Key takeaways
24
Non-canonical amino acid advances highlighted, each with a published research example from 2025
19×
Improvement in tumour-directed gene delivery using AzK-modified AAV capsids
95%
Enantiomeric excess achieved by a designer enzyme containing a biosynthesised ncAA
1,440 min
Serum stability of fluorinated antimicrobial peptides, up from 225 minutes for unmodified versions
Non-canonical amino acids (ncAAs) are building blocks that go beyond the 20 amino acids found in nature. By incorporating ncAAs into peptides and proteins at precise positions, it becomes possible to create molecules with chemical properties that natural biology cannot produce. This has direct applications in drug discovery, enzyme engineering, and industrial manufacturing.
Why ncAAs are accelerating across biotech
The pace of ncAA research has increased sharply. What was once limited to proof-of-concept studies in a handful of laboratories now spans clinical-stage drug programmes, industrial enzyme platforms, and entirely new classes of biomaterial. The examples below illustrate the breadth of the field in a single year.
Therapeutics and drug delivery
Cancer vaccines: beta-amino acids incorporated into MUC1-based glycopeptides improve proteolytic stability and immunogenicity while maintaining native epitope conformation. This addresses a core challenge in peptide vaccine design, where natural sequences are degraded before they can stimulate an immune response.
Targeted cancer therapy: BH3 mimetics containing ncAAs achieve fourfold improvements in binding affinity for MCL-1 and BCL-xL targets in acute myeloid leukaemia. Rigid cyclohexyl side chains provide shape complementarity that standard amino acids cannot access.
Cell-penetrating biologics: beta-lactam-lysine enables domain antibodies to cross cell membranes by forming intramolecular covalent straps, achieving spontaneous uptake at 40 nM with clean endosomal escape. This opens intracellular targets to antibody-based drugs.
Gene therapy targeting: azide-containing ncAAs (AzK) placed in AAV capsid proteins allow site-specific conjugation of targeting ligands, improving tumour-directed gene delivery 19-fold in vivo. This is a significant step toward tissue-selective gene therapy vectors.
Multi-receptor agonists: retatrutide, a triple GLP-1/GIP/glucagon receptor agonist, uses Aib and alpha-methylleucine to achieve the metabolic stability required for once-weekly dosing. These ncAA modifications are essential to the molecule’s pharmacokinetic profile.
Covalent binders: SuFEx-reactive amino acids (fluorosulfate-L-tyrosine) form selective covalent linkages with target proteins, enabling prolonged drug activity without the off-target risks of conventional covalent inhibitors.
Protein engineering and catalysis
Bispecific nanobodies: pAcF (p-acetylphenylalanine) enables controlled geometry in bispecific nanobodies for colon cancer immunotherapy, improving tumour-penetrating immune activation through precise linker positioning.
De novo enzyme design: E. coli engineered to both produce and incorporate pAPhC achieves complete biosynthesis of a designer enzyme that performs enantioselective Friedel-Crafts alkylation with 95% enantiomeric excess. No external ncAA supply is needed.
Gold catalysis in a protein scaffold: a noble-metal-binding ncAA (pSHF) installed in LmrR protein creates a hybrid gold catalyst for pi-activation chemistry within a biological scaffold.
Photoswitchable enzymes: azobenzene and spiropyran-based ncAAs allow light-controlled enzyme activation, with potential applications in spatially and temporally controlled biocatalysis.
Laccase optimisation: hydrophobic ncAAs improve catalytic activity by fine-tuning the active site environment, demonstrating that even subtle side-chain changes can have large effects on enzyme performance.
Antimicrobials and stability
Fluorinated antimicrobial peptides: fluorinated ncAAs in WK2 peptides boost serum stability from 225 to over 1,440 minutes while maintaining activity against multi-drug resistant bacteria. This addresses one of the main barriers to clinical use of antimicrobial peptides.
Machine learning-guided design: alpha/beta-peptide hybrids derived from aurein 1.2 achieve up to 52-fold higher antifungal selectivity, with candidates identified by screening 336,000 virtual candidates computationally before synthesis.
Materials and biomolecule design
Post-translational modification mimics: 11 distinct lysine PTM analogues generated from a single MeOK precursor, enabling systematic study of how modifications affect protein function.
Backbone editing: the BEAR approach uses reactive ester ncAAs to modify the peptide backbone after ribosomal synthesis, creating structural diversity that cannot be programmed genetically.
Tunable acid-base switching: histidine-like ncAAs with adjustable pKa values enable pH-responsive protein behaviour for drug delivery and biosensor applications.
Ribosomal pharmacophore embedding: keto-ncAAs enable intramolecular Friedlander cyclisation to embed quinoline pharmacophores directly into ribosomal peptides, merging medicinal chemistry with biological synthesis.
Collagen engineering: L-DOPA incorporation into collagen enhances self-assembly and biocompatibility, relevant to tissue engineering and medical device coatings.
What these advances mean for the field
These examples span clinical-stage drugs, computational enzyme design, and novel biomaterials. ncAA technology is now producing real results across multiple fields simultaneously. For a deeper introduction to ncAAs and how they are incorporated, see our overview of non-canonical amino acids and programmable biomolecules.
