Sinden R R, Hagerman P J
Biochemistry. 1984 Dec 18;23(26):6299-303. doi: 10.1021/bi00321a002.
Analysis of the X-ray crystallographic structure of an 8-methoxypsoralen-thymine monoadduct has led to the suggestion that psoralen cross-links would bend DNA by as much as 70 degrees [Peckler, S., Graves, B., Kanne, D., Rapoport, H., Hearst, J. E., & Kim, S.-H. (1982) J. Mol. Biol. 162, 157-172]. DNA can exist in a stably bent configuration in solution as recently demonstrated from analysis of polyacrylamide gel electrophoresis and differential decay of birefringence. Using these techniques, we have investigated the structure of DNA cross-linked with 8-methoxypsoralen and 4,5',8-trimethylpsoralen. The results are not consistent with cross-links introducing any appreciable stable bend in double-stranded DNA molecules. Results suggest that photobound 4,5',8-trimethylpsoralen molecules lengthen DNA by the equivalent of about one base pair per photobound adduct. We have also determined that 4,5',8-trimethylpsoralen cross-links are introduced preferentially into 5'-TA compared to 5'-AT DNA sequences.
对8-甲氧基补骨脂素-胸腺嘧啶单加合物的X射线晶体结构分析表明，补骨脂素交联会使DNA弯曲多达70度[Peckler, S., Graves, B., Kanne, D., Rapoport, H., Hearst, J. E., & Kim, S.-H. (1982) J. Mol. Biol. 162, 157 - 172]。正如最近通过聚丙烯酰胺凝胶电泳分析和双折射的差异衰减所证明的那样，DNA在溶液中可以以稳定的弯曲构型存在。使用这些技术，我们研究了与8-甲氧基补骨脂素和4,5',8-三甲基补骨脂素交联的DNA的结构。结果与交联在双链DNA分子中引入任何明显稳定弯曲的情况不一致。结果表明，光结合的4,5',8-三甲基补骨脂素分子使DNA延长，每个光结合加合物相当于约一个碱基对。我们还确定，与5'-AT DNA序列相比，4,5',8-三甲基补骨脂素交联优先引入到5'-TA中。
