在从益生元化学向生物学的转变过程中,一定发生了(寡)核苷酸的溶液相、非酶活化的时期,因此,磷酸盐活化的机制一定存在。在此,我们详细介绍了使用简单、益生元可用的腈类对益生元磷酸盐活化化学的研究结果,该腈类的反应性因 Cu 2+离子而增加。此外,尽管已知 Cu 2+离子可催化磷酸二酯键的水解,但我们发现这种有害活性几乎完全被氨基酸或二肽的抑制所抑制,这可能从一开始就表明蛋白质和 RNA 之间存在生产性关系。
在从益生元化学向生物学的转变过程中,一定发生了(寡)核苷酸的溶液相、非酶活化的时期,因此,磷酸盐活化的机制一定存在。在此,我们详细介绍了使用简单、益生元可用的腈类对益生元磷酸盐活化化学的研究结果,该腈类的反应性因 Cu 2+离子而增加。此外,尽管已知 Cu 2+离子可催化磷酸二酯键的水解,但我们发现这种有害活性几乎完全被氨基酸或二肽的抑制所抑制,这可能从一开始就表明蛋白质和 RNA 之间存在生产性关系。
Magnesium ion catalyzed phosphorus-nitrogen bond hydrolysis in imidazolide-activated nucleotides. Relevance to template-directed synthesis of polynucleotides
作者:Anastassia Kanavarioti、Claude F. Bernasconi、Donald L. Doodokyan、Diann J. Alberas
DOI:10.1021/ja00200a053
日期:1989.8
conclusion is based on a study of the N-methylated substrates N-MeImpG and 1,2-diMeImpg, respectively, which were generated in situ by the equilibrium reaction of ImpG with N-methylimidazole and 2-MeImpG with 1,2-dimethylimidazole, respectively. In contrast, the absence of Mg2+ the reaction of S- with water competes with the reaction of SH+/- with OH-. The present study bears on the mechanism of the Mg2(+)-catalyzed
Thermodynamics of the hydrolysis reactions of adenosine 3′,5′-(cyclic)phosphate(aq) and phosphoenolpyruvate(aq); the standard molar formation properties of 3′,5′-(cyclic)phosphate(aq) and phosphoenolpyruvate(aq)
作者:Robert N Goldberg、Yadu B Tewari
DOI:10.1016/j.jct.2003.08.002
日期:2003.11
Molar calorimetric enthalpy changes ΔrHm(cal) have been measured for the biochemical reactions cAMP(aq) + H2O(l)=AMP(aq)} and PEP(aq) + H2O(l)=pyruvate(aq) + phosphate(aq)}. The reactions were catalyzed, respectively, by phosphodiesterase 3′,5′-cyclic nucleotide and by alkaline phosphatase. The results were analyzed by using a chemical equilibrium model to obtain values of standard molar enthalpies
as buildingblocks. It is interesting to ask whether this is a coincidence or a consequence of the functional interplay of these biomolecules. One reaction that provides an opportunity to study this interplay is the formation of phosphoramidate-linked peptido RNA from amino acids and ribonucleotides in aqueous condensation buffer. Here we report how the diastereoselectivity of the first peptide coupling
Histidine triad nucleotide‐binding proteins HINT1 and HINT2 share similar substrate specificities and little affinity for the signaling dinucleotide Ap4A
作者:Alexander Strom、Cher Ling Tong、Carston R. Wagner
DOI:10.1002/1873-3468.13745
日期:2020.5
Human histidinetriadnucleotide‐bindingprotein 2 (hHINT2) is an important player in human mitochondrial bioenergetics, but little is known about its catalytic capabilities or its nucleotide phosphoramidate prodrug (proTide)‐activating activity akin to the cytosolic isozyme hHINT1. Here, a similarsubstratespecificity profile (kcat/Km) for model phosphoramidate substrates was found for hHINT2 but
Pulsed Electron Paramagnetic Resonance Spectroscopy of <sup>33</sup>S-Labeled Molybdenum Cofactor in Catalytically Active Bioengineered Sulfite Oxidase
作者:Eric L. Klein、Abdel Ali Belaidi、Arnold M. Raitsimring、Amanda C. Davis、Tobias Krämer、Andrei V. Astashkin、Frank Neese、Günter Schwarz、John H. Enemark
DOI:10.1021/ic4023954
日期:2014.1.21
(molybdopterin, MPT) moiety that coordinates Mo through two dithiolate (dithiolene) sulfur atoms. For sulfite oxidase (SO), hyperfineinteractions (hfi) and nuclear quadrupole interactions (nqi) of magnetic nuclei (I ≠ 0) near the Mo(V) (d1) center have been measured using high-resolution pulsed electron paramagnetic resonance (EPR) methods and interpreted with the help of density functional theory (DFT)
钼酶含有至少一个吡喃蝶呤二硫醇(钼蝶呤,MPT)部分,其通过两个二硫醇(二硫醇)硫原子配位Mo。对于亚硫酸盐氧化酶 (SO),Mo(V) (d 1 ) 中心附近磁核 ( I ≠ 0) 的超精细相互作用 ( hfi ) 和核四极相互作用 ( nqi ) 已使用高分辨率脉冲电子顺磁共振进行了测量 ( EPR)方法并借助密度泛函理论(DFT)计算进行解释。这些为酶的活性位点结构和反应机制提供了重要的见解。然而,由于天然丰富的32 S 没有核自旋 ( I = 0),因此不可能使用 EPR 直接探测二硫醇硫。在这里,我们描述了使用纯化蛋白质进行受控体外合成,将唯一稳定的磁性硫同位素33 S ( I = 3/2) 直接掺入 MPT。这种催化活性 SO 变体中33 S 标记的 MPT 的电子自旋回波包络调制 (ESEEM) 光谱主要由强核四极相互作用引起的“双峰间”跃迁主导, 33 S 标记的可交换赤道亚硫酸盐也发生这种情况配体