Thermodynamics and Extra-thermodynamics of Bacillus subtilis α-Amylase in Some Chromatographic Systems

The thermodynamics and extra-thermodynamics of Bacillus subtilis a-amylase in five kinds of chromatographic systems were studied by determining their adsorption equilibrium constant KsL,enthalpy change,entropy change,free energy change and compensation temperature under different temperature areas.The results showed that on anRP.C18 reversed-phase medium,a Zn-chelated Sepharose fast-flow affinity medium and a WCX-l cation-exchange medium,their In KsL separately linearly changed with the reciprocal of absolute temperatures under two different temperature ranges of 13-30 and 30-50℃:and on PEG-400 and modified PEG-400 hydrophobic media,their ln KsL separately linearly decreased with the reciprocal of absolute temperatures under the temperature areas of 13-40 and 13-30℃.while when the temperatures were separately over 40 and 30℃,they violently decreased with the reciprocal of absolute temperatures.Through studying the relations among the enthalpy change,entropy change.free energy change and the conformational change of a-amylase under the different temperature areas,it was found that on the RP-C18 reversed-phase medium and Zn-chelated Sepharose fast-flow affinity medium under the temperature range of 30-50℃and on the WCX-l cation-exchange medium under the temperature range of 13-30℃.their adsorption procedures were driven by both the enthalpy change and the entropy change;while on the Zn-chelated Sepharose fast-flow affinity medium under the temperature range of 13-30℃.on the WCX-1cation.exchange medium under the temperature range of 30-50℃and on the PEG-400 and modified PEG-400 hydrophobic media under the temperature range of 13-65℃.their adsorption procedures were driven only by the entropy change.Finally, by comparing the compensation temperatures of a-amylase in these chromatographic sys-terns each other,it Was further found that their enthalpy changes could be compensated only with their entropy changes rising from their conformational change.

作 者： BIAN,Liujiao WANG,Xiaohua YANG,Xiaoyan LIU,Li CHEN,Chao   作者單位： BIAN,Liujiao,YANG,Xiaoyan,LIU,Li,CHEN,Chao(National Engineering Research Centerfor Miniaturized Detection System,College of Life Science,Northwest University,Xi'an.Shaanxi 710069,China)

WANG,Xiaohua(The Clinic of the Fourth Military Medical University of PLA.Xi'an,Shaanxi 710032,China) 

刊 名： 中國化學（英文版）  SCI 英文刊名： CHINESE JOURNAL OF CHEMISTRY  年，卷(期)： 2009 27(3)  分類號： O6  關鍵詞： Bacillus subtilis &-amylase   thermodynamics   extra-thermodynamics   liquid chromatography