ter Haar E, Kowalski R J, Hamel E, Lin C M, Longley R E, Gunasekera S P, Rosenkranz H S, Day B W
Department of Environmental and Occupational Health, University of Pittsburgh, Pennsylvania 15238, USA.
Biochemistry. 1996 Jan 9;35(1):243-50. doi: 10.1021/bi9515127.
Computer-assisted structure analysis indicated (+)-discodermolide, a polyhydroxylated alkatetraene lactone marine natural product, was an antimitotic compound, and we confirmed this prediction. Previous work had shown an accumulation of discodermolide-treated cells in the G2/M portion of the cell cycle, and we have now found that discodermolide arrests Burkitt lymphoma cells in mitosis. Discodermolide-treated breast carcinoma cells displayed spectacular rearrangement of the microtubule cytoskeleton, including extensive microtubule bundling. Microtubule rearrangement that occurred with 10 nM discodermolide required 1 microM taxol. Discodermolide had equally impressive effects on tubulin assembly in vitro. Near-total polymerization occurred at 0 degree C with tubulin plus microtubule-associated proteins (MAPs) under conditions in which taxol at an identical concentration was inactive. Without MAPs and/or without GTP, tubulin assembly was also more vigorous with discodermolide than with taxol under every reaction condition examined. Discodermolide-induced polymer differed from taxol-induced polymer in that it was completely stable at 0 degree C in the presence of high concentrations of Ca2+. In a quantitative assay designed to select for agents more effective than taxol in inducing assembly, discodermolide had an EC50 value of 3.2 microM versus 23 microM for taxol.
计算机辅助结构分析表明，多羟基化的链状四烯内酯海洋天然产物（+）-盘尼西龙是一种抗有丝分裂化合物，我们证实了这一预测。先前的研究表明，经盘尼西龙处理的细胞在细胞周期的G2/M期会积累，我们现在发现盘尼西龙会使伯基特淋巴瘤细胞停滞在有丝分裂期。经盘尼西龙处理的乳腺癌细胞表现出微管细胞骨架的显著重排，包括广泛的微管束形成。10 nM盘尼西龙诱导的微管重排所需的紫杉醇浓度为1 microM。盘尼西龙在体外对微管蛋白组装也有同样显著的影响。在相同浓度的紫杉醇无活性的条件下，在0℃时，微管蛋白与微管相关蛋白（MAPs）一起几乎完全聚合。在每种检测的反应条件下，没有MAPs和/或没有GTP时，盘尼西龙诱导的微管蛋白组装也比紫杉醇更活跃。盘尼西龙诱导的聚合物与紫杉醇诱导的聚合物不同，因为在高浓度Ca2+存在下，它在0℃时完全稳定。在一项旨在筛选比紫杉醇更有效地诱导组装的药物的定量试验中，盘尼西龙的EC50值为3.2 microM，而紫杉醇为23 microM。
