• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemistry: A European journal >Striking improvement in peroxidase activity of cytochrome c by modulating hydrophobicity of surface-functionalized gold nanoparticles within cationic reverse micelles
【24h】

Striking improvement in peroxidase activity of cytochrome c by modulating hydrophobicity of surface-functionalized gold nanoparticles within cationic reverse micelles

机译：通过调节阳离子反胶束内表面官能化金纳米颗粒的疏水性，显着改善细胞色素c的过氧化物酶活性

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

This work demonstrates a remarkable enhancement in the peroxidase activity of mitochondrial membrane protein cytochrome c (cyt c) by perturbing its tertiary structure in the presence of surface-functionalised gold nanoparticles (GNPs) within cetyltrimethylammonium bromide (CTAB) reverse micelles. The loss in the tertiary structure of cyt c exposes its heme moiety (which is buried inside in the native globular form), which provides greater substrate (pyrogallol and H_2O_2) accessibility to the reactive heme residue. The surfactant shell of the CTAB reverse micelle in the presence of co-surfactant (n-hexanol) exerted higher crowding effects on the interfacially bound cyt c than similar anionic systems. The congested interface led to protein unfolding, which resulted in a 56-fold higher peroxidase activity of cyt c than that in water. Further perturbation in the protein's structure was achieved by doping amphiphile-capped GNPs with varying hydrophobicities in the water pool of the reverse micelles. The hydrophobic moiety on the surface of the GNPs was directed towards the interfacial region, which induced major steric strain at the interface. Consequently, interaction of the protein with the hydrophobic domain of the amphiphile further disrupted its tertiary structure, which led to better opening up of the heme residue and, thereby, superior activity of the cyt c. The cyt c activity in the reverse micelles proportionately enhanced with an increase in the hydrophobicity of the GNP-capping amphiphiles. A rigid cholesterol moiety as the hydrophobic end group of the GNP strikingly improved the cyt c activity by up to 200-fold relative to that found in aqueous buffer. Fluorescence studies with both a tryptophan residue (Trp59) of the native protein and the sodium salt of fluorescein delineated the crucial role of the hydrophobicity of the GNP-capping amphiphiles in improving the peroxidase activity of cyt c by unfolding its tertiary structure within the reverse micelles.
机译：这项工作证明了在十六烷基三甲基溴化铵（CTAB）反胶束中存在表面官能化金纳米颗粒（GNP）的情况下，通过扰动其三级结构，可以显着增强线粒体膜蛋白细胞色素c（cyt c）的过氧化物酶活性。 cyt c的三级结构损失暴露了其血红素部分（以天然球状形式埋在内部），从而为反应性血红素残基提供了更大的底物（邻苯三酚和H_2O_2）。在存在辅助表面活性剂（正己醇）的情况下，CTAB反胶束的表面活性剂壳对界面结合的cyt c的拥挤效应高于类似的阴离子体系。界面堵塞导致蛋白质解折叠，导致cyt c的过氧化物酶活性比水中的高56倍。通过在反胶束的水池中掺入具有不同疏水性的两亲封端的GNP，可以实现蛋白质结构的进一步扰动。 GNP表面上的疏水部分被引导到界面区域，这在界面处引起了主要的空间应变。因此，蛋白质与两亲物的疏水结构域的相互作用进一步破坏了其三级结构，这导致血红素残基更好的开放，并因此导致了cyt c的优异活性。反向胶束中的cyt c活性随着加盖GNP的两亲物的疏水性的增加而成比例地增加。刚性胆固醇部分作为GNP的疏水端基，与含水缓冲液相比，可显着提高cyt c活性200倍。用天然蛋白的色氨酸残基（Trp59）和荧光素的钠盐进行的荧光研究描述了GNP封端的两亲物的疏水性通过在反胶束中展开其三级结构来改善cyt c的过氧化物酶活性的关键作用。 。

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