J. Am. Chem. Soc. doi:10.1021/ja802248m (2008)

Credit: J. L. ENGLAND ET AL./J. AM. CHEM. SOC.

Water trapped inside barrel-shaped enzymes called chaperonins could be crucial to the way they help proteins fold. Without such attendance, complicated proteins would fail to form their proper arrangement, and consequently would not work.

Vijay Pande and his colleagues at Stanford University in California followed the change in shape that exposes hydrophilic chemical groups on the inner surface of a chaperonin complex called GroE (pictured) as the enzyme takes in an unfolded protein. Using computer simulations, they suggest this process enables GroE to sequester minute amounts of water (red and white) in its active site. This water creates a driving force for the protein to fold, burying its hydrophobic surfaces in the interior of the structure that it eventually forms.