NeutrAvidin

Neutralite Avidin protein is a deglycosylated version of chicken avidin, with a mass of approximately 60,000 daltons. As a result of carbohydrate removal, lectin binding is reduced to undetectable levels, yet biotin binding affinity is retained because the carbohydrate is not necessary for this activity. Avidin has a high pI but NeutrAvidin has a near-neutral pI (pH 6.3), minimizing non-specific interactions with the negatively-charged cell surface or with DNA/RNA. Neutravidin still has lysine residues that remain available for derivatization or conjugation.

Like avidin itself, NeutrAvidin is a tetramer with a strong affinity for biotin (K_d = 10⁻¹⁵ M). In biochemical applications, streptavidin, which also binds very tightly to biotin, may be used interchangeably with NeutrAvidin.

Avidin immobilized onto solid supports is also used as purification media to capture biotin-labelled protein or nucleic acid molecules. For example, cell surface proteins can be specifically labelled with membrane-impermeable biotin reagent, then specifically captured using a NeutrAvidin support.

References

• Bayer, Ed: "The avidin-biotin system", Dept. of Biological Chemistry, Weizmann Institute of Science, Israel
• Y. Hiller, J.M. Gershoni, E. A. Bayer, M. Wilchek (1987), "Biotin binding to avidin. Oligosaccharide side chain not required for ligand association", Biochemical Journal, vol. 248, no. 1, pp. 167–171, doi:10.1042/bj2480167, PMC 1148514, PMID 3435435{{citation}}: CS1 maint: multiple names: authors list (link)
• Edward A. Bayer, Fabien De Meester, Tikva Kulik, Meir Wilchek (1995), "Preparation of deglycosylated egg white avidin", Applied Biochemistry and Biotechnology, vol. 53, no. 1, pp. 1–9, doi:10.1007/BF02783477{{citation}}: CS1 maint: multiple names: authors list (link)
• Ari T. Marttila, Olli H. Laitinen, Kari J. Airenne, Tikva Kulik, Edward A. Bayer, Meir Wilchek, Markku S. Kulomaa (2000), "Recombinant NeutraLite Avidin: a non‐glycosylated, acidic mutant of chicken avidin that exhibits high affinity for biotin and low non‐specific binding properties", FEBS Letters, vol. 467, no. 1, pp. 31–36, doi:10.1016/S0014-5793(00)01119-4{{citation}}: CS1 maint: multiple names: authors list (link)