Molecularly Imprinted Synthetic Glucosidase for the Hydrolysis of Cellulose in Aqueous and Nonaqueous Solutions

Abstract

Molecular imprinting is a powerful and yet simple method to create multifunctional binding sites within a cross-linked polymer network. We report a new class of synthetic glucosidase prepared through molecular imprinting and postfunctionalization of cross-linked surfactant micelles. These catalysts are protein-sized water-soluble nanoparticles that can be modified in multiple ways. As their natural counterparts, they bind a glucose-containing oligo- or polysaccharide. They contain acidic groups near the glycosidic bond to be cleaved, with the number and distance of the acid groups tuned systematically. Hydrolysis of cellulose in a key step in biomass conversion but is hampered by the incalcitrance of the highly crystalline cellulose fibers. The synthetic glucosidases are shown to hydrolyze cellobiose and cellulose under a variety of conditions. The best catalyst, with a biomimetic double acid catalytic motif, can hydrolyze cellulose with one-fifth of the activity of commercial cellulases in aqueous buffer. As a highly cross-linked polymeric nanoparticle, the synthetic catalyst is stable at elevated temperatures in both aqueous and nonaqueous solvents. In a polar aprotic solvent/ionic liquid mixture, it hydrolyzes cellulose several times faster than commercial cellulases in aqueous buffer. When deposited on magnetic nanoparticles, it retains 75% of its activity after 10 cycles of usage.

Epitope-imprinted polymers: Design principles of synthetic binding partners for natural biomacromolecules

“…This carefully designed supramolecular construction allows the production of MINPs with sizes close to natural receptors (∼5 nm) that can precisely discriminate between closely related small peptides (204,205) and, as recently demonstrated, also glycans (39,40). This ability has been leveraged to achieve impressive biologically relevant results in sequence-selective protection of larger peptides (angiotensins, amyloid-) from proteolysis (206), selective phosphorylation of peptides and proteins (207), and synthetic hydrolysis of oligo-and polysaccharides (such as cellulose) (208,209). Although the synthesis of MINPs and its precursors involves nontrivial laborious processes, this is a versatile one-pot method that results in extraordinary templating effects for a variety of different biomolecule epitopes.…”

Highly selective water-compatible molecularly imprinted polymers for benzophenone-4

“…Molecularly imprinted polymers (MIPs) are smart synthetic materials which can be used for several applications: [1][2][3][4] as sorbents for solid phase extraction (SPE), [5][6][7][8][9] as stationary phase for chromatography, [10][11][12][13][14][15] as sensors, [16][17][18] artificial enzymes, [19][20][21] as systems for controlled drug delivery and release, [22][23][24] etc. Molecular imprinting technology (MIT) is based on interactions between template molecule and functional monomer in the presence of porogen.…”

Rational design of allosteric switchable catalysts

“…Recently, versatile molecular scaffolds were utilized to afford exceptional examples aiming at natural enzymes' expertise: facilitating the formation of enzymesubstrate complex and reducing the activation energy barrier of catalytic reactions. Essential knowledge and critical factors (e.g., hydrogen bonds, electrostatic potential, van der Waals' forces, coordination bonds) that govern the enzyme activity have been explored by studying different models such as small organic molecules, [14][15][16][17][18][19][20] polymers, [21][22][23][24][25][26][27][28][29] supramolecular complexes, [30][31][32][33][34][35][36][37] natural proteins, [38][39][40][41][42][43][44] and protein assemblies. [45][46][47][48][49][50][51][52] These multidisciplinary works have spawned many successful bioinspired enzymes, some of which even showed high efficiencies comparable to their natural counterparts.…”