Synthesis and properties of nucleoside 5'-phosphoazidates derived from guanosine and adenosine nucleotides: effect on elongation factors G and Tu dependent reactions

Abstract

A new type of nucleoside poly (5'-phosphate) analogue, nucleoside 5"-phosphoazidate, with an azido group on the terminal phosphate of GTP, ATP, GDP, GMP, AND AMP, has been synthesized by nucleophilic displacement of the corresponding activated nucleosides by azide ion in yields of 25-45%. Guanosine 5-phosphoazidates is readily photolyzed by ultraviolet light; the corresponding adenosine derivative photolyzes more slowly. Guanosine 5'-O-(2-azidodiphosphate) and guanosine 5"-O-(3-azidotrophosphate) are competitive inhibitors of the formation of the ribosome-EF-G-GDP-fusidic acid complex and of the ribosome-EF-G GTPase. The dissociation constants of the former reaction are calculated to be 27 and 7 micrometer, respectively, or 270 and 73 times that of GDP. In the latter reaction, which is conducted in the absence of fusidic acid, the Ki values are 330 and 28 micrometer, respectively, or 12 and 1 times that of GDP. Guanosine 5"-O-(2-azidodiphosphate) and guanosine 5'-O-(3-azidotriphosphate) also complete with GTP in the formation of the binary complex. EF-Tu-GTP, with respective Kd values of 750 and 75 relative to GTP.

Synthesis of α,δ-Disubstituted Tetraphosphates and Terminally-Functionalized Nucleoside Pentaphosphates

“…N 2 under irradiation and covalently attaching to a protein binding site. 20 Interestingly, anion 10 is an isomer of tetrametaphosphate consisting of an azidophosphate substituted trimetaphosphate. The isomer observed in 10 ostensibly results from nucleophile attack at a Q 2 phosphorus rather than attack at a Q 3 phosphorus (Figure 2A).…”

“…Anion 1 is also a suitable reagent for tetraphosphorylation of inorganic nucleophiles. Treatment with tetrabutylammonium azide ([TBA]­[N 3 ]) cleanly forms compound 10 in 24 h. Relatedly, phosphoazidate analogs of nucleoside 5′-triphosphates have been used as photolabile affinity labels, extruding N 2 under irradiation and covalently attaching to a protein binding site . Interestingly, anion 10 is an isomer of tetrametaphosphate consisting of an azidophosphate substituted trimetaphosphate.…”

Derivatives of guanosine triphosphate‐photoreactive substrates of escherichia coli RNA polymerase

“…Guanosine triphosphate, 'Reanal', Hungary, was purified by column chromatography on DEAE~ellulose (What- man DE-52) with the use of gradient elution (O.l-0.4 M) triethylammonium bicarbonate buffer (pH 7.5). ~-Azido~anosine tripl~osphate (II) [4] was synthesized at Novosibirsk State University to our order by a method soon to be published. [a-32P]-Uridinetriphosphate with spec.…”

“…If the substrate activity of y-derivatives of nucleoside triphosphates is a general property, then by introducing an azide group into various positions, we can modify different sites of the RNA polymerase active centre allowing more thorough investigation of its topography. Here we demonstrate that the y(p)azidobenzylamide of guanosine triphosphate (I) [3] and y-azidoguanosine triphosphate (II) [4] (fig.1) are substrates of RNA polymerase and that they can be used for photoaffinity modification of this enzyme.…”

Design of new photoaffinity labels for ribosomal peptidyltransferase

“…All operations with azido derivatives were carried out in the dark. Other general methods were as described in previous papers (Chládek et al, , 1977. NMR spectra were measured on a JEOL FX-100 in Me2SO-«fe using DSS as the internal standard.…”