Klebsiella aerogenes UreE, one of four accessory proteins involved in urease metallocenter assembly, contains a histidine-rich C terminus (10 of the last 15 residues) that is likely to participate in metal ion coordination by this nickel-binding protein. To study the function of the histidine-rich region in urease activation, ureE in the urease gene cluster was mutated to result in synthesis of...

The pathogenesis associated with Helicobacter pylori infection is the result of both bacterial factors and the host response. We have previously shown that H. pylori binds to CD74 on gastric epithelial cells. In this study, we sought to identify the bacterial protein responsible for this interaction. H. pylori urease from a pool of bacterial surface proteins was found to coprecipitate with CD74...

The uniformity of Xenobind covalent binding microwell plates was compared with that of passive binding plates by binding streptavidin to the plate surface, reacting the streptavidin with biotinylated alkaline phosphatase, and developing color with phenolphthalein monophosphate. Absorbance of the covalent binding plates at 570 nm was 0.95 A (CV 1.9%) compared with 0.35-0.5 A (CV 6.7-16.9%), for ...

Drug transporters have been shown to alter drug metabolism. Similarly, bioactivation of drugs may also be altered by drug transporters. The aim of this work was to examine the role of P-glycoprotein (Pgp) in the bioactivation of a Pgp substrate, raloxifene, and a non-Pgp substrate, naphthalene. To evaluate the extent of bioactivation, covalent binding was measured. In both freshly isolated and ...

The risk of idiosyncratic drug toxicity (IDT) is of great concern to the pharmaceutical industry. Current hypotheses based on retrospective studies suggest that the occurrence of IDT is related to covalent binding and daily dose. We determined the covalent binding of 42 radiolabeled drugs in three test systems (human liver microsomes and hepatocytes in vitro and rat liver in vivo) to assess the...

The immobilization of enzymes onto porous supports is a common strategy for obtaining improved stability, fast product separation, enzyme reusability, and, ultimately, lower operating costs. Therefore, the development new with specific surface functionalities that enable covalent attachment significant interest. Herein, stable three-dimensional (3D) materials were synthesized from polypyrrole b...

The formation of drug-protein adducts via metabolic activation and covalent binding may stimulate an immune response or may result in direct cell toxicity. Protein covalent binding is a potentially pivotal step in the development of idiosyncratic adverse drug reactions (IADRs). Trimethoprim (TMP)-sulfamethoxazole (SMX) is a combination antibiotic that commonly causes IADRs. Recent data suggest ...

Short peptides resembling the Helicobacter pylori urease antigen (UreB F8 Ser-Ile-Lys-Glu-Asp-Val-Gln-Phe) with deleted aspartic acid and glutamic acid residues, anchored through a triazine linker via the N-terminal moiety to cellulose plate were prepared. The peptides were used for binding of antibodies from sera of patients with medically confirmed atherosclerosis. Recognition of the peptides...

The nickel-containing enzyme urease is an essential colonization factor of the human gastric pathogen Helicobacter pylori which enables the bacteria to survive the low-pH conditions of the stomach. Transcription of the urease genes is positively controlled in response to increasing concentrations of nickel ions and acidic pH. Here we demonstrate that acid-induced transcription of the urease gen...