...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Conformational flexibility of domain III of annexin V at membrane/water interfaces.
【24h】

Conformational flexibility of domain III of annexin V at membrane/water interfaces.

机译：膜/水界面处膜联蛋白V域III的构象柔性。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The conformational dynamics of domain III in annexin V bound to negatively charged phospholipid vesicles of 1-palmitoyl-2-oleoyl-sn-glycerophosphocholine and 1-palmitoyl-2-oleoyl-sn-glycerophosphoserine or incorporated into reverse micelles of water/sodium bis(2-ethylhexyl) sulfosuccinate in isooctane, used to mimic the phospholipid/water interface, was studied by steady-state and time-resolved fluorescence of its single tryptophan residue (W187). Upon interaction with sonicated phospholipid vesicles in the presence of calcium, or upon incorporation into reverse micelles without calcium, a progressive 12-14 nm red shift of the fluorescence emission spectrum of W187 is observed. The indole environment becomes therefore more polar than in the unbound protein. Three major lifetime populations describe the fluorescence intensity decays of W187 in both systems. A long-lived excited-state population characterizes the membrane-bound state of the protein. The existence of local conformers with different subnanosecond mobility is suggested by specific association between lifetimes and correlation times both for the protein in buffer and in interaction with the membrane surface. The interaction of the protein with the membrane surface preserves the existence of a rapid unhindered rotational motion, which is coupled with all three lifetimes. The longest lifetime is coupled to restricted motions in subnanosecond and nanosecond time scales. The overall amplitude of rotation of the indole ring is increased in the membrane-bound conformation of the protein. In reverse micelles, the local dynamics reported by W187 is also considerably increased whereas the overall folding of the protein remains unaffected. The same conformational change of domain III can therefore be provoked by different conditions: calcium binding at high concentration, mild acidic pH [Sopkova, J., Vincent, M., Takahashi, M., Lewit-Bentley, A. , and Gallay, J. (1998) Biochemistry 37, 11962-11970] and the interaction of the protein with the membrane surface. The high flexibility of domain III in the membrane-bound protein suggests that this domain may not be crucial for the interaction of the protein with the membrane, in contrast with previous models. Our data are compatible with atomic force microscopy results which suggest that domain III of annexin V does not interact strongly with the membrane surface [Reviakine, I., Bergma-Schutter, W., and Brisson, A. (1998) J. Struct. Biol. 121, 356-361].
机译：膜联蛋白V中结构域III的构象动力学与1-棕榈酰基-2-油酰基-sn-甘油磷酸胆碱和1-棕榈酰基-2-油酰基-sn-甘油磷酸丝氨酸的带负电荷的磷脂囊泡结合或掺入水/双（钠）反胶束中通过模拟其单个色氨酸残基的稳态和时间分辨荧光（W187），研究了异辛烷中的2-乙基己基磺基琥珀酸酯（用于模拟磷脂/水界面）。在钙的存在下与超声处理的磷脂囊泡相互作用时，或者在掺入不含钙的反胶束中时，观察到W187的荧光发射光谱逐渐发生12-14 nm红移。因此，吲哚环境比未结合的蛋白质更具极性。三个主要寿命种群描述了两个系统中W187的荧光强度衰减。寿命长的激发态种群表征了蛋白质的膜结合态。通过蛋白质在缓冲液中以及与膜表面相互作用的寿命和相关时间之间的特定关联，表明存在具有不同的亚纳秒迁移率的局部构象异构体。蛋白质与膜表面的相互作用保留了快速无阻碍的旋转运动的存在，并伴随着这三个寿命。最长的寿命与纳秒级和纳秒级的运动受限有关。吲哚环的总旋转幅度在蛋白质的膜结合构象中增加。在反胶束中，W187报告的局部动力学也大大增加，而蛋白质的整体折叠仍然不受影响。因此，域III的构象变化可以通过不同条件引起：高浓度钙结合，弱酸性pH [Sopkova，J.，Vincent，M.，Takahashi，M.，Lewit-Bentley，A.和Gallay， J.（1998）Biochemistry 37，11962-11970]和蛋白质与膜表面的相互作用。与以前的模型相比，结构域III在膜结合蛋白中的高柔韧性表明该结构域对于蛋白与膜的相互作用可能不是至关重要的。我们的数据与原子力显微镜结果是相容的，该结果表明膜联蛋白V的结构域III与膜表面没有强烈的相互作用[Reviakine，I.，Bergma-Schutter，W。，和Brisson，A。（1998）J.Struct。生物学121，356-361]。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号