Streptavidin - Pharmavidin.com

Streptavidin | Bacterial Streptavidin | Iodinated Streptavidin

Due to its RYD segment, streptavidin generates number of false positive results where Neutralite avidin doesn’t. This absence of RYD segment in Neutralite avidin improves drastically the quality of the IVD’s.

Streptavidin | Bacterial Streptavidin | Iodinated Streptavidin

 Streptavidin is a 60 kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7). With a dissociation constant (Kd) on the order of ≈10−14 mol/L,[1] the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature (wikipedia.org).

Homologous residues/domains in both proteins are shown in bold type. Positively charged residues (Lys, Arg) are underlined. The RYD-containing sequence in streptavidin, which is homologous to that of fibronectin, appears in bold red. The N- and C-terminal sequences clipped by post-secretory processing (via proteolytic cleavage) on streptavidin are shown in purple. The position of the sugar residue, linked to Asn-17 of avidin in the typical NXT(S) type carbohydrate-containing consensus sequence, is identified by a star (*). Tyr-33 & -43, the nitrated amino acid residue in Nitro-Avidin & -Streptavidin, respectively, is similarly (*) identified. Cys-4 & 83 formed a disulfide bridge in native avidin; natural variant (Ile-34→Thr-34) in ~50% of the molecules.

Streptavidin | Bacterial Streptavidin | Iodinated Streptavidin

 Streptavidin is a chemically & enzymatically modified avidin characterized by a neutral isoelectric point and the absence of surface glycans. NeutraLite Avidin is carbohydrate-free and neutral, with the double advantage of the presence of a large number of amino acids available for derivatization, and the absence of RYD sequences. Altogether, these molecular characteristics yield the lowest nonspecific binding among known biotin-binding proteins, yet a specific activity near the theoretical maximum of approximately 14 μg/mg of protein Streptavidin | Bacterial Streptavidin | Iodinated Streptavidin