Investigating the effects of sodium dodecyl sulfate on the aggregative behavior of hen egg-white lysozyme at acidic pH.
The research presented here is aimed at examining the effects of sodium dodecyl sulfate on the aggregative behavior of hen egg-white lysozyme at pH 2.0. Through various spectroscopic techniques, dynamic light scattering, and electron microscopy, we first demonstrated that SDS exhibited a biphasic effect on lysozyme fibrillation. The presence of SDS at higher concentrations (e.g., 0.25, 5.00, or 20.00 mM SDS) was found to suppress fibril formation of lysozyme whereas fibrillogenic lysozyme-SDS ensemble containing beta-sheet-rich conformation was observed upon the addition of lower concentrations of SDS (e.g., 0.00, 0.06, or 0.1mM SDS). Next, our equilibrium urea-unfolding data revealed that lysozyme samples with higher SDS concentrations showed superior thermodynamic stabilities over the ones with no or lower levels of SDS. Finally, the correlation between SDS concentration and lysozyme aggregative/fibrillogenic propensity and the underlying interacting mechanism were further explored using surface tensiometry and isothermal titration calorimetry. We believe the outcome from this work may not only help decipher the molecular mechanism of amyloid fibrillation, but also shed light on a rational design of potential therapeutic strategies for amyloid pathology.
Hung
Ying-Tz
YT
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
Lin
Ming-Shen
MS
Chen
Wen-Yih
WY
Wang
Steven Sheng-Shih
SS
D000143:Acids / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002151:Calorimetry; D002645:Chickens; D002942:Circular Dichroism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D009113:Muramidase / Q000737:chemistry* / Q000648:ultrastructure; D011487:Protein Conformation / Q000187:drug effects; D017510:Protein Folding; D055550:Protein Stability / Q000187:drug effects; D017433:Protein Structure, Secondary; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry* / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D014508:Urea / Q000737:chemistry / Q000494:pharmacology
D000143:Acids; D012967:Sodium Dodecyl Sulfate; D014508:Urea; C421864:hen egg lysozyme; D009113:Muramidase