Epoxide hydrase and mixed-function oxidase activities of rat liver nuclear membranes.
Epoxide hydrase and mixed-function oxidase activities of rat liver nuclear membranes.
复制标题
大鼠肝核膜的环氧化物水酶和混合功能氧化酶活性。
DOI：
10.1016/0003-9861(79)90066-3
复制
发表时间：
1979
影响因子：
3.9
通讯作者：
J. Bend
中科院分区：
文献类型：
--
作者：
H. Mukhtar;T. H. Elmamlouk;J. Bend
大鼠肝细胞核具有2-12%的相应微体芳烃羟基酶、氨基比林和苯丙胺N-脱甲基酶、NADPH-细胞色素还原酶和环氧化物水合酶活性。用蔗糖密度离心法从分离的肝细胞核中制备核膜。核膜中的比酶活性是完整核的2.5-10.2倍。比较了大鼠肝核膜和微粒体环氧化物水合酶的几种性质。核环氧化物水合酶在苯巴比妥诱导下与相应的微粒体酶相似，而3-甲基胆蒽不产生任何作用。1，1，1-三氯丙烯氧化物、环己烯氧化物、二苯乙烯氧化物对核膜和微粒体环氧化物水合酶有相似的抑制作用。核膜环氧化物水合酶表观Km值为20μm，比相应的微粒体水合酶Km值(112μm)低5.5倍。用DNA酶消化法从大鼠肾、肺、脾、心等组织的细胞核中制备核膜。完整细胞核的环氧化物水合酶活性大小顺序为：肾、肺、⋙、脾、心。当核膜与完整核相比时，肾脏和肺的特定环氧化物水合酶活性分别增加了2.2倍和2.5倍。二甲基亚砜
Rat liver nuclei have 2 to 12% of the corresponding microsomal aryl hydrocarbon hydroxylase, aminopyrine and benzphetamineN-demethylase, NADPH-cytochromecreductase, and epoxide hydrase activities. Nuclear membranes were prepared from isolated liver nuclei by a sucrose density centrifugation technique. A 2.5- to 10.2-fold increase in the specific enzyme activities was observed in nuclear membrane as compared to intact nuclei. Several properties of the rat liver nuclear membrane and microsomal epoxide hydrase have been compared. Nuclear epoxide hydrase was similar to the corresponding microsomal enzyme in being induced by phenobarbital whereas 3-methylcholanthrene did not produce any effects. Nuclear membrane and microsomal epoxide hydrase were inhibited to a similar degree by 1,1,1-trichloropropene oxide, cyclohexene oxide, antrans-stilbene oxide. The apparentKmvalue of nuclear membrane epoxide hydrase was 20 μmfor benzo(a)pyrene 4,5-oxide, which is 5.5-fold lower than the corresponding microsomalKmvalue (112 μm). Nuclear membranes were prepared from isolated nuclei of rat kidney, lung, spleen, and heart by the DNase digestion method. Epoxide hydrase activity in intact nuclei was in the following order: kidney > lung ⋙ spleen, or heart. Increases of 2.2- and 2.5-fold in specific epoxide hydrase activity were observed in kidney and lung when nuclear membranes were compared to intact nuclei. DMSO, dimethylsulfoxide