Low Temperature Induced Conformation Changes of Aminoacylase  

作　　者：谢强 孟凡国 周海梦 

机构地区：[1]Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 [2]Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China [3]Protein Science Laboratory of the Ministry of Education, School of Life Science and Engineering, Tsinghua University, Beijing 100084, China

出　　处：《Tsinghua Science and Technology》2004年第1期76-80,共5页清华大学学报（自然科学版（英文版）

基　　金：the National Key Basic Research and Development (973) Program of China (No. G1999075607)

摘　　要：Control of aggregation, by lowering temperature and protein concentrations, can enhance the extent of successful refolding. The low temperature has been used in protein folding studies, as undesired aggregations often occur at higher temperatures. Therefore, it is very important to study the effects of low temperature on the native enzyme to help understand the factors that affect the structure of the proteins. In this paper, aminoacylase was studied at different temperatures by measuring enzyme activity, fluorescence emission spectra, and ultraviolet difference spectra. The results show that aminoacylase conformation changes as the temperature changes, becoming more compact at low temperatures, and having more secondary structural content. However, the activity is very low at low temperature, and totally diminishes at 4℃. Aminoacylase tends therefore to be more condense, with less residues exposed and low enzyme activities at low temperature. This observation might explain the self-protection of organisms under conditions of extreme temperature.Control of aggregation, by lowering temperature and protein concentrations, can enhance the extent of successful refolding. The low temperature has been used in protein folding studies, as undesired aggregations often occur at higher temperatures. Therefore, it is very important to study the effects of low temperature on the native enzyme to help understand the factors that affect the structure of the proteins. In this paper, aminoacylase was studied at different temperatures by measuring enzyme activity, fluorescence emission spectra, and ultraviolet difference spectra. The results show that aminoacylase conformation changes as the temperature changes, becoming more compact at low temperatures, and having more secondary structural content. However, the activity is very low at low temperature, and totally diminishes at 4℃. Aminoacylase tends therefore to be more condense, with less residues exposed and low enzyme activities at low temperature. This observation might explain the self-protection of organisms under conditions of extreme temperature.

关 键 词：low temperature AMINOACYLASE secondary structure 

分 类 号：Q51[生物学—生物化学] Q55