Molecular determinants of TNFR1:TNFα binding and dynamics in a physiological membrane environment.

Tumor Necrosis Factor alpha (TNFα) is a pro-inflammatory cytokine critical for regulating cell survival and death. Under pathological conditions, excessive TNFα activity can lead to chronic inflammation, contributing to diseases such as inflammatory bowel disease and other autoimmune disorders. While structural studies have elucidated the atomistic details of TNFα binding to its receptor, TNF Receptor 1 (TNFR1), the influence of the membrane environment on this interaction remains poorly characterized experimentally. In this study, we employed advanced all-atom Gaussian accelerated molecular dynamics simulations to investigate how lipid-mediated interactions modulate the TNFα-TNFR1 complex. We identified key residues on both the cytokine and its receptor that govern trimer assembly, receptor binding, and potential pathological alterations. Our analysis confirmed previously identified functional sites and revealed new residues likely to contribute to the structural stability and dynamics of the complex. These findings provide a more comprehensive understanding of the molecular determinants of TNF signaling and offer a foundation for future experimental investigations into the receptor-ligand interface and membrane-mediated regulation.