A practical synthesis of 2′-aminoacylamino-2′-deoxyadenosines

A practical and efficient synthesis of 2′-aminoacylamino-2′-deoxyadenosine derivatives is reported. EDCI/HOBt-mediated coupling of a 3′,5′-diprotected 2′-amino-2′-deoxyadenosine derivative to various N-Cbz-l-amino acid derivatives followed by global deprotection affords analytically pure 2′-aminoacylamino-2′-deoxyadenosine derivatives without the necessity for preparative HPLC purification. These compounds are non-hydrolysable isosteres of 2′-aminoacyladenosines, which are of use in X-ray studies for the elucidation of the editing mechanism of various tRNA synthetases.     

Calorimetric studies of thermal denaturation of DNA and tRNAs

The thermal denaturation of DNA and tRNAs was investigated by differential scanning calorimetry (DSC). Endothermic peaks were observed in the DSC curves when the samples were heated. The denaturation temperatures (T _d) and denaturation enthalpies (ΔH _d) of samples of lyophilized powder and of samples in 4 mol/dm³ urea solution were obtained. The experimental results showed that the thermal stabilities of DNA and tRNAs were obviously different under these conditions. This research was supported by the National Science Foundation of China.     

Non‐Hydrolyzable RNA–Peptide Conjugates: A Powerful Advance in the Synthesis of Mimics for 3′‐Peptidyl tRNA Termini

Translation of specific small peptides on the ribosome can confer resistance to macrolide antibiotics. To reveal the molecular details of this and related phenomena, stable RNA–peptide conjugates that mimic peptidyl‐tRNA would be desirable, especially for ribosome structural biology. A flexible solid‐phase synthesis strategy now allows efficient access to these highly requested derivatives without restriction on the RNA and peptide sequences.