How do hydrophobic interactions help a protein fold into its three-dimensional shape?

Hydrophobic interactions are a critical driving force in the folding of proteins into their functional three-dimensional shapes.

In an aqueous environment, proteins fold to bury their nonpolar, hydrophobic side chains—such as those found in valine, leucine, isoleucine, and phenylalanine—within the interior of the protein structure. This process occurs because these nonpolar side chains are "water-fearing" and their association results in the displacement of water molecules from the protein's core.12

By sequestering these hydrophobic groups away from the surrounding aqueous solution, the protein achieves a stable conformation. This internal clustering is a fundamental aspect of the tertiary structure of globular proteins, ensuring that the hydrophobic parts are shielded while hydrophilic groups remain on the surface to interact with the solvent.21