Acosta Javier, Del Arco Jon, Pisabarro Victor, Gago Federico, Fernández-Lucas Jesús
Applied Biotechnology Group, Universidad Europea de Madrid, Urbanización El Bosque, Madrid, Spain.
Department of Biomedical Sciences and "IQM-CSIC Associated Unit", School of Medicine and Health Sciences University of Alcalá, Madrid, Spain.
Front Bioeng Biotechnol. 2020 Jun 16;8:593. doi: 10.3389/fbioe.2020.00593. eCollection 2020.
Nucleoside-2'-deoxyribosyl-transferases (NDTs) catalyze a transglycosylation reaction consisting of the exchange of the 2'-deoxyribose moiety between a purine and/or pyrimidine nucleoside and a purine and/or pyrimidine base. Because NDTs are highly specific for 2'-deoxyribonucleosides they generally display poor activity on modified C2' and C3' nucleosides and this limitation hampers their applicability as biocatalysts for the synthesis of modified nucleosides. We now report the production and purification of a novel NDT from that is endowed with native ribosyltransferase activity and hence it is more properly classified as an -ribosyltransferase (NRT). Biophysical and biochemical characterization revealed that NRT is a homotetramer that displays maximum activity at 80°C and pH 6 and shows remarkably high stability at high temperatures (60-80°C). In addition, the activity of NRT was found to increase up to 2-fold in 4 M NaCl aqueous solution and to be retained in the presence of several water-miscible organic solvents. For completeness, and as a proof of concept for possible industrial applications, this thermophilic and halotolerant biocatalyst was successfully employed in the synthesis of different purine ribonucleoside analogs.
核苷-2'-脱氧核糖基转移酶（NDTs）催化一种转糖基化反应，该反应包括嘌呤和/或嘧啶核苷与嘌呤和/或嘧啶碱基之间2'-脱氧核糖部分的交换。由于NDTs对2'-脱氧核苷具有高度特异性，它们通常对修饰的C2'和C3'核苷活性较差，这种局限性阻碍了它们作为生物催化剂用于合成修饰核苷的应用。我们现在报道从[具体来源未给出]生产和纯化一种新型的NDT，它具有天然核糖基转移酶活性，因此更恰当地归类为一种核糖基转移酶（NRT）。生物物理和生化特性表明，NRT是一种同四聚体，在80°C和pH 6时显示最大活性，并且在高温（60 - 80°C）下表现出显著的高稳定性。此外，发现NRT的活性在4 M NaCl水溶液中可增加至2倍，并且在几种与水混溶的有机溶剂存在下仍能保持。为了完整起见，作为可能的工业应用概念验证，这种嗜热且耐盐的生物催化剂已成功用于合成不同的嘌呤核糖核苷类似物。
