Seela F, Berg H, Rosemeyer H
Laboratorium für Organische und Bioorganische Chemie, Fachbereich Biologie/Chemie, Universität Osnabrück, Federal Republic of Germany.
Biochemistry. 1989 Jul 25;28(15):6193-8. doi: 10.1021/bi00441a010.
Decanucleotide duplexes of the parent sequence d(GGCA6C).d(CCGT6G) containing various numbers of 2'-deoxytubercidin (c7Ad) in place of 2'-deoxyadenosine have been synthesized. Phosphoramidites of protected c7Ad (3a,b) were used in automated solid-phase synthesis together with those of regular nucleosides. Upon enzymic 5'-phosphorylation and ligation, multimers of 5 and 7-11 were analyzed by polyacrylamide gel electrophoresis and compared with regard to intrinsic, sequence-directed bending. Replacement of dA by c7Ad within the oligomers decreased bending, but the extent depends strongly on the position of incorporation: strong bending was still observed if the 3'- and 5'-terminal dA residues of the dA tract were replaced while the interruption of the d(A)6 tract by c7Ad reduced bending strongly.
已合成了亲本序列d(GGCA6C).d(CCGT6G)的十核苷酸双链体，其中含有不同数量的2'-脱氧结核菌素（c7Ad）以取代2'-脱氧腺苷。受保护的c7Ad（3a,b）的亚磷酰胺与常规核苷的亚磷酰胺一起用于自动固相合成。在进行酶促5'-磷酸化和连接后，通过聚丙烯酰胺凝胶电泳分析5聚体以及7至11聚体，并就内在的、序列导向的弯曲进行比较。在寡聚物中用c7Ad取代dA会降低弯曲度，但程度强烈依赖于掺入位置：如果dA序列的3'-和5'-末端dA残基被取代，仍会观察到强烈弯曲，而c7Ad对d(A)6序列的中断则会强烈降低弯曲度。
