Analogue
A compound structurally similar to a naturally occurring molecule but deliberately modified to alter its properties such as potency, stability, or duration of action. Many approved peptide drugs are analogues of natural human hormones — for example, semaglutide is a modified analogue of natural GLP-1.
Technical Context
Peptide analogues are designed by making strategic modifications to a natural peptide template. Common modification strategies include: amino acid substitutions to improve receptor binding or resist enzymatic cleavage; addition of chemical moieties (fatty acids, PEG chains) for half-life extension; truncation to identify the minimum active sequence; and cyclisation for conformational stability. Semaglutide is an analogue of GLP-1(7-37) with two key modifications: Aib at position 8 (DPP-4 resistance) and a C-18 fatty diacid via a linker at position 26 (albumin binding). Tesamorelin is a GHRH analogue with a trans-3-hexenoic acid modification. The development of improved analogues is a central strategy in peptide therapeutics.