Biotin is commonly used as a protein tag to facilitate the detection, purification, and immobilization of the proteins.
The bond between biotin and its binding partner Avidin (or Streptavidin) is unique in the following ways:
- Strong (Ka of 1015 M-1)
- Minimal interference
With characteristics mentioned above, biotin-avidin (streptavidin) system is now considered a versatile independent technology in following applications.
An exclusive collection of ready-to-use AvitagTM biotinylated proteins
The products in this series are exclusively produced using the AvitagTM technology. Briefly, a unique 15 amino acid peptide, the Avi tag, is introduced into the recombinant protein during expression vector construction. The single lysine residue in the Avi tag is enzymatically biotinylated by the E. Coli biotin ligase BirA.
This single-point enzymatic labeling technique brings many advantages for commonly used binding assays. The biotinylation happens on the lysine residue of Avi tag, and therefore does NOT interfere with the target protein’s natural binding activities. In addition, when immobilized on an avidin-coated surface, the protein orientation is uniform because the position of the Avi tag in the protein is precisely controlled since biotin is labeled at single lysine in the Avi tag.
A unique series of chemically labeled biotinylated proteins with ultra-sensitivity
The products in this series are produced using our in-house developed chemical labeling approach. The primary amines in the side chains of lysine residues and the N-terminus of protein are conjugated with biotins.
Chemical labeling usually results in multiple biotin attachment on a single protein molecule, which could potentially leads to higher detection sensitivity.
01 Biotinylated Proteins_Brochure_20161227.pdf