Investigation of the mycobacterial enzyme HsaD as a potential novel target for anti-tubercular agents using a fragment-based drug design approach

DOI: 10.1111/bph.13810

Authors: Ali Ryan (Kingston University London) , Elena Polycarpou (Kingston University London) , Nathan A. Lack (University of Oxford; Koç University) , Dimitrios Evangelopoulos (Birkbeck, University of London; University College London; The Francis Crick Institute) , Christian Sieg (Kingston University London) , Alice Halman (Kingston University London) , Sanjib Bhakta (Birkbeck, University of London) , Olga Eleftheriadou (Kingston University London) , Timothy D. Mchugh (University College London) , Sebastian Keany (University of Oxford) , Edward Lowe (University of Oxford) , Romain Ballet (University of Oxford) , Areej Abuhammad (University of Jordan) , William R. Jacobs (Albert Einstein College of Medicine) , Alessio Ciulli (University of Dundee; of Cambridge) , Edith Sim (Kingston University London; University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: British Journal Of Pharmacology

State: Published (Approved)
Published: April 2017

Abstract: Background and Purpose: With the emergence of extensively drug-resistant tuberculosis, there is a need for new anti-tubercular drugs that work through novel mechanisms of action. The meta cleavage product hydrolase, HsaD, has been demonstrated to be critical for the survival of Mycobacterium tuberculosis in macrophages and is encoded in an operon involved in cholesterol catabolism, which is identical in M. tuberculosis and M. bovis BCG. Experimental Approach: We generated a mutant strain of M. bovis BCG with a deletion of hsaD and tested its growth on cholesterol. Using a fragment based approach, over 1000 compounds were screened by a combination of differential scanning fluorimetry, NMR spectroscopy and enzymatic assay with pure recombinant HsaD to identify potential inhibitors. We used enzymological and structural studies to investigate derivatives of the inhibitors identified and to test their effects on growth of M. bovis BCG and M. tuberculosis. Key Results: The hsaD deleted strain was unable to grow on cholesterol as sole carbon source but did grow on glucose. Of seven chemically distinct ‘hits’ from the library, two chemical classes of fragments were found to bind in the vicinity of the active site of HsaD by X-ray crystallography. The compounds also inhibited growth of M. tuberculosis on cholesterol. The most potent inhibitor of HsaD was also found to be the best inhibitor of mycobacterial growth on cholesterol-supplemented minimal medium. Conclusions and Implications: We propose that HsaD is a novel therapeutic target, which should be fully exploited in order to design and discover new anti-tubercular drugs.

Diamond Keywords: Tuberculosis (TB); Bacteria

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Instruments: I03-Macromolecular Crystallography , I24-Microfocus Macromolecular Crystallography

Added On: 13/04/2017 09:01

Discipline Tags:

Pathogens Antibiotic Resistance Infectious Diseases Health & Wellbeing Biochemistry Chemistry Structural biology Organic Chemistry Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)