USE OF ADENINE-NUCLEOTIDE DERIVATIVES TO ASSESS THE POTENTIAL OF EXO-ACTIVE-SITE-DIRECTED REAGENTS AS SPECIES-SPECIFIC OR ISOZYME-SPECIFIC ENZYME INACTIVATORS .4. INTERACTIONS OF ADENOSINE 5'-TRIPHOSPHATE DERIVATIVES WITH ADENYLATE KINASES FROM ESCHERICHIA-COLI AND RAT-TISSUES
USE OF ADENINE-NUCLEOTIDE DERIVATIVES TO ASSESS THE POTENTIAL OF EXO-ACTIVE-SITE-DIRECTED REAGENTS AS SPECIES-SPECIFIC OR ISOZYME-SPECIFIC ENZYME INACTIVATORS .4. INTERACTIONS OF ADENOSINE 5'-TRIPHOSPHATE DERIVATIVES WITH ADENYLATE KINASES FROM ESCHERICHIA-COLI AND RAT-TISSUES
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DOI：
10.1021/jm00346a010
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发表时间：
1982-01-01
影响因子：
7.3
通讯作者：
MAEDA, M
中科院分区：
文献类型：
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作者：
HAMPTON, A;PICKER, D;MAEDA, M
N6-R-ATP 类型的 ATP 衍生物 [R = (CH2)nNHCOCH2I、(CH2)nNHCO(CH2)mNHCOCH2I 或 (CH2)nCON(Me)(CH2)mN(Me)CO(CH2)nNHCOCH2I]、N6-Me-N6-R-ATP [R = (CH2)nN-(Me)CO(CH2)mNHCOCH2I]，以及将 N6 或 C-8 与碘之间具有 5-19 个间隔原子的 8-R-ATP [R = NH(CH2)nNHCOCH2I] 作为腺苷酸激酶 (AK) 的底物、可逆抑制剂和灭活剂进行评估。对于大肠杆菌 AK，衍生物是非竞争性抑制剂，Ki = 4.7-7.3 mM，对 ATP 位点几乎没有亲和力，并且 N6-(CH2)nNHCOCH2I-ATP (n = 5 或 6) 实现非 ATP 位点定向的渐进抑制。对于大鼠肌肉 AK (M-AK)，一些化合物对 ATP 位点具有轻微的亲和力，如具有多达 8 个间隔原子的弱底物活性所证明，但所有测试的化合物都是弱的非竞争性抑制剂； Ki = 6-12 mM 与 ATP。 ATP 衍生物，特别是 N6-(CH2)8NHCOCH2I-ATP，介导 M-AK 的渐进抑制，通过用 H 取代 I 来消除这种抑制，因此可能涉及酶的烷基化。这种抑制似乎不是 ATP 位点定向的，因为动力学分析表明是随机双分子酶抑制剂反应，而且 N6-(CH2)8NHCOCH2I-AMP 及其腺苷对应物对 ATP 位点的亲和力相对较低，比 N6-(CH2)8NHCOCH2I-ATP 更有效。 ATP 衍生物是相对于大鼠同工酶 AK II 或 III 的 ATP 的底物 (KM = 0.4-1.6 mM) 和/或竞争性抑制剂 (Ki = 0.3-6.2 mM)。 AK II 或 III 在 22°C 下暴露 6 小时。 C，在 pH 7.6 至 10 mM 水平下，25 种 ATP 衍生物的 1:1 Mg 复合物在任何情况下都不会导致进行性酶抑制，表明 ATP 位点附近不存在适合烷基化的亲核基团。
ATP derivatives of the types N6-R-ATP [R = (CH2)nNHCOCH2I, (CH2)nNHCO(CH2)mNHCOCH2I, or (CH2)nCON(Me)(CH2)mN(Me)CO(CH2)nNHCOCH2I], N6-Me-N6-R-ATP [R = (CH2)nN-(Me)CO(CH2)mNHCOCH2I], and 8-R-ATP [R = NH(CH2)nNHCOCH2I] with 5-19 spacer atoms between N6 or C-8 and iodine were evaluated as substrates, reversible inhibitors, and inactivators of adenylate kinase (AK). With Escherichia coli AK, the derivatives were noncompetitive inhibitors, Ki = 4.7-7.3 mM, with little affinity for the ATP site, and N6-(CH2)nNHCOCH2I-ATP (n = 5 or 6) effected progressive inhibitions that were not ATP site directed. With rat muscle AK (M-AK), some compounds had slight affinity for the ATP site as evidenced by weak substrate activity with as much as 8 spacer atoms, but all compounds tested were weak noncompetitive inhibitors; Ki = 6-12 mM vs. ATP. The ATP derivatives, notably N6-(CH2)8NHCOCH2I-ATP, mediated a progressive inhibition of M-AK, which was abolished by substitution of H for the I and thus presumably involves alkylation of the enzyme. The inhibition appeared not to be ATP site directed because kinetic analysis indicated a random bimolecular enzyme-inhibitor reaction and because N6-(CH2)8NHCOCH2I-AMP and its adenosine counterpart, which have relatively low affinity for the ATP site, were more effective than N6-(CH2)8NHCOCH2I-ATP. The ATP derivatives were substrates (KM = 0.4-1.6 mM) and/or competitive inhibitors (Ki = 0.3-6.2 mM) vs. ATP of rat isozymes AK II or III. Exposure of AK II or III for 6 h, 22.degree. C, at pH 7.6 to 10 mM levels of the 1:1 Mg complexes of 25 of the ATP derivatives led in no case to progressive enzyme inhibition, suggesting the absence near the ATP sites of nucleophilic groups suitably positioned for alkylation.