Biotins, Streptavidins (253)

Biotin, previously referred to as coenzyme R and vitamin H, is a water-soluble compound, meaning it is not stored in the body. It plays a crucial role in various bodily functions by supporting the activity of specific enzymes known as carboxylases. These biotin-dependent enzymes are essential in key metabolic processes, including glucose and fatty acid production. Streptavidin, a 52.8 kDa protein derived from Streptomyces avidinii, forms homotetramers with an exceptionally high affinity for biotin. The interaction between biotin and streptavidin is among the strongest non-covalent bonds found in nature, with a dissociation constant of about 1 μmol/L. Due to the remarkable stability of the streptavidin-biotin complex against organic solvents, denaturants, detergents, proteolytic enzymes, and extreme temperature or pH conditions, streptavidin is extensively used in molecular biology and bionanotechnology applications.