A tripeptide is a peptide consisting of three amino acids joined by peptide bonds.
Examples of tripeptides are:
- Eisenin (pGlu-Gln-Ala-OH) is a peptide with immunological activity that is isolated from the Japanese marine alga, Eisenia bicyclis, which more commonly is known as, Arame
- GHK-Cu (glycyl--histidyl--lysine) is a human copper binding peptide with wound healing and skin remodeling activity, which is used in anti-aging cosmetics and more commonly referred to as copper peptide
- Glutathione (γ--Glutamyl--cysteinylglycine) is an important antioxidant in animal cells
- Isoleucine-proline-proline (IPP) found in milk products, acts as an ACE inhibitor
- Leupeptin (N-acetyl--leucyl--leucyl--argininal) is a protease inhibitor that also acts as an inhibitor of calpain
- Melanostatin (prolyl-leucyl-glycinamide) is a peptide hormone produced in the hypothalamus that inhibits the release of melanocyte-stimulating hormone (MSH)
- Ophthalmic acid (-γ-glutamyl--α-aminobutyryl-glycine) is an analogue of glutathione isolated from crystalline lens
- Norophthalmic acid (y-glutamyl-alanyl-glycine) is an analogue of glutathione (-cysteine replaced by -alanine) isolated from crystalline lens
- Thyrotropin-releasing hormone (TRH, thyroliberin or protirelin) (-pyroglutamyl--histidinyl--prolinamide) is a peptide hormone that stimulates the release of thyroid-stimulating hormone and prolactin by the anterior pituitary
- ACV (δ-(-α-aminoadipyl)--Cys--Val) is a key precursor in penicillin and cephalosporin biosyntheses.