Disentangling the role of solvent polarity and protein solvation in folding and self-assembly of α-lactalbumin

J Colloid Interface Sci. 2020 Mar 1:561:749-761. doi: 10.1016/j.jcis.2019.11.051. Epub 2019 Nov 15.

Abstract

Protein (mis)folding, stability and aggregation are of interest in numerous fields, such as food sciences, biotechnology, and health sciences, and efforts are directed towards the elucidation of the underlying molecular mechanisms. Through an integrative approach, we show that a subtle balance between hydrogen bond formation and hydrophobic interactions defines protein self-assembly pathways. Hydrophobic co-solvents, such as monohydric alcohols, modulate these two forces through a combination of direct solvent-protein and solvent-mediated interactions, depending on the size of the alcohol. This affects the initial conformation of the model protein α-lactalbumin, which can be linked to variations of its fibrillation propensity, as well as the morphology of the final structures. These findings pave the way towards a better understanding of the forces governing protein self-assembly, allowing the development of strategies to suppress unwanted aggregation and control the growth of tuneable protein-based biomaterials.

Keywords: Alcohols; Amyloid aggregation; Molecular dynamics; Protein hydration; Protein-protein Interactions; Smallangle X-ray scattering.

MeSH terms

  • Alcohols / chemistry
  • Animals
  • Cattle
  • Hydrogen Bonding
  • Hydrophobic and Hydrophilic Interactions
  • Lactalbumin / chemistry*
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Protein Conformation*
  • Protein Folding*
  • Protein Multimerization*
  • Solvents / chemistry*

Substances

  • Alcohols
  • Solvents
  • Lactalbumin