Exploring conformational preferences of proteins: ionic liquid effects on the energy landscape of avidin

摘要: In this work we experimentally investigate solvent and temperature induced conformational transitions of proteins examine the role ion–protein interactions in determining preferences avidin, a homotetrameric glycoprotein, choline-based ionic liquid (IL) solutions. Avidin was modified by surface cationisation addition anionic surfactants, structural, thermal, stabilities native avidin were examined using dynamic light scattering, differential scanning calorimetry, thermogravimetric analysis experiments. The protein-surfactant nanoconjugates showed higher thermostability behaviour compared to unmodified demonstrating distinct ensembles. Small-angle X-ray scattering data that with increasing IL concentration, became more compact, interpreted context molecular confinement. To determine detailed effects on energy landscape fluorimetry variable circular dichroism spectroscopy performed. We show different solutions can influence conformation thermal stability, provide insight into ILs folding pathways thermodynamics proteins. further study binding correlate heterogeneity, conducted study. found inhibited ligand while enhancing protein, indicating stability differently. Significantly, presents systematic strategy explore protein space detect characterise ‘invisible’ rare conformations ILs.