What does GEPPPGKPADDAGLV mean?

It is the single-letter sequence: glycine, glutamate, proline, proline, proline, glycine, lysine, proline, alanine, aspartate, aspartate, alanine, glycine, leucine, valine.

Why do three consecutive prolines matter?

They form a polyproline helix, an extended, rigid conformation that dominates the peptide's shape and resists most peptidases.

Can BPC-157 be quantified at 280 nm?

No. There is no tryptophan, tyrosine or phenylalanine, so it has no usable absorbance there.

BPC-157 Structure and Sequence

The short answer

BPC-157 is Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val: fifteen residues at 1419.5 Da for formula C62H98N16O22. Four prolines and three glycines dominate its backbone behaviour, and it carries no cysteine, methionine or aromatic residue, which makes it chemically robust and analytically awkward in equal measure.

Key facts

Sequence: GEPPPGKPADDAGLV
Residues: 15
Prolines: Four (positions 3, 4, 5, 8)
Glycines: Three (positions 1, 6, 13)
Acidic: Glu2, Asp10, Asp11
Basic: Lys7
Cys / Met / aromatic: None of any

The proline run

Positions 3, 4 and 5 are three consecutive prolines, with a fourth at position 8. A run of three prolines forms a polyproline helix, a distinctive extended, rigid conformation quite unlike an alpha helix. That segment is structurally locked, and it dominates the peptide's shape in a way no other feature does.

The glycines that answer it

Glycine has no side chain and is the most flexible residue available. Three of them sit at positions 1, 6 and 13: immediately after the proline run at 6, and near each terminus. The result is an alternating architecture, with rigid proline segments hinged by flexible glycines, rather than a uniformly stiff or uniformly floppy chain.

Research material referenced

BPC-157 5mg, third-party HPLC tested

Buy BPC-157 · £15.99

Charge distribution

Glutamate at 2 and two aspartates at 10 and 11 give three negative charges; lysine at 7 gives one positive. Net negative at physiological pH, with the acidic residues clustered toward the C-terminal half. That asymmetry means the two ends of the molecule have quite different electrostatic character.

What is absent

No cysteine, so no disulfide chemistry and no reducing agent needed. No methionine, so no thioether oxidation and no +16 Da satellite. No tryptophan, tyrosine or phenylalanine, so no usable absorbance at 280 nm and no spectrophotometric quantification. This is the same profile as Selank and TB-500: chemically robust, analytically awkward.

Why the composition may explain the stability claim

The literature calls it the stable gastric pentadecapeptide. Proline-adjacent peptide bonds are poor substrates for most peptidases because proline constrains the backbone geometry those enzymes require. A peptide with four prolines, three of them consecutive, has a lot of protease-resistant bonds, which is a structural reason the stability claim is at least plausible rather than merely asserted.

Frequently asked questions

What does GEPPPGKPADDAGLV mean?: It is the single-letter sequence: glycine, glutamate, proline, proline, proline, glycine, lysine, proline, alanine, aspartate, aspartate, alanine, glycine, leucine, valine.
Why do three consecutive prolines matter?: They form a polyproline helix, an extended, rigid conformation that dominates the peptide's shape and resists most peptidases.
Can BPC-157 be quantified at 280 nm?: No. There is no tryptophan, tyrosine or phenylalanine, so it has no usable absorbance there.

Extended research context

The BPC-157 (Pentadecapeptide) deep dive

Deep dive: the pentadecapeptide sequence

BPC-157 is a synthetic pentadecapeptide with the sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. It is derived from a fragment identified in human gastric juice by the Zagreb research group (Sikirić and colleagues), whose body of published work spans three decades and covers models ranging from tendon repair to gut integrity. The 'BPC' initials stand for 'body protection compound', the group's original characterisation term.

Two forms: acetate salt vs arginate

BPC-157 is supplied most commonly as an acetate salt; a small subset of suppliers offer the arginate form, which has slightly different solubility and stability properties. For research reproducibility, keep the salt form consistent across a study and confirm which form the CoA specifies (mass ± counterion changes the reading).

Reading a BPC-157 CoA

A trustworthy BPC-157 CoA lists HPLC purity (target ≥98% area), mass-spec confirmation (~1,419 Da for the free peptide), water content (Karl Fischer), acetate content, and residual solvents. Some batches also include endotoxin data. Any missing category is a red flag for a compromised supply chain.

Research applications

▸Cell-culture models of gut epithelial integrity
▸Tendon fibroblast migration and collagen-synthesis assays
▸Angiogenesis models involving VEGF and NO signalling
▸Stability studies comparing acetate vs arginate salt forms
▸Analytical reference for pentadecapeptide HPLC methods

Handling checklist

✓Store lyophilised vial at −20 °C long-term (2–8 °C short-term)
✓Reconstitute with bacteriostatic water; a 5 mg vial dissolves cleanly
✓Aliquot reconstituted solution; keep refrigerated 2–8 °C, use within 28 days
✓Protect from light and repeated warming
✓Verify CoA: HPLC ≥98%, mass ~1,419 Da, salt form declared

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Mixing acetate and arginate BPC-157 across a study

Fix: Choose one salt form and stay with it. Different masses and solubility.

✗ Assuming stability at room temperature

Fix: Refrigerate reconstituted solution; discard after 28 days.

✗ Buying without a CoA

Fix: Only source from suppliers that publish batch HPLC + mass-spec data.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

UKP

Written and reviewed by

The UK Peptides Editorial Team · Research library, UK Peptides

The editorial team is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate. Corrections are made in place and the review date updated.

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