Enzyme adsorption-induced activity changes: a quantitative study on TiO2 model agglomerates

Journal of Nanobiotechnology

Research

Krisztina Kocsis¹  Augusto Márquez¹  Gilles R. Bourret¹  Nicola Hüsing¹  Thomas Berger¹  Gregor Zickler¹  Andrea Feinle¹  Oliver Diwald¹  Albert Duschl²  Martin Himly² 

[1] Department of Chemistry and Physics of Materials, Paris Lodron University of Salzburg, Jakob-Haringer-Strasse 2a, 5020, Salzburg, Austria;Department of Molecular Biology, Paris Lodron University of Salzburg, Hellbrunnerstrasse 34/III, 5020, Salzburg, Austria;

关键词: Nanoparticles;    Agglomerates;    TiO;    β-galactosidase;    Adsorption;    Enzymatic activity;    IR spectroscopy;   

DOI  :  10.1186/s12951-017-0283-4

 received in 2017-02-28, accepted in 2017-06-16,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundActivity retention upon enzyme adsorption on inorganic nanostructures depends on different system parameters such as structure and composition of the support, composition of the medium as well as enzyme loading. Qualitative and quantitative characterization work, which aims at an elucidation of the microscopic details governing enzymatic activity, requires well-defined model systems.ResultsVapor phase-grown and thermally processed anatase TiO2 nanoparticle powders were transformed into aqueous particle dispersions and characterized by dynamic light scattering and laser Doppler electrophoresis. Addition of β-galactosidase (β-gal) to these dispersions leads to complete enzyme adsorption and the generation of β-gal/TiO2 heteroaggregates. For low enzyme loadings (~4% of the theoretical monolayer coverage) we observed a dramatic activity loss in enzymatic activity by a factor of 60–100 in comparison to that of the free enzyme in solution. Parallel ATR-IR-spectroscopic characterization of β-gal/TiO2 heteroaggregates reveals an adsorption-induced decrease of the β-sheet content and the formation of random structures leading to the deterioration of the active site.ConclusionsThe study underlines that robust qualitative and quantitative statements about enzyme adsorption and activity retention require the use of model systems such as anatase TiO2 nanoparticle agglomerates featuring well-defined structural and compositional properties.

【 授权许可】

CC BY   
© The Author(s) 2017

【 图 表 】

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Fig. 10