链霉亲和素SA

其它名称：链霉亲和素，Streptavidin，SA

货号：S7051

种类：抗原

应用：CLIA，POCT

特异性：SA

来源：重组蛋白

存贮：-20℃

产品说明

链霉亲和素（SA）最初来源于Streptomyces avidinii，工业IVD领域以重组原核表达SA为主，天然SA为同源四聚体蛋白，分子量约65 kDa，重组截短型SA分子量约52 kDa。四聚体包含4个独立生物素结合口袋，单分子可结合4分子生物素；SA‑生物素相互作用属于自然界最强非共价相互作用之一，Kd可达10⁻¹⁴‑10⁻¹⁵ M，远高于常规抗原‑抗体亲和力，耐受去污剂、宽pH、多次洗涤条件。SA无糖基化修饰，等电点pI≈5‑6，对比卵亲和素Avidin，非特异性吸附更低，是生物素‑链霉亲和素放大体系（BAS）的核心功能原料。

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin.  Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin.  The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L.  The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits.  The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14).  The complexes are also extremely stable over a wide range of temperature and pH.