输卵管分泌物中一种细胞外ATP酶的纯化与特性分析
Purification and characterization of an extracellular ATPase from oviductal secretions.
作者信息
Rosenberg M D, Gusovsky T, Cutler B, Berliner A F, Anderson B
出版信息
Biochim Biophys Acta. 1977 May 12;482(1):197-212. doi: 10.1016/0005-2744(77)90366-7.
Oviductal secretions include an ATPase (EC 3.6.1.3) that is transferred from the outer surface of the secretory cells to the surface of the ovulated oocyte. The enzyme has been purified and is a highly labile, very high molecular weight lipoprotein complex (greater than 4-10(6)). It consists of 47% protein and 53% lipid. Lipid composition is limited to phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. The basic protein subunit has a molecular weight of 170 000. The enzyme exhibits many of the characteristics of ectoenzyme ATPase. The enzyme is Mg2+ or Ca2+ dependent; the Mg2+-ATPase has pH optima at 6.0 and 7.8 and the Ca2+-ATPase at 9.0. Substrate specificity is limited to ATP with lesser activity towards GTP, CTP, UPT and ADP. Km for ATP is 0.88 mM and the enzyme is inhibited at substrate concentrations greater than 3 mM ATP.
输卵管分泌物中含有一种ATP酶（EC 3.6.1.3），它从分泌细胞的外表面转移至排卵后卵母细胞的表面。该酶已被纯化，是一种高度不稳定的、分子量非常大的脂蛋白复合物（大于4×10⁶）。它由47%的蛋白质和53%的脂质组成。脂质成分仅限于磷脂酰胆碱、磷脂酰乙醇胺和鞘磷脂。基本蛋白质亚基的分子量为170000。该酶表现出许多外切酶ATP酶的特性。该酶依赖Mg²⁺或Ca²⁺；Mg²⁺-ATP酶的最适pH值为6.0和7.8，Ca²⁺-ATP酶的最适pH值为9.0。底物特异性仅限于ATP，对GTP、CTP、UPT和ADP的活性较低。ATP的Km值为0.88 mM，当底物浓度大于3 mM ATP时，该酶受到抑制。
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