Ziemkowski Przemysław, Felczak Krzysztof, Poznański Jarosław, Kulikowski Tadeusz, Zieliński Zbigniew, Cieśla Joanna, Rode Wojciech
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawińskiego Street, 02-106 Warszawa, Poland.
Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warszawa, Poland.
Biochem Biophys Res Commun. 2007 Oct 12;362(1):37-43. doi: 10.1016/j.bbrc.2007.07.097. Epub 2007 Jul 27.
A series of 2'-fluoro-substituted dUMP/FdUMP analogues were synthesized, their interaction with human recombinant thymidylate synthase investigated, and structural (1)H and (19)F NMR study of the corresponding nucleosides performed. While 2'-F-dUMP (fluorine in the "down" configuration), in striking contrast to 2'-F-ara-UMP (fluorine in the "up" configuration) and 2',2''-diF-dUMP, showed substrate activity, 2'-F-ara-UMP and 2',2''-diF-dUMP were classic inhibitors, and 2',5-diF-ara-UMP behaved as a strong slow-binding inhibitor, suggesting the 2'-F substituent in the "up" position to interfere with the active center cysteine thiol addition to the pyrimidine C(6) and the pyrimidine C(5)-F to prevent this interference. In support, the direct through space heteronuclear coupling J(HF) was observed for the fluorine "up" derivatives, 2'-F-ara-U and 2',5-diF-ara-U, causing the splitting of the H(6) resonance lines. The absence of such splitting in 2',2''-diF-dUrd, indicating an unusual orientation of the base in relation to the furanose, was associated with an exceptionally weak interaction with the enzyme.
合成了一系列2'-氟取代的dUMP/FdUMP类似物，研究了它们与重组人胸苷酸合成酶的相互作用，并对相应核苷进行了结构¹H和¹⁹F NMR研究。与2'-F-ara-UMP（氟处于“上”构型）和2',2''-二氟-dUMP形成鲜明对比的是，2'-F-dUMP（氟处于“下”构型）表现出底物活性，而2'-F-ara-UMP和2',2''-二氟-dUMP是典型的抑制剂，2',5-二氟-ara-UMP则表现为强慢结合抑制剂，这表明处于“上”位置的2'-F取代基会干扰活性中心半胱氨酸硫醇加成到嘧啶C(6)上，而嘧啶C(5)-F可防止这种干扰。作为支持，在氟处于“上”构型的衍生物2'-F-ara-U和2',5-二氟-ara-U中观察到了直接的空间异核耦合J(HF)，导致H(6)共振线分裂。2',2''-二氟-dUrd中没有这种分裂，这表明碱基相对于呋喃糖的取向异常，这与它与酶的相互作用异常微弱有关。
