%A Madhumita Dey %A Arpit Gupta %A Maulik D Badmalia %A Ashish %A Deepak Sharma %J Int. J. Biol. Macromol. %T Visualizing gaussian-chain like structural models of human ?-synuclein in monomeric pre-fibrillar state: Solution SAXS data and modeling analysis %X Here, using small angle X-ray scattering (SAXS) data profile as reference, we attempted to visualize conformational ensemble accessible prefibrillar monomeric state of ?-synuclein in solution. In agreement with previous reports, our analysis also confirmed that ?-synuclein molecules adopted disordered shape profile under non-associating conditions. Chain-ensemble modeling protocol with dummy residues provided two weighted averaged clusters of semi-extended shapes. Further, Ensemble Optimization Method (EOM) computed mole fractions of semi-extended ``twisted'' conformations which might co-exist in solution. Since these were only C? traces of the models, ALPHAFOLD2 server was used to search for all-atom models. Comparison with experimental data showed all predicted models disagreed equally, as individuals. Finally, we employed molecular dynamics simulations and normal mode analysis-based search coupled with SAXS data to seek better agreeing models. Overall, our analysis concludes that a shifting equilibrium of curved models with low ?-helical content best-represents non-associating monomeric ?-synuclein. %N 138614 %K ALPHAFOLD2; EOM; Monomer; Normal mode analysis; Protein structure; SAXS; ?-Synuclein %P 138614 %V 288 %D 2025 %I Elsevier BV %L open3217