A tailored biocatalyst achieved by the rational anchoring of imidazole groups on a natural polymer: furnishing a potential artificial nuclease by sustainable materials engineering

Abstract

Foreseeing the development of artificial enzymes by sustainable materials engineering, we rationally anchored reactive imidazole groups on gum arabic, a natural biocompatible polymer. The tailored biocatalyst GAIMZ demonstrated catalytic activity (>10(5)-fold) in dephosphorylation reactions with recyclable features and was effective in cleaving plasmid DNA, comprising a potential artificial nuclease.

Degrading Pesticides with Waste Product: Imidazole-Functionalized Rice Husk Catalyst for Organophosphate Detoxification

“…7, and the higher value obtained has been observed previously with biopolymer and other IMZ-derived complex structures, therefore, confirms the targeted functionalization. 20 Moreover, in RHIMZ, IMZ corresponds to nearly 11% of the functional groups, confirming the expected functionalization.FTIR analysis of the samples are difficult firstly due to the complex nature of RH-derived materials and secondly because of the low degree of carboxymethylation and further IMZ functionalization targeted. Figure 3 presents the FTIR spectra obtained and when analyzing the region of 1800-400 cm -1 , some differences are noticeable.…”

“…The data were fitted using the program BEST7, 24 which we have shown to be a powerful tool to characterize complex samples such as biopolymers and nanostructured materials. 20,23 Even for low degrees of functionalization, we were able to characterize the functional groups, that other commonly used techniques cannot properly distinguish. Indeed, due to the complex nature of RH, we expect low degrees of functionalization, as will be confirmed in the following.…”

“…These values agree with other reported complex structures, i.e., typical values for hydroxyl groups, although less acidic carboxylic acid that can be accounted to the neighboring groups that increase the carboxylic acid pK a . 20,23 For RHIMZ, three pK a 's were determined (pK a1 = 6.14 ± 0.02; pK a2 = 7.44 ± 0.02; pK a3 = 9.52 ± 0.02), since fitting required an additional pK a , consistent with the IMZ group anchored. Commonly, IMZ has a pK a ca.…”

“…16,18 Based on the excellent catalytic properties of IMZ, we have pursued different scaffold for anchoring IMZ moieties such as gum arabic and graphene, seeking novel bio-and nanocatalysts. 19,20 These materials have been successfully applied as catalysts with model substrates such as DEDNP but not yet with the much less reactive Paraoxon pesticide. Given the optimal properties already confirmed for IMZ-derived catalysts, herein, we propose to reuse RH waste by functionalizing it with IMZ groups leading to a catalyst targeted for OP degradation.…”

“…For anchoring IMZ groups, we targeted the carboxylate sites of RHCOOH by the reaction with EDC, NHS and API that we had already reported for gum arabic and graphene oxide. 19,20 We showed that functionalization is accomplished by means of amide bonds which is stable, therefore ideal for ensuring recyclable features for the designed catalysts. Finally, we expect low degree of IMZ anchoring, since herein we targeted low carboymethylation and we know from previous studies 20 that IMZ functionalization degree is usually low (under 15%) following the proposed methodology.…”