Trypsin is a serine protease that hydrolyzes proteins in two sequential steps. The first acylation occurs when the nucleophilic serine attacks the substrate at the scissle bond (bond later to be broken). The tetrahedral intermediate is formed. Next, the C-terminal fragment is released, leaving only a covalently bound acyl-enzyme. A second deacylation reaction occurs after a water molecule attacks the acyl-enzyme. This series of events leads to the formation of a second terminal intermediate. Then, the N-terminal fragment is released. The histidine residue acts as a base in the first step by accepting a proton to activate serine as a nucleophile. The histidine later acts as an acid by donating the proton to the nitrogen of the peptide leaving group.
You may include any references to papers as in: the use of JSmol in Proteopedia [1] or to the article describing Jmol [2] to the rescue.
Function
Disease
Relevance
Structural highlights
This is a sample scene created with SAT to by Group, and another to make of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.
