CIESC Journal ›› 2021, Vol. 72 ›› Issue (9): 4854-4860.DOI: 10.11949/0438-1157.20210214

• Biochemical engineering and technology • Previous Articles     Next Articles

Study on the effect of 1-octyl-3-methylimidazole bromide aggregation state on protein crystallization

Xiaoxi YU1(),Zhenzhen YAN1,Qihui JIANG2,Xia WU1,Yuxiao ZHANG1,Xiaojuan WANG1,Fang HUANG1,3   

  1. 1.College of Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong, China
    2.Downhole Operation Research Department, CNPC Engineering Technology R&D Company Limited, Beijing 102206, China
    3.State Key Laboratory for Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580, Shandong, China
  • Received:2021-02-04 Revised:2021-05-07 Online:2021-09-05 Published:2021-09-05
  • Contact: Xiaoxi YU

溴化1-辛基-3-甲基咪唑聚集状态对蛋白质结晶的影响研究

于筱溪1(),闫真真1,蒋其辉2,吴霞1,张余晓1,王晓娟1,黄方1,3   

  1. 1.中国石油大学(华东)化学工程学院,山东 青岛 266580
    2.中国石油集团工程技术研究院有限公司井下作业研究所,北京 102206
    3.中国石油大学(华东)重质油国家重点实验室,山东 青岛 266580
  • 通讯作者: 于筱溪
  • 作者简介:于筱溪(1988—),女,博士,副教授,yuxiaoxi@upc.edu.cn
  • 基金资助:
    中国石油集团工程技术研究院有限公司开放课题(F2020185)

Abstract:

The effect of the aggregation state of the ionic liquid 1-octyl-3-methylimidazole bromide([C8mim]Br) additives on the protein crystallization process was studied. Hen egg white lysozyme was chosen as the model protein and [C8mim]Br was applied as the additive. It was found that the presence of [C8mim]Br could improve the crystal morphology as well as affect the number and size of crystals. The influence mechanism of ionic liquid [C8mim]Br on the crystallization of lysozyme was revealed by measuring the solubility, crystallization kinetics, aggregation state and zeta-potential at different [C8mim]Br concentrations. The results showed that the interaction mechanism between lysozyme and [C8mim]Br varied with the aggregation states of [C8mim]Br. When the concentration of [C8mim]Br was low (< 0.1 mol/L), there was hydrophobic interactions between [C8mim]+ and lysozyme molecules, which promoted the aggregation and crystallization process. When the concentration of [C8mim]Br was high (> 0.1 mol/L), [C8mim]+ self-aggregated into micelle and formed aggregate complex with lysozyme molecules. The results from DLS further showed that the lysozyme-micelle complex was the basic unit in nucleation and hence, a slower crystallization rate and a higher crystal quality were obtained.

Key words: ionic liquids, aggregation, protein, crystallization

摘要:

研究了离子液体溴化1-辛基-3-甲基咪唑([C8mim]Br)添加剂的聚集状态对蛋白质结晶过程的影响。实验发现[C8mim]Br可以改善溶菌酶晶体形貌,影响晶体数量和晶体尺寸。通过测定不同浓度[C8mim]Br下溶菌酶的溶解度、结晶动力学、聚集状态和ζ-电势,揭示了离子液体[C8mim]Br对溶菌酶结晶的影响机理。结果表明,[C8mim]Br与溶菌酶的作用方式随[C8mim]Br的聚集状态而改变。当[C8mim]Br浓度较低(<0.1 mol/L)时,[C8mim]+与溶菌酶分子之间存在疏水作用,可以促进蛋白质分子聚集,促进结晶过程。当[C8mim]Br浓度较高(>0.1 mol/L)时,[C8mim]+自发聚集成胶束,并与蛋白质分子相互作用形成溶菌酶-胶束复合物;动态光散射(DLS)结果显示结晶过程以溶菌酶-胶束复合物为基本单元聚集,因此结晶过程减缓,晶体质量提高。

关键词: 离子液体, 聚集, 蛋白质, 结晶

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