Metal–organic frameworks/materials (MOFs/MOMs) are advanced enzyme immobilization platforms that improve biocatalysis, materials science, and protein biophysics. A unique way to immobilize enzymes is co-crystallization/co-precipitation, which removes the limitation on enzyme/substrate size. Thus far, most enzyme@MOF composites rely on the use of non-sustainable chemicals and, in certain cases, heavy metals, which not only creates concerns regarding environmental conservation but also limits their applications in nutrition and biomedicine. Here, we show that a dimeric compound derived from lignin, 5,5′-dehydrodivanillate (DDVA), co-precipitates with enzymes and low-toxicity metals, Ca2+ and Zn2+, and forms stable enzyme@Ca/Zn–MOM composites. We demonstrated this strategy on four enzymes withmore »
Site-directed spin labeling-electron paramagnetic resonance spectroscopy in biocatalysis: Enzyme orientation and dynamics in nanoscale confinement
Site-directed spin labeling (SDSL) in combination with electron paramagnetic resonance (EPR) spectroscopy probes the otherwise inaccessible structural information in complex biological systems. We recently extended SDSL-EPR to reveal the relative orientation and backbone dynamics of enzymes upon encapsulation in mesoporous nanostructures, which set the structural basis underlying the observed biocatalytic activity. Our strategy had generated interest in the biocatalysis community, and thus in this resource article, we contribute an introduction to the principles and experimental procedure that generalize SDSL-EPR to heterogeneous biocatalysis. We will focus on enzymes in mesoporous materials with examples demonstrating the methods and cautions of potential pitfalls. The ultimate goal is to provide the biocatalysis community with a powerful resource to fill in a long-standing knowledge gap in heterogeneous biocatalysis and the structure-function relationship of enzymes at the interface of enzyme-mesoporous materials and utilize the structural insights to guide the rational design of porous platforms for enzyme immobilization.
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- Chem catalysis
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- National Science Foundation
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