Enzyme Shielding in an Enzyme‐thin and Soft Organosilica Layer

Abstract

The fragile nature of most enzymes is a major hindrance to their use in industrial processes. Herein, we describe a synthetic chemical strategy to produce hybrid organic/inorganic nanobiocatalysts; it exploits the self-assembly of silane building blocks at the surface of enzymes to grow an organosilica layer, of controlled thickness, that fully shields the enzyme. Remarkably, the enzyme triggers a rearrangement of this organosilica layer into a significantly soft structure. We demonstrate that this change in stiffness correlates with the biocatalytic turnover rate, and that the organosilica layer shields the enzyme in a soft environment with a markedly enhanced resistance to denaturing stresses.

A Biocatalytic Nanomaterial for the Label‐Free Detection of Virus‐Like Particles

“…Concomitantly, AP activity dropped from 90±1.2 U g −1 (U per gram of SNPs) to 11±0.2 U g −1 . This loss in activity was consistent with our previous results, where we demonstrated that a curing phase is necessary to recover enzymatic activity through reorganization of the protective organosilica layer . Accordingly, the particles were incubated at 25 °C for 24 h for the curing reaction.…”

Immobilization of an artificial imine reductase within silica nanoparticles improves its performance

“…16 Working on the development of nanomaterials endowed with virus recognition properties, 17,18 we have designed a chemical strategy that allows embedding enzymes in a biomimetic and soft organosilica layer. 19,20 In the present work, we have expanded this shielding strategy to artificial metalloenzymes and tested the resulting nanocatalysts for the reduction of cyclic imine 1 in the presence of various cellular extracts. As shown previously with soluble ArMs, embedding the biotinylated pianostool iridium complex [Cp*Ir(biot-p-L)Cl] within various streptavidin mutants (Sav hereafter) allows to access either (R)-and (S)-salsolidine 2 (Fig.…”

“…The time-point assay showed only a slight erosion of enantioselectivity over the course of 7 days (decrease of 11%), which could be explained by disruption of the protective layer and leakage of the catalyst caused by friction in solution. 20 However, the ICP-MS measurements of the reaction medium after the reaction revealed only traces of iridium. We thus argue that the decrease in activity is predominantly caused by loss of nanoparticles during centrifugation and washing cycles.…”

Materials Science at Swiss Universities of Applied Sciences

“…We have demonstrated that enzymes, when immobilized at the surface of silica and shielded in a soft organosilica shell, retain their enzymatic activity with a drastic improvement of their stability against external stress conditions. [49] In the same context, we also demonstrated that enzyme-polymer conjugates can be attached in a stable yet reversible fashion on polymeric filtration membranes exploiting surface supramolecular interactions. [50] The commercial implementation of the enzyme protection technology developed is now carried out by INOFEA AG, a biotech company that spun-off from the activities of our laboratory.…”