Regulation of the enzymatic catalysis of poly(ADP-ribose) polymerase by dsDNA, polyamines, Mg2+, Ca2+, histones H1 and H3 and ATP
Regulation of the enzymatic catalysis of poly(ADP-ribose) polymerase by dsDNA, polyamines, Mg2+, Ca2+, histones H1 and H3 and ATP
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DOI：
10.1021/bi0301791
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发表时间：
2004-01-13
期刊：
影响因子：
2.9
通讯作者：
Ordahl, CP
中科院分区：
文献类型：
--
作者：
Kun, E;Kirsten, E;Ordahl, CP
在两种体外系统中分析了聚（ADP-核糖）聚合酶（PARP-1）的酶促机制：（a）在溶液中和（B）当受体历史附着于固体表面时。在系统（a）中，确定了dsDNA的辅酶功能是不依赖于序列的。然而，从计算的特异性常数可以明显看出，AT均聚物是迄今为止最有效的辅酶，而随机损伤的DNA是最差的。以dsDNA作为辅酶的自动（聚ADP核糖基化）速率在20分钟内几乎是线性的，与dcDNA的速率相反，dcDNA显示产物[（ADPR）（n）]抑制。生理细胞成分，Mg 2+，Ca 2+和多胺，自动（聚ADP核糖基化）的变构激活被证明，精胺作为最强大的激活剂。在摩尔基础上，历史H-1和H-3是最有效的PARP-1激活剂，其作用被赖氨酸端基的乙酰化所消除。系统（B）表明，寡聚（ADP-核糖基）转移到组蛋白H-1的转移量是PARP-1自身（聚ADP-核糖基化）转移量的1%，并且这种反式（ADP-核糖基化）由腐胺（激活剂）选择性调节。ATP的生理细胞浓度抑制PARP-1自动（聚ADP-核糖基化），但较少抑制寡聚（ADP-核糖）转移到组蛋白，表明PARP-1自动（ADP-核糖基化）活性在生物能量完整的细胞中处于休眠状态，仅允许发生反式（ADP-核糖基化）。ATP对PARP-1的抑制机制包括与NAD位点的非竞争性相互作用和与辅酶DNA结合位点的竞争。提出了一种通过细胞生物能量学对PARP-1活性及其染色质相关功能的新调节，该调节发生在未暴露于灾难性DNA损伤的功能细胞中。
The enzymatic mechanism of poly(ADP-ribose) polymerase (PARP-1) has been analyzed in two in vitro systems: (a) in solution and (b) when the acceptor histories were attached to a solid surface. In system (a), it was established that the coenzymatic function of dsDNAs was sequence-independent. However, it is apparent from the calculated specificity constants that the AT homopolymer is by far the most effective coenzyme and randomly damaged DNA is the poorest. Rates of auto(poly-ADP-ribosylation) with dsDNAs as coenzymes were nearly linear for 20 min, in contrast to rates with dcDNA, which showed product [(ADPR)(n)] inhibition. An allosteric activation of auto(poly-ADP-ribosylation) by physiologic cellular components, Mg2+, Ca2+, and polyamines, was demonstrated, with spermine as the most powerful activator. On a molar basis, histories H-1 and H-3 Were the most effective PARP-1 activators, and their action was abolished by acetylation of lysine end groups. It was shown in system (b) that oligo(ADP-ribosyl) transfer to histone H-1 is 1% of that of auto(poly-ADP-ribosylation) of PARP-1, and this trans(ADP-ribosylation) is selectively regulated by putrescine (activator). Physiologic cellular concentrations of ATP inhibit PARP-1 auto(poly-ADP-ribosylation) but less so the transfer of oligo(ADP-ribose) to histones, indicating that PARP-1 auto(ADP-ribosylation) activity is dormant in bioenergetically intact cells, allowing only trans(ADP-ribosylation) to take place. The inhibitory mechanism of ATP on PARP-1 consists of a noncompetitive interaction with the NAD site and competition with the coenzymic DNA binding site. A novel regulation of PARP-1 activity and its chromatin-related functions by cellular bioenergetics is proposed that occurs in functional cells not exposed to catastrophic DNA damage.