BPC-157 vs Dermorphin

BPC-157

BPC-157 is a synthetic 15-residue peptide whose sequence was taken from a larger protein reported in human gastric juice. That parent protein, named body protection compound, is described mainly in the papers of the group that reported it, and the peptide is known almost entirely through its own studies. Most published work comes from that single research group and is in rodents, covering models of tendon, ligament, muscle and bone injury, lesions of the stomach and intestine, and some nervous-system models. Human data are very limited, consisting of a few small reports rather than controlled trials. Independent replication outside the originating group is limited.

Dermorphin

Dermorphin is a seven-residue opioid peptide first found in the skin secretions of South American frogs of the genus Phyllomedusa. Its second residue is D-alanine. Ribosomes incorporate only L-amino acids, so this residue arises by conversion of an ordinary L-amino acid after the peptide chain is made; dermorphin was among the first natural peptides in which this was shown, which gives it a place in peptide biochemistry beyond opioid research. Work on it has been largely pharmacological, using receptor-binding assays, isolated tissue preparations and animal models. It and its synthetic analogues serve as reference ligands for one opioid receptor type. Human data are minimal.

How BPC-157 acts

No receptor for BPC-157 has been identified. Rodent and cell studies have reported changes in several signalling systems, most often the nitric oxide system, VEGF receptor 2 signalling in endothelial cells, and the FAK–paxillin pathway in cultured tendon fibroblasts. Other papers describe interactions with dopamine and serotonin systems in animal models. Several studies have also examined growth-factor and early-response gene expression in injured tissue. Because many of these findings come from a small number of laboratories, using different models, the mechanism is best regarded as unsettled rather than as a known pathway.

How Dermorphin acts

Dermorphin has been reported to bind the mu-opioid receptor with high selectivity over the delta and kappa types. The mu receptor is a G protein-coupled receptor linked to Gi/o proteins; its activation inhibits adenylyl cyclase, opens inwardly rectifying potassium channels and closes voltage-gated calcium channels, which lowers neuronal excitability and transmitter release. Structure–activity work has focused on the N-terminal Tyr-D-Ala sequence, which is shared with other amphibian opioid peptides such as the deltorphins, and on how the D-residue slows breakdown by peptidases compared with the all-L form. Much of the literature uses dermorphin analogues as tools for mapping mu-receptor pharmacology.

The records side by side

• Type: BPC-157, Pentadecapeptide; Dermorphin, Heptapeptide
• Length: BPC-157, 15 amino acids; Dermorphin, 7 amino acids
• Molecular weight: BPC-157, 1419.5 g/mol; Dermorphin, 802.9 g/mol
• Molecular formula: BPC-157, C62H98N16O22; Dermorphin, C40H50N8O10

Reading a comparison

A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.