Hydrophobic effect

In this rendering of lysozyme the colouring matches charged, uncharged polar and nonpolar amino acids.

Both charged and polar amino acids are abundant on the surface, where they form hydrogen bonds with water ( water ).

If we cut through the molecule we can see what kind of residues are located on the surface and which are inside.

As you move the section plane backwards (using the slider below) you can notice how the inside of the molecule is mainly hydrophobic while the surface is hydrophilic, with many polar and charged amino acids.

backward

forward

(this only works after clicking the “prepare” button above; you can try again after reorienting the molecule)

This arrangement is beneficial in energy terms, stabilises the tertiary structure of the protein, and is known as the hydrophobic effect.