Similar Energetic Contributions of Packing in the Core of Membrane and Water-Soluble Proteins

摘要

The hydrophobic effect is a major contributor to the stability of water-soluble proteins but is essentially absent in the hydrocarbon core of a membrane. Thus, the relative importance of other factors such as hydrogen bonding and van der Waals packing interactions must increase. While some hydrogen bonds can be key drivers of helix association, we have argued that most appear to be modest contributors to tertiary structure stabilization in large membrane proteins. If so, it implies that van der Waals packing dominates. Indeed, transmembrane helix dimers can be formed without any polar residues in the interface.