【作者】 李娜； 王莹； 王占忠；

【Author】 Li Na;Wang Ying;Wang Zhanzhong;School of Chemical Engineering and Technology,Tianjin University;

【机构】 天津大学化工学院；

【摘要】 利用圆二色谱定性探测了室温条件下浓度为1%和5%的四种离子液体（1-丁基-3-甲基咪唑四氟硼酸盐（[C₄min] BF₄）、氯化1-丁基-3-甲基咪唑（[C₄min] Cl）、溴化1-丁基-3-甲基咪唑（[C₄min] Br）、碘化1,3-二甲基咪唑（[dmin]I））对pH=5.01的磷酸盐缓冲液中溶菌酶二级结构的影响。研究结果表明:不同离子液体对溶菌酶二级结构的影响不同。添加1%[C₄min] BF₄后,溶菌酶α-螺旋的含量减少,β-折叠的含量增多;添加5%[C₄min] BF₄后,与添加1%[C₄min] BF₄相比,二级结构中β-折叠的含量继续增多。添加1%C₄min] Cl后,β-折叠和无规则卷曲的含量增多;添加5%[C₄min] Cl后,与添加1%[C₄min] Cl相比,β-折叠的含量继续增多。添加1%[C₄min] Br后,β-折叠和无规则卷曲的含量增多;添加5%[C₄min] Br后,与添加1%[C₄min] Br相比,无规则卷曲的含量反而减少。添加1%[dmin] I后,β-折叠和β-转角的含量增多,α-螺旋的含量大幅减少;添加5%[dmin] I后,与添加1%[dmin]I相比,α-螺旋的含量继续减少,而β-折叠的含量也有所减少。溶液中离子液体与溶菌酶之间的相互作用存在复杂性,该研究为生物大分子组装前驱体研究提供重要信息。更多还原

【Abstract】 The effects of four ionic liquids（ILs）（1-butyl-3-methylimidazolium tetrafluoroborate（[C₄ min] BF₄）,1-butyl-3-methylimidazolium chloride（[C₄ min] Cl）,1-butyl-3-methylimidazolium bromide（[C₄ min] Br）,1,3-dimethylimidazolium iodine（[dmin] I）） with concentration of 1 % and 5% at room temperature on the secondary structure of lysozyme in phosphate buffer at pH 5.01 were investigated qualitatively by Circular Dichroism spectroscopy.The results showed that different ILs had different effects on the secondary structure of lysozyme.After adding 1 % [C₄ min] BF₄,the content of α-helix of lysozyme decreased and the content of β-sheet increased;and after adding 5% [C₄ min] BF₄,the content of β-sheet in the secondary structure continued to increase compared with that of adding 1% [C₄ min] BF₄.After adding 1% [C₄ min] Cl,the content of β-sheet and Random coil increased;and after adding 5% [C₄ min] Cl,the content of β-sheet continued to increase compared with that of adding 1% [C₄ min] Cl.After adding 1% [C₄ min] Br,the content of β-sheet and Random coil increased;but after adding 5% [C₄ min] Br,the content of Random coil decreased compared with that of adding1 % [C₄ min] Br.After adding 1% [dmin] I,the content of β-sheet and β-turn increased and the content of α-helix decreased greatly;and after adding 5% [dmin] I,the content of α-helix continued to decrease,while the content of β-sheet decreased compared with that of adding 1 % [dmin] I.From the results,it can be seen that the interaction between ionic liquid and lysozyme in the solution was complicated,and this work provided important information for the study of the precursors of the assembly of biological macromolecules.更多还原