Methyltetrazine-PEG5-nhs ester | CAS 1802907-92-1

Methyltetrazine-PEG5-nhs ester is a PEGylated N-hydroxysuccinimide (NHS) ester functionalized with a methyltetrazine click handle, designed for bioorthogonal conjugation workflows that commonly culminate in tetrazine-mediated inverse-electron-demand click chemistry. The reagent couples efficiently to primary amines on proteins, peptides, and other amine-bearing biomolecules, while the tetrazine moiety enables subsequent rapid labeling or assembly with complementary strained alkenes or trans-cyclooctenes. Its PEG5 spacer supports improved solubility and accessibility of the reactive tetrazine group in complex biological and materials environments, making it a widely used building block for probe generation, imaging reagent development, and modular bioconjugation.

1. Protein And Peptide Labeling

Methyltetrazine-PEG5-nhs ester is used to install tetrazine functionality onto proteins and peptides for downstream click-based tagging workflows. Researchers commonly apply it to prepare amine-functional targets such as antibodies, antibody fragments, enzymes, and affinity reagents, enabling controlled introduction of a bioorthogonal handle without disrupting overall biomolecule solubility. The PEG5 spacer helps maintain tetrazine accessibility for subsequent conjugation steps, which is particularly valuable when labeling bulky targets or when the final probe requires efficient coupling to strained-alkene partners.

2. Antibody Conjugate Platforms

Methyltetrazine-PEG5-nhs ester supports modular antibody conjugation strategies where a tetrazine-bearing antibody intermediate is generated first and then reacted with complementary click partners to attach fluorophores, affinity tags, or other functional payloads. This approach is favored in molecular imaging and diagnostic reagent development because it decouples amine-reactive installation of the click handle from the later payload attachment step. By using the NHS ester to target lysine residues and other accessible amines, the reagent enables flexible construction of antibody-based probes that can be rapidly diversified for different labeling schemes.

3. Molecular Imaging Probe Synthesis

Methyltetrazine-PEG5-nhs ester is widely incorporated into the synthesis of imaging probes that rely on tetrazine click chemistry for rapid, selective assembly. Probe developers use the NHS ester to functionalize biomolecular targeting vectors with a tetrazine group, then perform the final conjugation with strained-alkene or trans-cyclooctene reporters to generate fluorescent, luminescent, or other signal-bearing constructs. The PEG5 linker improves handling and reduces nonspecific aggregation, which is helpful when preparing sensitive conjugates intended for complex assay formats and multi-step probe pipelines.

4. Surface And Biomaterial Functionalization

Methyltetrazine-PEG5-nhs ester is used to introduce tetrazine functionality onto amine-bearing surfaces and biomaterials, enabling subsequent click-based immobilization or assembly of functional components. Materials scientists and chemical biology groups often employ it to functionalize polymer scaffolds, hydrogel networks, and coating layers that present primary amines, creating a reactive surface for later coupling with strained-alkene partners. This workflow is particularly useful for building modular biointerfaces, where tetrazine installation provides a convenient intermediate that can be reacted with different payloads while maintaining spatial and chemical control over surface reactivity.