Understanding the bonds that cause stomach infection

The diagrams show how H. pylori reaches the epithelium of the stomach.

IN a new paper published in the recent issue of ‘Science Signaling’, a group researchers from Britain has unravelled the hitherto unknown mechanism by which the bacterium Helicobacter pylori, which causes stomach ulcers and stomach cancer, binds itself to the stomach wall. The findings could form the basis for developing therapies to prevent H. pylori from clinging to and infecting the stomach. If successful, such strategies could be used to treat H. pylori infections, which are increasingly becoming resistant to conventional antibiotics.

Using X-ray crystallography, Naim Hage and associates have shown that H. pylori’s outer membrane protein, BabA, has selective binding properties based around a network of hydrogen bonds that allow the bacteria to latch on to a special class of antigen naturally found in the stomach epithelial lining. They also found that this network was so finely tuned that if a few of the hydrogen bonds between molecules on the surface of the epithelial cell and molecules on the surface of the bacterium are disturbed, the network doesn’t work and binding cannot occur. The results suggest that drugs designed to disrupt the hydrogen bonds could become the basis for developing therapies against H. pylori infection.

R. Ramachandran