Recombinant Proteins
Product List
Streptavidin
Streptavidin Recombinant
The molecular weight per tetramer is approximately 52kDa.
Streptavidin (37-159), His
Streptavidin (37-159 a.a) Recombinant, His Tag
Streptavidin Protein
Streptavidin
Streptavidin, His
Streptavidin Recombinant, His Tag
Streptavidin-NC
Streptavidin-NC Recombinant
Recombinant Streptavidin-NC produced in E.Coli is a single, non-glycosylated, polypeptide chain having a molecular mass of 24kDa. Streptavidin-NC is engineered to bind to nitrocellulose.
Introduction
Streptavidin is a tetrameric protein isolated from the bacterium Streptomyces avidinii. It is known for its extraordinarily high affinity for biotin (vitamin B7 or vitamin H), with a dissociation constant (Kd) on the order of ≈10^-14 mol/L . Streptavidin is composed of four identical subunits, each capable of binding one molecule of biotin . This protein is extensively used in molecular biology and biotechnology due to its strong and specific binding to biotin .
Streptavidin has several key biological properties:
- High Affinity for Biotin: Streptavidin binds biotin with one of the strongest non-covalent interactions known in nature .
- Tetrameric Structure: It forms a tetramer, with each subunit contributing to the biotin-binding site of its neighbor .
- Stability: The streptavidin-biotin complex is highly stable, resistant to organic solvents, denaturants, detergents, proteolytic enzymes, and extremes of temperature and pH .
- Expression Patterns and Tissue Distribution: Streptavidin is naturally produced by Streptomyces avidinii .
Streptavidin interacts with other molecules and cells primarily through its binding to biotin. The binding involves:
- Hydrogen Bonds: Extensive hydrogen bonding with biotin contributes to the high affinity .
- Multivalency: Each streptavidin tetramer can bind up to four biotin molecules, enhancing its binding capacity .
- Downstream Signaling Cascades: The streptavidin-biotin interaction can be used to link various molecules, facilitating downstream signaling in experimental setups .
The expression and activity of streptavidin are regulated by:
- Transcriptional Regulation: The gene encoding streptavidin is regulated at the transcriptional level in Streptomyces avidinii .
- Post-Translational Modifications: Streptavidin undergoes post-translational modifications to achieve its mature form, which is essential for its high biotin-binding affinity .
Streptavidin has numerous applications in biomedical research and diagnostics:
- Biomedical Research: It is used in various assays and techniques, including ELISA, western blotting, and immunohistochemistry .
- Diagnostic Tools: Streptavidin-biotin interactions are employed in diagnostic assays to detect specific biomolecules .
- Therapeutic Strategies: Streptavidin is used in targeted drug delivery and radioimmunotherapy .
Streptavidin plays a crucial role throughout the life cycle of Streptomyces avidinii:
