Construction of a smart temperature-responsive GPx mimic based on the self-assembly of supra-amphiphiles. Issue 4 (30th November 2015)

• Record Type: Journal Article
• Authors: Zou, Huixin; Sun, Hongcheng; Wang, Liang; Zhao, Linlu; Li, Jiaxi; Dong, Zeyuan; Luo, Quan; Xu, Jiayun; Liu, Junqiu
• Is Part Of: Soft matter. Volume 12:Issue 4(2016)
• Page Start: 1192
• Page End: 1199
• Publication Date: 2015-11-30
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c5sm02074c
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : A supra-amphiphilic thermosensitive vesicle-like structure was designed by the self-assembly of host–guest interaction to construct a smart artificial GPx mimic with controllable catalytic activity. Abstract : Glutathione peroxidase (GPx) is a major defense against hydroperoxides as a kind of seleno-enzyme that protects cells from oxidative damage. A supramolecular vesicle with controllable GPx activity and morphology has been successfully constructed by the self-assembly of supra-amphiphiles formed by host–guest recognition between cyclodextrin and adamantane derivatives. By introducing thermosensitive poly( N -isopropylacrylamide) (PNIPAM) scaffolds and the catalytic moiety selenium into adamantane and cyclodextrin, respectively, the complex of catalysis-functionalized cyclodextrin with thermosensitivity-functionalized adamantane directed the formation of a supramolecular vesicle which acted as a GPx mimic at 37 °C. The self-assembled nanoenzyme exhibited an obvious temperature responsive characteristic and high GPx-like catalytic activity promoting the reduction of hydrogen peroxide (H2 O2 ) with glutathione (GSH) as the reducing substrate at 37 °C. However, the vesicle disassembled when the temperature decreased to 25 °C due to the transition of PNIPAM between the coil and the globule. Interestingly, the catalytic activity changed along with the transformation of morphologies. The vesicle structure self-assembled at 37 °C provided the favorable microenvironment for the enzymatic reaction, hence we successfully developed a temperature-responsive nanoenzyme model. Moreover, the catalytic activity of the thermosensitive GPx mimic exhibited excellent reversibility and typical saturation kinetics behaviour similar to a natural enzyme catalyst. It is assumed that the proposed GPx model not only has remarkable advantages such as easy functionalization and facile preparation but also provided a new way to develop intelligent responsive materials.