV - Immune Research

1 Identity

Fixed-ratio four-component article: three all-L peptide free acids - one N-alpha-acetylated 28-mer, one N-alpha-acetylated 43-mer and one unmodified 15-mer - co-lyophilized with an unmodified tripeptide free acid. No metal center, no disulfide, no acylation beyond the two N-terminal acetyls, no non-proteinogenic residue. Each component's full identity lives on its own record and is cross-referenced from here rather than restated. "TB-4" is the hazardous abbreviation in this group and is treated below as a variant question rather than as a name.

Sequence

Per component, cross-referenced. Thymosin alpha-1: Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH, 28 residues. Thymosin beta-4, which is what "TB-4" is read as on this record: Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES-OH, 43 residues. BPC-157: H-GEPPPGKPADDAGLV-OH, 15 residues. KPV: H-Lys-Pro-Val-OH, three residues, free acid. Two N-terminal acetyls and two free alpha-amines share the vial, so any free-amine or Edman check reads two of the four components and reports a deficit that is not a defect.

Molecular formula

Per component; a mixture has no combined formula and none is written. Thymosin alpha-1 C129H215N33O55, with the des-acetyl species at C127H213N33O54. Thymosin beta-4 C212H350N56O78S. BPC-157 C62H98N16O22. KPV C16H30N4O4 as the free acid; the amide is C16H31N5O3 and is a different article. One sulfur atom exists in the whole vial, on thymosin beta-4's single methionine, and it does the heaviest analytical work in the record; if "TB-4" is resolved instead to Ac-SDKP, the article contains no sulfur at all and that handle disappears.

Average mass

Per component, on IUPAC 2021 abridged conventional atomic weights: thymosin alpha-1 3,108.315; thymosin beta-4 4,963.506; BPC-157 1,419.556; KPV 342.440, with the mono-acetate at 402.49 and the mono-trifluoroacetate at 456.46. Worked example at a stated nominal 10 plus 10 plus 10 plus 10 mg fill, 40 mg total: 3.217, 2.015, 7.044 and 29.202 micromol - a 1.60 : 1.00 : 3.50 : 14.49 molar ratio out of a 1 : 1 : 1 : 1 mass ratio. An equal-mass four-way fill is A 14.5-fold molar spread, entirely because a tripeptide and a 43-mer are in the same vial. That fill is a stated nominal for the arithmetic, not a market standard. No single blend molecular weight is printed; a mixture does not have one.

Monoisotopic mass

Per component, neutral: thymosin alpha-1 3,106.5041; thymosin beta-4 4,960.4863; BPC-157 1,418.7042; KPV 342.2267. The span forces two acquisition methods rather than one. KPV at 342 Da is observed singly protonated and is lost below the low-mass cut-off of a method tuned for a 4,963 Da chain, while the two large chains are observed only multiply charged and each requires a deconvoluted spectrum. A single MS method presented as covering 342 to 4,964 Da is demonstrated on the actual blend or it is not accepted.

Salt / variant note

"TB-4" is the worst abbreviation in this group: the market uses it for full-length thymosin beta-4 at 4,963.506 Da, for the Ac-LKKTETQ heptapeptide carried in the channel as TB-500 at 889.018 Da, and for the Ac-SDKP tetrapeptide at 487.510 Da - a 10.2-fold mass span under three letters. This record is written for the full-length 43-mer; the abbreviation must be expanded on the certificate before an analytical marker set can be chosen at all, because the choice changes that set completely rather than marginally. "KPV" separately covers the free acid at 342.440 and the C-terminal amide at 341.456, which are different molecules carried interchangeably under one name by two institutional suppliers. Counterion: KPV mono-acetate 402.49 and bis-acetate 462.54, mono-trifluoroacetate 456.46 and bis-trifluoroacetate 570.48 - on a 342 Da peptide the salt can be a third of the gross weight. Des-acetyl thymosin alpha-1 is that component's characteristic synthesis failure and a different molecule, not a lesser grade. Ratio: none standard.

2 Class & testing panel

Form

Fixed-ratio blend

Testing panel

P1 — panel definitionfor all four components, run per component and never once for the vial. This is the rare blend where one panel letter covers everything and the difficulty is entirely in separation rather than in chemistry: four peptides drawn from an overlapping residue pool, spanning 342.440 to 4,963.506 Da, sharing one tube. A lot offered as recombinant thymosin beta-4 moves that component to P4 in full - expression host declared, host-cell protein and residual host-cell DNA testing, aggregate measurement. One finding belongs to the composition rather than to any component: KPV has no unique marker residue here, its valine and proline both being conditioned by the other three chains, so the conditioning percentages are printed on the face of the certificate and a mandatory orthogonal method is attached to that component rather than a subtraction

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 and is cross-referenced from that component's record rather than restated here. None of it is literature about this four-component mixture: no published study of this fixed combination, and no consensus specification for it, has been identified - a statement about the search, not a finding about the article. The abbreviation question reaches the evidence as well as the specification. Full-length thymosin beta-4, the TB-500 heptapeptide and the Ac-SDKP tetrapeptide each carry a separate literature, so until the certificate expands "TB-4" no component file can be attached to that slot.

4 Storage & specification

Storage

Co-lyophilized solid in Type I amber glass with a PTFE-lined closure, nitrogen headspace re-blanketed after subdivision, in-pack desiccant, held at -20 degrees C plus or minus 5 degrees C and protected from light. A non-sterile laboratory chemical, no sterility claim, no injection format. The labeled condition is the most restrictive of the four components' requirements: the inert headspace is set by the single methionine in the vial, and the desiccation by KPV, whose moisture-assisted diketopiperazine pathway to cyclo(Lys-Pro) is the fastest route available in the solid state.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C from QA release, taken as the shorter of the component intervals and provisional pending this company's own data; the blend runs its own stability protocol and inherits no component study. The compatibility question the study must answer rather than assume: whether the molar dominance of the tripeptide - 14.5 moles of KPV for every mole of thymosin beta-4 at an equal-mass fill - changes the cake's water activity and with it the diketopiperazine rate. Stability-indicating attributes: per-component content, the four-way ratio, cyclo(Lys-Pro), des-acetyl thymosin alpha-1, methionine sulfoxide, water, counterion, and any new peak above 0.10 percent. Pulls at 0, 3, 6, 12, 18, 24 and 36 months.