UBQ-2 NHS Ester | CAS 916753-62-3

UBQ-2 NHS Ester is an NHS ester-activated ubiquitin conjugation reagent designed for efficient amide bond formation with primary amines on proteins and peptides. In chemical biology workflows, it enables preparation of ubiquitin-modified substrates and affinity reagents that support downstream studies of ubiquitin-dependent signaling, protein-protein interactions, and ubiquitin ligase assays. The reagent's electrophilic NHS group provides a practical route to stable coupling under standard bioconjugation conditions, making it useful for researchers building defined ubiquitin conjugates for fluorescence, pull-down, or mass spectrometry-oriented experiments.

1. Protein Ubiquitin Conjugation

UBQ-2 NHS Ester is commonly used by chemical biology and proteomics groups to attach ubiquitin to lysine-containing proteins, peptides, and protein domains. Researchers employ the resulting ubiquitin conjugates as standardized substrates for ubiquitin pathway assays, as well as reference materials for method development in ubiquitination and deubiquitination studies. This coupling format is also frequently leveraged when building defined ubiquitin-bearing constructs for downstream labeling strategies, such as attaching additional reporter tags or enrichment handles.

2. Affinity Reagent Construction

UBQ-2 NHS Ester supports the generation of ubiquitin-based affinity reagents by enabling immobilization or conjugation to amine-functional surfaces, resins, and carrier proteins. In practice, biochemistry and assay development teams use these ubiquitin conjugates to create capture tools for ubiquitin-binding proteins, ubiquitin-interacting domains, and related binding partners. The NHS-ester activation is particularly convenient for preparing robust, covalently linked ubiquitin reagents that can be incorporated into pull-down workflows, binding characterization experiments, and chromatography-based enrichment.

3. Ubiquitin Substrate Assay Development

UBQ-2 NHS Ester is used in the development and optimization of in vitro ubiquitin-related assays where a controlled ubiquitin-bearing substrate is required. Enzyme assay teams often prepare ubiquitin-modified proteins or peptides from amine-containing targets to create consistent substrates for monitoring ubiquitin ligase activity, transfer reactions, or deubiquitinase processing using fluorescence or other readouts. By providing a straightforward conjugation handle to introduce ubiquitin onto defined substrates, the reagent helps researchers standardize assay components for screening and method refinement.

4. Fluorescent Labeling Platforms

UBQ-2 NHS Ester is frequently integrated into fluorescent labeling workflows where ubiquitin conjugates serve as the biological recognition component for imaging or detection. Researchers prepare ubiquitin-modified proteins and then introduce fluorophores through additional amine-reactive or orthogonal labeling steps, enabling construction of fluorescent ubiquitin probes for microscopy-compatible experiments or fluorescence-based binding studies. This approach is particularly useful when the experimental design requires ubiquitin as a functional moiety while the fluorophore is used primarily for visualization or quantification.