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Biotinylated proteins for quantification, detection and purification
The specific interaction between biotin and avidin (or streptavidin) makes this pair an exceptional tool for facilitating the detection, purification, and immobilization of proteins. This versatile technology is utilized across a wide array of applications:
- **ELISA** for precise protein quantification,
- **FACS** to detect or isolate specific cells,
- **Biopanning** for selecting phage display candidates,
- **SPR** to study protein binding kinetics,
- **Immuno-capture** and **enrichment** to isolate antibodies from complex biological fluids like plasma.
Producing high-quality biotinylated proteins, however, poses significant challenges, including inconsistent labeling, batch-to-batch variability, and unpredictable performance. To address these issues, ACROBiosystems has developed an exclusive collection of pre-labeled and experimentally validated biotinylated recombinant proteins. The MABsol® biotinylated protein collection features over a hundred commonly studied drug targets and biomarkers. These high-quality recombinant proteins are designed to closely mimic the natural conformation and modifications of their native counterparts. The collection offers two unique and complementary product lines:
### 1. PrecisionAvi Series with Ready-to-Use Avitag™ Technology – A Unique 15-Amino Acid Peptide
This single-point enzymatic labeling technique provides numerous advantages for common binding assays:
- Biotinylation occurs exclusively on the lysine residue of the Avitag.
- It ensures no interference with the target protein's natural binding activities.
- When immobilized on an avidin-coated surface, the protein orientation remains uniform.
### 2. UltraLys Series with In-House Developed Chemical Biotin Labeling Method for Enhanced Detection Sensitivity
- Higher detection sensitivity.
- Utilizes an in-house developed chemical labeling approach.
### Key Features
#### 1. Closest to Natural Conformation and Modification
The production of these biotinylated proteins uses the proprietary HEKMax® expression platform. Compared to other cell types, human HEK293 cells offer several advantages, as illustrated in the table below:
| Expression Systems | Folding | Phosphorylation | Proteolytic Processing | Glycosylation |
|--------------------|---------|-----------------|------------------------|---------------|
| E. Coli | + | N/A | N/A | N/A |
| Insect Cell | ++ | ++ | ++ | Poor |
| Plant Cell | +++ | +++ | +++ | Poor |
| CHO Cell | ++++ | ++++ | ++++ | Non-Human Like|
| Human Cell | +++++ | +++++ | +++++ | Human Authentic|
#### 2. High Bioactivity & Detection Sensitivity
The bioactivity of biotinylated proteins depends on both the protein structure and the biotinylation method. Each protein undergoes multiple tag and biotinylation method tests, with evaluations conducted in various binding assays. Only the highest-performing products proceed to production. Figure 1 demonstrates internal evaluation experiments.
[Figure 1: Binding activity of different forms of biotinylated PD-1 evaluated in a functional ELISA against rhPD-L1 (Cat. No. PD1-H5258)]
These biotinylated proteins exhibit high bioactivity and superior detection sensitivity in diverse applications. In functional ELISA, biotinylated human BCMA demonstrates strong binding activity with BAFF, as shown in Figure 2. Figure 3 illustrates that biotinylated PD-1 works effectively in AlphaLISA to detect binding with PD-L2. Figure 4 shows that biotinylated proteins can easily determine protein-therapeutic antibody affinity in SPR assays. Additionally, these proteins are commonly used in cell-based assays, such as cytotoxicity assays and CAR expression evaluations (Figures 5 & 10).
### ELISA
[Figure 2: Immobilized Human BAFF, Fc Tag]
### AlphaLISA
[Figure 3: Biotinylated Human PD-1]
### SPR
[Figure 4: Affinity Constant of Human CD19 Protein]
### Cell-Based Assay
[Figure 5: Recombinant Human TNF-alpha]
For more information, feel free to explore our product series:
- Search for PrecisionAvi (AviTag) or UltraLys (Chemical labeling).
- Consult us for years of experience in immunoassays, immunoreagents, and ELISA kits.
- Review an extract from our BioSciences catalog (French only).
Don’t hesitate to reach out with any questions or inquiries!