妊娠豚鼠血清皮质类固醇结合球蛋白的纯化与特性分析

Purification and characterization of the corticosteroid-binding globulin of pregnant guinea pig serum.

作者信息

Mickelson K E, Westphal U

出版信息

Biochemistry. 1979 Jun 12;18(12):2685-90. doi: 10.1021/bi00579a040.

Abstract

The corticosteroid-binding globulin from guinea pig pregnancy serum was purified by the sequential use of affinity chromatography, hydroxylapatite chromatography, and gel filtration chromatography at a cumulative yield of 80%. The protein was found to be homogeneous by analytical gel electrophoresis, equilibrium sedimentation ultracentrifugation, immunoelectrophoresis, and stoichiometry (1:1) of steroid binding. Guinea pig corticosteroid-binding globulin has a molecular weight of 43 300 and contains 29% carbohydrate. The intrinsic fluorescence of the corticosteroid-binding globulin is quenched by about 73% when 1 mol of cortisol is bound. The association constants (pH 7.4) at 4 and 37 degrees C are 2.5 X 10(7) and 1.5 X 10(6) M-1 for cortisol and 1.4 X 10(6) and 0.2 X 10(6) M-1 for progesterone, respectively.

摘要

通过依次使用亲和色谱法、羟基磷灰石色谱法和凝胶过滤色谱法，从豚鼠妊娠血清中纯化出皮质类固醇结合球蛋白，累积产率为80%。通过分析凝胶电泳、平衡沉降超速离心、免疫电泳以及类固醇结合的化学计量比（1:1），发现该蛋白质是均一的。豚鼠皮质类固醇结合球蛋白的分子量为43300，含29%的碳水化合物。当结合1摩尔皮质醇时，皮质类固醇结合球蛋白的固有荧光被淬灭约73%。在4℃和37℃时，皮质醇的缔合常数（pH 7.4）分别为2.5×10⁷和1.5×10⁶ M⁻¹，孕酮的缔合常数分别为1.4×10⁶和0.2×10⁶ M⁻¹。