检索结果-内蒙古大学图书馆

Kinesins and microtubules: their structures and motor mechanisms

CURRENT OPINION IN CELL BIOLOGY 2000年第1期12卷 35-41页

作者： Sablin, EP Univ Calif San Francisco Dept Biochem & Biophys San Francisco CA 94143 USA

Atomic resolution three-dimensional structures of two oppositely directed kinesin motors - conventional kinesin and non-claret disjunctional (ncd) protein - are now available in their functional dimeric form. A detailed model of the microtubule has also been recently obtained by docking the 3.7 Angstrom structure of tubulin into a 20 Angstrom map of the microtubule. Recent structural studies of kinesin motors and their microtubule tracks are contributing to our current understanding of kinesin motor mechanisms.

关键词：氨基酸序列二聚作用果蝇蛋白质类驱动蛋白/化学驱动蛋白/代谢微管/化学微管/代谢分子马达蛋白质类/化学分子马达蛋白质类/代谢分子序列数据蛋白质构象动物

来源：评论

学校读者我要写书评

暂无评论

Tubulin binding sites on γ-tubulin:: Identification and molecular characterization

引用

BIOCHEMISTRY 1999年第48期38卷 15712-15720页

作者： Llanos, R Chevrier, V Ronjat, M Meurer-Grob, P Martinez, P Frank, R Bornens, M Wade, RH Wehland, J Job, D CEA Grenoble Dept Biol Mol & Struct CS INSERMU366 F-38054 Grenoble 9 France IBS LMES F-38027 Grenoble France AG Mol Recognit D-38124 Braunschweig Germany Gesell Biotechnol Forsch GmbH Div Cell Biol & Immunol D-38124 Braunschweig Germany Inst Curie CNRS UMR 144 Sect Rech F-75231 Paris 05 France

gamma-Tubulin is essential to microtubule organization in eukaryotic cells. It is believed that gamma-tubulin interacts with tubulin to accomplish its cellular functions. However, such an interaction has been difficult to demonstrate and to characterize at the molecular level. gamma-Tubulin is a poorly soluble protein, not amenable to biochemical studies in a purified form as yet. Therefore basic questions concerning the existence and properties of tubulin binding sites on gamma-tubulin have been difficult to address. Here we have performed a systematic search for tubulin binding sites on gamma-tubulin using the SPOT peptide technique. We find a specific interaction of tubulin with six distinct domains on gamma-tubulin. These domains are clustered in the central part of the gamma-tubulin primary amino acid sequence. Synthetic peptides corresponding to the tubulin binding domains of gamma-tubulin bind with nanomolar K(d)s to tubulin dimers. These peptides do not interfere measurably with microtubule assembly in vitro and associate with microtubule along the polymer length. On the tertiary structure, the gamma-tubulin peptides cluster to surface regions on both sides of the molecule. Using SPOT analysis, we also find peptides interacting with gamma-tubulin in both the alpha- and beta-tubulin subunits. The tubulin peptides cluster to surface regions on both sides of the alpha- and beta- subunits. These data establish gamma-tubulin as a tubulin ligand with unique tubulin-binding properties and suggests that gamma-tubulin and tubulin dimers associate through lateral interactions.

关键词：氨基酸序列结合部位二聚作用微管/化学微管/超微结构模型分子分子序列数据肽碎片/化学肽谱蛋白质亚型/化学蛋白质结构三级表面等离激元微管蛋白/分析微管蛋白/化学人类

来源：评论

学校读者我要写书评

暂无评论

Accessory protein regulation of microtubule dynamics throughout the cell cycle

引用

CURRENT OPINION IN CELL BIOLOGY 1999年第1期11卷 134-141页

作者： Cassimeris, L Lehigh Univ Dept Sci Biol Bethlehem PA 18015 USA

A number of accessory proteins capable of stabilizing or destabilizing microtubule polymers in dividing cells have been identified recently. Many of these accessory proteins are modified and regulated by cell-cycle-dependent phosphorylation. Through this regulation, microtubule dynamics are modified to generate rapid microtubule turnover during mitosis. In general, although some microtubule-stabilizing proteins are inactivated at entry into mitosis, a critical balance between microtubule stabilizers and destabilizers is necessary for assembly of the mitotic spindle.

