1. Structural insights into the disruption of TNF-TNFR1 signalling by small molecules stabilising a distorted TNF
- Author
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Tim Bourne, Prashant Mori, Rachel Davis, Tom Ceska, Alastair D. G. Lawson, O'connell James Philip, Bruce Carrington, John Robert Porter, David A. Fox, Carlos Martinez-Fleites, and David McMillan
- Subjects
0301 basic medicine ,Models, Molecular ,Protein Conformation ,Dimer ,Science ,General Physics and Astronomy ,Trimer ,Binding, Competitive ,General Biochemistry, Genetics and Molecular Biology ,Article ,Small Molecule Libraries ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cell surface receptor ,Molecule ,Animals ,Humans ,Receptor ,X-ray crystallography ,Multidisciplinary ,Mass spectrometry ,Chemistry ,Tumor Necrosis Factor-alpha ,Tumour-necrosis factors ,food and beverages ,General Chemistry ,respiratory system ,Small molecule ,030104 developmental biology ,Receptors, Tumor Necrosis Factor, Type I ,Biophysics ,Tumor necrosis factor alpha ,Extracellular signalling molecules ,Protein Multimerization ,030217 neurology & neurosurgery ,Function (biology) ,Algorithms ,Protein Binding ,Signal Transduction - Abstract
Tumour necrosis factor (TNF) is a trimeric protein which signals through two membrane receptors, TNFR1 and TNFR2. Previously, we identified small molecules that inhibit human TNF by stabilising a distorted trimer and reduce the number of receptors bound to TNF from three to two. Here we present a biochemical and structural characterisation of the small molecule-stabilised TNF-TNFR1 complex, providing insights into how a distorted TNF trimer can alter signalling function. We demonstrate that the inhibitors reduce the binding affinity of TNF to the third TNFR1 molecule. In support of this, we show by X-ray crystallography that the inhibitor-bound, distorted, TNF trimer forms a complex with a dimer of TNFR1 molecules. This observation, along with data from a solution-based network assembly assay, leads us to suggest a model for TNF signalling based on TNF-TNFR1 clusters, which are disrupted by small molecule inhibitors., Small molecules stabilising a distorted TNF trimer can inhibit TNF signaling, but the underlying mechanism is unclear. Here, the authors characterize the inhibitor-bound TNF-receptor complex structurally and biochemically, showing that the inhibitors alter TNF-receptor binding stoichiometry and cluster formation.
- Published
- 2021