Interaction of a fluorescent paclitaxel analogue with tubulin.
Interaction of a fluorescent paclitaxel analogue with tubulin.
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DOI：
10.1021/bi00037a029
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发表时间：
1995-09
期刊：
影响因子：
2.9
通讯作者：
S. Sengupta;T. Boge;Gunda Ingrid Georg;R. Himes
中科院分区：
文献类型：
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作者：
S. Sengupta;T. Boge;Gunda Ingrid Georg;R. Himes
为了研究抗肿瘤药物紫杉醇与微管和微管蛋白结合的机制，我们合成了该药物的荧光类似物。将二甲氨基引入到紫杉醇的3'-N-苯甲酰基上。该化合物由 N-去苯甲酰基紫杉醇和 3-(二甲基氨基)苯甲酰氯合成，产率 67%。 N-De苯甲酰基-N-[3-(二甲基氨基)苯甲酰基]-紫杉醇在诱导微管组装方面具有与紫杉醇类似的活性，并在紫杉醇结合位点与微管蛋白结合。在组装条件下，这种紫杉醇类似物与微管蛋白的结合以时间依赖性方式发生，并伴随着荧光强度的大幅增加以及发射最大值的大幅蓝移。此外，有证据表明该化合物还与二聚体状态的微管蛋白结合，但结合亲和力比报道的聚合微管蛋白低得多（25°C 时 Kd = 49 +/- 8 microM）。荧光紫杉醇类似物具有高量子产率，将成为研究紫杉醇与微管蛋白结合机制以及微管蛋白上紫杉醇结合位点环境的有用工具。
To study the mechanism of binding of the antitumor agent paclitaxel to microtubules and tubulin, we have synthesized a fluorescent analogue of the drug. A dimethylamino group was introduced onto the 3'-N-benzoyl group of paclitaxel. This compound was synthesized from N-debenzoylpaclitaxel and 3-(dimethylamino)benzoyl chloride in 67% yield. N-Debenzoyl-N-[3-(dimethylamino)benzoyl]-paclitaxel has activity similar to paclitaxel in inducing microtubule assembly and binds to tubulin at the paclitaxel-binding site. Under assembly conditions, binding of this paclitaxel analogue to tubulin occurs in a time-dependent manner and is accompanied by a large increase in fluorescence intensity, as well as a large blue shift in the emission maximum. In addition, evidence is presented to show that this compound also binds to tubulin in the dimeric state, but the binding affinity is much lower (Kd = 49 +/- 8 microM at 25 degrees C) than that reported for polymeric tubulin. The fluorescent paclitaxel analogue, with a high quantum yield, will be a useful tool in studying the mechanism of paclitaxel binding to tubulin and the environment of the paclitaxel-binding site on tubulin.