Burton D R, Forsén S, Reimarsson P
Nucleic Acids Res. 1981 Mar 11;9(5):1219-28. doi: 10.1093/nar/9.5.1219.
The interaction between a variety of polyamines, both naturally occurring and synthetic, and calf thymus DNA has been studied using 23Na NMR. The relaxation behaviour of 23Na reflects the extent of interaction of Na+ with DNA phosphate groups and therefore the extent of charge neutralisation of DNA phosphate groups (P) by polyamine amino and imino groups (N) in solutions of DNa, polyamine and Na+. The studies reveal that whereas spermine and spermidine are capable of expelling nearly all of the Na+ ions from DNA at N/P approximately 1, diamines such as putrescine and homologues of spermine and spermidine are capable of neutralising only roughly 50% of DNA phosphates. The results provide a challenge to current models of DNA-polyamine interactions.
利用23Na核磁共振研究了多种天然存在和合成的多胺与小牛胸腺DNA之间的相互作用。23Na的弛豫行为反映了Na+与DNA磷酸基团的相互作用程度,因此也反映了在DNA、多胺和Na+溶液中,多胺的氨基和亚氨基(N)对DNA磷酸基团(P)的电荷中和程度。研究表明,在N/P约为1时,精胺和亚精胺能够将几乎所有的Na+离子从DNA中排出,而诸如腐胺以及精胺和亚精胺同系物等二胺只能中和大约50%的DNA磷酸盐。这些结果对当前的DNA - 多胺相互作用模型提出了挑战。