Bio-catalytic synthesis of unnatural nucleosides possessing a large functional group such as a fluorescent molecule by purine nucleoside phosphorylase
作者:Akihiko Hatano、Hiroyuki Wakana、Nanae Terado、Aoi Kojima、Chisato Nishioka、Yu Iizuka、Takuya Imaizumi、Sanae Uehara
DOI:10.1039/c9cy01063g
日期:——
large functional fluorescent group, 5-(coumarin-7-oxyhex-5-yn) uracil (C4U). Conversion to 2′-deoxy-[5-(coumarin-7-oxyhex-5-yn)] uridine (dRC4U) was drastically enhanced by DMSO addition. Docking simulations between dRC4U and E. coli PNP (PDB 3UT6) showed the uracil moiety in the active-site pocket of PNP with the fluorescent moiety at the entrance of the pocket. Thus, the bulky fluorescent moiety has little
非天然核苷作为潜在的诊断工具,药物和功能分子引起了人们的兴趣。然而,难以以高收率和β-区域选择性将非天然核碱基偶联至核糖的1'-位置。嘌呤核苷磷酸化酶(PNP,EC2.4.2.1)是一种代谢酶,可在磷酸缓冲液中以100%α-选择性催化肌苷向核糖-1α-磷酸和游离次黄嘌呤的转化。我们探讨了PNP是否可用于合成非天然核苷。PNP催化作为核糖供体的胸腺嘧啶核苷与嘌呤的反应生成2'-deoxynebularine(3,β形式)的转化率很高(80%)。它还催化胸腺嘧啶的磷酸化,并以中等产率(52-73%)将核苷的5-位被卤素原子取代的嘧啶碱基引入核糖的1'-位,表明它显示出较弱的选择性。对于庞大的嘌呤底物[例如6-(N,N,N-二丙基氨基)],产率较低,但是添加极性溶剂例如二甲基亚砜(DMSO)将产率提高至74%。PNP还催化胸腺嘧啶与具有较大功能性荧光基团的尿嘧啶(5-香豆素-7-oxyhex-5