Helicobacter Pylori Summary

Article Reference:
Strugatsky, D., McNulty, R., Munson, K., Chen, C.-K., Soltis, S. M., Sachs, G., & Luecke, H. (2013). Structure of the proton-gated urea channel from the gastric pathogen Helicobacter pylori. Nature, 493(7431), 255+.

Purpose:
The purpose of this article is to figure out the structure of the proton-gated urea channel from the gastric pathogen Helicobacter pylori by using multi-wavelength anomalous dispersion. By figuring out this structure, the treatment of H. pylori can be more beneficial.

Unit Topic:
The unit of study that best relates to this article is unit four. This unit best relates to the article because in the article, the HpUrel channel would open at acidic pH; thus, allowing the flow of urea to cytoplasmic urease.

Helicobacter Pylori is something that much of the human population is infected with. The treatment of this infection is becoming less successful because of the increase in antibiotic resistance. This suggests that a more targeted approach would be advantageous to exterminate this organism. In order to find a treatment that will be effective, the unobserved structure of HpUrel must be determined.
The presence of HpUrel, which is a proton gated inner membrane urea channel, is essential for survival in the acidic mammalian stomach. The pH has a major role in determining whether or not the channel closes or opens. When the pH is neutral, the channel is closed. When the pH is acidic, the channel opens; thus, allowing the access of urea to cytoplasmic urease. The channel fully opens at a pH of about 5.0, which enables the entry of urea into the bacterium. Even in the acidic environment of the stomach, urease buffers the periplasm to a pH of about 6.1, and neutralizes the incoming protons. This is essential for the survival of Helicobacter

HpUrel is reported to measure 45 A in height and 95 A in diameter. The HpUrel is also reported to have the structure of six protomers put together in a hexametric ring, which surrounds a bilayer of lipids. This native hexametric structure for HpUrel was confirmed with the use of blue native gel electrophoresis. In the periplasmic leaflet there are six lipid tails. In the cytoplasmic leaflet, there are eighteen lipid tails. Each protomer surrounds a channel, which is formed by six trans-membrane helices. This bundle of helices has a fold, which is seen as a two-helix hairpin pattern that is repeated three times around the center axis of the channel. With these findings, effective treatments for Helicobacter Pylori, and possibly even a cure to this infection can now have a greater chance of being found.

New Vocabulary:
With reading such a difficult article, I learned a lot of new vocabulary. I learned that motif means a decorative design or pattern. Her dress featured a checkered motif. Another word I learned was urease, which is an enzyme that hydrolyzes urea into ammonium carbonate. The enzyme urease catalyzes the reaction of urea.

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