Abbreviated nomenclature for cyclic and branched homo- and hetero-detic peptides

Amino acid sequences and linear or head-to-tail cyclopeptides can be represented conveniently in one-line text formulae using the three-letter symbols. However, other - but nonetheless important - topologies of peptides are 'side chain-to-head (or tail)', 'backbone-to-backbone', 'side chain-to-side chain' cyclopeptides, 'side chain-to-side chain' connected peptide strands, and branched peptides (like peptide dendrimers). In general, such structures cannot be described using the three-letter symbols in one-line text: a chemical structure editor is required for symbolic representations according to the IUPAC-IUBMB recommendations. The aim of this contribution is to offer an unambiguous and general nomenclature system that enables researchers to represent all cyclic and branched homo- and hetero-detic peptides in a coherent manner in one-line text - as long as their as constituents can be represented in (three)-letter codes. The application of this new nomenclature would overcome the existing difficulties and provide a way to express complex situations in the shortest way in order to highlight more clearly the salient points in a given scientific communication.