Abstract:
Host and pathogen interactions like that of Helicobacter pylori and the human CEACAM1 N-domain are heavily reliant on specific amino acid interactions. Even a single change in a sequence can result in drastic changes in binding affinity for the interaction on either side. Understanding which amino acids create these significant bonds is key to developing treatments to common illnesses associated with H. pylori infection. CEACAM 1 interacts with H. pylori strains via one of two similar surface proteins called HopQ Type I and HopQ Type II. These proteins share a 70% sequence homology in the binding domain yet their relative binding affinities to H. pylori strains are relatively unknown. The goal of this study is to compare binding affinities of these two proteins with a variety of CEACAM 1 variants across humans and primates in order to identify the sequences that lead to these significant alterations in binding affinity.