Dasgupta D, Park H, Harriman G C, Georg G I, Himes R H
Department of Biochemistry, University of Kansas, Lawrence 66045.
J Med Chem. 1994 Sep 2;37(18):2976-80. doi: 10.1021/jm00044a019.
A photoaffinity analogue of taxol, N-([3,5-3H]-4-azidobenzoyl)-N-debenzoyltaxol (7), was synthesized and used to photolabel microtubules. Approximately 20% of the noncovalently bound analogue becomes covalently bound upon irradiation at 300 nm. Incorporated label was stable to a 50% ethanol solution and sodium dodecyl sulfate. About 80% of the incorporated label was found in the beta-subunit and 20% in the alpha-subunit. Incorporation did not occur into unpolymerized tubulin, consistent with the fact that taxol binds only to polymerized tubulin, and was decreased by the presence of taxol. Little or no nonspecific labeling occurs. This analogue is currently being used to identify taxol binding site(s) on tubulin.
合成了紫杉醇的一种光亲和类似物N-([3,5-³H]-4-叠氮苯甲酰基)-N-去苯甲酰基紫杉醇(7)，并用于对微管进行光标记。在300nm波长照射下，约20%的非共价结合类似物会发生共价结合。掺入的标记物对50%乙醇溶液和十二烷基硫酸钠稳定。发现掺入的标记物约80%存在于β亚基中，20%存在于α亚基中。未聚合的微管蛋白中不会发生掺入，这与紫杉醇仅与聚合的微管蛋白结合的事实一致，并且紫杉醇的存在会降低掺入量。几乎没有非特异性标记。目前正在使用这种类似物来鉴定微管蛋白上的紫杉醇结合位点。