关键词：新小杆线虫漂亮细胞周期/生理学微管相关蛋白质类/生理学微管/化学微管/生理学有丝分裂/生理学磷酰化时间因素爪蟾属动物

来源：评论

学校读者我要写书评

暂无评论

Synthesis of B-ring homologated estradiol analogues that modulate tubulin polymerization and microtubule stability

引用

JOURNAL OF MEDICINAL CHEMISTRY 2000年第12期43卷 2419-2429页

作者： Wang, ZQ Yang, DL Mohanakrishnan, AK Fanwick, PE Nampoothiri, P Hamel, E Cushman, M Purdue Univ Sch Pharm & Pharmacal Sci Dept Med Chem & Mol Pharmacol W Lafayette IN 47907 USA Purdue Univ Dept Chem W Lafayette IN 47907 USA NCI Screening Technol Branch Dev Therapeut Program Div Canc Treatment & DiagFrederick Canc Res & De Frederick MD 21702 USA

2-Methoxyestradiol is a cytotoxic human metabolite of estradiol with the ability to bind to the colchicine site of tubulin and inhibit its polymerization, and its 2-ethoxy analogue is even more potent. On the basis of a hypothetical relationship between the structures of colchicine and 2-methoxyestradiol, a B-ring-expanded 2-ethoxyestradiol analogue was synthesized in which the B-ring of the steroid is replaced by the B-ring of colchicine. The synthesis relied on the B-ring expansion of available B-keto estradiol derivatives as opposed to a total synthesis of the homologated steroid framework. The relative configurations of the acetamido substituents in both epimers of the final product were determined by NQESY NMR and confirmed by X-ray crystallography. The epimer having the 6 alpha-acetamido substituent was more active as an inhibitor of tubulin polymerization, and it was also more cytotoxic than the 6 beta-epimer. These results are consistent with the proposed structural resemblance of 2-methoxyestradiol and colchicine. Several of the synthetic intermediates proved to be potent inhibitors of tubulin polymerization. On the other hand, a 3,17 beta-diacetylated, B-ring-expanded analogue of 2-ethoxyestradiol having a ketone at C-6 resembled paclitaxel (Taxol) in its ability to enhance tubulin polymerization and stabilize microtubules. The corresponding 3-acetate and the 17 beta-acetate were both synthesized, and it was determined that the 17 beta-acetate, but not the 3-acetate, conferred on the steroid derivative its paclitaxel-like activity.

关键词：抗肿瘤药/化学合成抗肿瘤药/化学抗肿瘤药/药理学药物筛选试验抗肿瘤雌二醇/类似物和衍生物雌二醇/化学合成雌二醇/化学雌二醇/药理学微管/化学紫杉酚/化学构效关系微管蛋白/化学肿瘤细胞培养的动物牛人类

来源：评论

学校读者我要写书评

暂无评论

Viscoelastic properties of f-actin, microtubules, f-actin/α-actinin, and f-actin/hexokinase determined in microliter volumes with a novel nondestructive method

引用

BIOPHYSICAL JOURNAL 1999年第5期76卷 2784-2796页

作者： Wagner, O Zinke, J Dancker, P Grill, W Bereiter-Hahn, J Univ Frankfurt Inst Zool D-6000 Frankfurt Germany Univ Frankfurt Inst Phys D-6000 Frankfurt Germany Univ Leipzig Fak Phys & Geowissensch Inst Expt Phys 2 D-7010 Leipzig Germany Tech Univ Darmstadt Inst Zool D-64287 Darmstadt Germany

A nondestructive method to determine viscoelastic properties of gels and fluids involves an oscillating glass fiber serving as a sensor for the viscosity of the surrounding fluid. Extremely small displacements (typically 1-100 nm) are caused by the glass rod oscillating at its resonance frequency. These displacements are analyzed using a phase-sensitive acoustic microscope. Alterations of the elastic modulus of a fluid or gel change the propagation speed of a longitudinal acoustic wave. The system allows to study quantities as small as 10 mu l with temporal resolution >1 Hz. For 2-100 mu M f-actin gels a final viscosity of 1.3-9.4 mPa s and a final elastic modulus of 2.229-2.254 GPa (corresponding to 1493-1501 m/s sound velocity) have been determined. For 10- to 100-mu M microtubule gels (native, without stabilization by taxol), a final viscosity of 1.5-124 mPa s and a final elastic modulus of 2.288-2.547 GPa (congruent to 1513-1596 m/s) have been determined. During polymerization the sound velocity in low-concentration actin solutions increased up to +1.3 m/s (congruent to 1.69 kPa) and decreased up to -7 m/s (congruent to 49 kPa) at high actin concentrations. On polymerization of tubulin a concentration-dependent decrease of sound velocity was observed, too (+48 to -12 m/s congruent to 2.3-0.1 MPa, for 10- to 100-mu M tubulin). This decrease was interpreted by a nematic phase transition of the actin filaments and microtubules with increasing concentration. 2 mM ATP (when compared to 0.2 mM ATP) increased polymerization rate, final viscosity and elastic modulus of f-actin (17 mu M). The actin-binding glycolytic enzyme hexokinase also accelerated the polymerization rate and final viscosity but elastic modulus (2.26 GPa) was less than for f-actin polymerized in presence of 0.2 mM ATP (2.28 GPa).

