Stimulation of mouse liver corticosteroid side chain isomerase by cobaltous and nickelous ions: evidence for an endogenous inhibitor of isomerase activity.
Stimulation of mouse liver corticosteroid side chain isomerase by cobaltous and nickelous ions: evidence for an endogenous inhibitor of isomerase activity.
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钴离子和镍离子刺激小鼠肝脏皮质类固醇侧链异构酶：异构酶活性内源性抑制剂的证据。
DOI：
10.1016/0003-9861(84)90424-7
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发表时间：
1984
影响因子：
3.9
通讯作者：
Monder,C
中科院分区：
文献类型：
--
作者：
Iohan,F;Monder,C
Co2+和Ni2+刺激小鼠肝细胞质皮质类固醇侧链异构酶。刺激强度随孵育时间的延长而增加。对于Co2+和Ni2+，分别在15分钟和60分钟增强2.8倍和4.0倍和3.9倍和5.0倍。类固醇底物浓度（11-脱氧-[21-3H]皮质酮）与初始速度之间的关系与阳离子与异构酶活性的细胞质抑制剂反应的模型一致。经硫酸铵分馏和凝胶过滤部分纯化后，酶的比活性提高了6.8倍。Co2+和Ni2+分别使部分纯化酶的活性提高1.6倍和1.9倍。与细胞质溶胶不同，刺激的实现没有延迟，并且不因长时间孵育而改变。金属离子螯合剂对部分纯化酶的活性影响不一致。氰化物和α、α-二吡啶活性升高，双硫腙和8-羟基喹啉活性降低。这些数据与侧链异构酶是一种金属酶的假设不一致。结论是Co2+和Ni2+通过去除内源性抑制剂来刺激酶。
Corticosteroid side chain isomerase of mouse liver cytosol was stimulated by Co2+and Ni2+. The magnitude of stimulation increased with incubation time. For Co2+and Ni2+, respective enhancements were 2.8- and 4.0-fold at 15 min and 3.9- and 5.0-fold at 60 min. The relationship between steroid substrate concentration (11-deoxy-[21-3H]corticosterone) and initial velocity was consistent with a model in which the cations reacted with a cytosol inhibitor of isomerase activity. Enzyme, partially purified by ammonium sulfate fractionation and gel filtration, had a 6.8-fold increased specific activity. Co2+and Ni2+enhanced the activity of partially purified enzyme 1.6- and 1.9-fold. Unlike the cytosol, stimulation was achieved without lag and was not altered by prolonged incubation. Metal ion chelating agents did not have a consistent effect on the activity of the partially purified enzyme. Cyanide and α,α-dipyridyl increased, and dithizone and 8-hydroxyquinoline decreased activity. The data are not consistent with the hypothesis that side chain isomerase is a metalloenzyme. It is concluded that Co2+and Ni2+stimulate the enzyme by removing an endogenous inhibitor.