Figure 3.

3D representation of (A) human 20S proteasome with a focus on the β5 chymotrypsin like subunit; (B) Hib-ester and (D) Hib-carbaldehyde docked into the proteasome chymotrypsin-like binding pocket. The Hib-ester and the Hib-carbaldehyde are depicted, respectively, as green and yellow carbon sticks, the proteasome is shown as a light-blue cartoon and the enzyme residues involved in crucial contacts with the compounds are reported as light-blue carbon sticks. The water molecule is shown as red carbon sticks. Hydrogen bonds and pi-cation contacts are shown, respectively, as dashed yellow and dark-green lines. 2D representation of (C) Hib-ester and (E) Hib-carbaldehyde complexed into the proteasome chymotrypsin-like binding pocket. In the 2D representation, hydrogen bonds and pi-cation contacts are shown, respectively, as violet and red lines.