A novel nickel-chelated surfactant for affinity-based aqueous two-phase micellar extraction of histidine-rich protein

作者：Wang Shuo; Xiong Neng; Dong Xiao Yan; Sun Yan^*

来源：Journal of Chromatography A, 2013, 1320: 118-124.

DOI：10.1016/j.chroma.2013.10.074

• Aqueous two-phase micellar system
• Nickel-chelated surfactant
• Triton X-114
• Cloud point
• Affinity partitioning
• Green fluorescent protein

Aqueous two-phase micellar systems (ATPMSs) composed of nonionic surfactants are considered promising for the separation and purification of proteins. To improve the specificity of ATPMSs, a novel nickel-chelated surfactant was prepared by successive modifications of Triton X-114 (TX). Characterizations by Fourier transformation infrared spectroscopy demonstrated the successful synthesis of the nickel-chelated surfactant (TX-Ni). The cloud point, critical micelle concentration (CMC), molecular interaction parameter and micelle size were measured for the mixed surfactant system of TX-Ni and TX to achieve a full understanding of their aggregation behaviors. The results showed that mixed micelles were formed, and the cloud point increased with the mole fraction of TX-Ni because TX-Ni had a more hydrophilic head group than TX. Moreover, the reduction of micelle size revealed by light scattering experiments indicated that the insertion of TX-Ni inhibited the micellar growth due to the increased steric and electrostatic repulsion. Finally, the efficiency of TX-Ni as an affinity surfactant was demonstrated by the affinity partitioning of histidine-tagged enhanced green fluorescent protein with an over 20-fold increase of the partition coefficient (from 0.60 to 12.42). This affinity-based ATPMS is thus considered promising for providing a versatile platform for the separation of histidine-rich proteins.

• 出版日期2013-12-13
• 单位天津大学