Anti-microtubule activity of tubeimoside I and its colchicines binding site of tubulin
Tubeimoside I(TBMS1)was isolated fromthe tubers of Bolbostemma panieulatum(Maxim.)Franquet.TBMS1shows potent antitumor activity.The present studywas conducted to investigate the antimicrotubule roleof TBMS1 and its binding site oftubulin.Methods：Cell growth inhibition Was measuredby MTT after treatment with TBMS1.Uptake kinetics ofTBMS1 bv humannasopharyngeal carcinoma CNE-2Z cell line(CNE-2Z)Wasassayed by HPLC.Microtubule protein(MTP)Was preparedfrom porcinebrain through two cycles of polymerization-depolymerization in a high molaritybuffer.Inhibition of MTP polymerization induced byTBMS1 Was determined by a turbidity measurement and asedimentation assay；the interactions of TBMS1 withtubulin within CNE-2Zcells were investigated by immunofluoresceneemicroscopy and immunoblotting.TBMS1 Was tested forits ability to inhibit binding ofknown tubulin ligands through competitive bindingassay.Results：TBMS1 displayed growth inhibitoryactivity against CNE-2Z cellswith IC50 value of 16.7 μM for 72 h.HPLC analysis ofTBMS1 uptake by CNE-2Z eeHs displayed the initialslow TBMS1 uptake andthen gradually reaching an maximum uptake neax 18h.CNE-2Z cells treated with TBMS1(25μM，3 h)weresufficient to cause themicrotubular network disruption.Immunoblot analysisshowed that the proportion of cytosolic tubulin ofceils treated with TBMS1increased in a time-and concentration-dependentmanner.TBMS1 did not inhibit the binding ofvinblastine tO tubtdin.Colchicinebinding to tubulin was inhibited in the presence ofTBMS1.Conclusions：TBMS1 is an anti-mierotubuleagent，and its binding site oftubulin is the colchicine binding site of tubulin.
土贝母苷甲 微管蛋白 秋水仙碱
Rundi Ma Tingxi Yu Gang Song Wenbing You Lijian Yu Weiming Su Mingneng Liao Yongping Zhang Laizhen Huang Xiaoyu Zhang
Key Laboratory of Marine Materia Medica,Guangdong Ocean University,Jiefang East Avenue 40,Xiashan,Zh Key Laboratory of Marine Materia Medica,Guangdong Ocean University,Jiefang East Avenue 40,Xiashan,Zh Key Laboratory of Marine Materia Medica,Guangdong Ocean University,Jiefang East Avenue 40,Xiashan,Zh
国内会议
南昌
英文
188-197
2007-12-01（万方平台首次上网日期，不代表论文的发表时间）