Self-Assembled Fullerene Nanostructures for Mimicking and Understanding of Natural Enzymes

Abstract

Self-assembling enzyme mimics offer an easy way to imitate activities of natural enzymes but have not been thus far used to understand the effect of different amino acids on the catalytic activity and why they are evolutionarily preserved for specific catalytic roles. Here, we demonstrated that fullerene nanostructures functionalized with catalytically active amino acids, which form multiple active sites via the self-assembly process in the aqueous environment, serve as an effective system to distinguish the catalytic activity differences resulting from single amino acid changes. A nano-level tuning of intermolecular and intramolecular interactions enabled formation of efficient enzyme mimics. Furthermore, using the carboxyl–imidazole couple found in quite different enzymes as the main catalytic unit, we could mimic different enzyme classes, like hydrolases and lyases, with significant catalytic activities. These designed nanocatalysts were also reusable and catalytically active under physiological conditions like natural enzymes.

Ultrasmall Gold Nanospheres Engineered with Nisin Pectin Bioconjugate: A Multifunctional Solution for Dye Removal, Detoxification, and Antimicrobial Applications

“…Since the AuNP@NisPec nanoparticles contain histidine amino acids of the nisin and carboxyl groups of the pectin that are the inseparable parts of the catalytic triad motif found in phosphoesterases, which are used to detoxify organophosphorus toxic molecules like organophosphorus nerve agents and pesticides, , we estimated that assembly of those active units on AuNP could exert phosphoesterase-like activity, making AuNP@NisPec nanoparticles a possible organophosphorus molecule detoxifier. To test the validity of this hypothesis, we performed a kinetic assay using p -nitrophenyl phosphate (pNPP), which is a substrate analogue for the phosphate-containing molecules.…”

“…Upon the addition of all components, a kinetic reading at 405 nm, which is the absorption peak of the hydrolysis product p -nitrophenolate ion, was taken for 10 min with 1 min intervals at RT. Reaction velocities were calculated using the Beer–Lambert law ( A = ε × C × l ), where we took the molar extinction coefficient as 17.104 M –1 cm –1 …”

“…Second, due to the histidine residues in the nisin AMP and carboxyl groups in the pectin carbohydrate, AuNP@NisPec nanoparticles obtained phosphoesterase-like nanoregions and could cleave the phosphate groups, which is important for the detoxification of toxic organophosphorus pesticides and nerve agents (Figure ). ,, Third, AuNP@NisPec nanoparticles caused a significant decrease in the viable number of two opportunistic pathogens having different Gram types, Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S.…”

Rational Design Strategies for Nanozymes

“…The abundant catalytic types and tunable catalytic activities are the most valuable characteristics of nanozymes. Analogous to natural enzymes, nanozymes possess up to four different catalytic types, including oxidoreductase-, hydrolase-, lyase-, and isomerase-like nanozymes . Among them, oxidoreductase-like nanozymes are a large family that was the earliest discovered and most fully developed, accounting for more than 96% of the known nanozymes, e.g., oxidase (OXD)-, peroxidase (POD)-, catalase (CAT)-, and superoxide dismutase (SOD)-like nanozymes. , To date, the catalytic types and activities of nanozymes have been precisely modulated through a series of methods: for example, size engineering, valence engineering, surface modification, crystal surface engineering, and defect engineering .…”

Bioinspired Multi‐Layer Biopolymer‐Based Dental Implant Coating for Enhanced Osseointegration

“…[19] Recently, fullerene has been recognized as a powerful artificial enzymemimicking tool due to its surface characteristics and biocompatible nature. [17,[20][21][22] To this end, histidine and threonine functionalized fullerene nanoparticles (HT) have been utilized for phosphatase activity. The study from our group further demonstrated the phosphatase-mimicking capacity of such nanocatalysts with tunable bioactivity for both phosphomonoesterase and phosphodiesterase substrates (Figures S3 and S4, Supporting Information).…”