title: Identification and characterization of novel small molecule inhibitors of the acetyltransferase activity of Escherichia coli N-acetylglucosamine-1-phosphate-uridyltransferase/glucosamine-1-phosphate-acetyltransferase (GlmU).
abstract: This study aims at identifying novel chemical scaffolds as inhibitors specific to the acetyltransferase domain of a bifunctional enzyme, Escherichia coli GlmU, involved in the cell wall biosynthesis of Gram-negative organisms. A two-pronged approach was used to screen a 50,000 small-molecule library. Using the first approach, the library was in silico screened by docking the library against acetyltransferase domain of E. coli GlmU studies. In the second approach, complete library was screened against Escherichia coli ATCC 25922 to identify the whole cell active compounds. Active compounds from both the screens were screened in a colorimetric absorbance-based assay to identify inhibitors of acetyltransferase domain of E. coli GlmU which resulted in the identification of 1 inhibitor out of 56 hits identified by in silico screening and 4 inhibitors out of 35 whole cell active compounds on Gram-negative bacteria with the most potent inhibitor showing IC50 of 1.40 ± 0.69 μM. Mode of inhibition studies revealed these inhibitors to be competitive with AcCoA and uncompetitive with GlcN-1-P. These selected inhibitors were also tested for their antibacterial and cytotoxic activities. Compounds 5175178 and 5215319 exhibited antibacterial activity that co-related with GlmU inhibition. These compounds, therefore, represent novel chemical scaffolds targeting acetyltransferase activity of E. coli GlmU.
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Chitra
authors.initials: C
authors.lastname: Rani
authors.affiliation: Discovery Informatics Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu, 180001, India.
authors.forename: Rukmankesh
authors.initials: R
authors.lastname: Mehra
authors.affiliation: Discovery Informatics Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Nargotra
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.
authors.forename: Reena
authors.initials: R
authors.lastname: Chib
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Vikrant S
authors.initials: VS
authors.lastname: Rajput
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Sunil
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Samsher
authors.initials: S
authors.lastname: Singh
authors.affiliation: Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, 180001, India.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.
authors.forename: Parduman R
authors.initials: PR
authors.lastname: Sharma
authors.affiliation: Clinical Microbiology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, 180001, India. iakhan@iiim.res.in.|Academy of Scientific and Innovative Research, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India. iakhan@iiim.res.in.
authors.forename: Inshad A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D000105:Acetyl Coenzyme A / Q000737:chemistry / Q000378:metabolism; D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001667:Binding, Competitive; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D057166:High-Throughput Screening Assays; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D062105:Molecular Docking Simulation; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D029968:Escherichia coli Proteins; C520333:GlmU protein, E coli; D009097:Multienzyme Complexes; D054852:Small Molecule Libraries; C026146:N-acetylglucosamine-1-phosphate; D000105:Acetyl Coenzyme A; D000117:Acetylglucosamine
keywords: Acetyltransferase; Extended-spectrum β-lactamase; GlmU; Haemophilus influenzae