ATP-AMP phosphotransferase from Paracoccus denitrificans.
ATP-AMP phosphotransferase from Paracoccus denitrificans.
复制标题
来自脱氮副球菌的 ATP-AMP 磷酸转移酶。
DOI：
--
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
L. Noda
中科院分区：
文献类型：
--
作者：
S. Yeh;A. Tomasselli;L. Noda
用甲苯提取副球菌腺苷酸激酶，经DEAE-Cellulose DE-52、Matrex-Blue A和Sephadex G-75柱层析纯化370倍，总收率44%，554 U/mg，Mr 22000，pI 4.7，最适pH 7.5-8.0。十二烷基硫酸酯凝胶电泳显示该酶为均一酶，SephadexG-75柱层析显示该酶的比活力为单峰。在聚（乙二醇）-400中获得了重针状晶体。该酶对腺嘌呤（脱氧腺嘌呤）核苷酸具有特异性，对ATP、ADP和AMP的Km值分别为340 μ M、980 μ M和93 μ M，对ATP、MgATP和AMP的解离常数分别为7.3 μ M、7.1 μ M和6.9 μ M。注意到该酶没有二硫键，两个游离巯基和总共208个残基。加入50 mM KCl后，酶活力逐渐下降。该酶在中性pH和低于44 ℃的温度下稳定。来自嗜热假单胞菌的腺苷酸激酶类似于来自其他来源的腺苷酸激酶，其性质如依赖于特定的二价阳离子，在约1：1的Mg 2+：ATP比率和1：2的Mg 2+：ADP比率下的最大活性，具有MgATP（或MgADP）结合位点和AMP（或ADP）的另一底物结合位点，以及需要完整的组氨酸和一个或多个精氨酸残基用于酶活性。通过以下性质的比较，来自P. acetificans的腺苷酸激酶似乎类似于所谓的肌肉型（细胞质）而不是肌肉型腺苷酸激酶：低分子量，具有-SH基团并且没有二硫键，形成ADP的最适pH为8.0，通过ELISA测试的阳性交叉反应以及需要低浓度的Ap 5A来抑制95%的活性。
Adenylate kinase has been extracted from Paracoccus denitrificans by toluene treatment and purified 370-fold (overall yield of 44%, 554 U/mg, Mr 22 000, pI 4.7; pH optimum 7.5-8.0) by using successive column chromatography on DEAE-cellulose DE-52, Matrex-Blue A and Sephadex G-75. The enzyme was homogeneous by dodecylsulfate gel electrophoresis and constancy of specific activity across the single peak found in Sephadex G-75 chromatography. Crystals in the form of heavy needles have been obtained in poly(ethylene glycol)-400. The enzyme is specific for adenine (deoxyadenine) nucleotides with Km values for ATP, ADP and AMP of 340 microns, 980 microM and 93 microM respectively and dissociation constants, for ATP, MgATP and AMP of 7.3 microM, 7.1 microM and 6.9 microM respectively. The enzyme was noted to have no disulfide bond, two free sulfhydryl groups and a total of 208 residues. Aboe 50 mM KCl the enzyme activity drops off gradually. The enzyme is stable at neutral pH and below a temperature of 44 degrees C. Adenylate kinase from P. denitrificans resembles adenylate kinases from other sources with respect to such properties as the dependence on specific divalent cations, maximal activities at a ratio of Mg2+:ATP of about 1:1 and the ratio of Mg2+:ADP of 1:2, in having MgATP (or MgADP) binding site and another substrate binding site for AMP (or ADP), and in requiring an intact histidine and one or more arginine residues for enzymatic activity. Adenylate kinase from P. denitrificans appears to resemble the so-called muscle-type (cytoplasmic) rather than the mitochondrial-type adenylate kinase by comparisons of the following properties: low molecular weight, having --SH groups and no disulfide bonds, pH-optimum of 8.0 for formation of ADP, positive cross-reaction by ELISA test and in requiring a low concentration of Ap5A to inhibit 95% activity.
猪腺苷酸激酶核苷酸结合位点的核磁共振研究。
影响因子：
2.9
作者：
Smith,GM;Mildvan,AS
通讯作者：
Mildvan,AS