Ensemble-based design of tau to inhibit aggregation while preserving biological activity

The microtubule-associated protein tau is implicated in neurodegenerative diseases characterized by amyloid formation. Mutations associated with frontotemporal dementia increase tau aggregation propensity, disrupting its endogenous microtubule-binding activity. The structural relationship between aggregation propensity and biological activity remains unclear. We employed a multi-disciplinary approach, including computational modeling, NMR, cross-linking mass spectrometry, and cell models to design tau sequences that stabilize thier structural ensemble. Our findings show that substitutions near the conserved 'PGGG' β-turn motif can alter local conformations, promoting more stable interactions with the 306VQIVYK311 amyloid motif that reduce aggregation in vitro and in cells, even counteracting aggregation induced by turn destabilizing disease-associated proline-to-serine mutations. Designed tau sequences maintain microtubule binding and explain why 3R isoforms exhibit reduced pathogenesis over 4R isoforms. We propose a simple mechanism to reduce the formation of pathogenic species while preserving biological function, offering insights for therapeutic strategies aimed at reducing protein misfolding in neurodegenerative diseases. Description of Source Data and Supplementary Data: All MD, NMR (peptide and tauRD), ThT, XL-MS, MT stabilization, MT:tau modeling, and cell-based aggregation data are available in the Source_Data directory as Source Data 1, Source Data 2, Source Data 3 and 4, Source Data 5, Source Data 6, Source Data 7, and Source Data 8, respectively. Supplementary Data for raw MD trajectory files, structure files for MSM modeling and validation file, and tau:MT modeling are available as "Supplementary_Data_MD_Trajectories_Structures", "Supplementary_Data_MSM_models_Structures" and "Supplementary_Data_MT-tau_complex_models", respectively."