Fluorescently labelled thioacetazone for detecting the interaction with Mycobacterium dehydratases HadAB and HadBC. Issue 7 (27th January 2022)

• Record Type: Journal Article
• Authors: Singh, Bina K.; Singha, Monisha; Basak, Shyam; Biswas, Rupam; Das, Amit K.; Basak, Amit
• Is Part Of: Organic & biomolecular chemistry. Volume 20:Issue 7(2022)
• Page Start: 1444
• Page End: 1452
• Publication Date: 2022-01-27
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d1ob02080c
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Photo-cross-linking experiments demonstrated direct interactions of the drug thioacetazone with its target enzymes, namely both the dehydratases HadAB and HadBC via the monooxygenase EthA in Mycobacterium tuberculosis. Abstract : Thioacetazone (TAC) used to be a highly affordable, bacteriostatic anti-TB drug but its use has now been restricted, owing to severe side-effects and the frequent appearance of the TAC resistant M. tuberculosis strains. In order to develop new TAC analogues with fewer side-effects, its target enzymes need to be firmly established. It is now hypothesized that TAC, after being activated by a monooxygenase EthA, binds to the dehydratase complex HadAB that finally leads to a covalent modification of HadA, the main partner involved in dehydration. Another dehydratase enzyme, namely HadC in the HadBC complex, is also thought to be a possible target for TAC, for which definitive evidence is lacking. Herein, using a recently exploited azido naphthalimide template attached to thioacetazone and adopting a photo-affinity based labelling technique, coupled with electrophoresis and in-gel visualization, we have successfully demonstrated the involvement of these enzymes including HadBC along with a possible participation of an alternate mycobacterial monooxygenase MymA. In silico studies also revealed strong interactions between the TAC-probe and the concerned enzymes.