title: Reduction of urease activity by interaction with the flap covering the active site.
abstract: With the increasing appreciation for the human microbiome coupled with the global rise of antibiotic resistant organisms, it is imperative that new methods be developed to specifically target pathogens. To that end, a novel computational approach was devised to identify compounds that reduce the activity of urease, a medically important enzyme of Helicobacter pylori, Proteus mirabilis, and many other microorganisms. Urease contains a flexible loop that covers its active site; Glide was used to identify small molecules predicted to lock this loop in an open conformation. These compounds were screened against the model urease from Klebsiella aerogenes, and the natural products epigallocatechin and quercetin were shown to inhibit at low and high micromolar concentrations, respectively. These molecules exhibit a strong time-dependent inactivation of urease that was not due to their oxygen sensitivity. Rather, these compounds appear to inactivate urease by reacting with a specific Cys residue located on the flexible loop. Substitution of this cysteine by alanine in the C319A variant increased the urease resistance to both epigallocatechin and quercetin, as predicted by the computational studies. Protein dynamics are integral to the function of many enzymes; thus, identification of compounds that lock an enzyme into a single conformation presents a useful approach to define potential inhibitors.
authors.affiliation: Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences Building and ∥Department of Biochemistry & Molecular Biology, Biomedical Physical Sciences Building, Michigan State University , Room 2215, 567 Wilson Road, East Lansing, Michigan 48824, United States.
authors.forename: Lee
authors.initials: L
authors.lastname: Macomber
authors.forename: Mona S
authors.initials: MS
authors.lastname: Minkara
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hausinger
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Merz
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D020134:Catalytic Domain / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D003545:Cysteine / Q000737:chemistry; D021902:Enterobacter aerogenes / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D057166:High-Throughput Screening Assays / Q000379:methods; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011794:Quercetin / Q000494:pharmacology; D054852:Small Molecule Libraries; D013329:Structure-Activity Relationship; D014510:Urease / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics
chemical_list: D004791:Enzyme Inhibitors; D054852:Small Molecule Libraries; D002392:Catechin; D011794:Quercetin; D014510:Urease; C057580:gallocatechol; D003545:Cysteine