Genetic code expansion (GCE) has fundamentally transformed protein engineering by enabling the site-specific incorporation of non-canonical amino acids (ncAAs). As a pioneering provider of preclinical biotech services, we offer a proprietary GCEngine platform specifically optimized for the incorporation of cyclic ncAA. By leveraging high-throughput orthogonal aaRS/tRNA pair development, we enable the synthesis of proteins containing cyclic moieties, ranging from rigid proline analogs to bulky heterocyclic structures. These residues serve as powerful tools for controlling protein conformation, enhancing metabolic stability, and expanding the functional chemical space of synthetic biology.
Cyclic ncAA incorporation involves the genetic encoding of amino acids featuring cyclic structures within their side chains or backbone. Unlike their linear counterparts, these residues impose significant conformational constraints on the peptide backbone, effectively "locking" proteins into specific secondary structures or rigidifying flexible loops. This sophisticated application of GCE requires not only the development of efficient orthogonal aaRS/tRNA pairs but also insightful molecular design to predict and harness the impact on protein structure and dynamics. The technology is particularly transformative for engineering constrained macrocyclic scaffolds, stabilizing protein motifs, and creating novel biocatalysts, thereby dramatically expanding the functional chemical space for biomedical and synthetic biology applications.
Fig.1 Synthesis and cyclization of pCAF using thiol-based chemistry. (Franco, H. E. O., et al., 2022)
Cyclic ncAAs are unlocking new possibilities across multiple research and development domains.
| Application Area | Description |
| Therapeutic Peptides | Enables the design of next-generation cyclic peptide therapeutics with improved target affinity, selectivity, and in vivo stability. Cyclic ncAAs are instrumental for creating stabilized alpha-helices, hydrocarbon staples, and other constrained scaffolds. |
| Biotherapeutics Engineering | Allows for the site-specific stabilization of antibody loops, introduction of novel conjugation handles for antibody-drug conjugates (ADCs), and enhancement of enzyme stability and activity for therapeutic enzymes. |
| Biophysical Research | Site-specific insertion of rigid, spectroscopic probes (e.g., for NMR, EPR) to study protein folding, dynamics, and molecular interactions in real time. |
| Synthetic Biology & Biocatalysis | Facilitates the creation of enzymes with novel catalytic mechanisms by introducing non-biological catalytic moieties and the engineering of genetic circuits with ncAA-dependent switches. |
The end-to-end GCEngine platform provides a streamlined and integrated solution for cyclic ncAA incorporation projects. It integrates proprietary high-throughput orthogonal pair development with advanced computational modeling and validation workflows. We offer expert guidance and execution, from initial design and orthogonal aaRS/tRNA pair identification or evolution to in vitro and in vivo validation of ncAA incorporation. Whether enhancing a biocatalyst or developing a novel therapeutic, our services support high-yield, site-specific incorporation with high fidelity.
Utilizing structurally diverse cyclic ncAAs to impart unique functionalities, which are strategically employed to enhance protein stability, modulate protein-protein interactions, introduce novel catalytic activities, and improve pharmacological properties, thereby expanding the functional landscape of engineered biologics.
Aromatic-Fused Cyclic ncAAs
Representative ncAAs: 1-Naphthylalanine, 2-Quinolyalanine
Description: These ncAAs feature extended, rigid aromatic systems. They are valuable for enhancing hydrophobic core packing, promoting pi-pi stacking interactions, and improving binding affinity to flat surfaces.
Aliphatic Cyclic ncAAs
Representative ncAAs: Cyclopentylglycine, Cyclohexylalanine
Description: Characterized by saturated carbon rings, these amino acids are excellent for increasing local hydrophobicity and membrane permeability, ideal for modulating pharmacokinetic properties.
Heterocyclic ncAAs
Representative ncAAs: 4-Thiazolylalanine, 3-Pyridylalanine
Description: Incorporating heteroatoms (N, O, S) within the ring, these ncAAs can act as hydrogen bond acceptors/donors, participate in coordination chemistry, and fine-tune electronic properties, expanding the repertoire for molecular recognition and catalysis.
Backbone-Constrained ncAAs
Representative ncAAs: Proline Derivatives, α, α-disubstituted amino acids
Description: This class includes α, α-disubstituted amino acids and N-alkylated variants that directly restrict backbone conformation. They are crucial for inducing specific turns, stabilizing helices, and reducing the conformational flexibility of macrocyclic structures.
By leveraging our state-of-the-art GCEngine platform and deep expertise in cyclic ncAA incorporation, we empower researchers and developers to push the boundaries of protein science and create biologics with enhanced properties and novel functions. Our integrated, collaborative approach is designed to accelerate your project from concept to validated reality. To discuss how our cyclic ncAA incorporation services can advance your specific research or therapeutic development goals, please reach out to our scientific team.
All our services are exclusively intended for preclinical research purposes. They are not intended for diagnostic, therapeutic, or patient management applications.
A specialized platform advancing genetic code expansion through orthogonal tRNA/aaRS technologies, enabling precise ncAA incorporation for biotherapeutic development, synthetic biology, and diagnostics.