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亚临界/超临界CO2处理对Pseudomonas cepacia脂肪酶活力和结构的影响

发表时间:2012-09-15  浏览量:895  下载量:225
全部作者: 陈大伟,刘云
作者单位: 华中科技大学生命科学与技术学院
摘 要: 主要研究亚临界/超临界CO2介质中不同处理压力、温度和时间对Pseudomonas cepacia脂肪酶(Pseudomonas cepacia lipase, PCL)活力和结构的影响,以阐述PCL在高压条件下的构效关系。首先将PCL置于不同的亚临界/超临界CO2中处理一段时间,然后测定其活力和结构的变化。结果表明:在一定压力和温度范围内,PCL活力随压力和温度的升高而增加,但是处理时间对酶活力的影响较小。SDS-PAGE分析显示:高压处理不改变PCL的一级结构;圆二色和荧光图谱分析却表明:高压对PCL二级和三级结构影响较大。亚临界(6 MPa/35℃)处理对PCL活力的影响,主要是高压导致蛋白质二级结构α-螺旋和β-折叠含量的变化;而超临界(10 MPa/40℃)处理对PCL活力的影响,则是由蛋白质三级结构的变化所致,从而阐明亚临界/超临界处理对PCL酶活影响的机理。
关 键 词: 生物工程;酶活力;蛋白构象;亚临界/超临界CO2;Pseudomonas cepacia脂肪酶
Title: Effect of sub-and super-critical CO2 pretreatment on activity and structure of Pseudomonas cepacia lipase
Author: CHEN Dawei, LIU Yun
Organization: College of Life Science and Technology, Huazhong University of Science and Technology
Abstract: The effect of sub-and super-critical CO2 pretreatment on activity and structure of Pseudomonas cepacia lipase (PCL) was studied to explore the relationship between activity and conformation, including pressure, temperature and exposure time. The PCL was exposed in sub-/super-critical CO2 for a while, and the changes of its activity and conformation were measured. Results showed that the PCL activity increased with the rising of pressure and temperature, but exposure time showed little effect. SDS-PAGE analysis showed that high pressure had no effect on the primary structure of PCL. However, CD and fluorescence analysis showed that high pressure had obvious effect on its secondary structure and tertiary structure. The activity variance of PCL treated in subcritical CO2 (6 MPa/35℃) pretreatment was mainly related to the secondary structure changes in alpha helix and beta folding content, while the activity variance of PCL treated in supercritical CO2 (10 MPa/40℃) pretreatment depended on its tertiary structure changes. The results in this work are helpful to illustrate the mechanism of PCL activity variance in sub-and super-critical CO2.
Key words: bioengineering; enzyme activity; protein conformation; sub-/super-critical CO2; Pseudomonas cepacia lipase
发表期数: 2012年9月第17期
引用格式: 陈大伟,刘云. 亚临界/超临界CO2处理对Pseudomonas cepacia脂肪酶活力和结构的影响[J]. 中国科技论文在线精品论文,2012,5(17):1649-1654.
 
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