Aspartic protease endothiapepsin

Figure 15 Neutron difference map showing the active site region of endothiapepsin (an aspartate protease) complexed with a transition state analogue. In this 2.1 A resolution neutron study hy Myles et al., Asp32 was foimd to he in its deprotonated state, while Asp215 is protonated. (Reprinted with permission from Coates, Erskine, Wood, Myles and Cooper. 2001 American Chemical Society)...

The crystal structures of aspartic proteases helped elucidate the meehanism of action for this family of enzymes. For example, in the crystal structure of native endothiapepsin, a water... 

Figure 8. Stereoview of renin inhibitors extracted from the X-ray crystal structures of three different aspartic proteases. The yellow inhibitor, 20, is from an HIV-1 protease structure (unpublished), the cyan inhibitor is from an endothiapepsin structure [17] and the green inhibitor is from a renin structure [43],...

The first 3D models of the HIV protease by " Pearl and Taylor used one of the two symmetrical domains of endothiapepsin (Fig. 27.4) as their basis structure. The structure of the aspartic protease from the RSV was then solved. This provided a nearer structural homologue. This protease was a dimer with an active site very similar to monomeric cellular proteases. A second comparative model of the HIV protease was built with this new basis structure, enabling the active site to be described in detail and decreasing the uncertainty concerning the modelling of the long insertions and deletions which were made in constructing the models on the basis of pepsin-like aspartic proteinases. 

---