Biology subjects

Allegro, D.

Publications and source records attributed to Allegro, D..

3 recordsLinked to original sources

bioRxiv2025

Hydrodynamic Radius Determination of Tau and AT8 Phosphorylated Tau Mutants: A Combined Simulation and Experimental Study

Hyperphosphorylated Tau is a hallmark of Alzheimers disease leading to functional loss and fibrillar inclusions. We aim to understand how AT8 phosphorylation affects the Taus conformation and dynamics during early pathological transformation. We engineered an alanine Tau mutant to target specific phosphorylation sites restricted to the AT8 epitope, generating two distinct phosphorylation states. Using a combination of biophysical methods, and pCALVADOS forcefield, we found that AT8 phosphorylation do not alter the hydrodynamic radius or overall dynamics of Tau. Simulations revealed that local stiffening and extension at the AT8 epitope scale with phosphorylation extent. Interestingly, phosphorylation induces distant contact losses toward the N-terminus. This study advances our understanding of the structure-function-dynamics relationship of Tau in neurodegeneration.

biophysics↗

bioRxiv2024

A new nanoDSF approach to anti-tubulin compounds screening revealed novel MTAs among approved drugs.

Microtubule Targeting Agents (MTAs) constitute a vital category of tubulin-binding compounds, deployed across anticancer therapies. Despite the array of MTA drugs developed by pharmaceutical entities, the quest for novel efficacious molecules continues unabated. We unveil an innovative in vitro MTA screening methodology employing nano differential scanning fluorimetry (nanoDSF), presenting distinct advantages over known assays. This novel approach not only assesses compound-tubulin binding but also quantitatively analyzes their impact on tubulin polymerization. Proposed nanoDSF assay was rigorously validated using the Prestwick Chemical Library, which encompasses 1,520 approved compounds, successfully identifying all previously known MTAs. Furthermore, this screening has unearthed potential anti-tubulin agents among drugs currently utilized for non-related medical conditions, offering insights into their mechanisms of action in inhibiting cancer cell proliferation and/or inducing cytotoxicity. These discoveries herald new opportunities for drug repositioning involving the newly identified MTAs and substantially streamline the process of screening extensive chemical libraries for MTAs featuring novel chemical structures.

cancer biology↗

bioRxiv2021

Sequential binding of zinc triggers tau aggregation

Tau protein has been extensively studied due to its key roles in microtubular cytoskeleton regulation and in the formation of aggregates found in some neurodegenerative diseases. Recently it has been shown that zinc is able to induce tau aggregation by interacting with several binding sites. However, the precise location of these sites and the molecular mechanism of zinc-induced aggregation remain unknown. Here we used Nuclear Magnetic Resonance (NMR) to identify zinc binding sites on hTau40 isoform. These experiments revealed three distinct zinc binding sites on tau, located in the N-terminal part (H14, H32, H94, and H121), the repeat region (H299, C322, H329 and H330) and the C-terminal part (H362, H374, H388 and H407). Further analysis enabled us to show that the C-terminal and the N-terminal sites are independent of each other. Using molecular simulations, we modeled the structure of each site in a complex with zinc. Given the clinical importance of zinc in tau aggregation, our findings pave the way for designing potential therapies for tauopathies. HighlightsO_LIZinc is known to induce tau aggregation in neurodegenerative diseases C_LIO_LIZinc binding locations and mechanism are not yet clear C_LIO_LIUsing NMR we localized 3 zinc binding site on tau C_LIO_LIBy molecular simulations, we proposed a modeled structure of each site C_LIO_LIOur findings pave the way for designing potential therapies for tauopathies C_LI

molecular biology↗