interpeptide

Interpeptide is a descriptive term used in biochemistry and proteomics to refer to processes, bonds, or interactions that occur between peptide chains or peptide fragments, as opposed to within a single peptide chain (intra-peptide). The concept highlights connections that link distinct peptides and can be either covalent or non-covalent.

Covalent interpeptide bonds include crosslinks that form between residues on different peptides or protein chains. Examples include disulfide bonds between cysteines on separate peptides and isopeptide bonds created by enzymes such as transglutaminases that join lysine and glutamine residues on different chains. In structural proteins like collagen, interpeptide crosslinks between neighboring peptide chains help stabilize higher-order assemblies and contribute to tissue strength. Non-covalent interpeptide interactions, such as hydrogen bonding, ionic interactions, and hydrophobic contacts, also mediate associations between peptide chains and are important for protein complex formation and signaling.

In research contexts, interpeptide crosslinking is a central concept in crosslinking mass spectrometry, where identifying interpeptide crosslinks helps map proximities and interactions within protein complexes. The term is also used in peptide chemistry to describe ligation strategies that join two separate peptide fragments to form a longer peptide, such as native chemical ligation or other interpeptide coupling techniques.

Overall, interpeptide describes any connection or interaction bridging distinct peptide chains, highlighting the cooperative architecture of multi-peptide assemblies.