tripepti

Tripepti is a term used for a tripeptide, a short chain of three amino acids linked by peptide bonds. The term is widely used in English as "tripeptide," while "tripepti" may appear in some languages or contexts as a transliteration. A tripeptide has a free amino terminus (N-terminus) and a free carboxyl terminus (C-terminus) and can be described by the sequence of its amino acids.

Chemically, a tripeptide is linear and can be represented as H2N-CHR1-CO-NH-CHR2-CO-NH-CHR3-COOH, where R1, R2, R3 are the side chains of the amino acids. Any combination of the 20 standard amino acids is possible, leading to many possible sequences. Tripeptides can be formed by condensation reactions between amino acids, or generated during protein digestion by proteases.

In biology and medicine, tripeptides occur as short fragments during digestion and can be transported into cells by peptide transporters such as PepT1, which absorb di- and tri-peptides for further metabolism into amino acids. They are generally small, water-soluble molecules and are often transient intermediates rather than stable dietary end products.

Applications vary: in research, tripeptides are used as model substrates and in peptide chemistry; in cosmetics, certain tri-peptides such as palmitoyl tripeptide-5 are used as ingredients marketed to influence collagen synthesis, though efficacy evidence varies. Tripeptides are one class within the broader field of peptides, which also includes dipeptides and longer polypeptides.