Interaction requirements for an innate immune receptor and bacterial cell wall fragments
Date
2017
Authors
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Publisher
University of Delaware
Abstract
This work focuses on the implications for the development of Crohn’s disease. The two key players in this work are Nod2, a human innate immune receptor, and muramyl dipeptide, a bacterial cell wall fragment often considered the ligand of Nod2. Mutations to Nod2 are correlated with the development of Crohn’s disease, but the faults of these mutations are unknown. The biochemical characterization of Nod2 is one place to start to yield a more complete understanding of the underlying mechanisms of the Crohn’s disease. The work described in this thesis uses an analytical approach to biochemical and molecular biological techniques to characterize key protein and ligand interactions for the receptor Nod2. ☐ Functional, binding, activity, and stability assays were used to distinguish differences between WT and Crohn’s associated mutant Nod2. The key findings describe membrane dependence for Nod2 specificity for binding peptidoglycan ligands, the ligand requirements for binding Nod2, the incapacitating instability of the Nod2 mutants, and the ultimate rescue of the Nod2 mutants. This thorough biochemical evaluation of Nod2 and Nod2 mutants has emphasized the requirements for Nod2 recognition of bacterial fragments and highlighted the potential impact these interactions could have on the innate immune system.