BPC-157

BPC-157, or Body Protection Compound 157, is a synthetic pentadecapeptide corresponding to a partial sequence of a protein found in human gastric juice. Its fifteen residues include a proline-rich central region, which is why the backbone is modelled in a polyproline-II conformation in the PepXtide structural library.

The parent material is a roughly 40 kDa protein described from human gastric juice by Sikiric and colleagues in the early 1990s, and the fifteen-residue stretch supplied here is the fragment that the subsequent literature is built on. The sequence is Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val, carried as the free acid with no acetylation, amidation, disulfide or other terminal modification.

Three consecutive prolines at positions three to five dominate the conformation. Proline cannot donate a backbone hydrogen bond and its ring restricts the phi angle, so the central region resists folding into a regular helix and is modelled instead as a polyproline-II ribbon. The composition is also worth reading for what it lacks: there is no cysteine, methionine or tryptophan, so the molecule has no oxidation-prone side chain, and no tyrosine or phenylalanine either, which means there is no aromatic chromophore and concentration cannot be determined by absorbance at 280 nm. A colorimetric assay or a mass-based method is required instead.

The reported molecular targets are signalling proteins rather than a dedicated receptor; no BPC-157 receptor has been identified. In cultured endothelial cells the peptide has been reported to raise VEGFR2 (KDR) transcript and protein and to promote receptor internalisation, with downstream Akt and eNOS activation, an effect abolished by the endocytosis inhibitor dynasore; a separate VEGF-independent route through Src and caveolin-1 to eNOS has also been described. In cultured rat tendon fibroblasts the peptide has been reported to increase phosphorylation of focal adhesion kinase and paxillin without changing total protein, and to raise growth hormone receptor transcript and protein in the same cells.

Laboratory work with the compound is largely cell-based: tendon and fibroblast outgrowth and migration assays, endothelial tube-formation assays, viability and oxidative-stress survival assays, phalloidin staining of the actin cytoskeleton, and Western blotting of the kinases above. Pharmacokinetic characterisation in animal plasma uses reversed-phase LC-MS/MS with electrospray ionisation; those studies report a short elimination half-life for the intact peptide and rapid breakdown to short fragments and free amino acids, which is the practical reason assay design for this compound tends to be short-window.

Handling follows from the chemistry. The peptide is strongly hydrophilic, with a computed partition coefficient far below zero and a large polar surface area, so aqueous buffers present no solubility difficulty. With no thiol and no methionine there is no oxidation route to guard against, and the usual failure mode is instead adsorptive and hydrolytic loss in dilute solution. A review published in 2026 notes that formal pharmaceutical characterisation of this compound, including validated formulation and stability data, remains largely absent from the literature.