Streptavidin Applications

Potential Applications for MPT’s Recombinant Streptavidin Protein

Streptavidin Protein Use in NGS

Streptavidin protein plays a significant role in Next-Generation Sequencing (NGS), particularly in sample preparation and sequencing workflows. Its utility stems from its exceptionally strong and specific binding affinity to biotin (one of the strongest non-covalent interactions known, with a dissociation constant, Kd, of ~10^-15 M), which makes it an ideal tool for capturing, enriching, and immobilizing biotinylated molecules during NGS processes.

How Streptavidin Is Used in NGS

  1. Target Enrichment: In NGS workflows, streptavidin is commonly used in target capture or enrichment steps. Biotinylated probes or primers are designed to hybridize with specific DNA or RNA sequences of interest. Streptavidin, often conjugated to magnetic beads, binds these biotinylated hybrids, allowing researchers to pull down targeted regions from a complex sample. This is critical in applications like exome sequencing or targeted gene panels, where only specific genomic regions need to be sequenced.
  2. Library Preparation: During NGS library prep, streptavidin beads are used to purify biotinylated DNA fragments. For example, adapters with biotin tags can be ligated to DNA fragments, and streptavidin-coated beads can then isolate these fragments from unwanted material, improving the quality of the sequencing library.
  3. Immobilization in Sequencing Platforms: Some NGS platforms, like those from some Biotech companies, use streptavidin in their flow cells. Biotinylated DNA molecules are immobilized onto streptavidin-coated surfaces, enabling cluster generation and subsequent sequencing-by-synthesis. This ensures that DNA templates remain fixed during amplification and sequencing cycles.
  4. Single-Cell Sequencing: In single-cell NGS workflows, streptavidin is used to capture biotinylated barcodes or primers, facilitating the separation and identification of individual cell transcripts, which is essential for high-resolution genomic or transcriptomic analysis.

Streptavidin Use in Cell and Immunotherapy

Streptavidin protein is used in both cell therapy and immunotherapy, leveraging its strong biotin-binding capability to facilitate various processes in these fields. While its role is typically more prominent in research, development, and manufacturing stages rather than as a direct therapeutic agent, streptavidin is a versatile tool that supports key aspects of these therapies.

Streptavidin in Cell Therapy

Cell therapy, such as CAR-T cell therapy or stem cell therapy, involves manipulating cells outside the body before reintroducing them to treat diseases like cancer or regenerative conditions. Streptavidin contributes in the following ways:

  1. Cell Isolation and Purification: Streptavidin-coated magnetic beads or columns are used to isolate specific cell populations. For example, biotinylated antibodies targeting cell surface markers (e.g., CD3 or CD34) bind to cells, and streptavidin then captures these complexes, enabling separation of target cells (e.g., T cells or stem cells) from mixed populations. This is critical in preparing high-purity cell products for therapies.
  2. Cell Labeling and Tracking: In research and quality control, streptavidin conjugated to fluorophores or other reporters binds biotinylated markers on cells, allowing visualization or tracking of engineered cells during development or post-infusion studies.
  3. Gene Editing Support: In workflows like CRISPR-based editing for cell therapies, streptavidin can be used to enrich biotinylated DNA or RNA components, ensuring efficient delivery or purification of editing tools into cells.

 

For example, in CAR-T cell manufacturing, streptavidin beads might be used to select T cells from a patient’s blood or to enrich genetically modified cells, streamlining the process before expansion and infusion

Streptavidin in Immunotherapy

Immunotherapy, including monoclonal antibodies, checkpoint inhibitors, and cancer vaccines, harnesses the immune system to fight diseases. Streptavidin’s applications here include:

  1. Antibody Engineering and Conjugation: Streptavidin is used to create bispecific antibodies or antibody-drug conjugates (ADCs). A biotinylated antibody can be linked to a streptavidin-conjugated toxin, drug, or immune modulator, enabling targeted delivery to cancer cells. This “streptavidin-biotin bridge” is a flexible platform for designing novel Immunotherapeutics.
  2. Tumor Targeting and Pre-Targeting: In pre-targeting strategies (e.g., for radioimmunotherapy), a biotinylated antibody is first administered to bind tumor antigens. Streptavidin, conjugated to a radioactive isotope or drug, is then introduced, binding specifically to the biotinylated antibody at the tumor site. This reduces off-target effects and enhances therapeutic precision.
  3. Vaccine Development: Streptavidin is used in research to display antigens or peptides on its surface via biotinylating, creating multivalent complexes that stimulate immune responses. This is particularly useful in designing cancer vaccines or studying immune activation.
  4. Diagnostics and Monitoring: Streptavidin-based assays (e.g., ELISAs or flow cytometry) detect immune biomarkers or monitor patient responses to immunotherapy, indirectly supporting clinical applications.