关键词：声学辅肌动蛋白/化学肌动蛋白类/化学肌动蛋白类/超微结构生物物理学弹性凝胶类己糖激酶/化学显微镜检查电子微管/化学示波测量法/仪器和设备鬼笔环肽/化学流变学/仪器和设备微管蛋白/化学黏度动物兔

来源：评论

学校读者我要写书评

暂无评论

A unified and quantitative receptor model for the microtubule binding of paclitaxel and epothilone

引用

ORGANIC LETTERS 1999年第1期1卷 43-46页

作者： Wang, MM Xia, XY Kim, Y Hwang, D Jansen, JM Botta, M Liotta, DC Snyder, JP Emory Univ Dept Chem Atlanta GA 30322 USA Chiron Corp Emeryville CA 94608 USA Univ Siena Dip Farmaco Chim Tecnol I-53100 Siena Italy

Paclitaxel and epothilone represent the two major classes of antimicrotubule agents that promote tubulin polymerization and, presumably, mitotic arrest during cell division. A common minireceptor binding site model at beta-tubulin has been constructed for these structurally divergent compounds. Utilizing 20 amino acids identified in photoaffinity labeling experiments, the 3-D model correlates measured and predicted K-i's with r = 0.99 and rms(Delta G(calc) - Delta G(exp)) = 0.2 kcal/mol, In addition, the model predicts the affinity of compounds not used in the training set and explains much of the SAR for the paclitaxel and epothilone families.

关键词：抗肿瘤药/化学抗肿瘤药/代谢埃博霉素类环氧化合物/化学环氧化合物/代谢磁共振波谱学微管/化学微管/代谢模型分子蒙特卡罗法紫杉酚/化学紫杉酚/代谢蛋白质结合受体药物/化学受体药物/代谢构效关系噻唑类/化学噻唑类/代谢微管蛋白/化学微管蛋白/代谢

来源：评论

学校读者我要写书评

暂无评论

Antimitotic diterpenes from Erythropodium caribaeorum test pharmacophore models for microtubule stabilization

引用

ORGANIC LETTERS 2000年第3期2卷 257-260页

作者： Cinel, B Roberge, M Behrisch, H van Ofwegen, LP Castro, CB Andersen, RJ Univ British Columbia Dept Chem EOS Vancouver BC V6T 1Z1 Canada Univ British Columbia Dept Radiol EOS Vancouver BC V6T 1Z1 Canada Univ British Columbia Dept Biochem & Mol Biol Vancouver BC V6T 1Z3 Canada Natl Museum Nat Hist Leiden Netherlands Museu Nacl Rio De Janeiro Brazil

[GRAPHICS] Six new antimitotic diterpenes, 2-7, have been isolated from the Caribbean octocoral Erythropodium caribaeorum, Structural variations encountered in this group of natural products test recently proposed pha... 详细信息

关键词：生物碱类/化学生物碱类/分离和提纯生物碱类/药理学抗肿瘤药/化学抗肿瘤药/分离和提纯细胞周期/药物作用细胞死亡/药物作用腔肠动物门/化学二萜类/化学二萜类/分离和提纯二萜类/药理学半数抑制浓度微管/化学模型分子构效关系动物

来源：评论

学校读者我要写书评

暂无评论

Disulfide-cross-linked Tau and MAP2 homodimers readily promote microtubule assembly

引用

Molecular Cell Biology Research Communications 1999年第1期2卷 71-76页

作者： Di Noto, Luca DeTure, Michael A. Purich, Daniel L. Dept. of Biochem. and Molec. Biology Univ. of Florida College of Medicine Health Science Center Gainesville FL 32610-0245 United States

The neuronal proteins Tau and MAP2 use homologous C-terminal MT-binding regions (MTBRs) to interact with microtubules, F-actin, and intermediate filaments. Although Tau-MTBR is the principal component of pronase-treated Alzheimer paired helical filaments, both Tau and MAP2 form filaments in vitro from disulfide-linked homodimers. That the critical thiol lies within a domain needed for MT binding raised the question: Does disulfide formation block Tau-Tau or MAP2-MAP2 dimer binding to microtubules, thereby acting to divert dimers toward filament formation? We now report that cross-linked Tau and MAP2 homodimers readily promote tubulin polymerization and that monomer and dimer affinity for MTs is surprisingly similar. Therefore, disulfide cross-bridging into homodimers is unlikely to be a drive force for filament formation in Alzheimer's disease. © 1999 Academic Press.

关键词：氨基酸序列色谱法高压液相二聚作用二硫化物类/化学电泳聚丙烯酰氨凝胶显微镜检查电子微管相关蛋白质类/化学微管/化学微管/超微结构分子序列数据微管蛋白/化学微管蛋白/超微结构 tau蛋白质类/化学人类

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：