Interaction of Vinblastine with Calf Brain Microtubule protein.
Interaction of Vinblastine with Calf Brain Microtubule protein.
复制标题
长春花碱与小牛脑微管蛋白的相互作用。
DOI：
10.1016/s0021-9258(19)40640-6
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
S. N. Timasheff
中科院分区：
文献类型：
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作者：
J. Lee;D. Harrison;S. N. Timasheff
通过速度沉降、凝胶过滤和荧光研究了长春花碱与小牛脑微管蛋白的相互作用。已经确定长春花碱诱导稳定的微管蛋白二聚体进一步二聚化为四聚体。通过Cann和Goad的配体诱导二聚化理论((1972)Arch.Biochem.Biophys.153, 603-609)分析低长春花碱浓度下的沉降模式。通过凝胶过滤和荧光分光光度法测定，长春花碱与微管蛋白结合的缔合常数和化学计量在25度下为(2.3+/-0.1) X 10(4)升/摩尔，每个分子量为110,000的微管蛋白二聚体有两个长春花碱结合位点。长春花碱与微管蛋白的结合特征在于 5.8 kcal/mol 的焓变和正的酉熵变。根据圆二色性监测，长春花碱的结合不会引起微管蛋白的任何显着构象变化。然而，长春花碱-微管蛋白复合物显示出紫外差异光谱，这似乎主要反映了长春花碱向极性较小的环境的转移。除了结合长春花碱外，微管蛋白还以相同的自由能和化学计量结合长春新碱，并且每个微管蛋白二聚体具有 8-苯胺基-1-萘磺酸的单一结合位点，该结合位点独立于长春花碱。
The interaction of vinblastine with calf brain tubulin has been studied by velocity sedimentation, gel filtration, and fluorescence. It has been established that vinblastine induces the stable tubulin dimers to dimerize further to tetramers. The sedimentation patterns at low vinblastine concentration were analyzed by the ligand-induced dimerization theory of Cann and Goad ((1972) Arch. Biochem. Biophys. 153, 603-609). The association constant and stoichiometry for the binding of vinblastine to tubulin, determined by gel filtration and spectrofluorometry, were (2.3 +/- 0.1) X 10(4) liters/mol at 25 degrees and two vinblastine binding sites per tubulin dimer of molecular weight 110,000. The binding of vinblastine to tubulin is characterized by an enthalpy change of 5.8 kcal/mol and a positive unitary entropy change. Binding of vinblastine did not induce any significant conformational changes in tubulin as monitored by circular dichroism. However, the vinblastine-tubulin complex displayed an ultraviolet difference spectrum, which appears to reflect mostly the transfer of vinblastine to a less polar environment. Besides binding vinblastine, tubulin was shown to bind vincristine with identical free energy and stoichiometry and to have a single binding site for 8-anilino-1-naphthalene sulfonic acid per tubulin dimer, which is independent of those for vinblastine.