A fluorescence spectroscopy assay for real-time monitoring of enzyme immobilization into mesoporous silica particles
Journal article, 2015

Mesoporous silica particles are used as support material for immobilization of enzymes. Here we investigated a fluorescence-based assay for real-time monitoring of the immobilization of lipase, bovine serum albumin, and glucose oxidase into micrometer-sized mesoporous silica particles. The proteins are labeled with the dye epicocconone, and the interaction with the particles is observed as an increase in emission intensity of the protein–dye conjugates that can be quantified if correcting for a comparatively slow photobleaching. The immobilization occurs in tens of minutes to hours depending on particle concentration and type of protein. In the limit of excess particles over proteins, the formation of the particle–protein complexes can be described by a single exponential growth for all three investigated proteins, and the fitted pseudo-first-order rate constant increases linearly with particle concentration for each protein type. The derived second-order rate constant k varies with the protein hydrodynamic radius according to k ∼ RH−4.70±0.01, indicating that the rate-limiting step at high particle concentrations is not the diffusional encounter between proteins and particles but rather the entry into the pores, consistent with the hydrodynamic radii of the three proteins being smaller but comparable to the pore radius of the particles.

Kinetics

Mesoporous silica

Enzyme

Fluorescence

Immobilization

Epicocconone

Author

Pegah Sadat Nabavi Zadeh

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Kassam Abdel Mallak

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Nils Carlsson

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Björn Åkerman

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Analytical Biochemistry

0003-2697 (ISSN) 1096-0309 (eISSN)

Vol. 476 51-58

Subject Categories

Chemical Engineering

DOI

10.1016/j.ab.2015.02.005

More information

Created

10/7/2017