This application seeks to merge chemical biology, structural biology and pathogen biology (including metabolomics in vitro and infections in mice) for insight into the function of two enzymes in Mtb's intermediary metabolism, lipoamide dehydrogenase (Lpd) and 2-hydroxy-3-oxoadipate (HOA) synthase (HOAS). Lpd participates in 3 enzyme complexes in intermediary metabolism and anti-oxidant defense. Its knockout severely attenuates Mtb in the mouse. We have identified and co-crystallized a species-selective Lpd inhibitor and will identify (and subsequently co-crystallize) others by applying orthogonal high throughput screens: one that tests 2 million compounds against the recombinant enzyme and the other using the hits from the first screen against replicating and non-replicating Mtb. HOAS, which we have crystallized, carries out a newly identified function of the reportedly essential gene Rv1248c, originally mis-annotated as E1 of 1-ketoglutarate (1-KG ) dehydrogenase. This is the first identification of a specific gene product that catalyzes carboligation of 1-KG and glyoxylate, producing HOA and its spontaneous decarboxylation product, hydroxylevulinate. We will replace Rv1248c with a Tet-regulated allele have developed a novel strategy to synthesize HOAS inhibitors from an analog of the cofactor thiamine diphosphate. This work will provide insights about the metabolic constraints faced by Mtb in the mouse, furnish tool compounds for the study of the roles of Lpd and HOAS together with other enzymes, establish if Lpd and HOAS warrant consideration as drug targets, and reveal new aspects of Mtb's intermediary metabolism. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page

Public Health Relevance

Most antibiotics target biosynthetic processes and kill replicating bacteria. A major global health need is to eradicate substantially non-replicating subpopulations of Mtb with new chemophores active against new targets. Compounds developed here will inhibit two enzymes that are required by non-replicating Mtb (Lpd) or seem likely to be so (HOAS) and along with metabolomic studies will shed fundamental new light on Mtb's intermediary metabolism.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-BACP-B (09))
Program Officer
Boyce, Jim P
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Weill Medical College of Cornell University
Schools of Medicine
New York
United States
Zip Code
Nathan, Carl; Barry 3rd, Clifton E (2015) TB drug development: immunology at the table. Immunol Rev 264:308-18
Maksymiuk, Christina; Ioerger, Thomas; Balakrishnan, Anand et al. (2015) Comparison of transposon and deletion mutants in Mycobacterium tuberculosis: The case of rv1248c, encoding 2-hydroxy-3-oxoadipate synthase. Tuberculosis (Edinb) 95:689-694
Maksymiuk, Christina; Balakrishnan, Anand; Bryk, Ruslana et al. (2015) E1 of ?-ketoglutarate dehydrogenase defends Mycobacterium tuberculosis against glutamate anaplerosis and nitroxidative stress. Proc Natl Acad Sci U S A 112:E5834-43
Nathan, Carl (2015) What can immunology contribute to the control of the world's leading cause of death from bacterial infection? Immunol Rev 264:2-5
Bryk, Ruslana; Arango, Nancy; Maksymiuk, Christina et al. (2013) Lipoamide channel-binding sulfonamides selectively inhibit mycobacterial lipoamide dehydrogenase. Biochemistry 52:9375-84
Balakrishnan, Anand; Jordan, Frank; Nathan, Carl F (2013) Influence of allosteric regulators on individual steps in the reaction catalyzed by Mycobacterium tuberculosis 2-hydroxy-3-oxoadipate synthase. J Biol Chem 288:21688-702
Nathan, Carl (2012) Fresh approaches to anti-infective therapies. Sci Transl Med 4:140sr2
Mazloum, Nayef; Stegman, Melanie A; Croteau, Deborah L et al. (2011) Identification of a chemical that inhibits the mycobacterial UvrABC complex in nucleotide excision repair. Biochemistry 50:1329-35
Rhee, Kyu Y; de Carvalho, Luiz Pedro Sorio; Bryk, Ruslana et al. (2011) Central carbon metabolism in Mycobacterium tuberculosis: an unexpected frontier. Trends Microbiol 19:307-14
de Carvalho, Luiz Pedro S; Ling, Yan; Shen, Chun et al. (2011) On the chemical mechanism of succinic semialdehyde dehydrogenase (GabD1) from Mycobacterium tuberculosis. Arch Biochem Biophys 509:90-9

Showing the most recent 10 out of 15 publications