Title
Biophysical characterization of the homodimers of HomA and HomB, outer membrane proteins of Helicobacter pylori
Author
Anubhav Tamrakar, Rahul Singh, Amit Kumar, Ravindra D. Makde, Ashish, and Prashant Kodgire
Year
2021
Journal
Scientific Reports (2021) 11:24471
Abstract
Helicobacter pylori is a Gram-negative bacterium that causes chronic inflammations in the stomach
area and is involved in ulcers, which can develop into gastric malignancies. H. pylori attaches and
colonizes to the human epithelium using some of their outer membrane proteins (OMPs). HomB and
HomA are the most studied OMPs from H. pylori as they play a crucial role in adherence, hyper biofilm
formation, antibiotic resistance and are also associated with severe gastric malignancies. The role
of HomA and HomB in pathogenesis concerning their structure and function has not been evaluated
yet. In the present study, we explored the structural aspect of HomA and HomB proteins using
various computational, biophysical and small-angle X-ray scattering (SAXS) techniques. Interestingly,
the in-silico analysis revealed that HomA/B consists of 8 discontinuous N and C terminal β-strands
forming a small β-barrel, along with a large surface-exposed globular domain. Further, biophysical
experiments suggested that HomA and HomB are dimeric and most likely the cysteine residues
present on surface-exposed loops participate in protein–protein interactions. Our study provides
essential structural information of unexplored proteins of the Hom family that can help in a better
understanding of H. pylori pathogenesis.
Full Article
Instrument
J-815 spectropolarimeter