后备母猪子宫的细胞质雌激素受体系统。用[14C]碘乙酸标记的组分B的部分纯化。

Cytoplasmic estrogen receptor system of gilt uterus. Partial purification of component B labeled with [14C]iodoacetic acid.

作者信息

Fukai F, Murayama A

出版信息

J Biochem. 1981 Jun;89(6):1829-37. doi: 10.1093/oxfordjournals.jbchem.a133384.

DOI:10.1093/oxfordjournals.jbchem.a133384

Abstract

Analysis of the cytoplasmic estrogen receptor (ER) system of gilt uterus by protecting ER from proteolysis showed that the ER system of gilt uterus is similar to that of cow uterus described previously. There was only one native unit molecule [native "4S" ER (sedimentation coefficient, 4.5S; Stokes radius, 45 A; molecular weight, 82,000)] with specific affinity towards estradiol. This molecule was further designated as vero-ER. "8S" ER-forming factor [("8S"ER)-FF] (Stokes radius, 51 A) was separated from the cytosol under hypotonic (low salt) conditions, and this was further dissociated into component A ["5S" ER-forming factor, ("5S"ER)-FF] (Stokes radius, 37 A) and component B (Stokes radius, 18.5 A) in the presence of sodium thiocyanate. Vero-ER was proteolyzed in the absence of Ca2+ ion by a cytoplasmic protease into modified "4S" ER (sedimentation coefficient, 4.5S; Stokes radius, 35 A; molecular weight, 65,000) which was further designated as secto-ER. The constituents of the cytoplasmic ER system of cow and gilt uteri cross-reacted with each other to undergo similar molecular assembly as in their own systems. When analyzed for various uterine specimens, fluctuation of ("8S"ER)-FF-level (1-50 unit/g tissue) was more remarkable than that of ER-level (3-6 x (10(-12) mol/g tissue). Component B labeled with [14C]iodoacetic acid was purified over 1,500-fold. Mixture of vero-ER and component B labeled with [14C]iodoacetic acid formed "6S' ER with 14C-activities under hypotonic conditions. This clearly excluded the possibility that component B is a catalyzer of self-association (dimerization) of vero-ER.

摘要

通过保护雌激素受体（ER）免受蛋白水解作用来分析后备母猪子宫的细胞质ER系统，结果表明，后备母猪子宫的ER系统与先前描述的母牛子宫的ER系统相似。仅有一个对雌二醇具有特异性亲和力的天然单位分子[天然“4S”ER（沉降系数，4.5S；斯托克斯半径，45 Å；分子量，82,000）]。该分子进一步被命名为vero-ER。“8S”ER形成因子[（“8S”ER）-FF]（斯托克斯半径，51 Å）在低渗（低盐）条件下从细胞质中分离出来，并且在硫氰酸钠存在下进一步解离成组分A [“5S”ER形成因子，（“5S”ER）-FF]（斯托克斯半径，37 Å）和组分B（斯托克斯半径，18.5 Å）。在没有Ca2 +离子的情况下，vero-ER被细胞质蛋白酶水解成修饰的“4S”ER（沉降系数，4.5S；斯托克斯半径，35 Å；分子量，65,000），该分子进一步被命名为secto-ER。母牛和后备母猪子宫细胞质ER系统的成分相互交叉反应，以进行与其自身系统中相似的分子组装。当分析各种子宫标本时，（“8S”ER）-FF水平（1 - 50单位/克组织）的波动比ER水平（3 - 6×10（-12）摩尔/克组织）的波动更显著。用[14C]碘乙酸标记的组分B被纯化了1500倍以上。在低渗条件下，vero-ER与用[14C]碘乙酸标记的组分B的混合物形成具有14C活性的“6S”ER。这清楚地排除了组分B是vero-ER自缔合（二聚化）催化剂的可能性。