Figure 6.

Snapshots of the calculated TMD pathways showing, by ribbon representation of the backbone atoms of ΔA-chymotrypsin, the most important subsequent transitions during the activation process (Kraulis 1991). The amino acid residues that show important dihedral angle transitions during the activation process are indicated. In the inactive conformation (A), Ile 16 is still lying at the outside of the protein structure. During the reorientation of the N terminus of the B-chain, Ile 16 moves closer (B) to the place where a cavity is created by a reorientation of Met 192. After penetration of Ile 16 in this cavity (C), Asp 194 undergoes a big reorientation to form, in the next step (D), the stabilizing salt bridge with the Ile 16 N terminus.