The overarching goal of this project is to develop a platform for the chemoenzymatic synthesis and evaluation of trehalose analogs as tools for investigating trehalose metabolism in mycobacteria. Trehalose is a non-mammalian disaccharide that is essential for cell-wall biosynthesis and function in Mycobacterium tuberculosis (Mtb), the bacterium that causes human tuberculosis (TB). Because trehalose is integral to Mtb pathogenesis but absent from the human host, it is an attractive target for diagnostic and therapeutic development. Chemically-modified trehalose analogs have begun to emerge as important tools in TB research-for instance, detectable trehalose analogs have recently been explored as mycobacteria-specific imaging probes. However, a major hurdle to progress in this area is the difficulty associated with synthesizing trehalose analogs using conventional approaches. A central goal of this proposal is to develop a chemoenzymatic method for the rapid and efficient preparation of trehalose analogs employing the heat-stable enzyme TreT from Thermoproteus tenax, which is the focus of Aim 1. Using TreT, we show that a broad range of novel trehalose analogs can be prepared quickly (= 60 min) in high yield (up to > 99%) in a single step from readily available glucose analogs. Furthermore, the aqueous reaction conditions enable direct transfer of reaction mixtures to mycobacterial cells to allow rapid administration and evaluation of trehalose-based probes or inhibitors.
In Aim 1, we intend to further develop and characterize the TreT method, with a focus on expanding reaction scope and scale. We will also generate a panel of trehalose analogs for investigating two processes that are important for mycobacterial pathogenesis: trehalose recycling and biofilm formation.
Aim 2 involves using trehalose analogs to evaluate the substrate specificity of the trehalose-recycling transporter SugABC-LpqY, which will inform our efforts to design trehalose-based probes or inhibitors that hijack SugABC-LpqY to enter the cell.
In Aim 3, we will evaluate trehalose analogs as inhibitors of mycobacterial biofilm formation, which may contribute to Mtb persistence and drug tolerance during infection. In concert, we will also test a panel of trehalose metabolism mutants for impaired biofilm formation to explore the genetic link between trehalose and mycobacterial biofilms.

Public Health Relevance

Tuberculosis (TB) is a devastating disease that kills 1.5 million people per year and remains an urgent global health threat due to the emergence of drug resistance and the fatal synergy of TB/HIV co-infection. This project involves the development of new tools to aid in investigating the bacterium that causes TB, Mycobacterium tuberculosis, which has a complex life cycle within the host that is still not well-understood. The tools developed through this work are expected provide a better understanding of M. tuberculosis physiology and pathogenesis, ultimately contributing to diagnostic and therapeutic development efforts.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Academic Research Enhancement Awards (AREA) (R15)
Project #
1R15AI117670-01
Application #
8879392
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Boyce, Jim P
Project Start
2015-01-16
Project End
2018-12-31
Budget Start
2015-01-16
Budget End
2018-12-31
Support Year
1
Fiscal Year
2015
Total Cost
$420,085
Indirect Cost
$90,448
Name
Central Michigan University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
624134037
City
Mount Pleasant
State
MI
Country
United States
Zip Code
48859
Peña-Zalbidea, Santiago; Huang, Ashley Y-T; Kavunja, Herbert W et al. (2018) Chemoenzymatic radiosynthesis of 2-deoxy-2-[18F]fluoro-d-trehalose ([18F]-2-FDTre): A PET radioprobe for in vivo tracing of trehalose metabolism. Carbohydr Res 472:16-22
Higgins, Cassandra B; Zhang, Yiming; Mayer, Allyson L et al. (2018) Hepatocyte ALOXE3 is induced during adaptive fasting and enhances insulin sensitivity by activating hepatic PPAR?. JCI Insight 3:
Groenevelt, Jessica M; Meints, Lisa M; Stothard, Alicyn I et al. (2018) Chemoenzymatic Synthesis of Trehalosamine, an Aminoglycoside Antibiotic and Precursor to Mycobacterial Imaging Probes. J Org Chem 83:8662-8667
Meints, Lisa M; Poston, Anne W; Piligian, Brent F et al. (2017) Rapid One-step Enzymatic Synthesis and All-aqueous Purification of Trehalose Analogues. J Vis Exp :
Wolber, Jeffrey M; Urbanek, Bailey L; Meints, Lisa M et al. (2017) The trehalose-specific transporter LpqY-SugABC is required for antimicrobial and anti-biofilm activity of trehalose analogues in Mycobacterium smegmatis. Carbohydr Res 450:60-66
O'Neill, Mara K; Piligian, Brent F; Olson, Claire D et al. (2017) Tailoring Trehalose for Biomedical and Biotechnological Applications. Pure Appl Chem 89:1223-1249
Rundell, Sarah R; Wagar, Zachary L; Meints, Lisa M et al. (2016) Deoxyfluoro-d-trehalose (FDTre) analogues as potential PET probes for imaging mycobacterial infection. Org Biomol Chem 14:8598-609