Mechanism of interaction of vincristine sulphate and rifampicin with bovine serum albumin: A spectroscopic study
Mechanism of interaction of vincristine sulphate and rifampicin with bovine serum albumin: A spectroscopic study
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DOI：
10.1007/bf02708294
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发表时间：
2005-11-01
影响因子：
1.7
通讯作者：
Seetharamappa, J
中科院分区：
文献类型：
--
作者：
Kamat, BP;Seetharamappa, J
采用RF/VS猝灭牛血清白蛋白（BSA）荧光的方法，研究了硫酸长春新碱（VS）和利福平（RF）与牛血清白蛋白（BSA）相互作用的机理。斯特恩-沃尔默图表明在淬火机制中存在静态成分。高强度的猝灭速率常数表明，能量传递过程是通过分子间相互作用发生的，VS/ rf结合位点靠近牛血清白蛋白的色氨酸残基。在疏水探针8-苯胺-1-萘磺酸钠盐（ANS）存在下的结合研究表明，VS和RF与ANS竞争BSA表面的疏水位点。阴离子表面活性剂的临界胶束浓度（CMC）在VS/RF存在下略有下降，表明VS/RF的离子特性也有助于结合。结合常数的温度依赖性用于估计VS/RF与BSA相互作用的热力学参数值，结果表明疏水力在结合中起重要作用。圆二色性研究表明，牛血清白蛋白螺旋度的变化是由于VS/RF与牛血清白蛋白结合所致。
The mechanism of interaction of vincristine sulphate (VS) and rifampicin (RF) with bovine serum albumin (BSA) has been studied by quenching of BSA fluorescence by RF/VS. The Stern-Volmer plot indicates the presence of a static component in the quenching mechanism. Results also show that both the tryptophan residues of BSA are accessible to VS and RE The high magnitude of rate constant of quenching indicates that the process of energy transfer occurs by intermolecular interaction and VS/RFbinding site is in close proximity to the tryptophan residues of BSA. Binding studies in the presence of a hydrophobic probe, 8-anilino-1-naphthalene-sulphonic acid sodium salt (ANS) indicate that the VS and RF compete with ANS for hydrophobic sites on the surface of BSA. Small decreases in critical micellar concentrations (CMC) of anionic surfactants in presence of VS/RF show that the ionic character of VS/RF also contributes to binding. The temperature dependence of the association constant is used to estimate the values of the thermodynamic parameters involved in the interaction of VS/RF with BSA and the results indicate that hydrophobic forces play a significant role in the binding. Circular dichroism studies reveal that the change in helicity of BSA are due to binding of VS/RF to BSA.