Peptides

Peptides are short chains of amino acid linked by peptide bonds, typically defined as containing between 2 and 50 residues, distinguishing them from larger polypeptides and proteins. As fundamental biological molecules, peptides participate in virtually every physiological process: they function as hormones, neurotransmitters, Signaling molecules, antimicrobial agents, and structural components. Their relatively small size compared to full proteins confers key pharmacological advantages, including improved tissue penetration, lower immunogenicity, and the capacity to engage challenging molecular targets such as protein–protein interaction interfaces that are inaccessible to small-molecule drugs. Peptides are biosynthesized through ribosomal translation or non-ribosomal enzymatic pathways, and can also be generated through the hydrolysis of larger proteins by proteases, a process central to both digestion and the production of bioactive food-derived peptides.

From a therapeutic standpoint, peptides occupy a privileged position at the interface of small molecules and biologics. Their modular amino acid sequences can be rationally engineered to confer high specificity for receptor binding, enzyme inhibition, or immune modulation. Advances in solid-phase peptide synthesis, recombinant expression, and, more recently, artificial intelligence-guided design have dramatically expanded the accessible sequence and structural space for therapeutic peptide discovery. These attributes have made peptides central targets and tools across dermatology, oncology, nanomedicine, and food science.