Spatial, Hysteretic, and Adaptive Host–Guest Chemistry in a Metal–Organic Framework with Open Watson–Crick Sites

Abstract

Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing,u sually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects,a si nl ocal folding in protein-DNAb inding.H erein, we report an ew nucleobasetagged metal-organic framework (MOF), namely ZnBTCA (BTC = benzene-1,3,5-tricarboxyl, A = adenine), in whicht he exposed Watson-Crickf aces of adenine residues are immobilized periodically on the interior crystalline surface.Systematic control experiments demonstrated the cooperation of the open Watson-Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed ah ysteretic host-guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine-thymine binding within the constrained pores,and aglobally adaptive response of the MOF host was observed.

Biologically derived metal organic frameworks

“…Since the channels are large enough to host both MB + and PfH + , MB + has uptake priority, indicating that the framework and PfH + interact weakly, minimizing the uptake of PfH + . [162] In comparison to bio-MOF-1, ZnBTCA has smaller, less uniform channels and the uptake of guests is found to be much faster. [162] Furthermore, the hysteretic behavior of PfH + is absence in bio-MOF-1 due to open Watson-Crick sites contributing to chemisorption host-guest interactions in ZnBTCA.…”

“…[162] In comparison to bio-MOF-1, ZnBTCA has smaller, less uniform channels and the uptake of guests is found to be much faster. [162] Furthermore, the hysteretic behavior of PfH + is absence in bio-MOF-1 due to open Watson-Crick sites contributing to chemisorption host-guest interactions in ZnBTCA. [162] They further exploited this behavior for Ade-Thy (A-T as in RNA) binding within the constrained pores and found the host framework responded to the Thy binding, as supported indirectly by several pieces of consistent evidence.…”

“…[111,163] Highly porous Ade-based bio-MOFs have been prepared using co-ligands of different mono-, di-and tri-carboxylic acids. [52,111,115,130,161,164,165] [162] The channels are further interconnected giving an overall three-periodic pore connectivity, and the open Watson-Crick sites are aligned almost parallel to the contacting surface affording channelconnecting windows. [162] Twelve organic dyes that are commonly used as DNA-staining agents (nucleic-acid research) are used, to explore the host-guest chemistry of ZnBTCA, which differed in dimensions, contacting sites, and ionic charges.…”

“…[162] Twelve organic dyes that are commonly used as DNA-staining agents (nucleic-acid research) are used, to explore the host-guest chemistry of ZnBTCA, which differed in dimensions, contacting sites, and ionic charges. [162] The authors reported that two guests, PfH + and MB + had special properties in terms of sorption kinetics. [162] Uptake experiments were performed and found that because of the size of MB + , which exceeds the minimum channel diameter of ZnBTCA, it is limited to surface sorption, whereas PfH + takes priority with a moderate uptake amount.…”

“…[162] The authors reported that two guests, PfH + and MB + had special properties in terms of sorption kinetics. [162] Uptake experiments were performed and found that because of the size of MB + , which exceeds the minimum channel diameter of ZnBTCA, it is limited to surface sorption, whereas PfH + takes priority with a moderate uptake amount. Since the channels are large enough to host both MB + and PfH + , MB + has uptake priority, indicating that the framework and PfH + interact weakly, minimizing the uptake of PfH + .…”