Supramolecular enzyme engineering in complex nanometer-thin biomimetic organosilica layers

Abstract

Enzyme shielding at the surface of silica nanoparticles was performed using different mixtures of biomimetic building blocks. The performances of the nanobiocatalysts are strongly impacted by the chemical composition of the shielding layer.

Tuning the Properties of Natural Promiscuous Enzymes by Engineering Their Nano-environment

“…In order to produce the samples called EH 3 -T/A [1/1] , EH 3 -T/A [4/1] , EH 3 -T/A [6/1] , EH 3 -T/A [10/1] , EH 3 -TBz/A [4/1] , EH 3 -TUr/A [4/1] , EH 3 -TBu/A [4/1] , EH 3 -THm/A [4/1] , and EH 3 -TBzUrBuHm/A [4/1] , the EH 3 (100 μg mL –1 ) was immobilized according to the procedure described above. Consequently, the shielding was performed following the method previously published . TEOS and all the other silanes were added to the reaction mixture according to the quantities reported in Table S2 and allowed to react under moderate stirring (1 h, 20 °C, 400 g ).…”

“…Consequently, the shielding was performed following the method previously published. 19 TEOS and all the other silanes were added to the reaction mixture according to the quantities reported in Table S2 and allowed to react under moderate stirring (1 h, 20 °C, 400g). Subsequently, APTES (0.090 mmol) was added.…”

“…Enzyme properties may also be tuned by engineering enzyme microenvironments, immobilization on solid supports, or encapsulation. , With the aim of combining immobilization and environment engineering, we previously reported a strategy for immobilizing and shielding enzymes within enzyme-thick and soft organosilica materials, which resulted in the marked enhancement of resistance to denaturing stresses. , The shield was designed so as to avoid reducing protein mobility while increasing enzyme stability in response to different stress conditions ( e.g. , high temperature, freeze–thaw cycles, urea or sodium dodecyl sulfate treatment).…”

Engineering Nanosized Organosilica for Molecular Recognition and Biocatalysis Applications

“…Different mixtures of OSs building blocks sharing chemical similarities with natural amino acids were used. [13] In more detail: the hydroxyl group of hydroxymethyl-triethoxysilane mimics polar amino acids (e.g. serine, threonine); propyl-triethoxysilane and benzyltriethoxysilane serve as aliphatic and aromatic building blocks mimicking leucine and phenylalanine, respectively.…”

A proteolytic nanobiocatalyst with built-in disulphide reducing properties

“…15 We have previously introduced a synthetic chemical strategy to fully shield immobilised enzymes in an organosilica layer at the surface of silica particles (SPs). 16,17 We demonstrated that this organosilica layer protects the enzyme in a so environment enhancing enzyme stability while maintaining catalytic activity. However, fully shielded enzymes can only convert small substrates, which can diffuse through the protective layer.…”