Interactions between the mitochondrial adenosinetriphosphatase and periodate-oxidized adenosine 5'-triphosphate, an affinity label for adenosine 5'-triphosphate binding sites.
Interactions between the mitochondrial adenosinetriphosphatase and periodate-oxidized adenosine 5'-triphosphate, an affinity label for adenosine 5'-triphosphate binding sites.
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线粒体三磷酸腺苷酶和高碘酸盐氧化的 5-三磷酸腺苷（5-三磷酸腺苷结合位点的亲和标记）之间的相互作用。
DOI：
10.1021/bi00260a025
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Beechey Rb
中科院分区：
文献类型：
--
作者：
Lowe Pn;Beechey Rb
用高碘酸氧化的ATP（o-ATP）作为氯仿释放的牛心线粒体ATP酶核苷酸结合位点的亲和标记。在MgSO 4存在下，o-ATP是ATP酶的底物。它可以作为ATP酶活性的可逆竞争性抑制剂，也可以诱导ATP酶活性的不可逆抑制。与不可逆抑制平行，发生[3 H]o-ATP的共价掺入。当酶被抑制50%时，每摩尔ATP酶约有1.05摩尔o-ATP结合。大多数共价结合的o-ATP与α和β亚基相关，并且在它们之间均匀分布。MgADP、MgATP、EDTA/ATP或EDTA均能完全阻断o-ATP对ATP酶的不可逆抑制作用。的位置，数量和功能意义的o-ATP结合位点进行了讨论。o-ATP可以在β-消除反应机制中分解形成含腺苷的化合物和三聚磷酸根阴离子。测定了含腺嘌呤化合物及其硼氢化物还原产物的结构。含腺嘌呤的消除产物抑制线粒体ATP酶活性的速率大于观察到的o-ATP。本文对o-ATP及其消除产物抑制ATP酶活性的性质和机理进行了探讨。使用高碘酸氧化的核苷酸作为其他蛋白质上的核苷酸结合位点的亲和标记的β-消除反应的意义进行了讨论。
Periodate-oxidized ATP (o-ATP) was prepared as an affinity label of nucleotide binding sites on the chloroform-released ox heart mitochondrial ATPase. In the presence of MgSO4, o-ATP is a substrate for the ATPase. It can act as a reversible, competitive inhibitor of ATPase activity and can also induce an irreversible inhibition of ATPase activity. In parallel with the irreversible inhibition, covalent incorporation of [3H]o-ATP occurs. ATPase has about 1.05 mol of o-ATP bound per mol of ATPase when the enzyme is 50% inhibited. Most of the covalently bound o-ATP is associated with the alpha and beta subunits and is equally distributed between them. The incorporation of o-ATP into the ATPase is reduced, and the irreversible inhibition induced by o-ATP can be prevented totally by MgADP, MgATP, EDTA/ATP, or EDTA. The location, number, and the functional significance of the o-ATP binding sites are discussed. o-ATP can decompose to form an adenosine-containing compound and the tripolyphosphate anion in a beta-elimination reaction mechanism. The structures of the adenine-containing compound and its borohydride reduction product were determined. The adenine-containing elimination product inhibited the mitochondrial ATPase activity at a rate greater than that observed with o-ATP. The nature and mechanism of the inhibition of ATPase activity exerted by o-ATP and the elimination product were examined. The significance of the beta-elimination reaction to the use of periodate-oxidized nucleotides as affinity labels of nucleotide binding sites on other proteins is discussed.