Enzyme Activity Enhancement in Functionalized Nanoporous Support

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Project summary One of the key fundamental scientific questions is how isolated enzymes maintain their native active conformations in solution or in immobilization matrix. Our long-term goal is to elucidate the mechanisms for enzyme activity enhancements in functionalized nanoporous support to exploit highly-active and stable enzymes for detoxification, cancer treatment, biosensing, protein drug release and delivery. The specific hypothesis is that: a protein's enzymatic activity and stability can be significantly enhanced in an appropriately engineered open nanoporous support, which functions as a confined and interactive nanoenvironment for promoting a favorable protein conformational change. This hypothesis is based on the observations: First, we have entrapped three different enzymes in functionalized mesoporous silica (FMS). Mesoporous silica is a typical open nanoporous support with pore sizes as large as tens of nanometers. We demonstrated that all the three enzymes exhibit enhanced activity in FMS in comparison with the enzymes free in solution; Second, enzyme-specific activity can be increased or decreased to a large extent by changing protein loading density in FMS; Third, we found that FMS and chaotropic agents can act synergistically to enhance enzyme activity; Fourth, we found experimental evidences indicating there were favorable protein conformational changes occurring in FMS. We believe that, (i) FMS is a confined space, and (ii) FMS provides an interactive environment promoting a favorable protein conformational change, thereby enhancing enzyme activity and stability. Therefore, we propose the specific aims to: 1. Investigate necessity of mesoporous structure and effects of mesopore sizes on the enzyme activity enhancement; 2. Investigate the interactions of proteins with FMS to understanding FMS confinement and interactive effects on enzyme activity enhancement; 3. Develop molecular models and employ molecular docking and molecular dynamics simulations to probe the mechanism by which FMS steers enzyme conformational dynamics towards enhanced activity; 4. Evaluate the efficacy of highly-active and stable organophosphorus hydrolase in FMS to provide the in vivo detoxification towards organophosphorus neurotoxicity in the rat, to demonstrate an integrated all-in-one device of protein (enzyme) drug storage, release, and delivery. Project narrative One of the key fundamental scientific questions is how isolated enzymes maintain their native active conformations in solution or in immobilization matrix. Our long-term goal is to elucidate the mechanisms for enzyme activity enhancements in engineered nanoporous support to exploit highly-active and stable enzymes for medical applications including diagnostics, detoxification, and treatment for cancer and other diseases. As a result of this effort, we will evaluate the efficacy of highly-active and stable organophosphorus hydrolase in the functional nanoporous support to provide the in vivo detoxification towards organophosphorus neurotoxicity in the rat, to demonstrate an integrated all-in-one device of protein (enzyme) drug storage, release, and delivery.