Sorace R A, Sheid B
Chem Biol Interact. 1978 Dec;23(3):379-86. doi: 10.1016/0009-2797(78)90098-4.
The binding of [14C]ellipticine to native calf thymus DNA was studied using equilibrium dialysis. A Scatchard polt revealed the presence of high-and low-affinity binding sites in DNA, the former having a K of 4.0 X 10(7) M(-1) and an n (saturation limiting of binding) of 0.078 (1mol ellipticine/13 mol of DNA nucleotides). The forces involved in stabilizing the high-affinity binding, which has been equated with intercalative binding, were due to a combination of hydrophobic interactions and hydrogen bonding. Difference spectra of ellipticine in the presence of the polydeoxynucleotides, poly d(A-T) or poly d(G-C), showed that there was no base specificity involved in the high-affinity binding. Ellipticine binding to the low-affinity sites, which has been equated with surface binding, was due primarily to the participation of electrostatic interactions of ellipticine with the anionic phosphate groups on the double helical surface of DNA.
采用平衡透析法研究了[14C]玫瑰树碱与天然小牛胸腺DNA的结合。Scatchard作图显示DNA中存在高亲和力和低亲和力结合位点，前者的K为4.0×10(7) M(-1)，n（结合饱和限度）为0.078（1摩尔玫瑰树碱/13摩尔DNA核苷酸）。与嵌入结合等同的稳定高亲和力结合所涉及的作用力是疏水相互作用和氢键作用的共同结果。在聚脱氧核苷酸聚d(A-T)或聚d(G-C)存在下玫瑰树碱的差示光谱表明，高亲和力结合不存在碱基特异性。玫瑰树碱与低亲和力位点的结合，等同于表面结合，主要是由于玫瑰树碱与DNA双螺旋表面阴离子磷酸基团的静电相互作用。
