Artificial enzymes based on supramolecular scaffolds

Abstract

Enzymes are nanometer-sized molecules with three-dimensional structures created by the folding and self-assembly of polymeric chain-like components through supramolecular interactions. They are capable of performing catalytic functions usually accompanied by a variety of conformational states. The conformational diversities and complexities of natural enzymes exerted in catalysis seriously restrict the detailed understanding of enzymatic mechanisms in molecular terms. A supramolecular viewpoint is undoubtedly helpful in understanding the principle of enzyme catalysis. The emergence of supramolecular artificial enzymes therefore provides an alternative way to approach the structural complexity and thus to unravel the mystery of enzyme catalysis. This critical review covers the recent development of artificial enzymes designed based on supramolecular scaffolds ranging from the synthetic macrocycles to self-assembled nanometer-sized objects. Such findings are anticipated to facilitate the design of supramolecular artificial enzymes as well as their potential uses in important fields, such as manufacturing and food industries, environmental biosensors, pharmaceutics and so on.

Understanding the catalytic activity of single‐chain polymeric nanoparticles in water

“…oEGMA/BTAMA/LMA/SDP copolymer (P1) 3 were solubilized in toluened 8 under argon, in separate tubes. Then, the Ru(II) solution was transferred via the syringe technique into the tube containing 1 mL polymer solution (2 mM in toluene-d 8 ) where the ratio was thus 2.5 equivalents of Ru(II) per polymer chain.…”

“…Copolymers P1-P5 were studied using spectroscopic techniques (circular dichroism and fluorescence spectroscopy) and dynamic light scattering (DLS) before and after Ru(II) loading. 3 (Aldrich, 97%) was used as received and handled in a glove box under a moisture-and oxygen-free argon atmosphere (H 2 O < 1 ppm, O 2 < 1 ppm). Toluene (passed through purification columns; Solvent Dispensing System; Glass Contour) and hexane were bubbled with dry nitrogen for more than 15 min immediately before use.…”

“…A combination of circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) showed that all copolymers fold into a single chain polymeric nanoparticles (SCPNs) as a result of the helical selfassembly of the pendant BTA units and/or hydrophilic-hydrophobic phase separation. To create catalytic sites, RuCl 2 (PPh 3 ) 3 was incorporated into the copolymers. The Cotton effects of the copolymers before and after Ru(II) loading were identical, indicating that the helical self-assembly of the BTA units and the complexation of SDP ligands and Ru(II) occurs in an orthogonal manner.…”

“…On the other hand, creating sufficiently hydrophobic domains around the catalytic sites to ensure compatibility of the homogeneous organo-or metal-based catalysts with aqueous environments has remained a major challenge. [1][2][3] For this reason, artificial metalloenzymes, [4][5][6] DNA-based catalysts, 7 amphiphilic copolymers, [8][9][10] star polymers, [11][12][13][14][15] micellar systems, [16][17][18][19][20] molecularly imprinted nano and microgels, [21][22][23] and dendrimers [24][25][26][27][28] were designed to achieve the necessary compartmentalization for efficient catalysis in water. Supramolecular folding of polymer chains into single chain polymeric nanoparticles (SCPNs) is an attractive alternative to prepare compartmentalized, water-soluble, nanometersized particles with a hydrophobic interior.…”

G-Arylated Hydrogen-Bonded Cyclic Tetramer Assemblies with Remarkable Thermodynamic and Kinetic Stability

“…1 Shape-persistent covalent macrocycles, as well as their organized 2D porous networks 2 or 1D stacked nanotubes, 3 have been employed in organic electronics, 4 inclusion chemistry, sensing and catalysis, 5 rotaxane and catenane assembly, 1 or as nanomembranes and synthetic ion channels. 6 As opposed to covalent methods, 1,4,7 noncovalent synthesis can be viewed as a straightforward and versatile approach towards well-defined macrocycles.…”