Enzyme immobilization in a biomimetic silica support

Abstract

Robust immobilization techniques that preserve the activity of biomolecules have many potential applications. Silicates, primarily in the form of sol-gel composites or functionalized mesoporous silica, have been used to encapsulate a wide variety of biomolecules but the harsh conditions required for chemical synthesis limit their applicability. Silaffin polypeptides from diatoms catalyze the formation of silica in vitro at neutral pH and ambient temperature and pressure. Here we show that butyrylcholinesterase entrapped during the precipitation of silica nanospheres retained all of its activity. Ninety percent of the soluble enzyme was immobilized, and the immobilized enzyme was substantially more stable than the free enzyme. The mechanical properties of silica nanospheres facilitated application in a flow-through reactor. The use of biosilica for enzyme immobilization combines the excellent support properties of a silica matrix with a benign immobilization method that retains enzyme activity.

A synthetic nanomaterial for virus recognition produced by surface imprinting

“…The ability of silicatein proteins to act as templates/catalysts for the biomineralization of silica has been demonstrated 36 . Numerous biomimetic synthetic silica systems have been reported and are mainly based on the modification of the protein to introduce catalytic/template sequences [36][37][38] . Here, we demonstrated that the template effect could be obtained by using a mixture of organosilanes that self-assemble around the native virus.…”

Enzyme-mediated synthesis of ceramic materials

“…A short time later, the synthesis of silica from a silicic acid solution 73) and the synthesis of TiO 2 from Ti-BALDH 74) were attempted using R5 peptide.…”

Silica-Immobilized Enzyme Reactors

“…A matrix of spherical silica particles (typically ~500nm in diameter) is formed and provides effective encapsulation of a range of enzymes including esterases, hydrolases, peroxidases and reductases. [23,35,[56][57][58][59] The silica particles can be further integrated into flow-through systems by either: i) preparing the silica particles in batch mode and then packing them into a column or by ii) preparing the silica particles within a commercially available pre-packed column, in situ, by anchoring them to the column matrix.…”

“…[20][21][22] Using biological molecules as scaffold templates, biomimetic silicification reactions have been shown to provide a simple and effective alternative for enzyme encapsulation. [23,24] The biologically-derived silica particles physically entrap enzymes within silica nanospheres directly as the silica particles form, providing an effective 'cage' that limits enzyme denaturation and retains high enzyme activity. The application of biologically-derived silica (biosilica) as a method for enzyme immobilization and preparation of IMERs using this method will be discussed in more detail below.…”