Tripeptide

A tripeptide is a peptide consisting of three amino acids joined by peptide bonds.

Examples of tripeptides are:

Glutathione (γ-glutamyl-cysteinyl-glycine) is an antioxidant, protecting cells from toxins such as free radicals.
Thyrotropin-releasing hormone (TRH, thyroliberin or protirelin) (L-pyroglutamyl-L-histidinyl-L-prolinamide) is a peptide hormone that stimulates the release of thyroid-stimulating hormone and prolactin by the anterior pituitary.
Melanostatin (prolyl-leucyl-glycinamide) is a peptide hormone produced in the hypothalamus that inhibits the release of melanocyte-stimulating hormone (MSH).
Ophthalmic acid (L-γ-glutamyl-L-α-aminobutyryl-glycine) is an analogue of glutathione isolated from crystalline lens.
Norophthalmic acid (y-glutamyl-alanyl-glycine) is an analogue of glutathione (L-cysteine replaced by L-alanine) isolated from crystalline lens.
Eisenin (pGlu-Gln-Ala-OH) is a peptide with immunological activity isolated from the Japanese marine alga Eisenia bicyclis.

See also