Tripeptide

A tripeptide is a peptide derived from three amino acids joined by two or sometimes three peptide bonds.^[1] As for proteins, the function of peptides is determined by the constituent amino acids and their sequence. In terms of scientific investigations, the dominant tripeptide is glutathione (γ-L-Glutamyl-L-cysteinylglycine), which serves many roles in many forms of life.^[2]

A tripeptide (example Val-Gly-Ala) with
green marked amino end (L-Valine) and
blue marked carboxyl end (L-Alanine)

Examples

• 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-L-histidyl-L-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
• Lactotripeptides (Ile-Pro-Pro and Val-Pro-Pro) found in milk products, act as ACE inhibitors
• Leupeptin (N-acetyl-L-leucyl-L-leucyl-L-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 (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
• 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
• ACV (δ-(L-α-aminoadipyl)-L-Cys-D-Val) is a key biosynthetic precursor to penicillin and cephalosporin.

See also

• Dipeptide
• Tetrapeptide