STUDIES ON INTERACTION OF ANTHRACYCLINE ANTIBIOTICS AND DEOXYRIBONUCLEIC-ACID - EQUILIBRIUM BINDING-STUDIES ON INTERACTION OF DAUNOMYCIN WITH DEOXYRIBONUCLEIC-ACID
STUDIES ON INTERACTION OF ANTHRACYCLINE ANTIBIOTICS AND DEOXYRIBONUCLEIC-ACID - EQUILIBRIUM BINDING-STUDIES ON INTERACTION OF DAUNOMYCIN WITH DEOXYRIBONUCLEIC-ACID
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DOI：
10.1021/bi00260a005
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发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
CROTHERS, DM
中科院分区：
文献类型：
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作者：
CHAIRES, JB;DATTAGUPTA, N;CROTHERS, DM
用平衡透析法、荧光法和吸光度滴定法研究了柔红霉素与小牛胸腺DNA、产气荚膜梭菌DNA和黄微球菌DNA的相互作用。当Na+浓度为200 mM时，数据符合邻位排斥模型，K=7.0倍。105M-1和3-4个碱基对的排除参数。结合作用依赖于离子强度，dlogK/dlog[Na+]=-0.84，由此可以定量地估计离子释放，并用反离子释放自由能修正结合自由能。从结合常数对温度的依赖关系来看，结合是放热的，范氏热焓为-12.8千卡/摩尔。竞争透析实验表明，G+C碱基对作为药物的结合位点略有优先，这表明柔红霉素在低Hivin.r时优先与G+C对结合。氯化铯密度梯度沉淀实验为这一偏好提供了实验证明。柔红霉素将DNA熔化的Tm[熔化温度]提高约30度。C)当结合接近饱和时，在低药物/碱基对比率下两相熔化。这些平衡研究的数据与柔红霉素的插层结合一致，为进一步的结构和动力学研究提供了坚实的基础。
Equilibrium dialysis and fluorescence and absorbance titration were used to study the interaction of [the antineoplastic drug] daunomycin with DNA [from calf thymus, Clostridium perfringens and Micrococcus luteus]. At 200 mM Na+, the data are best fit by the neighbor exclusion model, with K = 7.0 .times. 105 M-1 and an exclusion parameter of 3-4 base pairs. The binding is dependent on ionic strength, with d log K/d log [Na+] = -0.84, from which ion release may be estimated quantitatively and the binding free energy corrected for the free energy of counterion release. From the temperature dependence of the binding constant, the binding was exothermic, with a van''t Hoff enthalpy of -12.8 kcal/mol. Competition dialysis experiments show that G+C base pairs are slightly preferred as binding sites for the drug and suggest that daunomycin binds preferentially to G+C pairs at low .hivin.r. Cesium chloride density gradient sedimentation experiments provide an experimental demonstration of this preference. Daunomycin increases the Tm [melting temperature] for DNA melting by some 30.degree. C as binding approaches saturation, with biphasic melting at low drug/base pair ratios. The data from these equilibrium studies are consistent with intercalative binding of daunomycin and provide a solid foundation for further structural and kinetic studies.