NeutrAvidin

NeutrAvidin protein is a deglycosylated version of 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. NeutrAvidin has a near-neutral pI (6.3) that minimizes nonspecific interactions, along with lysine residues that remain available for derivatization or conjugation.

Like avidin itself, NeutrAvidin is a tetramer with a strong affinity for biotin (kD = 10-15M-1). 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.