Effects of molybdenum and tungsten on induction of nitrate reductase and formate dehydrogenase in wild type and mutant Paracoccus denitrificans.
Effects of molybdenum and tungsten on induction of nitrate reductase and formate dehydrogenase in wild type and mutant Paracoccus denitrificans.
复制标题
钼和钨对野生型和突变型脱氮副球菌诱导硝酸还原酶和甲酸脱氢酶的影响。
DOI：
10.1007/bf00511221
复制
发表时间：
1980
影响因子：
2.8
通讯作者：
Lascelles,J
中科院分区：
文献类型：
--
作者：
Burke,KA;Calder,K;Lascelles,J
钼是必需的诱导硝酸还原酶和NAD-连接的甲酸脱氢酶活性在悬浮液中的野生型Paracoccus acetificans;钨防止这些酶的活动的发展。当与钨和硝酸还原酶诱导剂孵育时，野生型形成膜蛋白Mr 150，000，推测这代表酶的无活性形式。突变体M-1的悬浮液不产生硝酸还原酶或甲酸脱氢酶活性，但在所有测试条件下（包括无诱导剂和无钼）形成膜蛋白Mr 150，000。膜，溶解与脱氧胆酸盐，在非变性条件下通过聚丙烯酰胺凝胶电泳分析表明，突变蛋白质具有类似的电泳迁移率的活性硝酸还原酶形成的野生型。用~（55）Fe孵育的细胞制备物的放射自显影显示突变体和野生型蛋白质含有铁。然而，在类似的实验与99钼，纳入钼到突变蛋白是无法检测到的。我们的结论是，突变M-1是有缺陷的一个或多个步骤所需的处理钼纳入到辅酶。这种失败影响了硝酸还原酶蛋白的正常调节相对于诱导剂的作用。
Molybdenum is required for induction of nitrate reductase and of NAD-linked formate dehydrogenase activities in suspensions of wild typeParacoccus denitrificans; tungsten prevents the development of these enzyme activities. The wild type forms a membrane proteinMr150,000 when incubated with tungsten and inducers of nitrate reductase and this is presumed to represent an inactive form of the enzyme. Suspensions of mutant M-1 did not develop nitrate reductase or formate dehydrogenase activities but the membrane proteinMr150,000 was formed under all conditions tested, including without inducers and without molybdenum. Analysis of membranes, solubilized with deoxycholate, by polyacrylamide gel electrophoresis under nondenaturing conditions showed that the mutant protein had similar electrophoretic mobility to the active nitrate reductase formed by the wilde type. Autoradiography of preparations from cells incubated with55Fe showed that the mutant and wild type proteins contained iron. However, in similar experiments with99Mo, incorporation of molybdenum into the mutant protein was not detectable.We conclude that mutant M-1 is defective in one or more steps required to process molybdenum for incorporation into molybdoenzymes. This failure affects the normal regulation of nitrate reductase protein with respect to the role of inducers.