John C Jewett
Associate Professor, BIO5 Institute
Associate Professor, Chemistry and Biochemistry-Sci
Primary Department
Department Affiliations
(520) 626-3627
Work Summary
We seek to develop tools and strategies to expedite the understanding and treatment of the dengue virus. These advances will be transferable to other areas of virology and biochemistry. Along these lines, we are engaged in three core synergistic projects to answer the following questions: (1) Do unnatural metabolites incorporated into DENV serve as reporters for host-pathogen interactions? (2) What are the host-pathogen interactions in DENV that are targetable for diagnosis or treatment? (3) Is there a chemical reaction between two small molecules that reports on the interaction between DENV and host proteins?
Research Interest
Our goal is to merge the fields of synthetic organic chemistry with virology. We develop new reactions (and re-appropriate old ones) to gain insight into how viruses infects new host cells. Additionally, we are working to develop new methods to probe protein-protein interactions through the use of small molecules.Viruses can rapidly evolve and new tools are required to meet this ever-changing threat. While vaccinations have tamed many historically deadly viral diseases, there are still rogue viruses for which no vaccination strategy is available. Dengue virus (DENV), the virus that is responsible for dengue fever, hemorrhagic fever, and shock syndrome, is one such pathogen. The WHO estimates that the mosquito-borne pathogen infects over 50 million people each year. With a rapid increase in severe, potentially fatal, disease forms, DENV poses a significant risk to the 2.5 billion people who live in DENV endemic regions.

Publications

Jewett, J. C., & Rawal, V. H. (2010). Temporary restraints to overcome steric obstacles: An efficient strategy for the synthesis of mycalamideB. Angewandte Chemie - International Edition, 49(46), 8682-8685.

PMID: 20931583;Abstract:

Restrain and release: A one-pot MukaiyamaMichael/epoxidation sequence introduced three stereocenters, an intramolecular isocyanate trapping produced a rigid 10-membered cyclic carbamate, and the selective opening of the cyclic carbamate was used to reveal the fully constructed natural product. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Jensen, S. M., Nguyen, C. T., & Jewett, J. C. (2016). A gradient-free method for the purification of infective dengue virus for protein-level investigations. Journal of virological methods, 235, 125-30.

Dengue virus (DENV) is a mosquito-transmitted flavivirus that infects approximately 100 million people annually. Multi-day protocols for purification of DENV reduce the infective titer due to viral sensitivity to both temperature and pH. Herein we describe a 5-h protocol for the purification of all DENV serotypes, utilizing traditional gradient-free ultracentrifugation followed by selective virion precipitation. This protocol allows for the separation of DENV from contaminating proteins - including intact C6/36 densovirus, for the production of infective virus at high concentration for protein-level analysis.

Ahad, A. M., Jensen, S. M., & Jewett, J. C. (2013). A traceless staudinger reagent to deliver diazirines. Organic Letters, 15(19), 5060-5063.

PMID: 24059816;PMCID: PMC3857746;Abstract:

A triarylphosphine reagent that reacts with organic azides to install amide-linked diazirines is reported. This traceless Staudinger reagent reacts with complex organic azides to yield amide-linked diazirines, thus expanding the scope of the utility of both azide and diazirine chemistry. © 2013 American Chemical Society.

Jewett, J. C., Sletten, E. M., & Bertozzi, C. R. (2010). Rapid Cu-free click chemistry with readily synthesized biarylazacyclooctynones. Journal of the American Chemical Society, 132(11), 3688-3690.

PMID: 20187640;PMCID: PMC2840677;Abstract:

"Chemical equation presented" Bioorthogonal chemical reactions, those that do not interact or interfere with biology, have allowed for exploration of numerous biological processes that were previously difficult to study. The reaction of azides with strained alkynes, such as cyclooctynes, readily forms a triazole product without the need for a toxic catalyst. Here we describe a iarylazacyclooctynone (BARAC) that has exceptional reaction kinetics and whose synthesis is designed to be both modular and scalable. We employed BARAC for live cell fluorescence imaging of azide-labeled glycans. The high signal-to-background ratio obtained using nanomolar concentrations of BARAC obviated the need for washing steps. Thus, BARAC is a promising reagent for in vivo imaging. © 2010 American Chemical Society.

Sletten, E. M., Nakamura, H., Jewett, J. C., & Bertozzi, C. R. (2010). Difluorobenzocyclooctyne: Synthesis, reactivity, and stabilization by β-cyclodextrin. Journal of the American Chemical Society, 132(33), 11799-11805.

PMID: 20666466;PMCID: PMC2923465;Abstract:

Highly reactive cyclooctynes have been sought as substrates for Cu-free cycloaddition reactions with azides in biological systems. To elevate the reactivities of cyclooctynes, two strategies, LUMO lowering through propargylic fluorination and strain enhancement through fused aryl rings, have been explored. Here we report the facile synthesis of a difluorobenzocyclooctyne (DIFBO) that combines these modifications. DIFBO was so reactive that it spontaneously trimerized to form two asymmetric products that we characterized by X-ray crystallography. However, we were able to trap DIFBO by forming a stable inclusion complex with β-cyclodextrin in aqueous media. This complex could be stored as a lyophilized powder and then dissociated in organic solvents to produce free DIFBO for in situ kinetic and spectroscopic analysis. Using this procedure, we found that the rate constant for the cycloaddition reaction of DIFBO with an azide exceeds those for difluorinated cyclooctyne (DIFO) and dibenzocyclooctyne (DIBO). Cyclodextrin complexation is therefore a promising approach for stabilizing compounds that possess the high intrinsic reactivities desired for Cu-free click chemistry. © 2010 American Chemical Society.