Gly-Gly-Gly-PEG4-methyltetrazine | CAS 2353409-82-0

Gly-Gly-Gly-PEG4-methyltetrazine is a PEGylated, peptide-functionalized methyltetrazine click reagent designed for bioorthogonal tetrazine ligation chemistry. Its compact methyltetrazine warhead and flexible PEG4 spacer support efficient conjugation to strained trans-cyclooctene or related cyclooctene partners under mild aqueous conditions, which is widely used to label biomolecules and assemble imaging or materials constructs. The Gly-Gly-Gly handle further improves compatibility with peptide-based workflows, including conjugation to targeting scaffolds and incorporation into modular bioconjugation strategies.

1. Peptide And Protein Labeling

Gly-Gly-Gly-PEG4-methyltetrazine is used in research workflows that require site-specific or modular labeling of peptides and proteins with tetrazine–cyclooctene click chemistry. The PEG4 spacer helps reduce steric constraints and promotes uniform conjugation when attaching probes, affinity handles, or reporter tags to sensitive biomacromolecules. Researchers commonly incorporate this reagent into labeling schemes for creating defined conjugates for downstream assays, including fluorescent or affinity-tagged protein constructs and peptide-derived materials.

2. Molecular Imaging Probe Building

Gly-Gly-Gly-PEG4-methyltetrazine supports the rapid assembly of molecular imaging and detection probes through tetrazine ligation to cyclooctene-bearing reporter components. The reagent’s PEG-mediated solubility and bioconjugation-friendly architecture make it practical for constructing probe libraries where modular swapping of targeting or signal units is needed. In imaging reagent development, Gly-Gly-Gly-PEG4-methyltetrazine is frequently selected to generate well-behaved conjugates that can be integrated into platform workflows for fluorescent, luminescent, or other label formats used in chemical biology studies.

3. Diagnostic Reagent Conjugation

Gly-Gly-Gly-PEG4-methyltetrazine is applied to the preparation of diagnostic reagent conjugates where controlled, bioorthogonal coupling is advantageous for building multi-component assay reagents. The tetrazine functionality enables orthogonal attachment to cyclooctene-functional surfaces or capture reagents, supporting modular assembly of detection formats such as labeled binding reagents and multiplex-compatible reagent sets. The Gly-Gly-Gly motif and PEG4 spacer are particularly useful when conjugation needs to maintain accessibility of recognition elements and minimize nonspecific interactions in assay environments.

4. Surface And Biomaterials Functionalization

Gly-Gly-Gly-PEG4-methyltetrazine is used to functionalize biomaterial surfaces and soft materials with cyclooctene-presenting linkers for stable, covalent attachment of bioactive or sensing components. The PEG4 chain supports improved presentation of the reactive group and helps maintain surface wettability and conjugate accessibility, which is important for constructing reproducible material interfaces. This reagent is commonly incorporated into workflows that generate clickable coatings, immobilized probe layers, and modular material platforms for chemical biology and materials research, where tetrazine ligation offers convenient assembly under aqueous conditions.