Recombinant streptavidin from streptomyces avidinii, produced in E.coli. Biotin, a 244Da vitamin (Vitamin H) molecule, exhibits an extraordinary binding affinity for streptavidin (Ka=10 15 M -1 ). Biotin and streptavidin interaction is rapid and once the bond is established it can survive up…

Streptavidin is a protein produced by the bacterium Streptomyces avidinii. It has four binding sites for biotin, as does avidin. Both have been used extensively as probes in immunochemical systems, conjugated to antibodies, enzymes or fluorochromes. However, avidin is highly basic (pI ~ 10.5),…