Streptavidin (HRP)

Streptavidin is a protein which has similar biological characteristics as avidin, its molecular weight and ability to bind biotin are similar to the affinity in egg white. It’s nonspecific binding is far lower than affinity, with isoelectric 6.0. Streptavidin molecules consist of four identical peptides. The contents of glycine and alanine are higher in the amino acid composition. Moreover, the active groups of biotin are also tryptophan residues in peptide chains. Streptavidin is a protein with a slightly acidic (pH 6.0) and without any glycosyl. Under the action of proteolytic enzymes, streptavidin can rupture between the n-terminal 10 ~ 12 and c-terminal 19-21, forming core streptavidin and still maintain a complete ability to binding biotin. The active unit of streptavidin is expressed in terms of the amount of 1 μg biotin. The highest activity of 1 mg streptavidin can reach to 18 U. The combination of streptavidin and biotin has a characteristic of high specificity and high affinity, making it widely used in protein and nucleic acid analysis. Streptavidin (HRP) is widely used in the analysis of ELISA, Western Blot, Immunohistochemistry and nucleic acid hybridization.