title: High-throughput screen identifies small molecule inhibitors targeting acetyltransferase activity of Mycobacterium tuberculosis GlmU.
abstract: N-acetylglucosamine-1-phosphate uridyltransferase (GlmU) is a pivotal bifunctional enzyme, its N and C terminal domains catalyzes uridyltransferase and acetyltransferase activities, respectively. Final product of GlmU catalyzed reaction, uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), acts as sugar donor providing GlcNAc residues in the synthesis of peptidoglycan and a disaccharide linker (D-N-GlcNAc-1-rhamnose), the key structural components of Mycobacterium tuberculosis (M. tuberculosis) cell wall. In the present study, we have searched new inhibitors against acetyltransferase activity of M. tuberculosis GlmU. A subset of 1607 synthetic compounds, selected through dual approach i.e., in-silico and whole cell screen against 20,000 compounds from ChemBridge library, was further screened using an in-vitro high throughput bioassay to identify inhibitors of acetyltransferase domain of M. tuberculosis GlmU. Four compounds were found to inhibit GlmU enzyme specific to acetyltransferase activity, with IC50 values ranging from 9 to 70 μM. Two compounds (6624116, 5655606) also exhibited whole cell activity against drug susceptible as well as drug resistant M. tuberculosis. These two compounds also exhibited increased anti-TB activity when tested in combination with rifampicin, isoniazid and ethambutol, however 5655606 was cytotoxic to eukaryotic cell line. These results demonstrate that identified chemical scaffolds can be used as inhibitors of M. tuberculosis cell wall enzyme after optimizations for future anti-TB drug development program.
authors: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
authors: Chitra
authors: C
authors: Rani
authors: Discovery Informatics Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
authors: Rukmankesh
authors: R
authors: Mehra
authors: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
authors: Rashmi
authors: R
authors: Sharma
authors: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
authors: Reena
authors: R
authors: Chib
authors: Instrumentation Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India.
authors: Priya
authors: P
authors: Wazir
authors: Discovery Informatics Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India. Electronic address: anargotra@iiim.ac.in.
authors: Amit
authors: A
authors: Nargotra
authors: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India; Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu 180001, India. Electronic address: iakhan@iiim.res.in.
authors: Inshad Ali
authors: IA
authors: Khan
mesh_terms: D000995:Antitubercular Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery / Q000379:methods*; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D005944:Glucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D005958:Glucosephosphates / Q000378:metabolism; D056945:Hep G2 Cells; D057166:High-Throughput Screening Assays; D006801:Humans; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D058990:Molecular Targeted Therapy; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D013329:Structure-Activity Relationship
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; C532100:GlmU protein, Mycobacterium tuberculosis; D005958:Glucosephosphates; D009097:Multienzyme Complexes; C038515:glucosamine 1-phosphate; D005944:Glucosamine
keywords: Acetyltransferase; Drug resistant; GlmU; M. tuberculosis; Rifampicin; UDP-GlcNAc