Streptavidin

Streptavidin is a 52.8 kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7 or vitamin H). With a dissociation constant (Kd) on the order of ≈10−14 mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Streptavidin is used extensively in molecular biology and bionanotechnology due to the streptavidin-biotin complex's resistance to organic solvents, denaturants, detergents, proteolytic enzymes, and extremes of temperature and pH.

Streptavidin is commonly utilized in the fields of molecular biology with high affinity for biotin, with a dissociation constant in the femtomolar range. The binding of biotin to streptavidin is recognized as one of the most robust non-covalent interactions in the natural world. Derived from the bacterium streptomyces avidini, streptavidin is a homo-tetramer protein with a molecular weight of 52.8 KDa.

Streptavidin is a 66.0 (tetramer) kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7 or vitamin H).