KPV vs Alpha-MSH: The Tripeptide and Its Parent Hormone

KPV is the tripeptide Lys-Pro-Val, which corresponds to the last three residues, 11 to 13, of alpha-melanocyte-stimulating hormone (alpha-MSH). Alpha-MSH is a 13-residue hormone, acetylated at its N-terminus and amidated at its C-terminus, with a molecular weight of about 1664.9 Da. KPV, at about 342.4 Da, is roughly one fifth of that mass and lacks the central sequence of the hormone.

What is alpha-MSH?

Alpha-MSH is cleaved from the precursor proopiomelanocortin and is identical to the first 13 residues of adrenocorticotropic hormone, with modified ends. Its central sequence, His-Phe-Arg-Trp, is the core recognized by melanocortin receptors. The same region gives the hormone its best-known role in pigmentation.

Why study the C-terminal tripeptide?

Researchers reported that the C-terminal fragment retained anti-inflammatory activity in experimental models. In mouse models of colitis, KPV reduced markers of intestinal inflammation [1], and its uptake into intestinal cells was attributed to the peptide transporter PepT1 [2]. That points to a mechanism different from that of the full hormone acting on melanocortin receptors, although the full picture is still debated. These are animal and cell findings.

How do the two compare in the laboratory?

KPV is small and polar, contains no aromatic residues and absorbs weakly at 280 nanometers, so HPLC methods detect it near 214 to 220 nanometers. Its identity is confirmed by mass spectrometry against the theoretical mass. Alpha-MSH is larger, contains tryptophan, phenylalanine and tyrosine, and contains a methionine that oxidizes, so its impurity profile is very different.

Is there a link to Semax?

Yes. Residues 4 to 7 of alpha-MSH, Met-Glu-His-Phe, are the same sequence that forms the core of Semax, which was derived from ACTH(4-7). The two research peptides therefore come from different ends of the same hormone sequence.

Frequently asked questions

Is KPV the same as alpha-MSH?

No. KPV is a three-residue fragment; alpha-MSH has 13 residues and different receptor pharmacology.

Does FLASK list KPV?

Yes, as KPV 10 mg, and as a component of the KLOW blend.