Two-step synthesis of 5′-deoxy-5′-thioguanosine-5′-monophosphorothioate and its incorporation efficiency into 5′-terminus of RNA for preparation of thiol-functionalized RNA

Incorporation Efficiency of 5'-Azido-5'-Deoxyguanosine into 5'-Terminus of RNA for Preparation of Azido-Functionalized RNA

“…2, 3 In particular, several 5'-modifications of RNA molecules such as sulfhydryl modification for functionalizing the 5'-terminus of RNA by a transcription or kinase reaction have been shown to have broad applications in studying RNA structures, mapping RNA-protein interactions, and in vitro selection of catalytic RNAs, 4 since a unique functional group incorporated into the RNA can be subsequently conjugated to the desired molecule by a selective chemical reaction. However, there is still a need to develop coupling chemistry with high stability and yield to modify RNA and other biomolecules.…”

RNA Aptamer-Functionalized Quantum Dots for Detection of His-Tagged Proteins in Escherichia coli

“…RNA-based aptamers for specific binding to His-tagged proteins were synthesized, using the antisense oligonucleotide containing the T7 promoter sequence at the 5'-end (5'-GCCAG CTCCC GGGGC CAATC CCAAC CAGAC CACCC ATAGC CCCCC CTATA GTGAG TCGTA TTAGT CC-3'), 6 and the resulting RNA was modified to contain a 5'-thiol group, via an enzymatic method for the introduction of 5'-terminal sulfhydryl group at the 5'-termini of RNA molecules according to the literature. 6,10 Prior to the transcription, the 5'-deoxy-5'-thioguanosine-5'-monophosphorothioate (GSMP) was synthesized, 10 as substrate for T7 RNA polymerase that requires guanosine to efficiently initiate tran- Figure 1. Fluorescence images of His-tagged proteins in E. coli using anti-His-tag aptamer-conjugated QDs.…”

Preparation of 5'-Azido-5'-Deoxyguanosine and Its Efficiency for Click Chemistry

“…2, 3 In particular, several 5'-modifications of RNA molecules such as sulfhydryl modification for functionalizing the 5'-terminus of RNA by a transcription or kinase reaction have been shown to have broad applications in studying RNA structures, mapping RNA-protein interactions, and in vitro selection of catalytic RNAs, 4 since a unique functional group incorporated into the RNA can be subsequently conjugated to the desired molecule by a selective chemical reaction.…”

“…We report here a two-step synthetic method for 5'-azido-5'-deoxyguanosine by adapting literature procedures 3,7 (Scheme 1) and its efficiency for click chemistry using 6-heptynoyl p-nitroaniline (see Experimental Section), in consideration that the click chemistry with rapid reaction between the azide and alkyne groups to form a covalent triazole linkage without cross reacting with other functional groups has been used to great effect in bioconjugation chemistry and that RNA has an inherently much more labile ribophosphate backbone than DNA due to the existence of the 2'-hydroxy groups vicinal to the internucleotide phosphate, which has likely deterred researchers from using Cu I click chemistry on RNA.…”