WITHDRAWN: Coptisine, an alkaloid from Rhizoma Coptidis, inhibits Helicobacter pylori urease activity by targeting its active site and maturation process

Coptisine from Rhizoma Coptidis Suppresses HCT-116 Cells-related Tumor Growth in vitro and in vivo

Colorectal cancer is one of the most common causes of cancer-related death in humans. Coptisine (COP) is a natural alkaloid from Coptidis Rhizoma with unclear antitumor mechanism. Human colon cancer cells (HCT-116) and xenograft mice were used to systematically explore the anti-tumor activity of COP in this study. The results indicated that COP exhibited remarkably cytotoxic activities against ...

Helicobacter pylori Urease Activity is Influenced by Ferric Uptake Regulator

PURPOSE The role of the Ferric Uptake Regulator (FUR) in the acid resistance of Helicobacter pylori (H. pylori) has been thought to be independent of urease. However, we demonstrated in this study that Fur influences urease activity. MATERIALS AND METHODS A fur knockout mutant of H. pylori was constructed by replacing the Fur gene with a kanamycin resistant marker gene. The wild-type H. pylor...

Role of Helicobacter pylori methionine sulfoxide reductase in urease maturation.

The persistence of the gastric pathogen Helicobacter pylori is due in part to urease and Msr (methionine sulfoxide reductase). Upon exposure to relatively mild (21% partial pressure of O2) oxidative stress, a Δmsr mutant showed both decreased urease specific activity in cell-free extracts and decreased nickel associated with the partially purified urease fraction as compared with the parent str...

Isolation of Helicobacter pylori genes that modulate urease activity.

Helicobacter pylori urease, a nickel-requiring metalloenzyme, hydrolyzes urea to NH3 and CO2. We sought to identify H. pylori genes that modulate urease activity by constructing pHP8080, a plasmid which encodes both H. pylori urease and the NixA nickel transporter. Escherichia coli SE5000 and DH5alpha transformed with pHP8080 resulted in a high-level urease producer and a low-level urease produ...

[Toxicoderma due to Rhizoma coptidis].