Nucleotide Phosphohydrolase in Purified Vaccinia Virus
Nucleotide Phosphohydrolase in Purified Vaccinia Virus
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纯化痘苗病毒中的核苷酸磷酸水解酶
DOI：
10.1128/jvi.2.3.167-172.1968
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发表时间：
1968
影响因子：
5.4
通讯作者：
J. Grace
中科院分区：
文献类型：
--
作者：
W. Munyon;E. Paoletti;J. Ospina;J. Grace
纯化的传染性牛痘病毒已被证明含有一种或多种酶，可以去除三磷酸腺苷 (ATP)、三磷酸鸟苷 (GTP)、三磷酸尿苷 (UTP) 和三磷酸胞苷 (CTP) 的末端磷酸基团。该酶的 ATP 的 Km 为 5.5 × 10−4m，与 ATP、GTP、UTP 和 CTP 的反应相对速率分别为 1.00、0.34、0.15 和 0.29。病毒酶不与任何二磷酸盐发生反应。反应速率与添加的病毒量成正比，并且在 130 分钟内呈线性。 Mg++ 极大地刺激病毒核苷酸磷酸水解酶活性，而Ca++ 则极轻微地刺激病毒核苷酸磷酸水解酶活性。在不存在二价阳离子的情况下观察到的少量残余活性被乙二胺四乙酸完全抑制。 Na+ 离子、K+ 离子以及这些离子的任何混合物均未发现能显着刺激反应，而哇巴因在 10−4m 处仅抑制反应 27%。痘苗酶对单价和二价阳离子以及哇巴因的响应表明痘苗酶具有与微粒体和线粒体相关的那些不同的特性。
Purified infectious vaccinia virus has been shown to contain an enzyme or enzymes that remove the terminal phosphate group from adenosine triphosphate (ATP), guanosine triphosphate (GTP), uridine triphosphate (UTP), and cytidine triphosphate (CTP). The Km for ATP of this enzyme is 5.5 × 10−4m, and the relative rates of the reaction with ATP, GTP, UTP, and CTP are 1.00, 0.34, 0.15, and 0.29, respectively. The virus enzyme does not react with any of the diphosphates. The rate of the reaction is proportional to the amount of virus added and is linear for 130 min. The virus nucleotide phosphohydrolase activity is greatly stimulated by Mg++ and very slightly stimulated by Ca++. The small residual activity observed in the absence of divalent cations is completely inhibited by ethylenediaminetetraacetic acid. Neither Na+ nor K+ ions, nor any mixture of these, was found to stimulate the reaction significantly, and ouabain, at 10−4m, inhibited the reaction by only 27%. The response of the vaccinia enzyme to mono- and divalent cations and to ouabain indicates that the vaccinia enzyme has different properties from those associated with microsomes and mitochondria.