检索结果-南通市图书馆

Effect of urea on Activity and Conformation of a Glycoprotein

Tsinghua Science and Technology 2006年第4期11卷 400-407页

作者：魏香王晓云周波周海梦 Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China College of Life Science Shandong Agricultural University Taian 271018 China

The changes of the activity and conformation of Aspergillus niger phytase in urea were detected by farultraviolet circular dichroism （CD） spectra, fluorescence spectra, and enzyme activity assays. The results show that no enzyme activity can be detected after phytase is incubated for 10 h in 3.0 mol/L urea, even though at this urea concentration, less than 20% of the tertiary and secondary structures in the native enzyme changed. The inactivation reaction kinetics is found to be a monophasic first-order reaction, but the unfolding is a biphasic process consisting of two first-order reactions. The inactivation rates of the free enzyme and the substrate-enzyme complex are much faster than the conformational changes during urea denaturation. All of the results indicate that, as a glycoprotein, phytase＇s actiVity is strongly dependent on its conformational integrity. The phytase active sites seem to be located in a limited region in the molecule and display more conformational fragility and flexibility to denaturants than enzyme molecular structure as a whole.

关键词： phytase urea denaturation inactivation unfolding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dispersed OmpT may be partially folded

Dispersed OmpT may be partially folded

引用

中国化学会-生物物理化学专业委员会第四届全国生物物理化...

作者：卜佩璇赵新生 College of Chemistry and Molecular Engineering and Biodynamic Optical Imaging Center（BIOPIC） Peking University

It is believed that outer membrane proteins in Gram-negative bacteria are protected by chaporones during their translocation through the periplasm because they are structureless and prone to aggregation. The previous work on OmpC supported such an opinion. However, recently we found that OmpT has less tendency to aggregate and may be partially folded in its dispersed form. By using single molecule fluorescence resonance energy transfer（smFRET）, the equilibrium denaturation of OmpT induced by urea has been investigated. Double-cysteine mutant（S1C/F297C） of OmpT is engineered and labeled with FRET dyes. We observed subpopulations of denatured and partially folded form of OmpT and the two subpopulations show two-state transition as urea concentration changes. These resluts may help better understanding of outer membrane protein folding.

关键词： OmpT smFRET urea denaturation partial folding

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

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：