Alvarez-Gonzalez R
Department of Microbiology and Immunology, University of North Texas Health Science Center at Fort Worth 76107-2699.
Mol Cell Biochem. 1994 Sep;138(1-2):213-9. doi: 10.1007/BF00928464.
Recently, two deoxyribose analogs of beta NAD+ (2'-deoxy and 3'-deoxyNAD+) have been synthesized and purified in this laboratory. Whereas 2'-deoxyNAD+ was an efficient substrate for arg-specific mon(ADP-ribosyl) transferases, it was not a substrate for poly(ADP-ribose) polymerase (PARP). Instead, it was a non-competitive inhibitor of beta NAD+ in the ADP-ribose polymerization reaction catalyzed by PARP. Thus, 2'-deoxyNAD+ has been utilized to distinguish between mono(ADP-ribose) and poly(ADP-ribose) acceptor proteins. 2'-deoxyNAD+ has also been used to characterize the arg-specific mono(2'-deoxyADP-ribosyl)ation reaction of PARP with cholera toxin or avian mono(ADP-ribosyl)transferase. By contrast, 3'-deoxyNAD+ can effectively be utilized as a substrate by PARP. However, while the estimated Km and Kcat of polymerization with 3'-deoxyNAD+ were 20 microM and 0.11 moles/sec, the Km and Kcat with beta NAD+ as a substrate were 59 microM and 1.29 moles/sec, respectively. Determination of the average size of 3'-deoxyADP-ribose polymers indicated that chains no larger than four residues are synthesized with this substrate. Thus, the utilization of 3'-deoxyNAD+ has facilitated the electrophoretic identification of poly(ADP-ribose) acceptor proteins in mammalian chromatin.
最近，本实验室合成并纯化了两种β-NAD⁺的脱氧核糖类似物（2'-脱氧和3'-脱氧NAD⁺）。虽然2'-脱氧NAD⁺是精氨酸特异性单（ADP-核糖基）转移酶的有效底物，但它不是聚（ADP-核糖）聚合酶（PARP）的底物。相反，它是PARP催化的ADP-核糖聚合反应中β-NAD⁺的非竞争性抑制剂。因此，2'-脱氧NAD⁺已被用于区分单（ADP-核糖）和聚（ADP-核糖）受体蛋白。2'-脱氧NAD⁺也被用于表征PARP与霍乱毒素或禽单（ADP-核糖基）转移酶的精氨酸特异性单（2'-脱氧ADP-核糖基）化反应。相比之下，3'-脱氧NAD⁺可被PARP有效地用作底物。然而，虽然以3'-脱氧NAD⁺进行聚合反应的估计Km和Kcat分别为20μM和0.11摩尔/秒，但以β-NAD⁺作为底物时的Km和Kcat分别为59μM和1.29摩尔/秒。对3'-脱氧ADP-核糖聚合物平均大小的测定表明，用该底物合成的链不超过四个残基。因此，3'-脱氧NAD⁺的使用有助于在哺乳动物染色质中对聚（ADP-核糖）受体蛋白进行电泳鉴定。
