Gly-Gly-Gly-PEG4-DBCO | CAS 2353409-80-8

Gly-Gly-Gly-PEG4-DBCO is a PEGylated dibenzocyclooctyne (DBCO) click chemistry reagent designed for strain-promoted azide–alkyne cycloaddition (SPAAC). The Gly-Gly-Gly motif provides a short, flexible peptide handle for biomolecule-facing conjugation workflows, while the PEG4 spacer improves solubility and reduces steric congestion at the reactive DBCO terminus. This reagent is widely used to functionalize proteins, peptides, and biomaterials with bioorthogonal alkyne functionality for downstream attachment to azide-bearing targets, including imaging probes, affinity reagents, and engineered surfaces.

1. Protein And Peptide Labeling

Gly-Gly-Gly-PEG4-DBCO is commonly used in protein and peptide labeling workflows where a stable, catalyst-free SPAAC handle is required. Researchers attach the DBCO-bearing reagent to azide-functional biomolecules or, conversely, use it to introduce DBCO functionality onto peptide-based ligands and protein conjugates prior to assembly with azide-tagged reporters. The PEG4 spacer helps maintain conjugate accessibility, supporting efficient coupling to azide partners in complex buffers used for biochemical assays and proteomics sample preparation.

2. Surface And Hydrogel Functionalization

Gly-Gly-Gly-PEG4-DBCO is frequently employed to create azide-reactive material architectures and to pattern biointerfaces that require orthogonal, mild conjugation conditions. In biomaterials science, DBCO-bearing PEG constructs are used to functionalize polymer surfaces, nanoparticles, and hydrogel matrices that include azide groups, enabling the incorporation of cell-interactive motifs, affinity ligands, or fluorescent tags without harsh processing. The short Gly-Gly-Gly segment and PEG4 chain contribute to improved coupling uniformity and reduced nonspecific interactions during material fabrication and subsequent characterization.

3. Molecular Imaging Probe Construction

Gly-Gly-Gly-PEG4-DBCO is a practical building block for constructing molecular imaging and detection probes that rely on bioorthogonal assembly. Imaging probe developers often use DBCO-PEG conjugates to connect imaging reporters, targeting vectors, or scaffold molecules that carry azide functionality, producing well-defined conjugates under conditions compatible with sensitive fluorophores and probe components. The PEG4 linker supports solubility and helps preserve the accessibility of the imaging moiety after conjugation, which is valuable for probe formulation and in vitro imaging reagent optimization.

4. Diagnostic Reagent And Assay Platforms

Gly-Gly-Gly-PEG4-DBCO is used to generate assay-ready conjugates for diagnostic reagent development and analytical platform construction. Many workflows rely on SPAAC to assemble multicomponent systems such as affinity reagents, signal-generating tags, and capture elements that have been prefunctionalized with azides. By providing a DBCO-terminated PEG handle, Gly-Gly-Gly-PEG4-DBCO supports modular assembly of complex reagent formats while minimizing cross-reactivity that can occur with less selective chemistries, improving the robustness of reagent preparation for research and industrial analytical use cases.