Characterisation of stress protein LysU. Enzymic synthesis of diadenosine 5′,5‴-P1,P4-tetraphosphate (Ap4A) analogues by LysU
摘要:
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.
The effect of bisphosphonate acidity on the activity of a thymidylyltransferase
作者:Stephen A. Beaton、Patricia M. Jiang、Jonathan C. Melong、Matthew W. Loranger、Samy Mohamady、Thomas I. Veinot、David L. Jakeman
DOI:10.1039/c3ob41017j
日期:——
Thymidylyltransferases (thymidine diphospho pyrophosphorylases) are nucleotidylyltransferases that play key roles in the biosynthesis of carbohydrate components within bacterial cell walls and in the biosynthesis of glycosylated natural products. They catalyze the formation of sugar nucleotides concomitant with the release of pyrophosphate. Protein engineering of thymidylyltransferases has been an approach for the production of a variety of non-physiological sugar nucleotides. In this work, we have explored chemical approaches towards modifying the activity of the thymidylyltransferase (Cps2L) cloned from S. pneumoniae, through the use of chemically synthesized ‘activated’ nucleoside triphosphates with enhanced leaving groups, or by switching the metal ion co-factor specificity. Within a series of phosphonate-containing nucleoside triphosphate analogues, thymidylyltransferase activity is enhanced based on the acidity of the leaving group and a Brønsted-type analysis indicated that leaving group departure is rate limiting. We have also determined IC50 values for a series of bisphosphonates as inhibitors of thymidylyltransferases. No correlation between the acidity of the inhibitors (pKa) and the magnitude of enzyme inhibition was found.
4,5-Dicyanoimidazole-promoted synthesis of dinucleoside polyphosphates and their analogs
作者:Qi Sun、Shan-Shan Gong、Si Liu、Jian Sun、Guo-Dong Liu、Cha Ma
DOI:10.1016/j.tet.2014.05.013
日期:2014.7
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.