(Modeling proteins) (Chymotrypsin Mechanism: Step 1, Step 2, Step 3, Step 4, Step 5, Step 6)

Transition state between Steps 1 and 2 of Chymotrypsin Mechanism:
Serine 195 oxygen forms a covalent bond with substrate peptide carbon
The hydroxyl hydrogen bonds to imidazole ring of His 57

  (PDB file) (ARC file)

The first step in the chymotrypsin mechanism. The oxygen on Ser195 forms a covalent bond with the carbonyl carbon of Trp252.  At the same time, the hydroxyl hydrogen of Ser195 moves on to the nitrogen on His57. Toggle display all Toggle center picture Fit to screen Interesting parts: His57 Gly193 Asp194 Ser195 Trp252 Thr253 H2O Toggle spin Toggle stereo