Characterisation of stress protein LysU. Enzymic synthesis of diadenosine 5′,5‴-P<sup>1</sup>,P<sup>4</sup>-tetraphosphate (Ap<sub>4</sub>A) analogues by LysU
作者:Maria-Elena Theoclitou、E. Pernilla L. Wittung、Alison D. Hindley、Talal S. H. El-Thaher、Andrew D. Miller
DOI:10.1039/p19960002009
日期:——
The stress protein LysU (lysyl tRNA synthetase) has been purified from a recombinant strain of Escherichia coli expressing the plasmid pXLys5, and kinetically characterised. Preparative syntheses of analogues of the biologically important molecule diadenosine 5',5'''-P-1,P-4-tetraphosphate (Ap(4)A) are then achieved in good yield by enzyme catalysis, using purified LysU.
What is the conformation of physiologically-active dinucleoside polyphosphates in solution? Conformational analysis of free dinucleoside polyphosphates by NMR and molecular dynamics simulations
作者:Noa Stern、Dan Thomas Major、Hugo Emilio Gottlieb、Daniel Weizman、Bilha Fischer
DOI:10.1039/c005122e
日期:——
indicated by NMR. The conformation around the glycosidic angle in NpnN′s was found to be anti/high anti and the preferred conformation around the C4′–C5′, C5′–O5′ bonds was found to be gauche–gauche (gg). The ribose moiety in NpnN′s showed a small preference for the S conformation, but when attached to cytosine the ribose ring preferred the N conformation. However, no predominant conformation was observed
二核苷多磷酸盐或二核苷酸(Np n N'; N,N'= A,U,G,C;n = 2-7)是天然存在的生理活性化合物。尽管对二核苷酸的兴趣以及它们的构象与其生物学功能的相关性,但是对二核苷酸的构象的研究还不够充分。因此,在这里,我们通过各种NMR技术对一系列Np n N'Na +盐(N = A,G,U,C; N'= A,G,U,C;n = 2–5)进行了构象分析。。如NMR所示,除Up 4/5 U外,所有研究的二核苷酸均在水溶液中形成分子内碱基堆积相互作用。Np n中糖苷角周围的构象发现N's是抗/高抗性,并且发现C4'-C5',C5'-O5'键周围的优选构象是gauche – gauche(gg)。Np n N's中的核糖部分显示出对S构象的偏爱,但是当连接到胞嘧啶时,核糖环则优先选择N构象。然而,在任何二核苷酸中均未观察到核糖部分的主要构象。Ap 2 A和Ap 4 A Na +盐的分子动力学模拟支持了实验结果。此外,针对Ap
Engineering Human Fhit, a Diadenosine Triphosphate Hydrolase, into an Efficient Dinucleoside Polyphosphate Synthase
作者:Kaisheng Huang、Perry A. Frey
DOI:10.1021/ja0400640
日期:2004.8.1
dinucleoside polyphosphates. Fhit catalyzes the Mg2+-dependent hydrolysis of P1-5'-O-adenosine-P3-5'-O-adenosine triphosphate (Ap3A) to AMP and MgADP. Mutation of His96 to glycine disables Fhit as a catalyst for the hydrolysis of phosphoanhydrides such as Ap3A. However, the mutated enzyme H96G-Fhit efficiently catalyzes the synthesis of phosphoanhydride bonds in reactions of nucleoside-5'-phosphimidazolides